diff --git "a/all_data/AR6/AR6.yaml" "b/all_data/AR6/AR6.yaml" new file mode 100644--- /dev/null +++ "b/all_data/AR6/AR6.yaml" @@ -0,0 +1,11490 @@ +full_paragraphs: + A.1.1: + - Observed Warming and its Causes Global surface temperature was around 1.1°C above + 1850–1900 in 2011–2020 64, with larger increases over land than over the ocean + 65 . Observed warming is human-caused, with warming from greenhouse gases, dominated + by CO2 and methane, partly masked by aerosol cooling. Global surface temperature + in the first two decades of the 21st century was 0.99 [0.84 to 1.10]°C higher + than 1850–1900. Global surface temperature has increased faster since 1970 than + in any other 50-year period over at least the last 2000 years. The likely range + of total human-caused global surface temperature increase from 1850–1900 to 2010–201966 + is 0.8°C to 1.3°C, with a best estimate of 1.07°C. It is likely that well-mixed + GHGs 67 contributed a warming of 1.0°C to 2.0°C, and other human drivers contributed + a cooling of 0.0°C to 0.8°C, natural drivers changed global surface temperature + by ±0.1°C and internal variability changed it by ±0.2°C. Observed increases in + well-mixed GHG concentrations since around 1750 are unequivocally caused by GHG + emissions from human activities. Land and ocean sinks have taken up a near-constant + proportion of CO2 emissions from human activities over the past six decades, with + regional differences. In 2019, atmospheric CO2 concentrations reached 410 parts + per million, CH 4 reached 1866 parts per billion and nitrous oxide reached 332 + ppb. Other major contributors to warming are tropospheric ozone and halogenated + gases. Concentrations of CH 4 and N2 O have increased to levels unprecedented + in at least 800, years, and there is high confidence that current CO 2 concentrations + are higher than at any time over at least the past two million years. Since 1750, + increases in CO 2 and CH4 concentrations far exceed – and increases in N2 O are + similar to – the natural multi-millennial changes between glacial and interglacial + periods over at least the past 800, years. The net cooling effect which arises + from anthropogenic aerosols peaked in the late 20th century . Average annual + GHG emissions during 2010–2019 were higher than in any previous decade, but the + rate of growth between 2010 and 2019 was lower than that between 2000 and 2009 69 + . Historical cumulative net CO 2 emissions from 1850 to 2019 were 2400 ±240 GtCO2. + Of these, more than half occurred between 1850 and 1989 [1400 ±195 GtCO 2], and + about 42% between 1990 and 2019 [1000 ±90 GtCO2]. Global net anthropogenic GHG + emissions have been estimated to be 59±6.6 GtCO 2 -eq in 2019, about 12% higher + than in 2010 and 54% higher than in 1990. By 2019, the largest growth in gross + emissions occurred in CO2 from fossil fuels and industry followed by CH4, whereas + the highest relative growth occurred in fluorinated gases, starting from low levels + in 1990. Regional contributions to global human-caused GHG emissions continue + to differ widely. Historical contributions of CO2 emissions vary substantially + across regions in terms of total magnitude, but also in terms of contributions + to CO 2 -FFI and net CO2 -LULUCF emissions. Variations in regional and national + per capita emissions partly reflect different development stages, but they also + vary widely at similar income levels. Average per capita net anthropogenic GHG + emissions in 2019 ranged from 2.6 tCO 2-eq to 19 tCO 2-eq across regions. Least + Developed Countries and Small Island Developing States have much lower per capita + emissions than the global average, excluding CO2 -LULUCF. Around 48% of the global + population in 2019 lives in countries emitting on average more than 6 tCO 2-eq + per capita, 35% of the global population live in countries emitting more than + 9 tCO2 -eq per capita while another 41% live in countries emitting less than 3 + tCO 2 -eq per capita. A substantial share of the population in these low-emitting + countries lack access to modern energy services. Net GHG emissions have increased + since 2010 across all major sectors. In 2019, approximately 34% of net global + GHG emissions came from the energy sector, 24% from industry, 22% from AFOLU, + 15% from transport and 6% from buildings . Average annual GHG emissions growth + between 2010 and 2019 slowed compared to the previous decade in energy supply + and industry but remained roughly constant at about 2% yr –1 in the transport + sector . About half of total net AFOLU emissions are from CO2 LULUCF, predominantly + from deforestation. Land overall constituted a net sink of –6.6 GtCO 2 yr–1 for + the period 2010–201972. Human-caused climate change is a consequence of more + than a century of net GHG emissions from energy use, land-use and land use change, + lifestyle and patterns of consumption, and production. Emissions reductions in + CO2 from fossil fuels and industrial processes, due to improvements in energy + intensity of GDP and carbon intensity of energy, have been less than emissions + increases from rising global activity levels in industry, energy supply, transport, + agriculture and buildings. The 10% of households with the highest per capita emissions + contribute 34–45% of global consumption-based household GHG emissions, while the + middle 40% contribute 40–53%, and the bottom 50% contribute 13–15%. An increasing + share of emissions can be attributed to urban areas . The drivers of urban GHG + emissions 73 are complex and include population size, income, state of urbanisation + and urban form. + A.1.3: + - Observed Warming and its Causes Global surface temperature was around 1.1°C above + 1850–1900 in 2011–2020 64, with larger increases over land than over the ocean + 65 . Observed warming is human-caused, with warming from greenhouse gases, dominated + by CO2 and methane, partly masked by aerosol cooling. Global surface temperature + in the first two decades of the 21st century was 0.99 [0.84 to 1.10]°C higher + than 1850–1900. Global surface temperature has increased faster since 1970 than + in any other 50-year period over at least the last 2000 years. The likely range + of total human-caused global surface temperature increase from 1850–1900 to 2010–201966 + is 0.8°C to 1.3°C, with a best estimate of 1.07°C. It is likely that well-mixed + GHGs 67 contributed a warming of 1.0°C to 2.0°C, and other human drivers contributed + a cooling of 0.0°C to 0.8°C, natural drivers changed global surface temperature + by ±0.1°C and internal variability changed it by ±0.2°C. Observed increases in + well-mixed GHG concentrations since around 1750 are unequivocally caused by GHG + emissions from human activities. Land and ocean sinks have taken up a near-constant + proportion of CO2 emissions from human activities over the past six decades, with + regional differences. In 2019, atmospheric CO2 concentrations reached 410 parts + per million, CH 4 reached 1866 parts per billion and nitrous oxide reached 332 + ppb. Other major contributors to warming are tropospheric ozone and halogenated + gases. Concentrations of CH 4 and N2 O have increased to levels unprecedented + in at least 800, years, and there is high confidence that current CO 2 concentrations + are higher than at any time over at least the past two million years. Since 1750, + increases in CO 2 and CH4 concentrations far exceed – and increases in N2 O are + similar to – the natural multi-millennial changes between glacial and interglacial + periods over at least the past 800, years. The net cooling effect which arises + from anthropogenic aerosols peaked in the late 20th century . Average annual + GHG emissions during 2010–2019 were higher than in any previous decade, but the + rate of growth between 2010 and 2019 was lower than that between 2000 and 2009 69 + . Historical cumulative net CO 2 emissions from 1850 to 2019 were 2400 ±240 GtCO2. + Of these, more than half occurred between 1850 and 1989 [1400 ±195 GtCO 2], and + about 42% between 1990 and 2019 [1000 ±90 GtCO2]. Global net anthropogenic GHG + emissions have been estimated to be 59±6.6 GtCO 2 -eq in 2019, about 12% higher + than in 2010 and 54% higher than in 1990. By 2019, the largest growth in gross + emissions occurred in CO2 from fossil fuels and industry followed by CH4, whereas + the highest relative growth occurred in fluorinated gases, starting from low levels + in 1990. Regional contributions to global human-caused GHG emissions continue + to differ widely. Historical contributions of CO2 emissions vary substantially + across regions in terms of total magnitude, but also in terms of contributions + to CO 2 -FFI and net CO2 -LULUCF emissions. Variations in regional and national + per capita emissions partly reflect different development stages, but they also + vary widely at similar income levels. Average per capita net anthropogenic GHG + emissions in 2019 ranged from 2.6 tCO 2-eq to 19 tCO 2-eq across regions. Least + Developed Countries and Small Island Developing States have much lower per capita + emissions than the global average, excluding CO2 -LULUCF. Around 48% of the global + population in 2019 lives in countries emitting on average more than 6 tCO 2-eq + per capita, 35% of the global population live in countries emitting more than + 9 tCO2 -eq per capita while another 41% live in countries emitting less than 3 + tCO 2 -eq per capita. A substantial share of the population in these low-emitting + countries lack access to modern energy services. Net GHG emissions have increased + since 2010 across all major sectors. In 2019, approximately 34% of net global + GHG emissions came from the energy sector, 24% from industry, 22% from AFOLU, + 15% from transport and 6% from buildings . Average annual GHG emissions growth + between 2010 and 2019 slowed compared to the previous decade in energy supply + and industry but remained roughly constant at about 2% yr –1 in the transport + sector . About half of total net AFOLU emissions are from CO2 LULUCF, predominantly + from deforestation. Land overall constituted a net sink of –6.6 GtCO 2 yr–1 for + the period 2010–201972. Human-caused climate change is a consequence of more + than a century of net GHG emissions from energy use, land-use and land use change, + lifestyle and patterns of consumption, and production. Emissions reductions in + CO2 from fossil fuels and industrial processes, due to improvements in energy + intensity of GDP and carbon intensity of energy, have been less than emissions + increases from rising global activity levels in industry, energy supply, transport, + agriculture and buildings. The 10% of households with the highest per capita emissions + contribute 34–45% of global consumption-based household GHG emissions, while the + middle 40% contribute 40–53%, and the bottom 50% contribute 13–15%. An increasing + share of emissions can be attributed to urban areas . The drivers of urban GHG + emissions 73 are complex and include population size, income, state of urbanisation + and urban form. + A.1.5: + - Observed Warming and its Causes Global surface temperature was around 1.1°C above + 1850–1900 in 2011–2020 64, with larger increases over land than over the ocean + 65 . Observed warming is human-caused, with warming from greenhouse gases, dominated + by CO2 and methane, partly masked by aerosol cooling. Global surface temperature + in the first two decades of the 21st century was 0.99 [0.84 to 1.10]°C higher + than 1850–1900. Global surface temperature has increased faster since 1970 than + in any other 50-year period over at least the last 2000 years. The likely range + of total human-caused global surface temperature increase from 1850–1900 to 2010–201966 + is 0.8°C to 1.3°C, with a best estimate of 1.07°C. It is likely that well-mixed + GHGs 67 contributed a warming of 1.0°C to 2.0°C, and other human drivers contributed + a cooling of 0.0°C to 0.8°C, natural drivers changed global surface temperature + by ±0.1°C and internal variability changed it by ±0.2°C. Observed increases in + well-mixed GHG concentrations since around 1750 are unequivocally caused by GHG + emissions from human activities. Land and ocean sinks have taken up a near-constant + proportion of CO2 emissions from human activities over the past six decades, with + regional differences. In 2019, atmospheric CO2 concentrations reached 410 parts + per million, CH 4 reached 1866 parts per billion and nitrous oxide reached 332 + ppb. Other major contributors to warming are tropospheric ozone and halogenated + gases. Concentrations of CH 4 and N2 O have increased to levels unprecedented + in at least 800, years, and there is high confidence that current CO 2 concentrations + are higher than at any time over at least the past two million years. Since 1750, + increases in CO 2 and CH4 concentrations far exceed – and increases in N2 O are + similar to – the natural multi-millennial changes between glacial and interglacial + periods over at least the past 800, years. The net cooling effect which arises + from anthropogenic aerosols peaked in the late 20th century . Average annual + GHG emissions during 2010–2019 were higher than in any previous decade, but the + rate of growth between 2010 and 2019 was lower than that between 2000 and 2009 69 + . Historical cumulative net CO 2 emissions from 1850 to 2019 were 2400 ±240 GtCO2. + Of these, more than half occurred between 1850 and 1989 [1400 ±195 GtCO 2], and + about 42% between 1990 and 2019 [1000 ±90 GtCO2]. Global net anthropogenic GHG + emissions have been estimated to be 59±6.6 GtCO 2 -eq in 2019, about 12% higher + than in 2010 and 54% higher than in 1990. By 2019, the largest growth in gross + emissions occurred in CO2 from fossil fuels and industry followed by CH4, whereas + the highest relative growth occurred in fluorinated gases, starting from low levels + in 1990. Regional contributions to global human-caused GHG emissions continue + to differ widely. Historical contributions of CO2 emissions vary substantially + across regions in terms of total magnitude, but also in terms of contributions + to CO 2 -FFI and net CO2 -LULUCF emissions. Variations in regional and national + per capita emissions partly reflect different development stages, but they also + vary widely at similar income levels. Average per capita net anthropogenic GHG + emissions in 2019 ranged from 2.6 tCO 2-eq to 19 tCO 2-eq across regions. Least + Developed Countries and Small Island Developing States have much lower per capita + emissions than the global average, excluding CO2 -LULUCF. Around 48% of the global + population in 2019 lives in countries emitting on average more than 6 tCO 2-eq + per capita, 35% of the global population live in countries emitting more than + 9 tCO2 -eq per capita while another 41% live in countries emitting less than 3 + tCO 2 -eq per capita. A substantial share of the population in these low-emitting + countries lack access to modern energy services. Net GHG emissions have increased + since 2010 across all major sectors. In 2019, approximately 34% of net global + GHG emissions came from the energy sector, 24% from industry, 22% from AFOLU, + 15% from transport and 6% from buildings . Average annual GHG emissions growth + between 2010 and 2019 slowed compared to the previous decade in energy supply + and industry but remained roughly constant at about 2% yr –1 in the transport + sector . About half of total net AFOLU emissions are from CO2 LULUCF, predominantly + from deforestation. Land overall constituted a net sink of –6.6 GtCO 2 yr–1 for + the period 2010–201972. Human-caused climate change is a consequence of more + than a century of net GHG emissions from energy use, land-use and land use change, + lifestyle and patterns of consumption, and production. Emissions reductions in + CO2 from fossil fuels and industrial processes, due to improvements in energy + intensity of GDP and carbon intensity of energy, have been less than emissions + increases from rising global activity levels in industry, energy supply, transport, + agriculture and buildings. The 10% of households with the highest per capita emissions + contribute 34–45% of global consumption-based household GHG emissions, while the + middle 40% contribute 40–53%, and the bottom 50% contribute 13–15%. An increasing + share of emissions can be attributed to urban areas . The drivers of urban GHG + emissions 73 are complex and include population size, income, state of urbanisation + and urban form. + A.2.1: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.2.2: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + A.2.3: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.2.4: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.2.5: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.2.6: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.2.7: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + A.3.1: + - Adaptation Actions to Date Progress in adaptation planning and implementation + has been observed across all sectors and regions, generating multiple benefits. + The ambition, scope and progress on adaptation have risen among governments at + the local, national and international levels, along with businesses, communities + and civil society . Various tools, measures and processes are available that can + enable, accelerate and sustain adaptation implementation . Growing public and + political awareness of climate impacts and risks has resulted in at least 170 + countries and many cities including adaptation in their climate policies and planning + processes . Decision support tools and climate services are increasingly being + used and pilot projects and local experiments are being implemented in different + sectors . Adaptation to water-related risks and impacts make up the majority + of all documented adaptation. A large number of these adaptation responses are + in the agriculture sector and these include on-farm water management, water storage, + soil moisture conservation, and irrigation. Other adaptations in agriculture include + cultivar improvements, agroforestry, community-based adaptation and farm and landscape + diversification among others. For inland flooding, combinations of non-structural + measures like early warning systems, enhancing natural water retention such as + by restoring wetlands and rivers, and land use planning such as no build zones + or upstream forest management, can reduce flood risk . Some land-related adaptation + actions such as sustainable food production, improved and sustainable forest management, + soil organic carbon management, ecosystem conservation and land restoration, reduced + deforestation and degradation, and reduced food loss and waste are being undertaken, + and can have mitigation co-benefits. Adaptation actions that increase the resilience + of biodiversity and ecosystem services to climate change include responses like + minimising additional stresses or disturbances, reducing fragmentation, increasing + natural habitat extent, connectivity and heterogeneity, and protecting small-scale + refugia where microclimate conditions can allow species to persist. Most innovations + in urban adaptation have occurred through advances in disaster risk management, + social safety nets and green/blue infrastructure. Many adaptation measures that + benefit health and well-being are found in other sectors . Adaptation can generate + multiple additional benefits such as improving agricultural productivity, innovation, + health and well-being, food security, livelihood, and biodiversity conservation + as well as reduction of risks and damages. Globally tracked adaptation finance + has shown an upward trend since AR5, but represents only a small portion of total + climate finance, is uneven and has developed heterogeneously across regions and + sectors. Adaptation finance has come predominantly from public sources, largely + through grants, concessional and non-concessional instruments. Globally, private-sector + financing of adaptation from a variety of sources such as commercial financial + institutions, institutional investors, other private equity, non-financial corporations, + as well as communities and households has been limited, especially in developing + countries . Public mechanisms and finance can leverage private sector finance + for adaptation by addressing real and perceived regulatory, cost and market barriers, + for example via public-private partnerships. Innovations in adaptation and resilience + finance, such as forecast-based/anticipatory financing systems and regional risk + insurance pools, have been piloted and are growing in scale. There are adaptation + options which are effective in reducing climate risks 85 for specific contexts, + sectors and regions and contribute positively to sustainable development and other + societal goals. In the agriculture sector, cultivar improvements, on-farm water + management and storage, soil moisture conservation, irrigation 86, agroforestry, + community-based adaptation, and farm and landscape level diversification, and + sustainable land management approaches, provide multiple benefits and reduce climate + risks. Reduction of food loss and waste, and adaptation measures in support of + balanced diets contribute to nutrition, health, and biodiversity benefits. Ecosystem-based + Adaptation 87 approaches such as urban greening, restoration of wetlands and upstream + forest ecosystems reduce a range of climate change risks, including flood risks, + urban heat and provide multiple co-benefits. Some land-based adaptation options + provide immediate benefits ; while afforestation and reforestation, restoration + of high-carbon ecosystems, agroforestry, and the reclamation of degraded soils + take more time to deliver measurable results. Significant synergies exist between + adaptation and mitigation, for example through sustainable land management approaches. + Agroecological principles and practices and other approaches that work with natural + processes support food security, nutrition, health and well-being, livelihoods + and biodiversity, sustainability and ecosystem services. Combinations of non-structural + measures like early warning systems and structural measures like levees have reduced + loss of lives in case of inland flooding and early warning systems along with + flood-proofing of buildings have proven to be cost-effective in the context of + coastal flooding under current sea level rise . Heat Health Action Plans that + include early warning and response systems are effective adaptation options for + extreme heat . Effective adaptation options for water, food and vector-borne diseases + include improving access to potable water, reducing exposure of water and sanitation + systems to extreme weather events, and improved early warning systems, surveillance, + and vaccine development. Adaptation options such as disaster risk management, + early warning systems, climate services and social safety nets have broad applicability + across multiple sectors . Integrated, multi-sectoral solutions that address social + inequities, differentiate responses based on climate risk and cut across systems, + increase the feasibility and effectiveness of adaptation in multiple sectors. + A.3.2: + - Adaptation Actions to Date Progress in adaptation planning and implementation + has been observed across all sectors and regions, generating multiple benefits. + The ambition, scope and progress on adaptation have risen among governments at + the local, national and international levels, along with businesses, communities + and civil society . Various tools, measures and processes are available that can + enable, accelerate and sustain adaptation implementation . Growing public and + political awareness of climate impacts and risks has resulted in at least 170 + countries and many cities including adaptation in their climate policies and planning + processes . Decision support tools and climate services are increasingly being + used and pilot projects and local experiments are being implemented in different + sectors . Adaptation to water-related risks and impacts make up the majority + of all documented adaptation. A large number of these adaptation responses are + in the agriculture sector and these include on-farm water management, water storage, + soil moisture conservation, and irrigation. Other adaptations in agriculture include + cultivar improvements, agroforestry, community-based adaptation and farm and landscape + diversification among others. For inland flooding, combinations of non-structural + measures like early warning systems, enhancing natural water retention such as + by restoring wetlands and rivers, and land use planning such as no build zones + or upstream forest management, can reduce flood risk . Some land-related adaptation + actions such as sustainable food production, improved and sustainable forest management, + soil organic carbon management, ecosystem conservation and land restoration, reduced + deforestation and degradation, and reduced food loss and waste are being undertaken, + and can have mitigation co-benefits. Adaptation actions that increase the resilience + of biodiversity and ecosystem services to climate change include responses like + minimising additional stresses or disturbances, reducing fragmentation, increasing + natural habitat extent, connectivity and heterogeneity, and protecting small-scale + refugia where microclimate conditions can allow species to persist. Most innovations + in urban adaptation have occurred through advances in disaster risk management, + social safety nets and green/blue infrastructure. Many adaptation measures that + benefit health and well-being are found in other sectors . Adaptation can generate + multiple additional benefits such as improving agricultural productivity, innovation, + health and well-being, food security, livelihood, and biodiversity conservation + as well as reduction of risks and damages. Globally tracked adaptation finance + has shown an upward trend since AR5, but represents only a small portion of total + climate finance, is uneven and has developed heterogeneously across regions and + sectors. Adaptation finance has come predominantly from public sources, largely + through grants, concessional and non-concessional instruments. Globally, private-sector + financing of adaptation from a variety of sources such as commercial financial + institutions, institutional investors, other private equity, non-financial corporations, + as well as communities and households has been limited, especially in developing + countries . Public mechanisms and finance can leverage private sector finance + for adaptation by addressing real and perceived regulatory, cost and market barriers, + for example via public-private partnerships. Innovations in adaptation and resilience + finance, such as forecast-based/anticipatory financing systems and regional risk + insurance pools, have been piloted and are growing in scale. There are adaptation + options which are effective in reducing climate risks 85 for specific contexts, + sectors and regions and contribute positively to sustainable development and other + societal goals. In the agriculture sector, cultivar improvements, on-farm water + management and storage, soil moisture conservation, irrigation 86, agroforestry, + community-based adaptation, and farm and landscape level diversification, and + sustainable land management approaches, provide multiple benefits and reduce climate + risks. Reduction of food loss and waste, and adaptation measures in support of + balanced diets contribute to nutrition, health, and biodiversity benefits. Ecosystem-based + Adaptation 87 approaches such as urban greening, restoration of wetlands and upstream + forest ecosystems reduce a range of climate change risks, including flood risks, + urban heat and provide multiple co-benefits. Some land-based adaptation options + provide immediate benefits ; while afforestation and reforestation, restoration + of high-carbon ecosystems, agroforestry, and the reclamation of degraded soils + take more time to deliver measurable results. Significant synergies exist between + adaptation and mitigation, for example through sustainable land management approaches. + Agroecological principles and practices and other approaches that work with natural + processes support food security, nutrition, health and well-being, livelihoods + and biodiversity, sustainability and ecosystem services. Combinations of non-structural + measures like early warning systems and structural measures like levees have reduced + loss of lives in case of inland flooding and early warning systems along with + flood-proofing of buildings have proven to be cost-effective in the context of + coastal flooding under current sea level rise . Heat Health Action Plans that + include early warning and response systems are effective adaptation options for + extreme heat . Effective adaptation options for water, food and vector-borne diseases + include improving access to potable water, reducing exposure of water and sanitation + systems to extreme weather events, and improved early warning systems, surveillance, + and vaccine development. Adaptation options such as disaster risk management, + early warning systems, climate services and social safety nets have broad applicability + across multiple sectors . Integrated, multi-sectoral solutions that address social + inequities, differentiate responses based on climate risk and cut across systems, + increase the feasibility and effectiveness of adaptation in multiple sectors. + A.3.3: + - Adaptation Gaps and Barriers Despite progress, adaptation gaps exist between + current levels of adaptation and levels needed to respond to impacts and reduce + climate risks. While progress in adaptation implementation is observed across + all sectors and regions , many adaptation initiatives prioritise immediate and + near-term climate risk reduction, e.g., through hard flood protection, which reduces + the opportunity for transformational adaptation . Most observed adaptation is + fragmented, small in scale, incremental, sector-specific, and focused more on + planning rather than implementation. Further, observed adaptation is unequally + distributed across regions and the largest adaptation gaps exist among lower population + income groups. In the urban context, the largest adaptation gaps exist in projects + that manage complex risks, for example in the food–energy–water–health nexus or + the inter-relationships of air quality and climate risk. Many funding, knowledge + and practice gaps remain for effective implementation, monitoring and evaluation + and current adaptation efforts are not expected to meet existing goals. At current + rates of adaptation planning and implementation the adaptation gap will continue + to grow. Soft and hard adaptation limits 100 have already been reached in some + sectors and regions, in spite of adaptation having buffered some climate impacts. + Ecosystems already reaching hard adaptation limits include some warm water coral + reefs, some coastal wetlands, some rainforests, and some polar and mountain ecosystems. + Individuals and households in low lying coastal areas in Australasia and Small + Islands and smallholder farmers in Central and South America, Africa, Europe and + Asia have reached soft limits, resulting from financial, governance, institutional + and policy constraints and can be overcome by addressing these constraints. Transitioning + from incremental to transformational adaptation can help overcome soft adaptation + limits . Adaptation does not prevent all losses and damages, even with effective + adaptation and before reaching soft and hard limits. Losses and damages are unequally + distributed across systems, regions and sectors and are not comprehensively addressed + by current financial, governance and institutional arrangements, particularly + in vulnerable developing countries. There is increased evidence of maladaptation + in various sectors and regions. Examples of maladaptation are observed in urban + areas , agriculture , ecosystems (e.g. fire suppression in naturally + A.3.6: + - Adaptation Gaps and Barriers Despite progress, adaptation gaps exist between + current levels of adaptation and levels needed to respond to impacts and reduce + climate risks. While progress in adaptation implementation is observed across + all sectors and regions , many adaptation initiatives prioritise immediate and + near-term climate risk reduction, e.g., through hard flood protection, which reduces + the opportunity for transformational adaptation . Most observed adaptation is + fragmented, small in scale, incremental, sector-specific, and focused more on + planning rather than implementation. Further, observed adaptation is unequally + distributed across regions and the largest adaptation gaps exist among lower population + income groups. In the urban context, the largest adaptation gaps exist in projects + that manage complex risks, for example in the food–energy–water–health nexus or + the inter-relationships of air quality and climate risk. Many funding, knowledge + and practice gaps remain for effective implementation, monitoring and evaluation + and current adaptation efforts are not expected to meet existing goals. At current + rates of adaptation planning and implementation the adaptation gap will continue + to grow. Soft and hard adaptation limits 100 have already been reached in some + sectors and regions, in spite of adaptation having buffered some climate impacts. + Ecosystems already reaching hard adaptation limits include some warm water coral + reefs, some coastal wetlands, some rainforests, and some polar and mountain ecosystems. + Individuals and households in low lying coastal areas in Australasia and Small + Islands and smallholder farmers in Central and South America, Africa, Europe and + Asia have reached soft limits, resulting from financial, governance, institutional + and policy constraints and can be overcome by addressing these constraints. Transitioning + from incremental to transformational adaptation can help overcome soft adaptation + limits . Adaptation does not prevent all losses and damages, even with effective + adaptation and before reaching soft and hard limits. Losses and damages are unequally + distributed across systems, regions and sectors and are not comprehensively addressed + by current financial, governance and institutional arrangements, particularly + in vulnerable developing countries. There is increased evidence of maladaptation + in various sectors and regions. Examples of maladaptation are observed in urban + areas , agriculture , ecosystems (e.g. fire suppression in naturally + - 'Lack of Finance as a Barrier to Climate Action Insufficient financing, and a + lack of political frameworks and incentives for finance, are key causes of the + implementation gaps for both mitigation and adaptation. Financial flows remained + heavily focused on mitigation, are uneven, and have developed heterogeneously + across regions and sectors. In 2018, public and publicly mobilised private climate + finance flows from developed to developing countries were below the collective + goal under the UNFCCC and Paris Agreement to mobilise USD 100 billion per year + by 2020 in the context of meaningful mitigation action and transparency on implementation + . Public and private finance flows for fossil fuels are still greater than those + for climate adaptation and mitigation . The overwhelming majority of tracked climate + finance is directed towards mitigation. Nevertheless, average annual modelled + investment requirements for 2020 to 2030 in scenarios that limit warming to 2°C + or 1.5°C are a factor of three to six greater than current levels, and total mitigation + investments would need to increase across all sectors and regions. Challenges + remain for green bonds and similar products, in particular around integrity and + additionality, as well as the limited applicability of these markets to many developing + countries. Current global financial flows for adaptation including from public + and private finance sources, are insufficient for and constrain implementation + of adaptation options, especially in developing countries. There are widening + disparities between the estimated costs of adaptation and the documented finance + allocated to adaptation. Adaptation finance needs are estimated to be higher than + those assessed in AR5, and the enhanced mobilisation of and access to financial + resources are essential for implementation of adaptation and to reduce adaptation + gaps. Annual finance flows targeting adaptation for Africa, for example, are billions + of USD less than the lowest adaptation cost estimates for near-term climate change. + Adverse climate impacts can further reduce the availability of financial resources + by causing losses and damages and impeding national economic growth, thereby further + increasing financial constraints for adaptation particularly for developing countries + and LDCs. Without effective mitigation and adaptation, losses and damages will + continue to disproportionately affect the poorest and most vulnerable populations. + Accelerated financial support for developing countries from developed countries + and other sources is a critical enabler to enhance mitigation action . Many developing + countries lack comprehensive data at the scale needed and lack adequate financial + resources needed for adaptation for reducing associated economic and non-economic + losses and damages. There are barriers to redirecting capital towards climate + action both within and outside the global financial sector. These barriers include: + the inadequate assessment of climate-related risks and investment opportunities, + regional mismatch between available capital and investment needs, home bias factors, + country indebtedness levels, economic vulnerability, and limited institutional + capacities. Challenges from outside the financial sector include: limited local + capital markets; unattractive risk-return profiles, in particular due to missing + or weak regulatory environments that are inconsistent with ambition levels; limited + institutional capacity to ensure safeguards; standardisation, aggregation, scalability + and replicability of investment opportunities and financing models; and, a pipeline + ready for commercial investments.' + A.4.1: + - Global Policy Setting The United Nations Framework Convention on Climate Change, + Kyoto Protocol, and Paris Agreement are supporting rising levels of national ambition + and encouraging the development and implementation of climate policies at multiple + levels of governance. The Kyoto Protocol led to reduced emissions in some countries + and was instrumental in building national and international capacity for GHG reporting, + accounting and emissions markets . The Paris Agreement, adopted under the UNFCCC, + with near universal participation, has led to policy development and target-setting + at national and sub-national levels, particularly in relation to mitigation but + also for adaptation, as well as enhanced transparency of climate action and support. + Nationally Determined Contributions, required under the Paris Agreement, have + required countries to articulate their priorities and ambition with respect to + climate action. Loss & Damage was formally recognized in 2013 through establishment + of the Warsaw International Mechanism on Loss and Damage, and in 2015, Article + 8 of the Paris Agreement provided a legal basis for the WIM. There is improved + understanding of both economic and non-economic losses and damages, which is informing + international climate policy and which has highlighted that losses and damages + are not comprehensively addressed by current financial, governance and institutional + arrangements, particularly in vulnerable developing countries . Other recent + global agreements that influence responses to climate change include the Sendai + Framework for Disaster Risk Reduction , the finance-oriented Addis Ababa Action + Agenda and the New Urban Agenda, and the Kigali Amendment to the Montreal Protocol + on Substances that Deplete the Ozone Layer , among others. In addition, the 2030 + Agenda for Sustainable Development, adopted in 2015 by UN member states, sets + out 17 Sustainable Development Goals and seeks to align efforts globally to prioritise + ending extreme poverty, protect the planet and promote more peaceful, prosperous + and inclusive societies. If achieved, these agreements would reduce climate change, + and the impacts on health, well-being, migration, and conflict, among others . Since + AR5, rising public awareness and an increasing diversity of actors, have overall + helped accelerate political commitment and global efforts to address climate change. + Mass social movements have emerged as catalysing agents in some regions, often + building on prior movements including Indigenous Peoples-led movements, youth + movements, human rights movements, gender activism, and climate litigation, which + is raising awareness and, in some cases, has influenced the outcome and ambition + of climate governance. Engaging Indigenous Peoples and local communities using + just-transition and rights-based decision-making approaches, implemented through + collective and participatory decision-making processes has enabled deeper ambition + and accelerated action in different ways, and at all scales, depending on national + circumstances. The media helps shape the public discourse about climate change. + This can usefully build public support to accelerate climate action . In some + instances, public discourses of media and organised counter movements have impeded + climate action, exacerbating helplessness and disinformation and fuelling polarisation, + with negative implications for climate action . + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + A.4.2: + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + A.4.3: + - The Gap Between Mitigation Policies, Pledges and Pathways that Limit Warming + to 1.5°C or Below 2°C Global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP2691 would make it likely that warming will exceed + 1.5°C during the 21st century and would make it harder to limit warming below + 2°C – if no additional commitments are made or actions taken. A substantial ‘emissions + gap’ exists as global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP26 would be similar to or only slightly below 2019 + emission levels and higher than those associated with modelled mitigation pathways + that limit warming to 1.5°C with no or limited overshoot or to 2°C, assuming immediate + action, which implies deep, rapid, and sustained global GHG emission reductions + this decade . 92 The magnitude of the emissions gap depends on the global warming + level considered and whether only unconditional or also conditional elements of + NDCs 93 are considered . Modelled pathways that are consistent with NDCs announced + prior to COP26 until 2030 and assume no increase in ambition thereafter have higher + emissions, leading to a median global warming of 2.8 [2.1 to 3.4]°C by 2100 . + If the ‘emission gap’ is not reduced, global GHG emissions in 2030 consistent + with NDCs announced prior to COP26 make it likely that warming will exceed 1.5°C + during the 21st century, while limiting warming to 2°C would imply an unprecedented + acceleration of mitigation efforts during 2030–2050 . Policies implemented by + the end of 2020 are projected to result in higher global GHG emissions in 2030 + than those implied by NDCs, indicating an ‘implementation gap 94 ’ . Projected + global emissions implied by policies implemented by the end of 2020 are 57 GtCO2 + -eq in 2030. This points to an implementation gap compared with the NDCs of 4 + to 7 GtCO 2-eq in 2030; without a strengthening of policies, emissions are projected + to rise, leading to a median global warming of 2.2°C to 3.5°C by 2100 . Projected + cumulative future CO2 emissions over the lifetime of existing fossil fuel infrastructure + without additional abatement exceed the total cumulative net CO2 emissions in + pathways that limit warming to 1.5°C with no or limited overshoot. They are approximately + equal to total cumulative net CO2 emissions in pathways that limit warming to + 2°C with a likelihood of 83% 96. Limiting warming to 2°C or lower will result + in stranded assets. About 80% of coal, 50% of gas, and 30% of oil reserves cannot + be burned and emitted if warming is limited to 2°C. Significantly more reserves + are expected to remain unburned if warming is limited to 1.5°C. Many countries + have signalled an intention to achieve net zero GHG or net zero CO 2 emissions + by around mid-century . More than 100 countries have either adopted, announced + or are discussing net zero GHG or net zero CO 2 emissions commitments, covering + more than two-thirds of global GHG emissions. A growing number of cities are setting + climate targets, including net zero GHG targets. Many companies and institutions + have also announced net zero emissions targets in recent years. The various net + zero emission pledges differ across countries in terms of scope and specificity, + and limited policies are to date in place to deliver on them. All mitigation + strategies face implementation challenges, including technology risks, scaling, + and costs. Almost all mitigation options also face institutional barriers that + need to be addressed to enable their application at scale . Current development + pathways may create behavioural, spatial, economic and social barriers to accelerated + mitigation at all scales. Choices made by policymakers, citizens, the private + sector and other stakeholders influence societies’ development pathways. Structural + factors of national circumstances and capabilities affect the breadth and depth + of climate governance. The extent to which civil society actors, political actors, + businesses, youth, labour, media, Indigenous Peoples, and local communities are + engaged influences political support for climate change mitigation and eventual + policy outcomes. The adoption of low-emission technologies lags in most developing + countries, particularly least developed ones, due in part to weaker enabling conditions, + including limited finance, technology development and transfer, and capacity . + In many countries, especially those with limited institutional capacity, several + adverse side-effects have been observed as a result of diffusion of low-emission + technology, e.g., low-value employment, and dependency on foreign knowledge and + suppliers. Low-emission innovation along with strengthened enabling conditions + can reinforce development benefits, which can, in turn, create feedbacks towards + greater public support for policy. Persistent and region-specific barriers also + continue to hamper the economic and political feasibility of deploying AFOLU mitigation + options. Barriers to implementation of AFOLU mitigation include insufficient institutional + and financial support, uncertainty over long-term additionality and trade-offs, + weak governance, insecure land ownership, low incomes and the lack of access to + alternative sources of income, and the risk of reversal . + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + A.4.4: + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + - The Gap Between Mitigation Policies, Pledges and Pathways that Limit Warming + to 1.5°C or Below 2°C Global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP2691 would make it likely that warming will exceed + 1.5°C during the 21st century and would make it harder to limit warming below + 2°C – if no additional commitments are made or actions taken. A substantial ‘emissions + gap’ exists as global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP26 would be similar to or only slightly below 2019 + emission levels and higher than those associated with modelled mitigation pathways + that limit warming to 1.5°C with no or limited overshoot or to 2°C, assuming immediate + action, which implies deep, rapid, and sustained global GHG emission reductions + this decade . 92 The magnitude of the emissions gap depends on the global warming + level considered and whether only unconditional or also conditional elements of + NDCs 93 are considered . Modelled pathways that are consistent with NDCs announced + prior to COP26 until 2030 and assume no increase in ambition thereafter have higher + emissions, leading to a median global warming of 2.8 [2.1 to 3.4]°C by 2100 . + If the ‘emission gap’ is not reduced, global GHG emissions in 2030 consistent + with NDCs announced prior to COP26 make it likely that warming will exceed 1.5°C + during the 21st century, while limiting warming to 2°C would imply an unprecedented + acceleration of mitigation efforts during 2030–2050 . Policies implemented by + the end of 2020 are projected to result in higher global GHG emissions in 2030 + than those implied by NDCs, indicating an ‘implementation gap 94 ’ . Projected + global emissions implied by policies implemented by the end of 2020 are 57 GtCO2 + -eq in 2030. This points to an implementation gap compared with the NDCs of 4 + to 7 GtCO 2-eq in 2030; without a strengthening of policies, emissions are projected + to rise, leading to a median global warming of 2.2°C to 3.5°C by 2100 . Projected + cumulative future CO2 emissions over the lifetime of existing fossil fuel infrastructure + without additional abatement exceed the total cumulative net CO2 emissions in + pathways that limit warming to 1.5°C with no or limited overshoot. They are approximately + equal to total cumulative net CO2 emissions in pathways that limit warming to + 2°C with a likelihood of 83% 96. Limiting warming to 2°C or lower will result + in stranded assets. About 80% of coal, 50% of gas, and 30% of oil reserves cannot + be burned and emitted if warming is limited to 2°C. Significantly more reserves + are expected to remain unburned if warming is limited to 1.5°C. Many countries + have signalled an intention to achieve net zero GHG or net zero CO 2 emissions + by around mid-century . More than 100 countries have either adopted, announced + or are discussing net zero GHG or net zero CO 2 emissions commitments, covering + more than two-thirds of global GHG emissions. A growing number of cities are setting + climate targets, including net zero GHG targets. Many companies and institutions + have also announced net zero emissions targets in recent years. The various net + zero emission pledges differ across countries in terms of scope and specificity, + and limited policies are to date in place to deliver on them. All mitigation + strategies face implementation challenges, including technology risks, scaling, + and costs. Almost all mitigation options also face institutional barriers that + need to be addressed to enable their application at scale . Current development + pathways may create behavioural, spatial, economic and social barriers to accelerated + mitigation at all scales. Choices made by policymakers, citizens, the private + sector and other stakeholders influence societies’ development pathways. Structural + factors of national circumstances and capabilities affect the breadth and depth + of climate governance. The extent to which civil society actors, political actors, + businesses, youth, labour, media, Indigenous Peoples, and local communities are + engaged influences political support for climate change mitigation and eventual + policy outcomes. The adoption of low-emission technologies lags in most developing + countries, particularly least developed ones, due in part to weaker enabling conditions, + including limited finance, technology development and transfer, and capacity . + In many countries, especially those with limited institutional capacity, several + adverse side-effects have been observed as a result of diffusion of low-emission + technology, e.g., low-value employment, and dependency on foreign knowledge and + suppliers. Low-emission innovation along with strengthened enabling conditions + can reinforce development benefits, which can, in turn, create feedbacks towards + greater public support for policy. Persistent and region-specific barriers also + continue to hamper the economic and political feasibility of deploying AFOLU mitigation + options. Barriers to implementation of AFOLU mitigation include insufficient institutional + and financial support, uncertainty over long-term additionality and trade-offs, + weak governance, insecure land ownership, low incomes and the lack of access to + alternative sources of income, and the risk of reversal . + - Long-term Climate Change The uncertainty range on assessed future changes in + global surface temperature is narrower than in the AR5. For the first time in + an IPCC assessment cycle, multi-model projections of global surface temperature, + ocean warming and sea level are constrained using observations and the assessed + climate sensitivity. The likely range of equilibrium climate sensitivity has been + narrowed to 2.5°C to 4.0°C based on multiple lines of evidence , including improved + understanding of cloud feedbacks. For related emissions scenarios, this leads + to narrower uncertainty ranges for long-term projected global temperature change + than in AR5. Future warming depends on future GHG emissions, with cumulative + net CO 2 dominating. The assessed best estimates and very likely ranges of warming + for 2081-2100 with respect to 1850–1900 vary from 1.4 [1.0 to 1.8]°C in the very + low GHG emissions scenario to 2.7 [2.1 to 3.5]°C in the intermediate GHG emissions + scenario and 4.4 [3.3 to 5.7]°C in the very high GHG emissions scenario 113 . Modelled + pathways consistent with the continuation of policies implemented by the end of + 2020 lead to global warming of 3.2 [2.2 to 3.5]°C by 2100 . Pathways of >4°C by + 2100 would imply a reversal of current technology and/or mitigation policy trends + . However, such warming could occur in emissions pathways consistent with policies + implemented by the end of 2020 if climate sensitivity or carbon cycle feedbacks + are higher than the best estimate. Global warming will continue to increase in + the near term in nearly all considered scenarios and modelled pathways. Deep, + rapid, and sustained GHG emissions reductions, reaching net zero CO2 emissions + and including strong emissions reductions of other GHGs, in particular CH4, are + necessary to limit warming to 1.5°C or less than 2°C by the end of century . The + best estimate of reaching 1.5°C of global warming lies in the first half of the + 2030s in most of the considered scenarios and modelled pathways 114. In the very + low GHG emissions scenario, CO 2 emissions reach net zero around 2050 and the + best-estimate end-of-century warming is 1.4°C, after a temporary overshoot of + no more than 0.1°C above 1.5°C global warming. Global warming of 2°C will be exceeded + during the 21st century unless deep reductions in CO 2 and other GHG emissions + occur in the coming decades. Deep, rapid, and sustained reductions in GHG emissions + would lead to improvements in air quality within a few years, to reductions in + trends of global surface temperature discernible after around 20 years, and over + longer time periods for many other climate impact-drivers 115 . Targeted reductions + of air pollutant emissions lead to more rapid improvements in air quality compared + to reductions in GHG emissions only, but in the long term, further improvements + are projected in scenarios that combine efforts to reduce air pollutants as well + as GHG emissions 116 . Changes in short-lived climate forcers resulting from + the five considered scenarios lead to an additional net global warming in the + near and long term. Simultaneous stringent climate change mitigation and air pollution + control olicies limit this additional warming and lead to strong benefits for + air quality. In high and very high GHG emissions scenarios, combined changes in + SLCF emissions, such as CH 4, aerosol and ozone precursors, lead to a net global + warming by 2100 of likely 0.4°C to 0.9°C relative to 2019. This is due to projected + increases in atmospheric concentration of CH4, tropospheric ozone, hydrofluorocarbons + and, when strong air pollution control is considered, reductions of cooling aerosols. + In low and very low GHG emissions scenarios, air pollution control policies, reductions + in CH 4 and other ozone precursors lead to a net cooling, whereas reductions in + anthropogenic cooling aerosols lead to a net warming. Altogether, this causes + a likely net warming of 0.0°C to 0.3°C due to SLCF changes in 2100 relative to + 2019 and strong reductions in global surface ozone and particulate matter . Continued + GHG emissions will further affect all major climate system components, and many + changes will be irreversible on centennial to millennial time scales. Many changes + in the climate system become larger in direct relation to increasing global warming. + With every additional increment of global warming, changes in extremes continue + to become larger. Additional warming will lead to more frequent and intense marine + heatwaves and is projected to further amplify permafrost thawing and loss of seasonal + snow cover, glaciers, land ice and Arctic sea ice. Continued global warming is + projected to further intensify the global water cycle, including its variability, + global monsoon precipitation , and very wet and very dry weather and climate events + and seasons. The portion of global land experiencing detectable changes in seasonal + mean precipitation is projected to increase with more variable precipitation and + surface water flows over most land regions within seasons and from year to year + . Many changes due to past and future GHG emissions are irreversible on centennial + to millennial time scales, especially in the ocean, ice sheets and global sea + level. Ocean acidification , ocean deoxygenation and global mean sea level will + continue to increase in the 21st century, at rates dependent on future emissions. With + further global warming, every region is projected to increasingly experience concurrent + and multiple changes in climatic impact-drivers. Increases in hot and decreases + in cold climatic impact-drivers, such as temperature extremes, are projected in + all regions. At 1.5°C global warming, heavy precipitation and flooding events + are projected to intensify and become more frequent in most regions in Africa, + Asia , North America and Europe . At 2°C or above, these changes expand to more + regions and/or become more significant, and more frequent and/or severe agricultural + and ecological droughts are projected in Europe, Africa, Australasia and North, + Central and South America . Other projected regional changes include intensification + of tropical cyclones and/or extratropical storms , and increases in aridity and + fire weather . Compound heatwaves and droughts become likely more frequent, including + concurrently at multiple locations. + A.4.5: + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + - The Gap Between Mitigation Policies, Pledges and Pathways that Limit Warming + to 1.5°C or Below 2°C Global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP2691 would make it likely that warming will exceed + 1.5°C during the 21st century and would make it harder to limit warming below + 2°C – if no additional commitments are made or actions taken. A substantial ‘emissions + gap’ exists as global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP26 would be similar to or only slightly below 2019 + emission levels and higher than those associated with modelled mitigation pathways + that limit warming to 1.5°C with no or limited overshoot or to 2°C, assuming immediate + action, which implies deep, rapid, and sustained global GHG emission reductions + this decade . 92 The magnitude of the emissions gap depends on the global warming + level considered and whether only unconditional or also conditional elements of + NDCs 93 are considered . Modelled pathways that are consistent with NDCs announced + prior to COP26 until 2030 and assume no increase in ambition thereafter have higher + emissions, leading to a median global warming of 2.8 [2.1 to 3.4]°C by 2100 . + If the ‘emission gap’ is not reduced, global GHG emissions in 2030 consistent + with NDCs announced prior to COP26 make it likely that warming will exceed 1.5°C + during the 21st century, while limiting warming to 2°C would imply an unprecedented + acceleration of mitigation efforts during 2030–2050 . Policies implemented by + the end of 2020 are projected to result in higher global GHG emissions in 2030 + than those implied by NDCs, indicating an ‘implementation gap 94 ’ . Projected + global emissions implied by policies implemented by the end of 2020 are 57 GtCO2 + -eq in 2030. This points to an implementation gap compared with the NDCs of 4 + to 7 GtCO 2-eq in 2030; without a strengthening of policies, emissions are projected + to rise, leading to a median global warming of 2.2°C to 3.5°C by 2100 . Projected + cumulative future CO2 emissions over the lifetime of existing fossil fuel infrastructure + without additional abatement exceed the total cumulative net CO2 emissions in + pathways that limit warming to 1.5°C with no or limited overshoot. They are approximately + equal to total cumulative net CO2 emissions in pathways that limit warming to + 2°C with a likelihood of 83% 96. Limiting warming to 2°C or lower will result + in stranded assets. About 80% of coal, 50% of gas, and 30% of oil reserves cannot + be burned and emitted if warming is limited to 2°C. Significantly more reserves + are expected to remain unburned if warming is limited to 1.5°C. Many countries + have signalled an intention to achieve net zero GHG or net zero CO 2 emissions + by around mid-century . More than 100 countries have either adopted, announced + or are discussing net zero GHG or net zero CO 2 emissions commitments, covering + more than two-thirds of global GHG emissions. A growing number of cities are setting + climate targets, including net zero GHG targets. Many companies and institutions + have also announced net zero emissions targets in recent years. The various net + zero emission pledges differ across countries in terms of scope and specificity, + and limited policies are to date in place to deliver on them. All mitigation + strategies face implementation challenges, including technology risks, scaling, + and costs. Almost all mitigation options also face institutional barriers that + need to be addressed to enable their application at scale . Current development + pathways may create behavioural, spatial, economic and social barriers to accelerated + mitigation at all scales. Choices made by policymakers, citizens, the private + sector and other stakeholders influence societies’ development pathways. Structural + factors of national circumstances and capabilities affect the breadth and depth + of climate governance. The extent to which civil society actors, political actors, + businesses, youth, labour, media, Indigenous Peoples, and local communities are + engaged influences political support for climate change mitigation and eventual + policy outcomes. The adoption of low-emission technologies lags in most developing + countries, particularly least developed ones, due in part to weaker enabling conditions, + including limited finance, technology development and transfer, and capacity . + In many countries, especially those with limited institutional capacity, several + adverse side-effects have been observed as a result of diffusion of low-emission + technology, e.g., low-value employment, and dependency on foreign knowledge and + suppliers. Low-emission innovation along with strengthened enabling conditions + can reinforce development benefits, which can, in turn, create feedbacks towards + greater public support for policy. Persistent and region-specific barriers also + continue to hamper the economic and political feasibility of deploying AFOLU mitigation + options. Barriers to implementation of AFOLU mitigation include insufficient institutional + and financial support, uncertainty over long-term additionality and trade-offs, + weak governance, insecure land ownership, low incomes and the lack of access to + alternative sources of income, and the risk of reversal . + - 'Lack of Finance as a Barrier to Climate Action Insufficient financing, and a + lack of political frameworks and incentives for finance, are key causes of the + implementation gaps for both mitigation and adaptation. Financial flows remained + heavily focused on mitigation, are uneven, and have developed heterogeneously + across regions and sectors. In 2018, public and publicly mobilised private climate + finance flows from developed to developing countries were below the collective + goal under the UNFCCC and Paris Agreement to mobilise USD 100 billion per year + by 2020 in the context of meaningful mitigation action and transparency on implementation + . Public and private finance flows for fossil fuels are still greater than those + for climate adaptation and mitigation . The overwhelming majority of tracked climate + finance is directed towards mitigation. Nevertheless, average annual modelled + investment requirements for 2020 to 2030 in scenarios that limit warming to 2°C + or 1.5°C are a factor of three to six greater than current levels, and total mitigation + investments would need to increase across all sectors and regions. Challenges + remain for green bonds and similar products, in particular around integrity and + additionality, as well as the limited applicability of these markets to many developing + countries. Current global financial flows for adaptation including from public + and private finance sources, are insufficient for and constrain implementation + of adaptation options, especially in developing countries. There are widening + disparities between the estimated costs of adaptation and the documented finance + allocated to adaptation. Adaptation finance needs are estimated to be higher than + those assessed in AR5, and the enhanced mobilisation of and access to financial + resources are essential for implementation of adaptation and to reduce adaptation + gaps. Annual finance flows targeting adaptation for Africa, for example, are billions + of USD less than the lowest adaptation cost estimates for near-term climate change. + Adverse climate impacts can further reduce the availability of financial resources + by causing losses and damages and impeding national economic growth, thereby further + increasing financial constraints for adaptation particularly for developing countries + and LDCs. Without effective mitigation and adaptation, losses and damages will + continue to disproportionately affect the poorest and most vulnerable populations. + Accelerated financial support for developing countries from developed countries + and other sources is a critical enabler to enhance mitigation action . Many developing + countries lack comprehensive data at the scale needed and lack adequate financial + resources needed for adaptation for reducing associated economic and non-economic + losses and damages. There are barriers to redirecting capital towards climate + action both within and outside the global financial sector. These barriers include: + the inadequate assessment of climate-related risks and investment opportunities, + regional mismatch between available capital and investment needs, home bias factors, + country indebtedness levels, economic vulnerability, and limited institutional + capacities. Challenges from outside the financial sector include: limited local + capital markets; unattractive risk-return profiles, in particular due to missing + or weak regulatory environments that are inconsistent with ambition levels; limited + institutional capacity to ensure safeguards; standardisation, aggregation, scalability + and replicability of investment opportunities and financing models; and, a pipeline + ready for commercial investments.' + B.1.1: + - Long-term Climate Change The uncertainty range on assessed future changes in + global surface temperature is narrower than in the AR5. For the first time in + an IPCC assessment cycle, multi-model projections of global surface temperature, + ocean warming and sea level are constrained using observations and the assessed + climate sensitivity. The likely range of equilibrium climate sensitivity has been + narrowed to 2.5°C to 4.0°C based on multiple lines of evidence , including improved + understanding of cloud feedbacks. For related emissions scenarios, this leads + to narrower uncertainty ranges for long-term projected global temperature change + than in AR5. Future warming depends on future GHG emissions, with cumulative + net CO 2 dominating. The assessed best estimates and very likely ranges of warming + for 2081-2100 with respect to 1850–1900 vary from 1.4 [1.0 to 1.8]°C in the very + low GHG emissions scenario to 2.7 [2.1 to 3.5]°C in the intermediate GHG emissions + scenario and 4.4 [3.3 to 5.7]°C in the very high GHG emissions scenario 113 . Modelled + pathways consistent with the continuation of policies implemented by the end of + 2020 lead to global warming of 3.2 [2.2 to 3.5]°C by 2100 . Pathways of >4°C by + 2100 would imply a reversal of current technology and/or mitigation policy trends + . However, such warming could occur in emissions pathways consistent with policies + implemented by the end of 2020 if climate sensitivity or carbon cycle feedbacks + are higher than the best estimate. Global warming will continue to increase in + the near term in nearly all considered scenarios and modelled pathways. Deep, + rapid, and sustained GHG emissions reductions, reaching net zero CO2 emissions + and including strong emissions reductions of other GHGs, in particular CH4, are + necessary to limit warming to 1.5°C or less than 2°C by the end of century . The + best estimate of reaching 1.5°C of global warming lies in the first half of the + 2030s in most of the considered scenarios and modelled pathways 114. In the very + low GHG emissions scenario, CO 2 emissions reach net zero around 2050 and the + best-estimate end-of-century warming is 1.4°C, after a temporary overshoot of + no more than 0.1°C above 1.5°C global warming. Global warming of 2°C will be exceeded + during the 21st century unless deep reductions in CO 2 and other GHG emissions + occur in the coming decades. Deep, rapid, and sustained reductions in GHG emissions + would lead to improvements in air quality within a few years, to reductions in + trends of global surface temperature discernible after around 20 years, and over + longer time periods for many other climate impact-drivers 115 . Targeted reductions + of air pollutant emissions lead to more rapid improvements in air quality compared + to reductions in GHG emissions only, but in the long term, further improvements + are projected in scenarios that combine efforts to reduce air pollutants as well + as GHG emissions 116 . Changes in short-lived climate forcers resulting from + the five considered scenarios lead to an additional net global warming in the + near and long term. Simultaneous stringent climate change mitigation and air pollution + control olicies limit this additional warming and lead to strong benefits for + air quality. In high and very high GHG emissions scenarios, combined changes in + SLCF emissions, such as CH 4, aerosol and ozone precursors, lead to a net global + warming by 2100 of likely 0.4°C to 0.9°C relative to 2019. This is due to projected + increases in atmospheric concentration of CH4, tropospheric ozone, hydrofluorocarbons + and, when strong air pollution control is considered, reductions of cooling aerosols. + In low and very low GHG emissions scenarios, air pollution control policies, reductions + in CH 4 and other ozone precursors lead to a net cooling, whereas reductions in + anthropogenic cooling aerosols lead to a net warming. Altogether, this causes + a likely net warming of 0.0°C to 0.3°C due to SLCF changes in 2100 relative to + 2019 and strong reductions in global surface ozone and particulate matter . Continued + GHG emissions will further affect all major climate system components, and many + changes will be irreversible on centennial to millennial time scales. Many changes + in the climate system become larger in direct relation to increasing global warming. + With every additional increment of global warming, changes in extremes continue + to become larger. Additional warming will lead to more frequent and intense marine + heatwaves and is projected to further amplify permafrost thawing and loss of seasonal + snow cover, glaciers, land ice and Arctic sea ice. Continued global warming is + projected to further intensify the global water cycle, including its variability, + global monsoon precipitation , and very wet and very dry weather and climate events + and seasons. The portion of global land experiencing detectable changes in seasonal + mean precipitation is projected to increase with more variable precipitation and + surface water flows over most land regions within seasons and from year to year + . Many changes due to past and future GHG emissions are irreversible on centennial + to millennial time scales, especially in the ocean, ice sheets and global sea + level. Ocean acidification , ocean deoxygenation and global mean sea level will + continue to increase in the 21st century, at rates dependent on future emissions. With + further global warming, every region is projected to increasingly experience concurrent + and multiple changes in climatic impact-drivers. Increases in hot and decreases + in cold climatic impact-drivers, such as temperature extremes, are projected in + all regions. At 1.5°C global warming, heavy precipitation and flooding events + are projected to intensify and become more frequent in most regions in Africa, + Asia , North America and Europe . At 2°C or above, these changes expand to more + regions and/or become more significant, and more frequent and/or severe agricultural + and ecological droughts are projected in Europe, Africa, Australasia and North, + Central and South America . Other projected regional changes include intensification + of tropical cyclones and/or extratropical storms , and increases in aridity and + fire weather . Compound heatwaves and droughts become likely more frequent, including + concurrently at multiple locations. + - 'Overshoot Pathways: Increased Risks and Other Implications Exceeding a specific + remaining carbon budget results in higher global warming. Achieving and sustaining + net negative global CO 2 emissions could reverse the resulting temperature exceedance. + Continued reductions in emissions of short-lived climate forcers, particularly + methane, after peak temperature has been reached, would also further reduce warming. + Only a small number of the most ambitious global modelled pathways limit global + warming to 1.5°C without overshoot. Overshoot of a warming level results in more + adverse impacts, some irreversible, and additional risks for human and natural + systems compared to staying below that warming level, with risks growing with + the magnitude and duration of overshoot. Compared to pathways without overshoot, + societies and ecosystems would be exposed to greater and more widespread changes + in climatic impact-drivers, such as extreme heat and extreme precipitation, with + increasing risks to infrastructure, low-lying coastal settlements, and associated + livelihoods. Overshooting 1.5°C will result in irreversible adverse impacts on + certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, + impacted by ice-sheet melt, glacier melt, or by accelerating and higher committed + sea level rise. Overshoot increases the risks of severe impacts, such as increased + wildfires, mass mortality of trees, drying of peatlands, thawing of permafrost + and weakening natural land carbon sinks; such impacts could increase releases + of GHGs making temperature reversal more challenging. The larger the overshoot, + the more net negative CO2 emissions needed to return to a given warming level. + Reducing global temperature by removing CO 2 would require net negative emissions + of 220 GtCO 2 for every tenth of a degree. Modelled pathways that limit warming + to 1.5°C with no or limited overshoot reach median values of cumulative net negative + emissions of 220 GtCO2 by 2100, pathways that return warming to 1.5°C after high + overshoot reach median values of 360 GtCO2. 137 More rapid reduction in CO 2 and + non-CO2 emissions, particularly methane, limits peak warming levels and reduces + the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility + and sustainability concerns, and social and environmental risks .' + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + B.1.4: + - Long-term Climate Change The uncertainty range on assessed future changes in + global surface temperature is narrower than in the AR5. For the first time in + an IPCC assessment cycle, multi-model projections of global surface temperature, + ocean warming and sea level are constrained using observations and the assessed + climate sensitivity. The likely range of equilibrium climate sensitivity has been + narrowed to 2.5°C to 4.0°C based on multiple lines of evidence , including improved + understanding of cloud feedbacks. For related emissions scenarios, this leads + to narrower uncertainty ranges for long-term projected global temperature change + than in AR5. Future warming depends on future GHG emissions, with cumulative + net CO 2 dominating. The assessed best estimates and very likely ranges of warming + for 2081-2100 with respect to 1850–1900 vary from 1.4 [1.0 to 1.8]°C in the very + low GHG emissions scenario to 2.7 [2.1 to 3.5]°C in the intermediate GHG emissions + scenario and 4.4 [3.3 to 5.7]°C in the very high GHG emissions scenario 113 . Modelled + pathways consistent with the continuation of policies implemented by the end of + 2020 lead to global warming of 3.2 [2.2 to 3.5]°C by 2100 . Pathways of >4°C by + 2100 would imply a reversal of current technology and/or mitigation policy trends + . However, such warming could occur in emissions pathways consistent with policies + implemented by the end of 2020 if climate sensitivity or carbon cycle feedbacks + are higher than the best estimate. Global warming will continue to increase in + the near term in nearly all considered scenarios and modelled pathways. Deep, + rapid, and sustained GHG emissions reductions, reaching net zero CO2 emissions + and including strong emissions reductions of other GHGs, in particular CH4, are + necessary to limit warming to 1.5°C or less than 2°C by the end of century . The + best estimate of reaching 1.5°C of global warming lies in the first half of the + 2030s in most of the considered scenarios and modelled pathways 114. In the very + low GHG emissions scenario, CO 2 emissions reach net zero around 2050 and the + best-estimate end-of-century warming is 1.4°C, after a temporary overshoot of + no more than 0.1°C above 1.5°C global warming. Global warming of 2°C will be exceeded + during the 21st century unless deep reductions in CO 2 and other GHG emissions + occur in the coming decades. Deep, rapid, and sustained reductions in GHG emissions + would lead to improvements in air quality within a few years, to reductions in + trends of global surface temperature discernible after around 20 years, and over + longer time periods for many other climate impact-drivers 115 . Targeted reductions + of air pollutant emissions lead to more rapid improvements in air quality compared + to reductions in GHG emissions only, but in the long term, further improvements + are projected in scenarios that combine efforts to reduce air pollutants as well + as GHG emissions 116 . Changes in short-lived climate forcers resulting from + the five considered scenarios lead to an additional net global warming in the + near and long term. Simultaneous stringent climate change mitigation and air pollution + control olicies limit this additional warming and lead to strong benefits for + air quality. In high and very high GHG emissions scenarios, combined changes in + SLCF emissions, such as CH 4, aerosol and ozone precursors, lead to a net global + warming by 2100 of likely 0.4°C to 0.9°C relative to 2019. This is due to projected + increases in atmospheric concentration of CH4, tropospheric ozone, hydrofluorocarbons + and, when strong air pollution control is considered, reductions of cooling aerosols. + In low and very low GHG emissions scenarios, air pollution control policies, reductions + in CH 4 and other ozone precursors lead to a net cooling, whereas reductions in + anthropogenic cooling aerosols lead to a net warming. Altogether, this causes + a likely net warming of 0.0°C to 0.3°C due to SLCF changes in 2100 relative to + 2019 and strong reductions in global surface ozone and particulate matter . Continued + GHG emissions will further affect all major climate system components, and many + changes will be irreversible on centennial to millennial time scales. Many changes + in the climate system become larger in direct relation to increasing global warming. + With every additional increment of global warming, changes in extremes continue + to become larger. Additional warming will lead to more frequent and intense marine + heatwaves and is projected to further amplify permafrost thawing and loss of seasonal + snow cover, glaciers, land ice and Arctic sea ice. Continued global warming is + projected to further intensify the global water cycle, including its variability, + global monsoon precipitation , and very wet and very dry weather and climate events + and seasons. The portion of global land experiencing detectable changes in seasonal + mean precipitation is projected to increase with more variable precipitation and + surface water flows over most land regions within seasons and from year to year + . Many changes due to past and future GHG emissions are irreversible on centennial + to millennial time scales, especially in the ocean, ice sheets and global sea + level. Ocean acidification , ocean deoxygenation and global mean sea level will + continue to increase in the 21st century, at rates dependent on future emissions. With + further global warming, every region is projected to increasingly experience concurrent + and multiple changes in climatic impact-drivers. Increases in hot and decreases + in cold climatic impact-drivers, such as temperature extremes, are projected in + all regions. At 1.5°C global warming, heavy precipitation and flooding events + are projected to intensify and become more frequent in most regions in Africa, + Asia , North America and Europe . At 2°C or above, these changes expand to more + regions and/or become more significant, and more frequent and/or severe agricultural + and ecological droughts are projected in Europe, Africa, Australasia and North, + Central and South America . Other projected regional changes include intensification + of tropical cyclones and/or extratropical storms , and increases in aridity and + fire weather . Compound heatwaves and droughts become likely more frequent, including + concurrently at multiple locations. + - 'The Likelihood and Risks of Abrupt and Irreversible Change The likelihood of + abrupt and irreversible changes and their impacts increase with higher global + warming levels. As warming levels increase, so do the risks of species extinction + or irreversible loss of biodiversity in ecosystems such as forests , coral reefs + and in Arctic regions . Risks associated with large-scale singular events or tipping + points, such as ice sheet instability or ecosystem loss from tropical forests, + transition to high risk between 1.5°C to 2.5°C and to very high risk between + 2.5°C to 4°C. The response of biogeochemical cycles to anthropogenic perturbations + can be abrupt at regional scales and irreversible on decadal to century time scales. + The probability of crossing uncertain regional thresholds increases with further + warming. Sea level rise is unavoidable for centuries to millennia due to continuing + deep ocean warming and ice sheet melt, and sea levels will remain elevated for + thousands of years . Global mean sea level rise will continue in the 21st century, + with projected regional relative sea level rise within 20% of the global mean + along two-thirds of the global coastline . The magnitude, the rate, the timing + of threshold exceedances, and the long-term commitment of sea level rise depend + on emissions, with higher emissions leading to greater and faster rates of sea + level rise. Due to relative sea level rise, extreme sea level events that occurred + once per century in the recent past are projected to occur at least annually at + more than half of all tide gauge locations by 2100 and risks for coastal ecosystems, + people and infrastructure will continue to increase beyond 2100. At sustained + warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets + will be lost almost completely and irreversibly over multiple millennia. The probability + and rate of ice mass loss increase with higher global surface temperatures. Over + the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming + is limited to 1.5°C and 2 to 6 m if limited to 2°C . Projections of multi-millennial + global mean sea level rise are consistent with reconstructed levels during past + warm climate periods: global mean sea level was very likely 5 to 25 m higher than + today roughly 3 million years ago, when global temperatures were 2.5°C to 4°C + higher than 1850–1900. Further examples of unavoidable changes in the climate + system due to multi-decadal or longer response timescales include continued glacier + melt and permafrost carbon loss. The probability of low-likelihood outcomes + associated with potentially very large impacts increases with higher global warming + levels. Warming substantially above the assessed very likely range for a given + scenario cannot be ruled out, and there is high confidence this would lead to + regional changes greater than assessed in many aspects of the climate system. + Low-likelihood, high-impact outcomes could occur at regional scales even for global + warming within the very likely assessed range for a given GHG emissions scenario. + Global mean sea level rise above the likely range – approaching 2 m by 2100 and + in excess of 15 m by 2300 under a very high GHG emissions scenario – cannot be + ruled out due to deep uncertainty in ice-sheet processes 123 and would have severe + impacts on populations in low elevation coastal zones. If global warming increases, + some compound extreme events 124 will become more frequent, with higher likelihood + of unprecedented intensities, durations or spatial extent. The Atlantic Meridional + Overturning Circulation is very likely to weaken over the 21st century for all + considered scenarios, however an abrupt collapse is not expected before 2100 . + If such a low probability event were to occur, it would very likely cause abrupt + shifts in regional weather patterns and water cycle, such as a southward shift + in the tropical rain belt, and large impacts on ecosystems and human activities. + A sequence of large explosive volcanic eruptions within decades, as have occurred + in the past, is a low-likelihood high-impact event that would lead to substantial + cooling globally and regional climate perturbations over several decades.' + B.1.5: + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + B.2.1: + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + B.2.2: + - Impacts and Related Risks For a given level of warming, many climate-related + risks are assessed to be higher than in AR5. Levels of risk for all Reasons for + Concern 121 are assessed to become high to very high at lower global warming levels + compared to what was assessed in AR5. This is based upon recent evidence of observed + impacts, improved process understanding, and new knowledge on exposure and vulnerability + of human and natural systems, including limits to adaptation. Depending on the + level of global warming, the assessed long-term impacts will be up to multiple + times higher than currently observed for 127 identified key risks, e.g., in terms + of the number of affected people and species. Risks, including cascading risks + and risks from overshoot, are projected to become increasingly severe with every + increment of global warming. Climate-related risks for natural and human systems + are higher for global warming of 1.5°C than at present but lower than at 2°C . + Climate-related risks to health, livelihoods, food security, water supply, human + security, and economic growth are projected to increase with global warming of + 1.5°C. In terrestrial ecosystems, 3 to 14% of the tens of thousands of species + assessed will likely face a very high risk of extinction at a GWL of 1.5°C. Coral + reefs are projected to decline by a further 70–90% at 1.5°C of global warming. + At this GWL, many low-elevation and small glaciers around the world would lose + most of their mass or disappear within decades to centuries. Regions at disproportionately + higher risk include Arctic ecosystems, dryland regions, small island developing + states and Least Developed Countries . At 2°C of global warming, overall risk + levels associated with the unequal distribution of impacts, global aggregate impacts + and large-scale singular events would be transitioning to high , those associated + with extreme weather events would be transitioning to very high, and those associated + with unique and threatened systems would be very high . With about 2°C warming, + climate-related changes in food availability and diet quality are estimated to + increase nutrition-related diseases and the number of undernourished people, affecting + tens to hundreds of millions of people, particularly among low-income households + in low- and middle-income countries in sub-Saharan Africa, South Asia and Central + America. For example, snowmelt water availability for irrigation is projected + to decline in some snowmelt dependent river basins by up to 20% . Climate change + risks to cities, settlements and key infrastructure will rise sharply in the mid + and long term with further global warming, especially in places already exposed + to high temperatures, along coastlines, or with high vulnerabilities . At global + warming of 3°C, additional risks in many sectors and regions reach high or very + high levels, implying widespread systemic impacts, irreversible change and many + additional adaptation limits . For example, very high extinction risk for endemic + species in biodiversity hotspots is projected to increase at least tenfold if + warming rises from 1.5°C to 3°C. Projected increases in direct flood damages are + higher by 1.4 to 2 times at 2°C and 2.5 to 3.9 times at 3°C, compared to 1.5°C + global warming without adaptation. Global warming of 4°C and above is projected + to lead to far-reaching impacts on natural and human systems. Beyond 4°C of warming, + projected impacts on natural systems include local extinction of ~50% of tropical + marine species and biome shifts across 35% of global land area. At this level + of warming, approximately 10% of the global land area is projected to face both + increasing high and decreasing low extreme streamflow, affecting, without additional + adaptation, over 2.1 billion people and about 4 billion people are projected to + experience water scarcity. At 4°C of warming, the global burned area is projected + to increase by 50 to 70% and the fire frequency by ~30% compared to today. Projected + adverse impacts and related losses and damages from climate change escalate with + every increment of global warming , but they will also strongly depend on socio-economic + development trajectories and adaptation actions to reduce vulnerability and exposure. + For example, development pathways with higher demand for food, animal feed, and + water, more resource-intensive consumption and production, and limited technological + improvements result in higher risks from water scarcity in drylands, land degradation + and food insecurity . Changes in, for example, demography or investments in health + systems have effect on a variety of health-related outcomes including heat-related + morbidity and mortality. With every increment of warming, climate change impacts + and risks will become increasingly complex and more difficult to manage. Many + regions are projected to experience an increase in the probability of compound + events with higher global warming, such as concurrent heatwaves and droughts, + compound flooding and fire weather. In addition, multiple climatic and non-climatic + risk drivers such as biodiversity loss or violent conflict will interact, resulting + in compounding overall risk and risks cascading across sectors and regions. Furthermore, + risks can arise from some responses that are intended to reduce the risks of climate + change, e.g., adverse side effects of some emission reduction and carbon dioxide + removal measures . Solar Radiation Modification approaches, if they were to be + implemented, introduce a widespread range of new risks to people and ecosystems, + which are not well understood. SRM has the potential to offset warming within + one or two decades and ameliorate some climate hazards but would not restore climate + to a previous state, and substantial residual or overcompensating climate change + would occur at regional and seasonal scales. Effects of SRM would depend on the + specific approach used 122, and a sudden and sustained termination of SRM in a + high CO 2 emissions scenario would cause rapid climate change. SRM would not stop + atmospheric CO 2 concentrations from increasing nor reduce resulting ocean acidification + under continued anthropogenic emissions. Large uncertainties and knowledge gaps + are associated with the potential of SRM approaches to reduce climate change risks. + Lack of robust and formal SRM governance poses risks as deployment by a limited + number of states could create international tensions. + - 'The Likelihood and Risks of Abrupt and Irreversible Change The likelihood of + abrupt and irreversible changes and their impacts increase with higher global + warming levels. As warming levels increase, so do the risks of species extinction + or irreversible loss of biodiversity in ecosystems such as forests , coral reefs + and in Arctic regions . Risks associated with large-scale singular events or tipping + points, such as ice sheet instability or ecosystem loss from tropical forests, + transition to high risk between 1.5°C to 2.5°C and to very high risk between + 2.5°C to 4°C. The response of biogeochemical cycles to anthropogenic perturbations + can be abrupt at regional scales and irreversible on decadal to century time scales. + The probability of crossing uncertain regional thresholds increases with further + warming. Sea level rise is unavoidable for centuries to millennia due to continuing + deep ocean warming and ice sheet melt, and sea levels will remain elevated for + thousands of years . Global mean sea level rise will continue in the 21st century, + with projected regional relative sea level rise within 20% of the global mean + along two-thirds of the global coastline . The magnitude, the rate, the timing + of threshold exceedances, and the long-term commitment of sea level rise depend + on emissions, with higher emissions leading to greater and faster rates of sea + level rise. Due to relative sea level rise, extreme sea level events that occurred + once per century in the recent past are projected to occur at least annually at + more than half of all tide gauge locations by 2100 and risks for coastal ecosystems, + people and infrastructure will continue to increase beyond 2100. At sustained + warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets + will be lost almost completely and irreversibly over multiple millennia. The probability + and rate of ice mass loss increase with higher global surface temperatures. Over + the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming + is limited to 1.5°C and 2 to 6 m if limited to 2°C . Projections of multi-millennial + global mean sea level rise are consistent with reconstructed levels during past + warm climate periods: global mean sea level was very likely 5 to 25 m higher than + today roughly 3 million years ago, when global temperatures were 2.5°C to 4°C + higher than 1850–1900. Further examples of unavoidable changes in the climate + system due to multi-decadal or longer response timescales include continued glacier + melt and permafrost carbon loss. The probability of low-likelihood outcomes + associated with potentially very large impacts increases with higher global warming + levels. Warming substantially above the assessed very likely range for a given + scenario cannot be ruled out, and there is high confidence this would lead to + regional changes greater than assessed in many aspects of the climate system. + Low-likelihood, high-impact outcomes could occur at regional scales even for global + warming within the very likely assessed range for a given GHG emissions scenario. + Global mean sea level rise above the likely range – approaching 2 m by 2100 and + in excess of 15 m by 2300 under a very high GHG emissions scenario – cannot be + ruled out due to deep uncertainty in ice-sheet processes 123 and would have severe + impacts on populations in low elevation coastal zones. If global warming increases, + some compound extreme events 124 will become more frequent, with higher likelihood + of unprecedented intensities, durations or spatial extent. The Atlantic Meridional + Overturning Circulation is very likely to weaken over the 21st century for all + considered scenarios, however an abrupt collapse is not expected before 2100 . + If such a low probability event were to occur, it would very likely cause abrupt + shifts in regional weather patterns and water cycle, such as a southward shift + in the tropical rain belt, and large impacts on ecosystems and human activities. + A sequence of large explosive volcanic eruptions within decades, as have occurred + in the past, is a low-likelihood high-impact event that would lead to substantial + cooling globally and regional climate perturbations over several decades.' + B.3.1: + - 'The Likelihood and Risks of Abrupt and Irreversible Change The likelihood of + abrupt and irreversible changes and their impacts increase with higher global + warming levels. As warming levels increase, so do the risks of species extinction + or irreversible loss of biodiversity in ecosystems such as forests , coral reefs + and in Arctic regions . Risks associated with large-scale singular events or tipping + points, such as ice sheet instability or ecosystem loss from tropical forests, + transition to high risk between 1.5°C to 2.5°C and to very high risk between + 2.5°C to 4°C. The response of biogeochemical cycles to anthropogenic perturbations + can be abrupt at regional scales and irreversible on decadal to century time scales. + The probability of crossing uncertain regional thresholds increases with further + warming. Sea level rise is unavoidable for centuries to millennia due to continuing + deep ocean warming and ice sheet melt, and sea levels will remain elevated for + thousands of years . Global mean sea level rise will continue in the 21st century, + with projected regional relative sea level rise within 20% of the global mean + along two-thirds of the global coastline . The magnitude, the rate, the timing + of threshold exceedances, and the long-term commitment of sea level rise depend + on emissions, with higher emissions leading to greater and faster rates of sea + level rise. Due to relative sea level rise, extreme sea level events that occurred + once per century in the recent past are projected to occur at least annually at + more than half of all tide gauge locations by 2100 and risks for coastal ecosystems, + people and infrastructure will continue to increase beyond 2100. At sustained + warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets + will be lost almost completely and irreversibly over multiple millennia. The probability + and rate of ice mass loss increase with higher global surface temperatures. Over + the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming + is limited to 1.5°C and 2 to 6 m if limited to 2°C . Projections of multi-millennial + global mean sea level rise are consistent with reconstructed levels during past + warm climate periods: global mean sea level was very likely 5 to 25 m higher than + today roughly 3 million years ago, when global temperatures were 2.5°C to 4°C + higher than 1850–1900. Further examples of unavoidable changes in the climate + system due to multi-decadal or longer response timescales include continued glacier + melt and permafrost carbon loss. The probability of low-likelihood outcomes + associated with potentially very large impacts increases with higher global warming + levels. Warming substantially above the assessed very likely range for a given + scenario cannot be ruled out, and there is high confidence this would lead to + regional changes greater than assessed in many aspects of the climate system. + Low-likelihood, high-impact outcomes could occur at regional scales even for global + warming within the very likely assessed range for a given GHG emissions scenario. + Global mean sea level rise above the likely range – approaching 2 m by 2100 and + in excess of 15 m by 2300 under a very high GHG emissions scenario – cannot be + ruled out due to deep uncertainty in ice-sheet processes 123 and would have severe + impacts on populations in low elevation coastal zones. If global warming increases, + some compound extreme events 124 will become more frequent, with higher likelihood + of unprecedented intensities, durations or spatial extent. The Atlantic Meridional + Overturning Circulation is very likely to weaken over the 21st century for all + considered scenarios, however an abrupt collapse is not expected before 2100 . + If such a low probability event were to occur, it would very likely cause abrupt + shifts in regional weather patterns and water cycle, such as a southward shift + in the tropical rain belt, and large impacts on ecosystems and human activities. + A sequence of large explosive volcanic eruptions within decades, as have occurred + in the past, is a low-likelihood high-impact event that would lead to substantial + cooling globally and regional climate perturbations over several decades.' + B.3.2: + - Impacts and Related Risks For a given level of warming, many climate-related + risks are assessed to be higher than in AR5. Levels of risk for all Reasons for + Concern 121 are assessed to become high to very high at lower global warming levels + compared to what was assessed in AR5. This is based upon recent evidence of observed + impacts, improved process understanding, and new knowledge on exposure and vulnerability + of human and natural systems, including limits to adaptation. Depending on the + level of global warming, the assessed long-term impacts will be up to multiple + times higher than currently observed for 127 identified key risks, e.g., in terms + of the number of affected people and species. Risks, including cascading risks + and risks from overshoot, are projected to become increasingly severe with every + increment of global warming. Climate-related risks for natural and human systems + are higher for global warming of 1.5°C than at present but lower than at 2°C . + Climate-related risks to health, livelihoods, food security, water supply, human + security, and economic growth are projected to increase with global warming of + 1.5°C. In terrestrial ecosystems, 3 to 14% of the tens of thousands of species + assessed will likely face a very high risk of extinction at a GWL of 1.5°C. Coral + reefs are projected to decline by a further 70–90% at 1.5°C of global warming. + At this GWL, many low-elevation and small glaciers around the world would lose + most of their mass or disappear within decades to centuries. Regions at disproportionately + higher risk include Arctic ecosystems, dryland regions, small island developing + states and Least Developed Countries . At 2°C of global warming, overall risk + levels associated with the unequal distribution of impacts, global aggregate impacts + and large-scale singular events would be transitioning to high , those associated + with extreme weather events would be transitioning to very high, and those associated + with unique and threatened systems would be very high . With about 2°C warming, + climate-related changes in food availability and diet quality are estimated to + increase nutrition-related diseases and the number of undernourished people, affecting + tens to hundreds of millions of people, particularly among low-income households + in low- and middle-income countries in sub-Saharan Africa, South Asia and Central + America. For example, snowmelt water availability for irrigation is projected + to decline in some snowmelt dependent river basins by up to 20% . Climate change + risks to cities, settlements and key infrastructure will rise sharply in the mid + and long term with further global warming, especially in places already exposed + to high temperatures, along coastlines, or with high vulnerabilities . At global + warming of 3°C, additional risks in many sectors and regions reach high or very + high levels, implying widespread systemic impacts, irreversible change and many + additional adaptation limits . For example, very high extinction risk for endemic + species in biodiversity hotspots is projected to increase at least tenfold if + warming rises from 1.5°C to 3°C. Projected increases in direct flood damages are + higher by 1.4 to 2 times at 2°C and 2.5 to 3.9 times at 3°C, compared to 1.5°C + global warming without adaptation. Global warming of 4°C and above is projected + to lead to far-reaching impacts on natural and human systems. Beyond 4°C of warming, + projected impacts on natural systems include local extinction of ~50% of tropical + marine species and biome shifts across 35% of global land area. At this level + of warming, approximately 10% of the global land area is projected to face both + increasing high and decreasing low extreme streamflow, affecting, without additional + adaptation, over 2.1 billion people and about 4 billion people are projected to + experience water scarcity. At 4°C of warming, the global burned area is projected + to increase by 50 to 70% and the fire frequency by ~30% compared to today. Projected + adverse impacts and related losses and damages from climate change escalate with + every increment of global warming , but they will also strongly depend on socio-economic + development trajectories and adaptation actions to reduce vulnerability and exposure. + For example, development pathways with higher demand for food, animal feed, and + water, more resource-intensive consumption and production, and limited technological + improvements result in higher risks from water scarcity in drylands, land degradation + and food insecurity . Changes in, for example, demography or investments in health + systems have effect on a variety of health-related outcomes including heat-related + morbidity and mortality. With every increment of warming, climate change impacts + and risks will become increasingly complex and more difficult to manage. Many + regions are projected to experience an increase in the probability of compound + events with higher global warming, such as concurrent heatwaves and droughts, + compound flooding and fire weather. In addition, multiple climatic and non-climatic + risk drivers such as biodiversity loss or violent conflict will interact, resulting + in compounding overall risk and risks cascading across sectors and regions. Furthermore, + risks can arise from some responses that are intended to reduce the risks of climate + change, e.g., adverse side effects of some emission reduction and carbon dioxide + removal measures . Solar Radiation Modification approaches, if they were to be + implemented, introduce a widespread range of new risks to people and ecosystems, + which are not well understood. SRM has the potential to offset warming within + one or two decades and ameliorate some climate hazards but would not restore climate + to a previous state, and substantial residual or overcompensating climate change + would occur at regional and seasonal scales. Effects of SRM would depend on the + specific approach used 122, and a sudden and sustained termination of SRM in a + high CO 2 emissions scenario would cause rapid climate change. SRM would not stop + atmospheric CO 2 concentrations from increasing nor reduce resulting ocean acidification + under continued anthropogenic emissions. Large uncertainties and knowledge gaps + are associated with the potential of SRM approaches to reduce climate change risks. + Lack of robust and formal SRM governance poses risks as deployment by a limited + number of states could create international tensions. + - 'The Likelihood and Risks of Abrupt and Irreversible Change The likelihood of + abrupt and irreversible changes and their impacts increase with higher global + warming levels. As warming levels increase, so do the risks of species extinction + or irreversible loss of biodiversity in ecosystems such as forests , coral reefs + and in Arctic regions . Risks associated with large-scale singular events or tipping + points, such as ice sheet instability or ecosystem loss from tropical forests, + transition to high risk between 1.5°C to 2.5°C and to very high risk between + 2.5°C to 4°C. The response of biogeochemical cycles to anthropogenic perturbations + can be abrupt at regional scales and irreversible on decadal to century time scales. + The probability of crossing uncertain regional thresholds increases with further + warming. Sea level rise is unavoidable for centuries to millennia due to continuing + deep ocean warming and ice sheet melt, and sea levels will remain elevated for + thousands of years . Global mean sea level rise will continue in the 21st century, + with projected regional relative sea level rise within 20% of the global mean + along two-thirds of the global coastline . The magnitude, the rate, the timing + of threshold exceedances, and the long-term commitment of sea level rise depend + on emissions, with higher emissions leading to greater and faster rates of sea + level rise. Due to relative sea level rise, extreme sea level events that occurred + once per century in the recent past are projected to occur at least annually at + more than half of all tide gauge locations by 2100 and risks for coastal ecosystems, + people and infrastructure will continue to increase beyond 2100. At sustained + warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets + will be lost almost completely and irreversibly over multiple millennia. The probability + and rate of ice mass loss increase with higher global surface temperatures. Over + the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming + is limited to 1.5°C and 2 to 6 m if limited to 2°C . Projections of multi-millennial + global mean sea level rise are consistent with reconstructed levels during past + warm climate periods: global mean sea level was very likely 5 to 25 m higher than + today roughly 3 million years ago, when global temperatures were 2.5°C to 4°C + higher than 1850–1900. Further examples of unavoidable changes in the climate + system due to multi-decadal or longer response timescales include continued glacier + melt and permafrost carbon loss. The probability of low-likelihood outcomes + associated with potentially very large impacts increases with higher global warming + levels. Warming substantially above the assessed very likely range for a given + scenario cannot be ruled out, and there is high confidence this would lead to + regional changes greater than assessed in many aspects of the climate system. + Low-likelihood, high-impact outcomes could occur at regional scales even for global + warming within the very likely assessed range for a given GHG emissions scenario. + Global mean sea level rise above the likely range – approaching 2 m by 2100 and + in excess of 15 m by 2300 under a very high GHG emissions scenario – cannot be + ruled out due to deep uncertainty in ice-sheet processes 123 and would have severe + impacts on populations in low elevation coastal zones. If global warming increases, + some compound extreme events 124 will become more frequent, with higher likelihood + of unprecedented intensities, durations or spatial extent. The Atlantic Meridional + Overturning Circulation is very likely to weaken over the 21st century for all + considered scenarios, however an abrupt collapse is not expected before 2100 . + If such a low probability event were to occur, it would very likely cause abrupt + shifts in regional weather patterns and water cycle, such as a southward shift + in the tropical rain belt, and large impacts on ecosystems and human activities. + A sequence of large explosive volcanic eruptions within decades, as have occurred + in the past, is a low-likelihood high-impact event that would lead to substantial + cooling globally and regional climate perturbations over several decades.' + B.4.1: + - Long-term Adaptation Options and Limits With increasing warming, adaptation options + will become more constrained and less effective. At higher levels of warming, + losses and damages will increase, and additional human and natural systems will + reach adaptation limits. Integrated, cross-cutting multi-sectoral solutions increase + the effectiveness of adaptation. Maladaptation can create lock-ins of vulnerability, + exposure and risks but can be avoided by long-term planning and the implementation + of adaptation actions that are flexible, multi-sectoral and inclusive. The effectiveness + of adaptation to reduce climate risk is documented for specific contexts, sectors + and regions and will decrease with increasing warming 125 . For example, common + adaptation responses in agriculture – adopting improved cultivars and agronomic + practices, and changes in cropping patterns and crop systems – will become less + effective from 2°C to higher levels of warming. The effectiveness of most water-related + adaptation options to reduce projected risks declines with increasing warming. + Adaptations for hydropower and thermo-electric power generation are effective + in most regions up to 1.5°C to 2°C, with decreasing effectiveness at higher levels + of warming . Ecosystem-based Adaptation is vulnerable to climate change impacts, + with effectiveness declining with increasing global warming. Globally, adaptation + options related to agroforestry and forestry have a sharp decline in effectiveness + at 3°C, with a substantial increase in residual risk. With increasing global + warming, more limits to adaptation will be reached and losses and damages, strongly + concentrated among the poorest vulnerable populations, will increase. Already + below 1.5°C, autonomous and evolutionary adaptation responses by terrestrial and + aquatic ecosystems will increasingly face hard limits. Above 1.5°C, some ecosystem-based + adaptation measures will lose their effectiveness in providing benefits to people + as these ecosystems will reach hard adaptation limits. Adaptation to address the + risks of heat stress, heat mortality and reduced capacities for outdoor work for + humans face soft and hard limits across regions that become significantly more + severe at 1.5°C, and are particularly relevant for regions with warm climates. + Above 1.5°C global warming level, limited freshwater resources pose potential + hard limits for small islands and for regions dependent on glacier and snow melt + . By 2°C, soft limits are projected for multiple staple crops, particularly in + tropical regions. By 3°C, soft limits are projected for some water management + measures for many regions, with hard limits projected for parts of Europe . Integrated, + cross-cutting multi-sectoral solutions increase the effectiveness of adaptation. + For example, inclusive, integrated and long-term planning at local, municipal, + sub-national and national scales, together with effective regulation and monitoring + systems and financial and technological resources and capabilities foster urban + and rural system transition. There are a range of cross-cutting adaptation options, + such as disaster risk management, early warning systems, climate services and + risk spreading and sharing that have broad applicability across sectors and provide + greater benefits to other adaptation options when combined. Transitioning from + incremental to transformational adaptation, and addressing a range of constraints, + primarily in the financial, governance, institutional and policy domains, can + help overcome soft adaptation limits. However, adaptation does not prevent all + losses and damages, even with effective adaptation and before reaching soft and + hard limits. Maladaptive responses to climate change can create lock-ins of vulnerability, + exposure and risks that are difficult and expensive to change and exacerbate existing + inequalities. Actions that focus on sectors and risks in isolation and on short-term + gains often lead to maladaptation. Adaptation options can become maladaptive due + to their environmental impacts that constrain ecosystem services and decrease + biodiversity and ecosystem resilience to climate change or by causing adverse + outcomes for different groups, exacerbating inequity. Maladaptation can be avoided + by flexible, multi-sectoral, inclusive and long-term planning and implementation + of adaptation actions with benefits to many sectors and systems. Sea level rise + poses a distinctive and severe adaptation challenge as it implies both dealing + with slow onset changes and increases in the frequency and magnitude of extreme + sea level events . Such adaptation challenges would occur much earlier under high + rates of sea level rise. Responses to ongoing sea level rise and land subsidence + include protection, accommodation, advance and planned relocation. These responses + are more effective if combined and/or sequenced, planned well ahead, aligned with + sociocultural values and underpinned by inclusive community engagement processes. + Ecosystem-based solutions such as wetlands provide co-benefits for the environment + and climate mitigation, and reduce costs for flood defences , but have site-specific + physical limits, at least above 1.5ºC of global warming and lose effectiveness + at high rates of sea level rise beyond 0.5 to 1 cm yr -1. Seawalls can be maladaptive + as they effectively reduce impacts in the short term but can also result in lock-ins + and increase exposure to climate risks in the long term unless they are integrated + into a long-term adaptive plan. + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + B.4.2: + - Adaptation Gaps and Barriers Despite progress, adaptation gaps exist between + current levels of adaptation and levels needed to respond to impacts and reduce + climate risks. While progress in adaptation implementation is observed across + all sectors and regions , many adaptation initiatives prioritise immediate and + near-term climate risk reduction, e.g., through hard flood protection, which reduces + the opportunity for transformational adaptation . Most observed adaptation is + fragmented, small in scale, incremental, sector-specific, and focused more on + planning rather than implementation. Further, observed adaptation is unequally + distributed across regions and the largest adaptation gaps exist among lower population + income groups. In the urban context, the largest adaptation gaps exist in projects + that manage complex risks, for example in the food–energy–water–health nexus or + the inter-relationships of air quality and climate risk. Many funding, knowledge + and practice gaps remain for effective implementation, monitoring and evaluation + and current adaptation efforts are not expected to meet existing goals. At current + rates of adaptation planning and implementation the adaptation gap will continue + to grow. Soft and hard adaptation limits 100 have already been reached in some + sectors and regions, in spite of adaptation having buffered some climate impacts. + Ecosystems already reaching hard adaptation limits include some warm water coral + reefs, some coastal wetlands, some rainforests, and some polar and mountain ecosystems. + Individuals and households in low lying coastal areas in Australasia and Small + Islands and smallholder farmers in Central and South America, Africa, Europe and + Asia have reached soft limits, resulting from financial, governance, institutional + and policy constraints and can be overcome by addressing these constraints. Transitioning + from incremental to transformational adaptation can help overcome soft adaptation + limits . Adaptation does not prevent all losses and damages, even with effective + adaptation and before reaching soft and hard limits. Losses and damages are unequally + distributed across systems, regions and sectors and are not comprehensively addressed + by current financial, governance and institutional arrangements, particularly + in vulnerable developing countries. There is increased evidence of maladaptation + in various sectors and regions. Examples of maladaptation are observed in urban + areas , agriculture , ecosystems (e.g. fire suppression in naturally + - Long-term Adaptation Options and Limits With increasing warming, adaptation options + will become more constrained and less effective. At higher levels of warming, + losses and damages will increase, and additional human and natural systems will + reach adaptation limits. Integrated, cross-cutting multi-sectoral solutions increase + the effectiveness of adaptation. Maladaptation can create lock-ins of vulnerability, + exposure and risks but can be avoided by long-term planning and the implementation + of adaptation actions that are flexible, multi-sectoral and inclusive. The effectiveness + of adaptation to reduce climate risk is documented for specific contexts, sectors + and regions and will decrease with increasing warming 125 . For example, common + adaptation responses in agriculture – adopting improved cultivars and agronomic + practices, and changes in cropping patterns and crop systems – will become less + effective from 2°C to higher levels of warming. The effectiveness of most water-related + adaptation options to reduce projected risks declines with increasing warming. + Adaptations for hydropower and thermo-electric power generation are effective + in most regions up to 1.5°C to 2°C, with decreasing effectiveness at higher levels + of warming . Ecosystem-based Adaptation is vulnerable to climate change impacts, + with effectiveness declining with increasing global warming. Globally, adaptation + options related to agroforestry and forestry have a sharp decline in effectiveness + at 3°C, with a substantial increase in residual risk. With increasing global + warming, more limits to adaptation will be reached and losses and damages, strongly + concentrated among the poorest vulnerable populations, will increase. Already + below 1.5°C, autonomous and evolutionary adaptation responses by terrestrial and + aquatic ecosystems will increasingly face hard limits. Above 1.5°C, some ecosystem-based + adaptation measures will lose their effectiveness in providing benefits to people + as these ecosystems will reach hard adaptation limits. Adaptation to address the + risks of heat stress, heat mortality and reduced capacities for outdoor work for + humans face soft and hard limits across regions that become significantly more + severe at 1.5°C, and are particularly relevant for regions with warm climates. + Above 1.5°C global warming level, limited freshwater resources pose potential + hard limits for small islands and for regions dependent on glacier and snow melt + . By 2°C, soft limits are projected for multiple staple crops, particularly in + tropical regions. By 3°C, soft limits are projected for some water management + measures for many regions, with hard limits projected for parts of Europe . Integrated, + cross-cutting multi-sectoral solutions increase the effectiveness of adaptation. + For example, inclusive, integrated and long-term planning at local, municipal, + sub-national and national scales, together with effective regulation and monitoring + systems and financial and technological resources and capabilities foster urban + and rural system transition. There are a range of cross-cutting adaptation options, + such as disaster risk management, early warning systems, climate services and + risk spreading and sharing that have broad applicability across sectors and provide + greater benefits to other adaptation options when combined. Transitioning from + incremental to transformational adaptation, and addressing a range of constraints, + primarily in the financial, governance, institutional and policy domains, can + help overcome soft adaptation limits. However, adaptation does not prevent all + losses and damages, even with effective adaptation and before reaching soft and + hard limits. Maladaptive responses to climate change can create lock-ins of vulnerability, + exposure and risks that are difficult and expensive to change and exacerbate existing + inequalities. Actions that focus on sectors and risks in isolation and on short-term + gains often lead to maladaptation. Adaptation options can become maladaptive due + to their environmental impacts that constrain ecosystem services and decrease + biodiversity and ecosystem resilience to climate change or by causing adverse + outcomes for different groups, exacerbating inequity. Maladaptation can be avoided + by flexible, multi-sectoral, inclusive and long-term planning and implementation + of adaptation actions with benefits to many sectors and systems. Sea level rise + poses a distinctive and severe adaptation challenge as it implies both dealing + with slow onset changes and increases in the frequency and magnitude of extreme + sea level events . Such adaptation challenges would occur much earlier under high + rates of sea level rise. Responses to ongoing sea level rise and land subsidence + include protection, accommodation, advance and planned relocation. These responses + are more effective if combined and/or sequenced, planned well ahead, aligned with + sociocultural values and underpinned by inclusive community engagement processes. + Ecosystem-based solutions such as wetlands provide co-benefits for the environment + and climate mitigation, and reduce costs for flood defences , but have site-specific + physical limits, at least above 1.5ºC of global warming and lose effectiveness + at high rates of sea level rise beyond 0.5 to 1 cm yr -1. Seawalls can be maladaptive + as they effectively reduce impacts in the short term but can also result in lock-ins + and increase exposure to climate risks in the long term unless they are integrated + into a long-term adaptive plan. + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + B.4.3: + - Adaptation Gaps and Barriers Despite progress, adaptation gaps exist between + current levels of adaptation and levels needed to respond to impacts and reduce + climate risks. While progress in adaptation implementation is observed across + all sectors and regions , many adaptation initiatives prioritise immediate and + near-term climate risk reduction, e.g., through hard flood protection, which reduces + the opportunity for transformational adaptation . Most observed adaptation is + fragmented, small in scale, incremental, sector-specific, and focused more on + planning rather than implementation. Further, observed adaptation is unequally + distributed across regions and the largest adaptation gaps exist among lower population + income groups. In the urban context, the largest adaptation gaps exist in projects + that manage complex risks, for example in the food–energy–water–health nexus or + the inter-relationships of air quality and climate risk. Many funding, knowledge + and practice gaps remain for effective implementation, monitoring and evaluation + and current adaptation efforts are not expected to meet existing goals. At current + rates of adaptation planning and implementation the adaptation gap will continue + to grow. Soft and hard adaptation limits 100 have already been reached in some + sectors and regions, in spite of adaptation having buffered some climate impacts. + Ecosystems already reaching hard adaptation limits include some warm water coral + reefs, some coastal wetlands, some rainforests, and some polar and mountain ecosystems. + Individuals and households in low lying coastal areas in Australasia and Small + Islands and smallholder farmers in Central and South America, Africa, Europe and + Asia have reached soft limits, resulting from financial, governance, institutional + and policy constraints and can be overcome by addressing these constraints. Transitioning + from incremental to transformational adaptation can help overcome soft adaptation + limits . Adaptation does not prevent all losses and damages, even with effective + adaptation and before reaching soft and hard limits. Losses and damages are unequally + distributed across systems, regions and sectors and are not comprehensively addressed + by current financial, governance and institutional arrangements, particularly + in vulnerable developing countries. There is increased evidence of maladaptation + in various sectors and regions. Examples of maladaptation are observed in urban + areas , agriculture , ecosystems (e.g. fire suppression in naturally + - Long-term Adaptation Options and Limits With increasing warming, adaptation options + will become more constrained and less effective. At higher levels of warming, + losses and damages will increase, and additional human and natural systems will + reach adaptation limits. Integrated, cross-cutting multi-sectoral solutions increase + the effectiveness of adaptation. Maladaptation can create lock-ins of vulnerability, + exposure and risks but can be avoided by long-term planning and the implementation + of adaptation actions that are flexible, multi-sectoral and inclusive. The effectiveness + of adaptation to reduce climate risk is documented for specific contexts, sectors + and regions and will decrease with increasing warming 125 . For example, common + adaptation responses in agriculture – adopting improved cultivars and agronomic + practices, and changes in cropping patterns and crop systems – will become less + effective from 2°C to higher levels of warming. The effectiveness of most water-related + adaptation options to reduce projected risks declines with increasing warming. + Adaptations for hydropower and thermo-electric power generation are effective + in most regions up to 1.5°C to 2°C, with decreasing effectiveness at higher levels + of warming . Ecosystem-based Adaptation is vulnerable to climate change impacts, + with effectiveness declining with increasing global warming. Globally, adaptation + options related to agroforestry and forestry have a sharp decline in effectiveness + at 3°C, with a substantial increase in residual risk. With increasing global + warming, more limits to adaptation will be reached and losses and damages, strongly + concentrated among the poorest vulnerable populations, will increase. Already + below 1.5°C, autonomous and evolutionary adaptation responses by terrestrial and + aquatic ecosystems will increasingly face hard limits. Above 1.5°C, some ecosystem-based + adaptation measures will lose their effectiveness in providing benefits to people + as these ecosystems will reach hard adaptation limits. Adaptation to address the + risks of heat stress, heat mortality and reduced capacities for outdoor work for + humans face soft and hard limits across regions that become significantly more + severe at 1.5°C, and are particularly relevant for regions with warm climates. + Above 1.5°C global warming level, limited freshwater resources pose potential + hard limits for small islands and for regions dependent on glacier and snow melt + . By 2°C, soft limits are projected for multiple staple crops, particularly in + tropical regions. By 3°C, soft limits are projected for some water management + measures for many regions, with hard limits projected for parts of Europe . Integrated, + cross-cutting multi-sectoral solutions increase the effectiveness of adaptation. + For example, inclusive, integrated and long-term planning at local, municipal, + sub-national and national scales, together with effective regulation and monitoring + systems and financial and technological resources and capabilities foster urban + and rural system transition. There are a range of cross-cutting adaptation options, + such as disaster risk management, early warning systems, climate services and + risk spreading and sharing that have broad applicability across sectors and provide + greater benefits to other adaptation options when combined. Transitioning from + incremental to transformational adaptation, and addressing a range of constraints, + primarily in the financial, governance, institutional and policy domains, can + help overcome soft adaptation limits. However, adaptation does not prevent all + losses and damages, even with effective adaptation and before reaching soft and + hard limits. Maladaptive responses to climate change can create lock-ins of vulnerability, + exposure and risks that are difficult and expensive to change and exacerbate existing + inequalities. Actions that focus on sectors and risks in isolation and on short-term + gains often lead to maladaptation. Adaptation options can become maladaptive due + to their environmental impacts that constrain ecosystem services and decrease + biodiversity and ecosystem resilience to climate change or by causing adverse + outcomes for different groups, exacerbating inequity. Maladaptation can be avoided + by flexible, multi-sectoral, inclusive and long-term planning and implementation + of adaptation actions with benefits to many sectors and systems. Sea level rise + poses a distinctive and severe adaptation challenge as it implies both dealing + with slow onset changes and increases in the frequency and magnitude of extreme + sea level events . Such adaptation challenges would occur much earlier under high + rates of sea level rise. Responses to ongoing sea level rise and land subsidence + include protection, accommodation, advance and planned relocation. These responses + are more effective if combined and/or sequenced, planned well ahead, aligned with + sociocultural values and underpinned by inclusive community engagement processes. + Ecosystem-based solutions such as wetlands provide co-benefits for the environment + and climate mitigation, and reduce costs for flood defences , but have site-specific + physical limits, at least above 1.5ºC of global warming and lose effectiveness + at high rates of sea level rise beyond 0.5 to 1 cm yr -1. Seawalls can be maladaptive + as they effectively reduce impacts in the short term but can also result in lock-ins + and increase exposure to climate risks in the long term unless they are integrated + into a long-term adaptive plan. + B.5.1: + - Long-term Climate Change The uncertainty range on assessed future changes in + global surface temperature is narrower than in the AR5. For the first time in + an IPCC assessment cycle, multi-model projections of global surface temperature, + ocean warming and sea level are constrained using observations and the assessed + climate sensitivity. The likely range of equilibrium climate sensitivity has been + narrowed to 2.5°C to 4.0°C based on multiple lines of evidence , including improved + understanding of cloud feedbacks. For related emissions scenarios, this leads + to narrower uncertainty ranges for long-term projected global temperature change + than in AR5. Future warming depends on future GHG emissions, with cumulative + net CO 2 dominating. The assessed best estimates and very likely ranges of warming + for 2081-2100 with respect to 1850–1900 vary from 1.4 [1.0 to 1.8]°C in the very + low GHG emissions scenario to 2.7 [2.1 to 3.5]°C in the intermediate GHG emissions + scenario and 4.4 [3.3 to 5.7]°C in the very high GHG emissions scenario 113 . Modelled + pathways consistent with the continuation of policies implemented by the end of + 2020 lead to global warming of 3.2 [2.2 to 3.5]°C by 2100 . Pathways of >4°C by + 2100 would imply a reversal of current technology and/or mitigation policy trends + . However, such warming could occur in emissions pathways consistent with policies + implemented by the end of 2020 if climate sensitivity or carbon cycle feedbacks + are higher than the best estimate. Global warming will continue to increase in + the near term in nearly all considered scenarios and modelled pathways. Deep, + rapid, and sustained GHG emissions reductions, reaching net zero CO2 emissions + and including strong emissions reductions of other GHGs, in particular CH4, are + necessary to limit warming to 1.5°C or less than 2°C by the end of century . The + best estimate of reaching 1.5°C of global warming lies in the first half of the + 2030s in most of the considered scenarios and modelled pathways 114. In the very + low GHG emissions scenario, CO 2 emissions reach net zero around 2050 and the + best-estimate end-of-century warming is 1.4°C, after a temporary overshoot of + no more than 0.1°C above 1.5°C global warming. Global warming of 2°C will be exceeded + during the 21st century unless deep reductions in CO 2 and other GHG emissions + occur in the coming decades. Deep, rapid, and sustained reductions in GHG emissions + would lead to improvements in air quality within a few years, to reductions in + trends of global surface temperature discernible after around 20 years, and over + longer time periods for many other climate impact-drivers 115 . Targeted reductions + of air pollutant emissions lead to more rapid improvements in air quality compared + to reductions in GHG emissions only, but in the long term, further improvements + are projected in scenarios that combine efforts to reduce air pollutants as well + as GHG emissions 116 . Changes in short-lived climate forcers resulting from + the five considered scenarios lead to an additional net global warming in the + near and long term. Simultaneous stringent climate change mitigation and air pollution + control olicies limit this additional warming and lead to strong benefits for + air quality. In high and very high GHG emissions scenarios, combined changes in + SLCF emissions, such as CH 4, aerosol and ozone precursors, lead to a net global + warming by 2100 of likely 0.4°C to 0.9°C relative to 2019. This is due to projected + increases in atmospheric concentration of CH4, tropospheric ozone, hydrofluorocarbons + and, when strong air pollution control is considered, reductions of cooling aerosols. + In low and very low GHG emissions scenarios, air pollution control policies, reductions + in CH 4 and other ozone precursors lead to a net cooling, whereas reductions in + anthropogenic cooling aerosols lead to a net warming. Altogether, this causes + a likely net warming of 0.0°C to 0.3°C due to SLCF changes in 2100 relative to + 2019 and strong reductions in global surface ozone and particulate matter . Continued + GHG emissions will further affect all major climate system components, and many + changes will be irreversible on centennial to millennial time scales. Many changes + in the climate system become larger in direct relation to increasing global warming. + With every additional increment of global warming, changes in extremes continue + to become larger. Additional warming will lead to more frequent and intense marine + heatwaves and is projected to further amplify permafrost thawing and loss of seasonal + snow cover, glaciers, land ice and Arctic sea ice. Continued global warming is + projected to further intensify the global water cycle, including its variability, + global monsoon precipitation , and very wet and very dry weather and climate events + and seasons. The portion of global land experiencing detectable changes in seasonal + mean precipitation is projected to increase with more variable precipitation and + surface water flows over most land regions within seasons and from year to year + . Many changes due to past and future GHG emissions are irreversible on centennial + to millennial time scales, especially in the ocean, ice sheets and global sea + level. Ocean acidification , ocean deoxygenation and global mean sea level will + continue to increase in the 21st century, at rates dependent on future emissions. With + further global warming, every region is projected to increasingly experience concurrent + and multiple changes in climatic impact-drivers. Increases in hot and decreases + in cold climatic impact-drivers, such as temperature extremes, are projected in + all regions. At 1.5°C global warming, heavy precipitation and flooding events + are projected to intensify and become more frequent in most regions in Africa, + Asia , North America and Europe . At 2°C or above, these changes expand to more + regions and/or become more significant, and more frequent and/or severe agricultural + and ecological droughts are projected in Europe, Africa, Australasia and North, + Central and South America . Other projected regional changes include intensification + of tropical cyclones and/or extratropical storms , and increases in aridity and + fire weather . Compound heatwaves and droughts become likely more frequent, including + concurrently at multiple locations. + - Remaining Carbon Budgets Limiting global temperature increase to a specific level + requires limiting cumulative net CO2 emissions to within a finite carbon budget + , along with strong reductions in other GHGs. For every 1000 GtCO2 emitted by + human activity, global mean temperature rises by likely 0.27°C to 0.63°C. This + relationship implies that there is a finite carbon budget that cannot be exceeded + in order to limit warming to any given level. The best estimates of the remaining + carbon budget from the beginning of 2020 for limiting warming to 1.5°C with a + 50% likelihood is estimated to be 500 GtCO2; for 2°C this is 1150 GtCO2.128 Remaining + carbon budgets have been quantified based on the assessed value of TCRE and its + uncertainty, estimates of historical warming, climate system feedbacks such as + emissions from thawing permafrost, and the global surface temperature change after + global anthropogenic CO 2 emissions reach net zero, as well as variations in projected + warming from non-CO2 emissions due in part to mitigation action. The stronger + the reductions in non-CO2 emissions the lower the resulting temperatures are for + a given RCB or the larger RCB for the same level of temperature change. For instance, + the RCB for limiting warming to 1.5°C with a 50% likelihood could vary between + 300 to 600 GtCO 2 depending on non-CO 2 warming 129 . Limiting warming to 2°C + with a 67% likelihood would imply a RCB of 1150 GtCO2 from the beginning of 2020. + To stay below 2°C with a 50% likelihood, the RCB is higher, i.e., 1350 GtCO 2 + If the annual CO2 emissions between 2020–2030 stayed, on average, at the same + level as 2019, the resulting cumulative emissions would almost exhaust the remaining + carbon budget for 1.5°C, and exhaust more than a third of the remaining carbon + budget for 2°C . Based on central estimates only, historical cumulative net CO2 + emissions between 1850 and 2019 amount to about four-fifths of the total carbon + budget for a 50% probability of limiting global warming to 1.5°C and to about + two-thirds of the total carbon budget for a 67% probability to limit global warming + to 2°C. In scenarios with increasing CO 2 emissions, the land and ocean carbon + sinks are projected to be less effective at slowing the accumulation of CO2 in + the atmosphere. While natural land and ocean carbon sinks are projected to take + up, in absolute terms, a progressively larger amount of CO 2 under higher compared + to lower CO2 emissions scenarios, they become less effective, that is, the proportion + of emissions taken up by land and ocean decreases with increasing cumulative net + CO2 emissions. Additional ecosystem responses to warming not yet fully included + in climate models, such as GHG fluxes from wetlands, permafrost thaw, and wildfires, + would further increase concentrations of these gases in the atmosphere . In scenarios + where CO2 concentrations peak and decline during the 21st century, the land and + ocean begin to take up less carbon in response to declining atmospheric CO2 concentrations and + turn into a weak net source by 2100 in the very low GHG emissions scenario 133. + - 'Net Zero Emissions: Timing and Implications From a physical science perspective, + limiting human-caused global warming to a specific level requires limiting cumulative + CO2 emissions, reaching net zero or net negative CO2 emissions, along with strong + reductions of other GHG emissions . Global modelled pathways that reach and sustain + net zero GHG emissions are projected to result in a gradual decline in surface + temperature. Reaching net zero GHG emissions primarily requires deep reductions + in CO2, methane, and other GHG emissions, and implies net negative CO2 emissions.134 + Carbon dioxide removal will be necessary to achieve net negative CO2 emissions + 135. Achieving global net zero CO2 emissions, with remaining anthropogenic CO + 2 emissions balanced by durably stored CO 2 from anthropogenic removal, is a requirement + to stabilise CO2-induced global surface temperature increase . This is different + from achieving net zero GHG emissions, where metric-weighted anthropogenic GHG + emissions equal CO 2 removal. Emissions pathways that reach and sustain net zero + GHG emissions defined by the 100-year global warming potential imply net negative + CO2 emissions and are projected to result in a gradual decline in surface temperature + after an earlier peak. While reaching net zero CO2 or net zero GHG emissions requires + deep and rapid reductions in gross emissions, the deployment of CDR to counterbalance + hardto-abate residual emissions is unavoidable . In modelled pathways, the timing + of net zero CO2 emissions, followed by net zero GHG emissions, depends on several + variables, including the desired climate outcome, the mitigation strategy and + the gases covered. Global net zero CO2 emissions are reached in the early 2050s + in pathways that limit warming to 1.5°C with no or limited overshoot, and around + the early 2070s in pathways that limit warming to 2°C. While non-CO2 GHG emissions + are strongly reduced in all pathways that limit warming to 2°C or lower, residual + emissions of CH4 and N2O and F-gases of about 8 [5–11] GtCO2 -eq yr -1 remain + at the time of net zero GHG, counterbalanced by net negative CO2 emissions. As + a result, net zero CO2 would be reached before net zero GHGs .' + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + B.5.3: + - The Gap Between Mitigation Policies, Pledges and Pathways that Limit Warming + to 1.5°C or Below 2°C Global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP2691 would make it likely that warming will exceed + 1.5°C during the 21st century and would make it harder to limit warming below + 2°C – if no additional commitments are made or actions taken. A substantial ‘emissions + gap’ exists as global GHG emissions in 2030 associated with the implementation + of NDCs announced prior to COP26 would be similar to or only slightly below 2019 + emission levels and higher than those associated with modelled mitigation pathways + that limit warming to 1.5°C with no or limited overshoot or to 2°C, assuming immediate + action, which implies deep, rapid, and sustained global GHG emission reductions + this decade . 92 The magnitude of the emissions gap depends on the global warming + level considered and whether only unconditional or also conditional elements of + NDCs 93 are considered . Modelled pathways that are consistent with NDCs announced + prior to COP26 until 2030 and assume no increase in ambition thereafter have higher + emissions, leading to a median global warming of 2.8 [2.1 to 3.4]°C by 2100 . + If the ‘emission gap’ is not reduced, global GHG emissions in 2030 consistent + with NDCs announced prior to COP26 make it likely that warming will exceed 1.5°C + during the 21st century, while limiting warming to 2°C would imply an unprecedented + acceleration of mitigation efforts during 2030–2050 . Policies implemented by + the end of 2020 are projected to result in higher global GHG emissions in 2030 + than those implied by NDCs, indicating an ‘implementation gap 94 ’ . Projected + global emissions implied by policies implemented by the end of 2020 are 57 GtCO2 + -eq in 2030. This points to an implementation gap compared with the NDCs of 4 + to 7 GtCO 2-eq in 2030; without a strengthening of policies, emissions are projected + to rise, leading to a median global warming of 2.2°C to 3.5°C by 2100 . Projected + cumulative future CO2 emissions over the lifetime of existing fossil fuel infrastructure + without additional abatement exceed the total cumulative net CO2 emissions in + pathways that limit warming to 1.5°C with no or limited overshoot. They are approximately + equal to total cumulative net CO2 emissions in pathways that limit warming to + 2°C with a likelihood of 83% 96. Limiting warming to 2°C or lower will result + in stranded assets. About 80% of coal, 50% of gas, and 30% of oil reserves cannot + be burned and emitted if warming is limited to 2°C. Significantly more reserves + are expected to remain unburned if warming is limited to 1.5°C. Many countries + have signalled an intention to achieve net zero GHG or net zero CO 2 emissions + by around mid-century . More than 100 countries have either adopted, announced + or are discussing net zero GHG or net zero CO 2 emissions commitments, covering + more than two-thirds of global GHG emissions. A growing number of cities are setting + climate targets, including net zero GHG targets. Many companies and institutions + have also announced net zero emissions targets in recent years. The various net + zero emission pledges differ across countries in terms of scope and specificity, + and limited policies are to date in place to deliver on them. All mitigation + strategies face implementation challenges, including technology risks, scaling, + and costs. Almost all mitigation options also face institutional barriers that + need to be addressed to enable their application at scale . Current development + pathways may create behavioural, spatial, economic and social barriers to accelerated + mitigation at all scales. Choices made by policymakers, citizens, the private + sector and other stakeholders influence societies’ development pathways. Structural + factors of national circumstances and capabilities affect the breadth and depth + of climate governance. The extent to which civil society actors, political actors, + businesses, youth, labour, media, Indigenous Peoples, and local communities are + engaged influences political support for climate change mitigation and eventual + policy outcomes. The adoption of low-emission technologies lags in most developing + countries, particularly least developed ones, due in part to weaker enabling conditions, + including limited finance, technology development and transfer, and capacity . + In many countries, especially those with limited institutional capacity, several + adverse side-effects have been observed as a result of diffusion of low-emission + technology, e.g., low-value employment, and dependency on foreign knowledge and + suppliers. Low-emission innovation along with strengthened enabling conditions + can reinforce development benefits, which can, in turn, create feedbacks towards + greater public support for policy. Persistent and region-specific barriers also + continue to hamper the economic and political feasibility of deploying AFOLU mitigation + options. Barriers to implementation of AFOLU mitigation include insufficient institutional + and financial support, uncertainty over long-term additionality and trade-offs, + weak governance, insecure land ownership, low incomes and the lack of access to + alternative sources of income, and the risk of reversal . + - Remaining Carbon Budgets Limiting global temperature increase to a specific level + requires limiting cumulative net CO2 emissions to within a finite carbon budget + , along with strong reductions in other GHGs. For every 1000 GtCO2 emitted by + human activity, global mean temperature rises by likely 0.27°C to 0.63°C. This + relationship implies that there is a finite carbon budget that cannot be exceeded + in order to limit warming to any given level. The best estimates of the remaining + carbon budget from the beginning of 2020 for limiting warming to 1.5°C with a + 50% likelihood is estimated to be 500 GtCO2; for 2°C this is 1150 GtCO2.128 Remaining + carbon budgets have been quantified based on the assessed value of TCRE and its + uncertainty, estimates of historical warming, climate system feedbacks such as + emissions from thawing permafrost, and the global surface temperature change after + global anthropogenic CO 2 emissions reach net zero, as well as variations in projected + warming from non-CO2 emissions due in part to mitigation action. The stronger + the reductions in non-CO2 emissions the lower the resulting temperatures are for + a given RCB or the larger RCB for the same level of temperature change. For instance, + the RCB for limiting warming to 1.5°C with a 50% likelihood could vary between + 300 to 600 GtCO 2 depending on non-CO 2 warming 129 . Limiting warming to 2°C + with a 67% likelihood would imply a RCB of 1150 GtCO2 from the beginning of 2020. + To stay below 2°C with a 50% likelihood, the RCB is higher, i.e., 1350 GtCO 2 + If the annual CO2 emissions between 2020–2030 stayed, on average, at the same + level as 2019, the resulting cumulative emissions would almost exhaust the remaining + carbon budget for 1.5°C, and exhaust more than a third of the remaining carbon + budget for 2°C . Based on central estimates only, historical cumulative net CO2 + emissions between 1850 and 2019 amount to about four-fifths of the total carbon + budget for a 50% probability of limiting global warming to 1.5°C and to about + two-thirds of the total carbon budget for a 67% probability to limit global warming + to 2°C. In scenarios with increasing CO 2 emissions, the land and ocean carbon + sinks are projected to be less effective at slowing the accumulation of CO2 in + the atmosphere. While natural land and ocean carbon sinks are projected to take + up, in absolute terms, a progressively larger amount of CO 2 under higher compared + to lower CO2 emissions scenarios, they become less effective, that is, the proportion + of emissions taken up by land and ocean decreases with increasing cumulative net + CO2 emissions. Additional ecosystem responses to warming not yet fully included + in climate models, such as GHG fluxes from wetlands, permafrost thaw, and wildfires, + would further increase concentrations of these gases in the atmosphere . In scenarios + where CO2 concentrations peak and decline during the 21st century, the land and + ocean begin to take up less carbon in response to declining atmospheric CO2 concentrations and + turn into a weak net source by 2100 in the very low GHG emissions scenario 133. + B.6.1: + - 'Net Zero Emissions: Timing and Implications From a physical science perspective, + limiting human-caused global warming to a specific level requires limiting cumulative + CO2 emissions, reaching net zero or net negative CO2 emissions, along with strong + reductions of other GHG emissions . Global modelled pathways that reach and sustain + net zero GHG emissions are projected to result in a gradual decline in surface + temperature. Reaching net zero GHG emissions primarily requires deep reductions + in CO2, methane, and other GHG emissions, and implies net negative CO2 emissions.134 + Carbon dioxide removal will be necessary to achieve net negative CO2 emissions + 135. Achieving global net zero CO2 emissions, with remaining anthropogenic CO + 2 emissions balanced by durably stored CO 2 from anthropogenic removal, is a requirement + to stabilise CO2-induced global surface temperature increase . This is different + from achieving net zero GHG emissions, where metric-weighted anthropogenic GHG + emissions equal CO 2 removal. Emissions pathways that reach and sustain net zero + GHG emissions defined by the 100-year global warming potential imply net negative + CO2 emissions and are projected to result in a gradual decline in surface temperature + after an earlier peak. While reaching net zero CO2 or net zero GHG emissions requires + deep and rapid reductions in gross emissions, the deployment of CDR to counterbalance + hardto-abate residual emissions is unavoidable . In modelled pathways, the timing + of net zero CO2 emissions, followed by net zero GHG emissions, depends on several + variables, including the desired climate outcome, the mitigation strategy and + the gases covered. Global net zero CO2 emissions are reached in the early 2050s + in pathways that limit warming to 1.5°C with no or limited overshoot, and around + the early 2070s in pathways that limit warming to 2°C. While non-CO2 GHG emissions + are strongly reduced in all pathways that limit warming to 2°C or lower, residual + emissions of CH4 and N2O and F-gases of about 8 [5–11] GtCO2 -eq yr -1 remain + at the time of net zero GHG, counterbalanced by net negative CO2 emissions. As + a result, net zero CO2 would be reached before net zero GHGs .' + - 'Overshoot Pathways: Increased Risks and Other Implications Exceeding a specific + remaining carbon budget results in higher global warming. Achieving and sustaining + net negative global CO 2 emissions could reverse the resulting temperature exceedance. + Continued reductions in emissions of short-lived climate forcers, particularly + methane, after peak temperature has been reached, would also further reduce warming. + Only a small number of the most ambitious global modelled pathways limit global + warming to 1.5°C without overshoot. Overshoot of a warming level results in more + adverse impacts, some irreversible, and additional risks for human and natural + systems compared to staying below that warming level, with risks growing with + the magnitude and duration of overshoot. Compared to pathways without overshoot, + societies and ecosystems would be exposed to greater and more widespread changes + in climatic impact-drivers, such as extreme heat and extreme precipitation, with + increasing risks to infrastructure, low-lying coastal settlements, and associated + livelihoods. Overshooting 1.5°C will result in irreversible adverse impacts on + certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, + impacted by ice-sheet melt, glacier melt, or by accelerating and higher committed + sea level rise. Overshoot increases the risks of severe impacts, such as increased + wildfires, mass mortality of trees, drying of peatlands, thawing of permafrost + and weakening natural land carbon sinks; such impacts could increase releases + of GHGs making temperature reversal more challenging. The larger the overshoot, + the more net negative CO2 emissions needed to return to a given warming level. + Reducing global temperature by removing CO 2 would require net negative emissions + of 220 GtCO 2 for every tenth of a degree. Modelled pathways that limit warming + to 1.5°C with no or limited overshoot reach median values of cumulative net negative + emissions of 220 GtCO2 by 2100, pathways that return warming to 1.5°C after high + overshoot reach median values of 360 GtCO2. 137 More rapid reduction in CO 2 and + non-CO2 emissions, particularly methane, limits peak warming levels and reduces + the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility + and sustainability concerns, and social and environmental risks .' + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + B.6.2: + - 'Net Zero Emissions: Timing and Implications From a physical science perspective, + limiting human-caused global warming to a specific level requires limiting cumulative + CO2 emissions, reaching net zero or net negative CO2 emissions, along with strong + reductions of other GHG emissions . Global modelled pathways that reach and sustain + net zero GHG emissions are projected to result in a gradual decline in surface + temperature. Reaching net zero GHG emissions primarily requires deep reductions + in CO2, methane, and other GHG emissions, and implies net negative CO2 emissions.134 + Carbon dioxide removal will be necessary to achieve net negative CO2 emissions + 135. Achieving global net zero CO2 emissions, with remaining anthropogenic CO + 2 emissions balanced by durably stored CO 2 from anthropogenic removal, is a requirement + to stabilise CO2-induced global surface temperature increase . This is different + from achieving net zero GHG emissions, where metric-weighted anthropogenic GHG + emissions equal CO 2 removal. Emissions pathways that reach and sustain net zero + GHG emissions defined by the 100-year global warming potential imply net negative + CO2 emissions and are projected to result in a gradual decline in surface temperature + after an earlier peak. While reaching net zero CO2 or net zero GHG emissions requires + deep and rapid reductions in gross emissions, the deployment of CDR to counterbalance + hardto-abate residual emissions is unavoidable . In modelled pathways, the timing + of net zero CO2 emissions, followed by net zero GHG emissions, depends on several + variables, including the desired climate outcome, the mitigation strategy and + the gases covered. Global net zero CO2 emissions are reached in the early 2050s + in pathways that limit warming to 1.5°C with no or limited overshoot, and around + the early 2070s in pathways that limit warming to 2°C. While non-CO2 GHG emissions + are strongly reduced in all pathways that limit warming to 2°C or lower, residual + emissions of CH4 and N2O and F-gases of about 8 [5–11] GtCO2 -eq yr -1 remain + at the time of net zero GHG, counterbalanced by net negative CO2 emissions. As + a result, net zero CO2 would be reached before net zero GHGs .' + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + B.6.3: + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - Near-Term Mitigation and Adaptation Actions Rapid and far-reaching transitions + across all sectors and systems are necessary to achieve deep and sustained emissions + reductions and secure a liveable and sustainable future for all. These system + transitions involve a significant upscaling of a wide portfolio of mitigation + and adaptation options. Feasible, effective and low-cost options for mitigation + and adaptation are already available, with differences across systems and regions. Rapid + and far-reaching transitions across all sectors and systems are necessary to achieve + deep emissions reductions and secure a liveable and sustainable future for all. + System transitions consistent with pathways that limit warming to 1.5°C with no + or limited overshoot are more rapid and pronounced in the near-term than in those + that limit warming to 2°C . Such a systemic change is unprecedented in terms of + scale, but not necessarily in terms of speed. The system transitions make possible + the transformative adaptation required for high levels of human health and well-being, + economic and social resilience, ecosystem health, and planetary health. Feasible, + effective and low-cost options for mitigation and adaptation are already available. + Mitigation options costing USD 100 tCO 2-eq–1 or less could reduce global GHG + emissions by at least half the 2019 level by 2030 . The availability, feasibility + 152 and potential of mitigation or effectiveness of adaptation options in the + near term differ across systems and regions. Demand-side measures and new ways + of end-use service provision can reduce global GHG emissions in end-use sectors + by 40 to 70% by 2050 compared to baseline scenarios, while some regions and socioeconomic + groups require additional energy and resources. Demand-side mitigation encompasses + changes in infrastructure use, end-use technology adoption, and socio-cultural + and behavioural change. . + B.6.4: + - Synergies and trade-offs, costs and benefits Mitigation and adaptation options + can lead to synergies and trade-offs with other aspects of sustainable development + . Synergies and trade-offs depend on the pace and magnitude of changes and the + development context including inequalities, with consideration of climate justice. + The potential or effectiveness of some adaptation and mitigation options decreases + as climate change intensifies . In the energy sector, transitions to low-emission + systems will have multiple co-benefits, including improvements in air quality + and health. There are potential synergies between sustainable development and, + for instance, energy efficiency and renewable energy. For agriculture, land, + and food systems, many land management options and demand-side response options can + contribute to eradicating poverty and eliminating hunger while promoting good + health and well-being, clean water and sanitation, and life on land . In contrast, + certain adaptation options that promote intensification of production, such as + irrigation, may have negative effects on sustainability . Reforestation, improved + forest management, soil carbon sequestration, peatland restoration and coastal + blue carbon management are examples of CDR methods that can enhance biodiversity + and ecosystem functions, employment and local livelihoods, depending on context + . However, afforestation or production of biomass crops for bioenergy with carbon + dioxide capture and storage or biochar can have adverse socio-economic and environmental + impacts, including on biodiversity, food and water security, local livelihoods + and the rights of Indigenous Peoples, especially if implemented at large scales + and where land tenure is insecure. Modelled pathways that assume using resources + more efficiently or shift global development towards sustainability include fewer + challenges, such as dependence on CDR and pressure on land and biodiversity, and + have the most pronounced synergies with respect to sustainable development . Strengthening + climate change mitigation action entails more rapid transitions and higher up-front + investments, but brings benefits from avoiding damages from climate change and + reduced adaptation costs. The aggregate effects of climate change mitigation on + global GDP are small compared to global projected GDP growth. Projected estimates + of global aggregate net economic damages and the costs of adaptation generally + increase with global warming level. Cost-benefit analysis remains limited in + its ability to represent all damages from climate change, including non-monetary + damages, or to capture the heterogeneous nature of damages and the risk of catastrophic + damages. Even without accounting for these factors or for the co-benefits of mitigation, + the global benefits of limiting warming to 2°C exceed the cost of mitigation . + This finding is robust against a wide range of assumptions about social preferences + on inequalities and discounting over time . Limiting global warming to 1.5°C instead + of 2°C would increase the costs of mitigation, but also increase the benefits + in terms of reduced impacts and related risks and reduced adaptation needs 140. Considering + other sustainable development dimensions, such as the potentially strong economic + benefits on human health from air quality improvement, may enhance the estimated + benefits of mitigation . The economic effects of strengthened mitigation action + vary across regions and countries, depending notably on economic structure, regional + emissions reductions, policy design and level of international cooperation. Ambitious + mitigation pathways imply large and sometimes disruptive changes in economic structure, + with implications for near-term actions, equity , sustainability, and finance + . + B.7.1: + - 'Net Zero Emissions: Timing and Implications From a physical science perspective, + limiting human-caused global warming to a specific level requires limiting cumulative + CO2 emissions, reaching net zero or net negative CO2 emissions, along with strong + reductions of other GHG emissions . Global modelled pathways that reach and sustain + net zero GHG emissions are projected to result in a gradual decline in surface + temperature. Reaching net zero GHG emissions primarily requires deep reductions + in CO2, methane, and other GHG emissions, and implies net negative CO2 emissions.134 + Carbon dioxide removal will be necessary to achieve net negative CO2 emissions + 135. Achieving global net zero CO2 emissions, with remaining anthropogenic CO + 2 emissions balanced by durably stored CO 2 from anthropogenic removal, is a requirement + to stabilise CO2-induced global surface temperature increase . This is different + from achieving net zero GHG emissions, where metric-weighted anthropogenic GHG + emissions equal CO 2 removal. Emissions pathways that reach and sustain net zero + GHG emissions defined by the 100-year global warming potential imply net negative + CO2 emissions and are projected to result in a gradual decline in surface temperature + after an earlier peak. While reaching net zero CO2 or net zero GHG emissions requires + deep and rapid reductions in gross emissions, the deployment of CDR to counterbalance + hardto-abate residual emissions is unavoidable . In modelled pathways, the timing + of net zero CO2 emissions, followed by net zero GHG emissions, depends on several + variables, including the desired climate outcome, the mitigation strategy and + the gases covered. Global net zero CO2 emissions are reached in the early 2050s + in pathways that limit warming to 1.5°C with no or limited overshoot, and around + the early 2070s in pathways that limit warming to 2°C. While non-CO2 GHG emissions + are strongly reduced in all pathways that limit warming to 2°C or lower, residual + emissions of CH4 and N2O and F-gases of about 8 [5–11] GtCO2 -eq yr -1 remain + at the time of net zero GHG, counterbalanced by net negative CO2 emissions. As + a result, net zero CO2 would be reached before net zero GHGs .' + - 'Overshoot Pathways: Increased Risks and Other Implications Exceeding a specific + remaining carbon budget results in higher global warming. Achieving and sustaining + net negative global CO 2 emissions could reverse the resulting temperature exceedance. + Continued reductions in emissions of short-lived climate forcers, particularly + methane, after peak temperature has been reached, would also further reduce warming. + Only a small number of the most ambitious global modelled pathways limit global + warming to 1.5°C without overshoot. Overshoot of a warming level results in more + adverse impacts, some irreversible, and additional risks for human and natural + systems compared to staying below that warming level, with risks growing with + the magnitude and duration of overshoot. Compared to pathways without overshoot, + societies and ecosystems would be exposed to greater and more widespread changes + in climatic impact-drivers, such as extreme heat and extreme precipitation, with + increasing risks to infrastructure, low-lying coastal settlements, and associated + livelihoods. Overshooting 1.5°C will result in irreversible adverse impacts on + certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, + impacted by ice-sheet melt, glacier melt, or by accelerating and higher committed + sea level rise. Overshoot increases the risks of severe impacts, such as increased + wildfires, mass mortality of trees, drying of peatlands, thawing of permafrost + and weakening natural land carbon sinks; such impacts could increase releases + of GHGs making temperature reversal more challenging. The larger the overshoot, + the more net negative CO2 emissions needed to return to a given warming level. + Reducing global temperature by removing CO 2 would require net negative emissions + of 220 GtCO 2 for every tenth of a degree. Modelled pathways that limit warming + to 1.5°C with no or limited overshoot reach median values of cumulative net negative + emissions of 220 GtCO2 by 2100, pathways that return warming to 1.5°C after high + overshoot reach median values of 360 GtCO2. 137 More rapid reduction in CO 2 and + non-CO2 emissions, particularly methane, limits peak warming levels and reduces + the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility + and sustainability concerns, and social and environmental risks .' + B.7.2: + - Impacts and Related Risks For a given level of warming, many climate-related + risks are assessed to be higher than in AR5. Levels of risk for all Reasons for + Concern 121 are assessed to become high to very high at lower global warming levels + compared to what was assessed in AR5. This is based upon recent evidence of observed + impacts, improved process understanding, and new knowledge on exposure and vulnerability + of human and natural systems, including limits to adaptation. Depending on the + level of global warming, the assessed long-term impacts will be up to multiple + times higher than currently observed for 127 identified key risks, e.g., in terms + of the number of affected people and species. Risks, including cascading risks + and risks from overshoot, are projected to become increasingly severe with every + increment of global warming. Climate-related risks for natural and human systems + are higher for global warming of 1.5°C than at present but lower than at 2°C . + Climate-related risks to health, livelihoods, food security, water supply, human + security, and economic growth are projected to increase with global warming of + 1.5°C. In terrestrial ecosystems, 3 to 14% of the tens of thousands of species + assessed will likely face a very high risk of extinction at a GWL of 1.5°C. Coral + reefs are projected to decline by a further 70–90% at 1.5°C of global warming. + At this GWL, many low-elevation and small glaciers around the world would lose + most of their mass or disappear within decades to centuries. Regions at disproportionately + higher risk include Arctic ecosystems, dryland regions, small island developing + states and Least Developed Countries . At 2°C of global warming, overall risk + levels associated with the unequal distribution of impacts, global aggregate impacts + and large-scale singular events would be transitioning to high , those associated + with extreme weather events would be transitioning to very high, and those associated + with unique and threatened systems would be very high . With about 2°C warming, + climate-related changes in food availability and diet quality are estimated to + increase nutrition-related diseases and the number of undernourished people, affecting + tens to hundreds of millions of people, particularly among low-income households + in low- and middle-income countries in sub-Saharan Africa, South Asia and Central + America. For example, snowmelt water availability for irrigation is projected + to decline in some snowmelt dependent river basins by up to 20% . Climate change + risks to cities, settlements and key infrastructure will rise sharply in the mid + and long term with further global warming, especially in places already exposed + to high temperatures, along coastlines, or with high vulnerabilities . At global + warming of 3°C, additional risks in many sectors and regions reach high or very + high levels, implying widespread systemic impacts, irreversible change and many + additional adaptation limits . For example, very high extinction risk for endemic + species in biodiversity hotspots is projected to increase at least tenfold if + warming rises from 1.5°C to 3°C. Projected increases in direct flood damages are + higher by 1.4 to 2 times at 2°C and 2.5 to 3.9 times at 3°C, compared to 1.5°C + global warming without adaptation. Global warming of 4°C and above is projected + to lead to far-reaching impacts on natural and human systems. Beyond 4°C of warming, + projected impacts on natural systems include local extinction of ~50% of tropical + marine species and biome shifts across 35% of global land area. At this level + of warming, approximately 10% of the global land area is projected to face both + increasing high and decreasing low extreme streamflow, affecting, without additional + adaptation, over 2.1 billion people and about 4 billion people are projected to + experience water scarcity. At 4°C of warming, the global burned area is projected + to increase by 50 to 70% and the fire frequency by ~30% compared to today. Projected + adverse impacts and related losses and damages from climate change escalate with + every increment of global warming , but they will also strongly depend on socio-economic + development trajectories and adaptation actions to reduce vulnerability and exposure. + For example, development pathways with higher demand for food, animal feed, and + water, more resource-intensive consumption and production, and limited technological + improvements result in higher risks from water scarcity in drylands, land degradation + and food insecurity . Changes in, for example, demography or investments in health + systems have effect on a variety of health-related outcomes including heat-related + morbidity and mortality. With every increment of warming, climate change impacts + and risks will become increasingly complex and more difficult to manage. Many + regions are projected to experience an increase in the probability of compound + events with higher global warming, such as concurrent heatwaves and droughts, + compound flooding and fire weather. In addition, multiple climatic and non-climatic + risk drivers such as biodiversity loss or violent conflict will interact, resulting + in compounding overall risk and risks cascading across sectors and regions. Furthermore, + risks can arise from some responses that are intended to reduce the risks of climate + change, e.g., adverse side effects of some emission reduction and carbon dioxide + removal measures . Solar Radiation Modification approaches, if they were to be + implemented, introduce a widespread range of new risks to people and ecosystems, + which are not well understood. SRM has the potential to offset warming within + one or two decades and ameliorate some climate hazards but would not restore climate + to a previous state, and substantial residual or overcompensating climate change + would occur at regional and seasonal scales. Effects of SRM would depend on the + specific approach used 122, and a sudden and sustained termination of SRM in a + high CO 2 emissions scenario would cause rapid climate change. SRM would not stop + atmospheric CO 2 concentrations from increasing nor reduce resulting ocean acidification + under continued anthropogenic emissions. Large uncertainties and knowledge gaps + are associated with the potential of SRM approaches to reduce climate change risks. + Lack of robust and formal SRM governance poses risks as deployment by a limited + number of states could create international tensions. + - 'Overshoot Pathways: Increased Risks and Other Implications Exceeding a specific + remaining carbon budget results in higher global warming. Achieving and sustaining + net negative global CO 2 emissions could reverse the resulting temperature exceedance. + Continued reductions in emissions of short-lived climate forcers, particularly + methane, after peak temperature has been reached, would also further reduce warming. + Only a small number of the most ambitious global modelled pathways limit global + warming to 1.5°C without overshoot. Overshoot of a warming level results in more + adverse impacts, some irreversible, and additional risks for human and natural + systems compared to staying below that warming level, with risks growing with + the magnitude and duration of overshoot. Compared to pathways without overshoot, + societies and ecosystems would be exposed to greater and more widespread changes + in climatic impact-drivers, such as extreme heat and extreme precipitation, with + increasing risks to infrastructure, low-lying coastal settlements, and associated + livelihoods. Overshooting 1.5°C will result in irreversible adverse impacts on + certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, + impacted by ice-sheet melt, glacier melt, or by accelerating and higher committed + sea level rise. Overshoot increases the risks of severe impacts, such as increased + wildfires, mass mortality of trees, drying of peatlands, thawing of permafrost + and weakening natural land carbon sinks; such impacts could increase releases + of GHGs making temperature reversal more challenging. The larger the overshoot, + the more net negative CO2 emissions needed to return to a given warming level. + Reducing global temperature by removing CO 2 would require net negative emissions + of 220 GtCO 2 for every tenth of a degree. Modelled pathways that limit warming + to 1.5°C with no or limited overshoot reach median values of cumulative net negative + emissions of 220 GtCO2 by 2100, pathways that return warming to 1.5°C after high + overshoot reach median values of 360 GtCO2. 137 More rapid reduction in CO 2 and + non-CO2 emissions, particularly methane, limits peak warming levels and reduces + the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility + and sustainability concerns, and social and environmental risks .' + B.7.3: + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + - 'Overshoot Pathways: Increased Risks and Other Implications Exceeding a specific + remaining carbon budget results in higher global warming. Achieving and sustaining + net negative global CO 2 emissions could reverse the resulting temperature exceedance. + Continued reductions in emissions of short-lived climate forcers, particularly + methane, after peak temperature has been reached, would also further reduce warming. + Only a small number of the most ambitious global modelled pathways limit global + warming to 1.5°C without overshoot. Overshoot of a warming level results in more + adverse impacts, some irreversible, and additional risks for human and natural + systems compared to staying below that warming level, with risks growing with + the magnitude and duration of overshoot. Compared to pathways without overshoot, + societies and ecosystems would be exposed to greater and more widespread changes + in climatic impact-drivers, such as extreme heat and extreme precipitation, with + increasing risks to infrastructure, low-lying coastal settlements, and associated + livelihoods. Overshooting 1.5°C will result in irreversible adverse impacts on + certain ecosystems with low resilience, such as polar, mountain, and coastal ecosystems, + impacted by ice-sheet melt, glacier melt, or by accelerating and higher committed + sea level rise. Overshoot increases the risks of severe impacts, such as increased + wildfires, mass mortality of trees, drying of peatlands, thawing of permafrost + and weakening natural land carbon sinks; such impacts could increase releases + of GHGs making temperature reversal more challenging. The larger the overshoot, + the more net negative CO2 emissions needed to return to a given warming level. + Reducing global temperature by removing CO 2 would require net negative emissions + of 220 GtCO 2 for every tenth of a degree. Modelled pathways that limit warming + to 1.5°C with no or limited overshoot reach median values of cumulative net negative + emissions of 220 GtCO2 by 2100, pathways that return warming to 1.5°C after high + overshoot reach median values of 360 GtCO2. 137 More rapid reduction in CO 2 and + non-CO2 emissions, particularly methane, limits peak warming levels and reduces + the requirement for net negative CO2 emissions and CDR, thereby reducing feasibility + and sustainability concerns, and social and environmental risks .' + - Synergies and trade-offs, costs and benefits Mitigation and adaptation options + can lead to synergies and trade-offs with other aspects of sustainable development + . Synergies and trade-offs depend on the pace and magnitude of changes and the + development context including inequalities, with consideration of climate justice. + The potential or effectiveness of some adaptation and mitigation options decreases + as climate change intensifies . In the energy sector, transitions to low-emission + systems will have multiple co-benefits, including improvements in air quality + and health. There are potential synergies between sustainable development and, + for instance, energy efficiency and renewable energy. For agriculture, land, + and food systems, many land management options and demand-side response options can + contribute to eradicating poverty and eliminating hunger while promoting good + health and well-being, clean water and sanitation, and life on land . In contrast, + certain adaptation options that promote intensification of production, such as + irrigation, may have negative effects on sustainability . Reforestation, improved + forest management, soil carbon sequestration, peatland restoration and coastal + blue carbon management are examples of CDR methods that can enhance biodiversity + and ecosystem functions, employment and local livelihoods, depending on context + . However, afforestation or production of biomass crops for bioenergy with carbon + dioxide capture and storage or biochar can have adverse socio-economic and environmental + impacts, including on biodiversity, food and water security, local livelihoods + and the rights of Indigenous Peoples, especially if implemented at large scales + and where land tenure is insecure. Modelled pathways that assume using resources + more efficiently or shift global development towards sustainability include fewer + challenges, such as dependence on CDR and pressure on land and biodiversity, and + have the most pronounced synergies with respect to sustainable development . Strengthening + climate change mitigation action entails more rapid transitions and higher up-front + investments, but brings benefits from avoiding damages from climate change and + reduced adaptation costs. The aggregate effects of climate change mitigation on + global GDP are small compared to global projected GDP growth. Projected estimates + of global aggregate net economic damages and the costs of adaptation generally + increase with global warming level. Cost-benefit analysis remains limited in + its ability to represent all damages from climate change, including non-monetary + damages, or to capture the heterogeneous nature of damages and the risk of catastrophic + damages. Even without accounting for these factors or for the co-benefits of mitigation, + the global benefits of limiting warming to 2°C exceed the cost of mitigation . + This finding is robust against a wide range of assumptions about social preferences + on inequalities and discounting over time . Limiting global warming to 1.5°C instead + of 2°C would increase the costs of mitigation, but also increase the benefits + in terms of reduced impacts and related risks and reduced adaptation needs 140. Considering + other sustainable development dimensions, such as the potentially strong economic + benefits on human health from air quality improvement, may enhance the estimated + benefits of mitigation . The economic effects of strengthened mitigation action + vary across regions and countries, depending notably on economic structure, regional + emissions reductions, policy design and level of international cooperation. Ambitious + mitigation pathways imply large and sometimes disruptive changes in economic structure, + with implications for near-term actions, equity , sustainability, and finance + . + C.1.1: + - Long-Term Interactions Between Adaptation, Mitigation and Sustainable Development Mitigation + and adaptation can lead to synergies and trade-offs with sustainable development. + Accelerated and equitable mitigation and adaptation bring benefits from avoiding + damages from climate change and are critical to achieving sustainable development. + Climate resilient development 138 pathways are progressively constrained by every + increment of further warming. There is a rapidly closing window of opportunity + to secure a liveable and sustainable future for all. + - 'Advancing Integrated Climate Action for Sustainable Development An inclusive, + equitable approach to integrating adaptation, mitigation and development can advance + sustainable development in the long term. Integrated responses can harness synergies + for sustainable development and reduce trade-offs. Shifting development pathways + towards sustainability and advancing climate resilient development is enabled + when governments, civil society and the private sector make development choices + that prioritise risk reduction, equity and justice, and when decision-making processes, + finance and actions are integrated across governance levels, sectors and timeframes. + Inclusive processes involving local knowledge and Indigenous Knowledge increase + these prospects. However, opportunities for action differ substantially among + and within regions, driven by historical and ongoing patterns of development. + Accelerated financial support for developing countries is critical to enhance + mitigation and adaptation action. Policies that shift development pathways towards + sustainability can broaden the portfolio of available mitigation and adaptation + responses. Combining mitigation with action to shift development pathways, such + as broader sectoral policies, approaches that induce lifestyle or behaviour changes, + financial regulation, or macroeconomic policies can overcome barriers and open + up a broader range of mitigation options. Integrated, inclusive planning and investment + in everyday decisionmaking about urban infrastructure can significantly increase + the adaptive capacity of urban and rural settlements. Coastal cities and settlements + play an important role in advancing climate resilient development due to the high + number of people living in the Low Elevation Coastal Zone, the escalating and + climate compounded risk that they face, and their vital role in national economies + and beyond . Observed adverse impacts and related losses and damages, projected + risks, trends in vulnerability, and adaptation limits demonstrate that transformation + for sustainability and climate resilient development action is more urgent than + previously assessed. Climate resilient development integrates adaptation and GHG + mitigation to advance sustainable development for all. Climate resilient development + pathways have been constrained by past development, emissions and climate change + and are progressively constrained by every increment of warming, in particular + beyond 1.5°C. Climate resilient development will not be possible in some regions + and sub-regions if global warming exceeds 2°C. Safeguarding biodiversity and ecosystems + is fundamental to climate resilient development, but biodiversity and ecosystem + services have limited capacity to adapt to increasing global warming levels, making + climate resilient development progressively harder to achieve beyond 1.5°C warming. The + cumulative scientific evidence is unequivocal: climate change is a threat to human + well-being and planetary health . Any further delay in concerted anticipatory + global action on adaptation and mitigation will miss a brief and rapidly closing + window of opportunity to secure a liveable and sustainable future for all. Opportunities + for near-term action are assessed in the following section.' + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + C.1.2: + - Long-Term Interactions Between Adaptation, Mitigation and Sustainable Development Mitigation + and adaptation can lead to synergies and trade-offs with sustainable development. + Accelerated and equitable mitigation and adaptation bring benefits from avoiding + damages from climate change and are critical to achieving sustainable development. + Climate resilient development 138 pathways are progressively constrained by every + increment of further warming. There is a rapidly closing window of opportunity + to secure a liveable and sustainable future for all. + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - Near-Term Mitigation and Adaptation Actions Rapid and far-reaching transitions + across all sectors and systems are necessary to achieve deep and sustained emissions + reductions and secure a liveable and sustainable future for all. These system + transitions involve a significant upscaling of a wide portfolio of mitigation + and adaptation options. Feasible, effective and low-cost options for mitigation + and adaptation are already available, with differences across systems and regions. Rapid + and far-reaching transitions across all sectors and systems are necessary to achieve + deep emissions reductions and secure a liveable and sustainable future for all. + System transitions consistent with pathways that limit warming to 1.5°C with no + or limited overshoot are more rapid and pronounced in the near-term than in those + that limit warming to 2°C . Such a systemic change is unprecedented in terms of + scale, but not necessarily in terms of speed. The system transitions make possible + the transformative adaptation required for high levels of human health and well-being, + economic and social resilience, ecosystem health, and planetary health. Feasible, + effective and low-cost options for mitigation and adaptation are already available. + Mitigation options costing USD 100 tCO 2-eq–1 or less could reduce global GHG + emissions by at least half the 2019 level by 2030 . The availability, feasibility + 152 and potential of mitigation or effectiveness of adaptation options in the + near term differ across systems and regions. Demand-side measures and new ways + of end-use service provision can reduce global GHG emissions in end-use sectors + by 40 to 70% by 2050 compared to baseline scenarios, while some regions and socioeconomic + groups require additional energy and resources. Demand-side mitigation encompasses + changes in infrastructure use, end-use technology adoption, and socio-cultural + and behavioural change. . + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + - 'Strengthening the Response: Finance, International Cooperation and Technology Finance, + international cooperation and technology are critical enablers for accelerated + climate action. If climate goals are to be achieved, both adaptation and mitigation + financing would have to increase many-fold. There is sufficient global capital + to close the global investment gaps but there are barriers to redirect capital + to climate action. Barriers include institutional, regulatory and market access + barriers, which can be reduced to address the needs and opportunities, economic + vulnerability and indebtedness in many developing countries. Enhancing international + cooperation is possible through multiple channels. Enhancing technology innovation + systems is key to accelerate the widespread adoption of technologies and practices.' + C.1.3: + - 'The Likelihood and Risks of Abrupt and Irreversible Change The likelihood of + abrupt and irreversible changes and their impacts increase with higher global + warming levels. As warming levels increase, so do the risks of species extinction + or irreversible loss of biodiversity in ecosystems such as forests , coral reefs + and in Arctic regions . Risks associated with large-scale singular events or tipping + points, such as ice sheet instability or ecosystem loss from tropical forests, + transition to high risk between 1.5°C to 2.5°C and to very high risk between + 2.5°C to 4°C. The response of biogeochemical cycles to anthropogenic perturbations + can be abrupt at regional scales and irreversible on decadal to century time scales. + The probability of crossing uncertain regional thresholds increases with further + warming. Sea level rise is unavoidable for centuries to millennia due to continuing + deep ocean warming and ice sheet melt, and sea levels will remain elevated for + thousands of years . Global mean sea level rise will continue in the 21st century, + with projected regional relative sea level rise within 20% of the global mean + along two-thirds of the global coastline . The magnitude, the rate, the timing + of threshold exceedances, and the long-term commitment of sea level rise depend + on emissions, with higher emissions leading to greater and faster rates of sea + level rise. Due to relative sea level rise, extreme sea level events that occurred + once per century in the recent past are projected to occur at least annually at + more than half of all tide gauge locations by 2100 and risks for coastal ecosystems, + people and infrastructure will continue to increase beyond 2100. At sustained + warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets + will be lost almost completely and irreversibly over multiple millennia. The probability + and rate of ice mass loss increase with higher global surface temperatures. Over + the next 2000 years, global mean sea level will rise by about 2 to 3 m if warming + is limited to 1.5°C and 2 to 6 m if limited to 2°C . Projections of multi-millennial + global mean sea level rise are consistent with reconstructed levels during past + warm climate periods: global mean sea level was very likely 5 to 25 m higher than + today roughly 3 million years ago, when global temperatures were 2.5°C to 4°C + higher than 1850–1900. Further examples of unavoidable changes in the climate + system due to multi-decadal or longer response timescales include continued glacier + melt and permafrost carbon loss. The probability of low-likelihood outcomes + associated with potentially very large impacts increases with higher global warming + levels. Warming substantially above the assessed very likely range for a given + scenario cannot be ruled out, and there is high confidence this would lead to + regional changes greater than assessed in many aspects of the climate system. + Low-likelihood, high-impact outcomes could occur at regional scales even for global + warming within the very likely assessed range for a given GHG emissions scenario. + Global mean sea level rise above the likely range – approaching 2 m by 2100 and + in excess of 15 m by 2300 under a very high GHG emissions scenario – cannot be + ruled out due to deep uncertainty in ice-sheet processes 123 and would have severe + impacts on populations in low elevation coastal zones. If global warming increases, + some compound extreme events 124 will become more frequent, with higher likelihood + of unprecedented intensities, durations or spatial extent. The Atlantic Meridional + Overturning Circulation is very likely to weaken over the 21st century for all + considered scenarios, however an abrupt collapse is not expected before 2100 . + If such a low probability event were to occur, it would very likely cause abrupt + shifts in regional weather patterns and water cycle, such as a southward shift + in the tropical rain belt, and large impacts on ecosystems and human activities. + A sequence of large explosive volcanic eruptions within decades, as have occurred + in the past, is a low-likelihood high-impact event that would lead to substantial + cooling globally and regional climate perturbations over several decades.' + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + - Synergies and trade-offs, costs and benefits Mitigation and adaptation options + can lead to synergies and trade-offs with other aspects of sustainable development + . Synergies and trade-offs depend on the pace and magnitude of changes and the + development context including inequalities, with consideration of climate justice. + The potential or effectiveness of some adaptation and mitigation options decreases + as climate change intensifies . In the energy sector, transitions to low-emission + systems will have multiple co-benefits, including improvements in air quality + and health. There are potential synergies between sustainable development and, + for instance, energy efficiency and renewable energy. For agriculture, land, + and food systems, many land management options and demand-side response options can + contribute to eradicating poverty and eliminating hunger while promoting good + health and well-being, clean water and sanitation, and life on land . In contrast, + certain adaptation options that promote intensification of production, such as + irrigation, may have negative effects on sustainability . Reforestation, improved + forest management, soil carbon sequestration, peatland restoration and coastal + blue carbon management are examples of CDR methods that can enhance biodiversity + and ecosystem functions, employment and local livelihoods, depending on context + . However, afforestation or production of biomass crops for bioenergy with carbon + dioxide capture and storage or biochar can have adverse socio-economic and environmental + impacts, including on biodiversity, food and water security, local livelihoods + and the rights of Indigenous Peoples, especially if implemented at large scales + and where land tenure is insecure. Modelled pathways that assume using resources + more efficiently or shift global development towards sustainability include fewer + challenges, such as dependence on CDR and pressure on land and biodiversity, and + have the most pronounced synergies with respect to sustainable development . Strengthening + climate change mitigation action entails more rapid transitions and higher up-front + investments, but brings benefits from avoiding damages from climate change and + reduced adaptation costs. The aggregate effects of climate change mitigation on + global GDP are small compared to global projected GDP growth. Projected estimates + of global aggregate net economic damages and the costs of adaptation generally + increase with global warming level. Cost-benefit analysis remains limited in + its ability to represent all damages from climate change, including non-monetary + damages, or to capture the heterogeneous nature of damages and the risk of catastrophic + damages. Even without accounting for these factors or for the co-benefits of mitigation, + the global benefits of limiting warming to 2°C exceed the cost of mitigation . + This finding is robust against a wide range of assumptions about social preferences + on inequalities and discounting over time . Limiting global warming to 1.5°C instead + of 2°C would increase the costs of mitigation, but also increase the benefits + in terms of reduced impacts and related risks and reduced adaptation needs 140. Considering + other sustainable development dimensions, such as the potentially strong economic + benefits on human health from air quality improvement, may enhance the estimated + benefits of mitigation . The economic effects of strengthened mitigation action + vary across regions and countries, depending notably on economic structure, regional + emissions reductions, policy design and level of international cooperation. Ambitious + mitigation pathways imply large and sometimes disruptive changes in economic structure, + with implications for near-term actions, equity , sustainability, and finance + . + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + C.2.1: + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + C.2.2: + - Observed Climate System Changes and Impacts to Date It is unequivocal that human + influence has warmed the atmosphere, ocean and land. Widespread and rapid changes + in the atmosphere, ocean, cryosphere and biosphere have occurred . The scale of + recent changes across the climate system as a whole and the present state of many + aspects of the climate system are unprecedented over many centuries to many thousands + of years. It is very likely that GHG emissions were the main driver of tropospheric + warming and extremely likely that human-caused stratospheric ozone depletion was + the main driver of stratospheric cooling between 1979 and the mid-1990s. It is + virtually certain that the global upper ocean has warmed since the 1970s and extremely + likely that human influence is the main driver. Ocean warming accounted for 91% + of the heating in the climate system, with land warming, ice loss and atmospheric + warming accounting for about 5%, 3% and 1%, respectively. Global mean sea level + increased by 0.20 [0.15 to 0.25] m between 1901 and 2018. The average rate of + sea level rise was 1.3 [0.6 to 2.1]mm yr-1 between 1901 and 1971, increasing to + 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and further increasing to 3.7 + [3.2 to –4.2] mm yr -1 between 2006 and 2018. Human influence was very likely + the main driver of these increases since at least 1971. Human influence is very + likely the main driver of the global retreat of glaciers since the 1990s and the + decrease in Arctic sea ice area between 1979–1988 and 2010–2019. Human influence + has also very likely contributed to decreased Northern Hemisphere spring snow + cover and surface melting of the Greenland ice sheet. It is virtually certain + that human-caused CO2 emissions are the main driver of current global acidification + of the surface open ocean. Human-caused climate change is already affecting many + weather and climate extremes in every region across the globe. Evidence of observed + changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical + cyclones, and, in particular, their attribution to human influence, has strengthened + since AR5. It is virtually certain that hot extremes have become more frequent + and more intense across most land regions since the 1950s, while cold extremes + have become less frequent and less severe, with high confidence that human-caused + climate change is the main driver of these changes. Marine heatwaves have approximately + doubled in frequency since the 1980s, and human influence has very likely contributed + to most of them since at least 2006. The frequency and intensity of heavy precipitation + events have increased since the 1950s over most land areas for which observational + data are sufficient for trend analysis, and human-caused climate change is likely + the main driver. Human-caused climate change has contributed to increases in agricultural + and ecological droughts in some regions due to increased land evapotranspiration + . It is likely that the global proportion of major tropical cyclone occurrence + has increased over the last four decades. Climate change has caused substantial + damages, and increasingly irreversible losses, in terrestrial, freshwater, cryospheric + and coastal and open ocean ecosystems. The extent and magnitude of climate change + impacts are larger than estimated in previous assessments. Approximately half + of the species assessed globally have shifted polewards or, on land, also to higher + elevations. Biological responses including changes in geographic placement and + shifting seasonal timing are often not sufficient to cope with recent climate + change. Hundreds of local losses of species have been driven by increases in the + magnitude of heat extremes and mass mortality events on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. Impacts in ecosystems + from slow-onset processes such as ocean acidification, sea level rise or regional + decreases in precipitation have also been attributed to human-caused climate change. + Climate change has contributed to desertification and exacerbated land degradation, + particularly in low lying coastal areas, river deltas, drylands and in permafrost + areas. Nearly 50% of coastal wetlands have been lost over the last 100 years, + as a result of the combined effects of localised human pressures, sea level rise, + warming and extreme climate events. Climate change has reduced food security + and affected water security due to warming, changing precipitation patterns, reduction + and loss of cryospheric elements, and greater frequency and intensity of climatic + extremes, thereby hindering efforts to meet Sustainable Development Goals. Although + overall agricultural productivity has increased, climate change has slowed this + growth in agricultural productivity over the past 50 years globally , with related + negative crop yield impacts mainly recorded in mid- and low latitude regions, + and some positive impacts in some high latitude regions. Ocean warming in the + 20th century and beyond has contributed to an overall decrease in maximum catch + potential, compounding the impacts from overfishing for some fish stocks. Ocean + warming and ocean acidification have adversely affected food production from shellfish + aquaculture and fisheries in some oceanic regions . Current levels of global warming + are associated with moderate risks from increased dryland water scarcity. Roughly + half of the world’s population currently experiences severe water scarcity for + at least some part of the year due to a combination of climatic and non-climatic + drivers. Unsustainable agricultural expansion, driven in part by unbalanced diets + , increases ecosystem and human vulnerability and leads to competition for land + and/or water resources. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest impacts observed in many locations and/or communities in Africa, Asia, + Central and South America, LDCs, Small Islands and the Arctic, and for small-scale + food producers, low-income households and Indigenous Peoples globally. In urban + settings, climate change has caused adverse impacts on human health, livelihoods + and key infrastructure. Hot extremes including heatwaves have intensified in cities + , where they have also worsened air pollution events and limited functioning of + key infrastructure . Urban infrastructure, including transportation, water, sanitation + and energy systems have been compromised by extreme and slow-onset events , with + resulting economic losses, disruptions of services and impacts to well-being. + Observed impacts are concentrated amongst economically and socially marginalised + urban residents, e.g., those living in informal settlements. Cities intensify + human-caused warming locally, while urbanisation also increases mean and heavy + precipitation over and/or downwind of cities and resulting runoff intensity . Climate + change has adversely affected human physical health globally and mental health + in assessed regions, and is contributing to humanitarian crises where climate + hazards interact with high vulnerability. In all regions increases in extreme + heat events have resulted in human mortality and morbidity . The occurrence of + climate-related food-borne and water-borne diseases has increased. The incidence + of vector-borne diseases has increased from range expansion and/or increased reproduction + of disease vectors. Animal and human diseases, including zoonoses, are emerging + in new areas . In assessed regions, some mental health challenges are associated + with increasing temperatures, trauma from extreme events, and loss of livelihoods + and culture . Climate change impacts on health are mediated through natural and + human systems, including economic and social conditions and disruptions. Climate + and weather extremes are increasingly driving displacement in Africa, Asia, North + America, and Central and South America , with small island states in the Caribbean + and South Pacific being disproportionately affected relative to their small population + size. Through displacement and involuntary migration from extreme weather and + climate events, climate change has generated and perpetuated vulnerability . Human + influence has likely increased the chance of compound extreme events since the + 1950s. Concurrent and repeated climate hazards have occurred in all regions, increasing + impacts and risks to health, ecosystems, infrastructure, livelihoods and food + . Compound extreme events include increases in the frequency of concurrent heatwaves + and droughts; fire weather in some regions; and compound flooding in some locations. + Multiple risks interact, generating new sources of vulnerability to climate hazards, + and compounding overall risk. Compound climate hazards can overwhelm adaptive + capacity and substantially increase damage ). Economic impacts attributable to + climate change are increasingly affecting peoples’ livelihoods and are causing + economic and societal impacts across national boundaries. Economic damages from + climate change have been detected in climate-exposed sectors, with regional effects + to agriculture, forestry, fishery, energy, and tourism, and through outdoor labour + productivity with some exceptions of positive impacts in regions with low energy + demand and comparative advantages in agricultural markets and tourism. Individual + livelihoods have been affected through changes in agricultural productivity, impacts + on human health and food security, destruction of homes and infrastructure, and + loss of property and income, with adverse effects on gender and social equity + . Tropical cyclones have reduced economic growth in the short-term. Event attribution + studies and physical understanding indicate that human-caused climate change increases + heavy precipitation associated with tropical cyclones. Wildfires in many regions + have affected built assets, economic activity, and health. In cities and settlements, + climate impacts to key infrastructure are leading to losses and damages across + water and food systems, and affect economic activity, with impacts extending beyond + the area directly impacted by the climate hazard. Climate change has caused widespread + adverse impacts and related losses and damages to nature and people . Losses and + damages are unequally distributed across systems, regions and sectors. Cultural + losses, related to tangible and intangible heritage, threaten adaptive capacity + and may result in irrevocable losses of sense of belonging, valued cultural practices, + identity and home, particularly for Indigenous Peoples and those more directly + reliant on the environment for subsistence. For example, changes in snow cover, + lake and river ice, and permafrost in many Arctic regions, are harming the livelihoods + and cultural identity of Arctic residents including Indigenous populations. Infrastructure, + including transportation, water, sanitation and energy systems have been compromised + by extreme and slow-onset events, with resulting economic losses, disruptions + of services and impacts to well-being. Across sectors and regions, the most vulnerable + people and systems have been disproportionately affected by the impacts of climate + change. LDCs and SIDS who have much lower per capita emissions than the global + average excluding CO2-LULUCF, also have high vulnerability to climatic hazards, + with global hotspots of high human vulnerability observed in West-, Central- and + East Africa, South Asia, Central and South America, SIDS and the Arctic. Regions + and people with considerable development constraints have high vulnerability to + climatic hazards. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Vulnerability at different + spatial levels is exacerbated by inequity and marginalisation linked to gender, + ethnicity, low income or combinations thereof, especially for many Indigenous + Peoples and local communities. Approximately 3.3 to 3.6 billion people live in + contexts that are highly vulnerable to climate change. Between 2010 and 2020, + human mortality from floods, droughts and storms was 15 times higher in highly + vulnerable regions, compared to regions with very low vulnerability. In the Arctic + and in some high mountain regions, negative impacts of cryosphere change have + been especially felt among Indigenous Peoples. Human and ecosystem vulnerability + are interdependent. Vulnerability of ecosystems and people to climate change differs + substantially among and within regions, driven by patterns of intersecting socio-economic + development, unsustainable ocean and land use, inequity, marginalisation, historical + and ongoing patterns of inequity such as colonialism, and governance. + - Impacts and Related Risks For a given level of warming, many climate-related + risks are assessed to be higher than in AR5. Levels of risk for all Reasons for + Concern 121 are assessed to become high to very high at lower global warming levels + compared to what was assessed in AR5. This is based upon recent evidence of observed + impacts, improved process understanding, and new knowledge on exposure and vulnerability + of human and natural systems, including limits to adaptation. Depending on the + level of global warming, the assessed long-term impacts will be up to multiple + times higher than currently observed for 127 identified key risks, e.g., in terms + of the number of affected people and species. Risks, including cascading risks + and risks from overshoot, are projected to become increasingly severe with every + increment of global warming. Climate-related risks for natural and human systems + are higher for global warming of 1.5°C than at present but lower than at 2°C . + Climate-related risks to health, livelihoods, food security, water supply, human + security, and economic growth are projected to increase with global warming of + 1.5°C. In terrestrial ecosystems, 3 to 14% of the tens of thousands of species + assessed will likely face a very high risk of extinction at a GWL of 1.5°C. Coral + reefs are projected to decline by a further 70–90% at 1.5°C of global warming. + At this GWL, many low-elevation and small glaciers around the world would lose + most of their mass or disappear within decades to centuries. Regions at disproportionately + higher risk include Arctic ecosystems, dryland regions, small island developing + states and Least Developed Countries . At 2°C of global warming, overall risk + levels associated with the unequal distribution of impacts, global aggregate impacts + and large-scale singular events would be transitioning to high , those associated + with extreme weather events would be transitioning to very high, and those associated + with unique and threatened systems would be very high . With about 2°C warming, + climate-related changes in food availability and diet quality are estimated to + increase nutrition-related diseases and the number of undernourished people, affecting + tens to hundreds of millions of people, particularly among low-income households + in low- and middle-income countries in sub-Saharan Africa, South Asia and Central + America. For example, snowmelt water availability for irrigation is projected + to decline in some snowmelt dependent river basins by up to 20% . Climate change + risks to cities, settlements and key infrastructure will rise sharply in the mid + and long term with further global warming, especially in places already exposed + to high temperatures, along coastlines, or with high vulnerabilities . At global + warming of 3°C, additional risks in many sectors and regions reach high or very + high levels, implying widespread systemic impacts, irreversible change and many + additional adaptation limits . For example, very high extinction risk for endemic + species in biodiversity hotspots is projected to increase at least tenfold if + warming rises from 1.5°C to 3°C. Projected increases in direct flood damages are + higher by 1.4 to 2 times at 2°C and 2.5 to 3.9 times at 3°C, compared to 1.5°C + global warming without adaptation. Global warming of 4°C and above is projected + to lead to far-reaching impacts on natural and human systems. Beyond 4°C of warming, + projected impacts on natural systems include local extinction of ~50% of tropical + marine species and biome shifts across 35% of global land area. At this level + of warming, approximately 10% of the global land area is projected to face both + increasing high and decreasing low extreme streamflow, affecting, without additional + adaptation, over 2.1 billion people and about 4 billion people are projected to + experience water scarcity. At 4°C of warming, the global burned area is projected + to increase by 50 to 70% and the fire frequency by ~30% compared to today. Projected + adverse impacts and related losses and damages from climate change escalate with + every increment of global warming , but they will also strongly depend on socio-economic + development trajectories and adaptation actions to reduce vulnerability and exposure. + For example, development pathways with higher demand for food, animal feed, and + water, more resource-intensive consumption and production, and limited technological + improvements result in higher risks from water scarcity in drylands, land degradation + and food insecurity . Changes in, for example, demography or investments in health + systems have effect on a variety of health-related outcomes including heat-related + morbidity and mortality. With every increment of warming, climate change impacts + and risks will become increasingly complex and more difficult to manage. Many + regions are projected to experience an increase in the probability of compound + events with higher global warming, such as concurrent heatwaves and droughts, + compound flooding and fire weather. In addition, multiple climatic and non-climatic + risk drivers such as biodiversity loss or violent conflict will interact, resulting + in compounding overall risk and risks cascading across sectors and regions. Furthermore, + risks can arise from some responses that are intended to reduce the risks of climate + change, e.g., adverse side effects of some emission reduction and carbon dioxide + removal measures . Solar Radiation Modification approaches, if they were to be + implemented, introduce a widespread range of new risks to people and ecosystems, + which are not well understood. SRM has the potential to offset warming within + one or two decades and ameliorate some climate hazards but would not restore climate + to a previous state, and substantial residual or overcompensating climate change + would occur at regional and seasonal scales. Effects of SRM would depend on the + specific approach used 122, and a sudden and sustained termination of SRM in a + high CO 2 emissions scenario would cause rapid climate change. SRM would not stop + atmospheric CO 2 concentrations from increasing nor reduce resulting ocean acidification + under continued anthropogenic emissions. Large uncertainties and knowledge gaps + are associated with the potential of SRM approaches to reduce climate change risks. + Lack of robust and formal SRM governance poses risks as deployment by a limited + number of states could create international tensions. + - Long-term Adaptation Options and Limits With increasing warming, adaptation options + will become more constrained and less effective. At higher levels of warming, + losses and damages will increase, and additional human and natural systems will + reach adaptation limits. Integrated, cross-cutting multi-sectoral solutions increase + the effectiveness of adaptation. Maladaptation can create lock-ins of vulnerability, + exposure and risks but can be avoided by long-term planning and the implementation + of adaptation actions that are flexible, multi-sectoral and inclusive. The effectiveness + of adaptation to reduce climate risk is documented for specific contexts, sectors + and regions and will decrease with increasing warming 125 . For example, common + adaptation responses in agriculture – adopting improved cultivars and agronomic + practices, and changes in cropping patterns and crop systems – will become less + effective from 2°C to higher levels of warming. The effectiveness of most water-related + adaptation options to reduce projected risks declines with increasing warming. + Adaptations for hydropower and thermo-electric power generation are effective + in most regions up to 1.5°C to 2°C, with decreasing effectiveness at higher levels + of warming . Ecosystem-based Adaptation is vulnerable to climate change impacts, + with effectiveness declining with increasing global warming. Globally, adaptation + options related to agroforestry and forestry have a sharp decline in effectiveness + at 3°C, with a substantial increase in residual risk. With increasing global + warming, more limits to adaptation will be reached and losses and damages, strongly + concentrated among the poorest vulnerable populations, will increase. Already + below 1.5°C, autonomous and evolutionary adaptation responses by terrestrial and + aquatic ecosystems will increasingly face hard limits. Above 1.5°C, some ecosystem-based + adaptation measures will lose their effectiveness in providing benefits to people + as these ecosystems will reach hard adaptation limits. Adaptation to address the + risks of heat stress, heat mortality and reduced capacities for outdoor work for + humans face soft and hard limits across regions that become significantly more + severe at 1.5°C, and are particularly relevant for regions with warm climates. + Above 1.5°C global warming level, limited freshwater resources pose potential + hard limits for small islands and for regions dependent on glacier and snow melt + . By 2°C, soft limits are projected for multiple staple crops, particularly in + tropical regions. By 3°C, soft limits are projected for some water management + measures for many regions, with hard limits projected for parts of Europe . Integrated, + cross-cutting multi-sectoral solutions increase the effectiveness of adaptation. + For example, inclusive, integrated and long-term planning at local, municipal, + sub-national and national scales, together with effective regulation and monitoring + systems and financial and technological resources and capabilities foster urban + and rural system transition. There are a range of cross-cutting adaptation options, + such as disaster risk management, early warning systems, climate services and + risk spreading and sharing that have broad applicability across sectors and provide + greater benefits to other adaptation options when combined. Transitioning from + incremental to transformational adaptation, and addressing a range of constraints, + primarily in the financial, governance, institutional and policy domains, can + help overcome soft adaptation limits. However, adaptation does not prevent all + losses and damages, even with effective adaptation and before reaching soft and + hard limits. Maladaptive responses to climate change can create lock-ins of vulnerability, + exposure and risks that are difficult and expensive to change and exacerbate existing + inequalities. Actions that focus on sectors and risks in isolation and on short-term + gains often lead to maladaptation. Adaptation options can become maladaptive due + to their environmental impacts that constrain ecosystem services and decrease + biodiversity and ecosystem resilience to climate change or by causing adverse + outcomes for different groups, exacerbating inequity. Maladaptation can be avoided + by flexible, multi-sectoral, inclusive and long-term planning and implementation + of adaptation actions with benefits to many sectors and systems. Sea level rise + poses a distinctive and severe adaptation challenge as it implies both dealing + with slow onset changes and increases in the frequency and magnitude of extreme + sea level events . Such adaptation challenges would occur much earlier under high + rates of sea level rise. Responses to ongoing sea level rise and land subsidence + include protection, accommodation, advance and planned relocation. These responses + are more effective if combined and/or sequenced, planned well ahead, aligned with + sociocultural values and underpinned by inclusive community engagement processes. + Ecosystem-based solutions such as wetlands provide co-benefits for the environment + and climate mitigation, and reduce costs for flood defences , but have site-specific + physical limits, at least above 1.5ºC of global warming and lose effectiveness + at high rates of sea level rise beyond 0.5 to 1 cm yr -1. Seawalls can be maladaptive + as they effectively reduce impacts in the short term but can also result in lock-ins + and increase exposure to climate risks in the long term unless they are integrated + into a long-term adaptive plan. + - Remaining Carbon Budgets Limiting global temperature increase to a specific level + requires limiting cumulative net CO2 emissions to within a finite carbon budget + , along with strong reductions in other GHGs. For every 1000 GtCO2 emitted by + human activity, global mean temperature rises by likely 0.27°C to 0.63°C. This + relationship implies that there is a finite carbon budget that cannot be exceeded + in order to limit warming to any given level. The best estimates of the remaining + carbon budget from the beginning of 2020 for limiting warming to 1.5°C with a + 50% likelihood is estimated to be 500 GtCO2; for 2°C this is 1150 GtCO2.128 Remaining + carbon budgets have been quantified based on the assessed value of TCRE and its + uncertainty, estimates of historical warming, climate system feedbacks such as + emissions from thawing permafrost, and the global surface temperature change after + global anthropogenic CO 2 emissions reach net zero, as well as variations in projected + warming from non-CO2 emissions due in part to mitigation action. The stronger + the reductions in non-CO2 emissions the lower the resulting temperatures are for + a given RCB or the larger RCB for the same level of temperature change. For instance, + the RCB for limiting warming to 1.5°C with a 50% likelihood could vary between + 300 to 600 GtCO 2 depending on non-CO 2 warming 129 . Limiting warming to 2°C + with a 67% likelihood would imply a RCB of 1150 GtCO2 from the beginning of 2020. + To stay below 2°C with a 50% likelihood, the RCB is higher, i.e., 1350 GtCO 2 + If the annual CO2 emissions between 2020–2030 stayed, on average, at the same + level as 2019, the resulting cumulative emissions would almost exhaust the remaining + carbon budget for 1.5°C, and exhaust more than a third of the remaining carbon + budget for 2°C . Based on central estimates only, historical cumulative net CO2 + emissions between 1850 and 2019 amount to about four-fifths of the total carbon + budget for a 50% probability of limiting global warming to 1.5°C and to about + two-thirds of the total carbon budget for a 67% probability to limit global warming + to 2°C. In scenarios with increasing CO 2 emissions, the land and ocean carbon + sinks are projected to be less effective at slowing the accumulation of CO2 in + the atmosphere. While natural land and ocean carbon sinks are projected to take + up, in absolute terms, a progressively larger amount of CO 2 under higher compared + to lower CO2 emissions scenarios, they become less effective, that is, the proportion + of emissions taken up by land and ocean decreases with increasing cumulative net + CO2 emissions. Additional ecosystem responses to warming not yet fully included + in climate models, such as GHG fluxes from wetlands, permafrost thaw, and wildfires, + would further increase concentrations of these gases in the atmosphere . In scenarios + where CO2 concentrations peak and decline during the 21st century, the land and + ocean begin to take up less carbon in response to declining atmospheric CO2 concentrations and + turn into a weak net source by 2100 in the very low GHG emissions scenario 133. + - 'Sectoral Contributions to Mitigation All global modelled pathways that limit + warming to 2°C or lower by 2100 involve rapid and deep and in most cases immediate + GHG emissions reductions in all sectors. Reductions in GHG emissions in industry, + transport, buildings, and urban areas can be achieved through a combination of + energy efficiency and conservation and a transition to low-GHG technologies and + energy carriers. Socio-cultural options and behavioural change can reduce global + GHG emissions of end-use sectors, with most of the potential in developed countries, + if combined with improved infrastructure design and access. Global modelled mitigation + pathways reaching net zero CO2 and GHG emissions include transitioning from fossil + fuels without carbon capture and storage to very low- or zero-carbon energy sources, + such as renewables or fossil fuels with CCS, demand-side measures and improving + efficiency, reducing non-CO2 GHG emissions, and CDR 136. In global modelled pathways + that limit warming to 2°C or below, almost all electricity is supplied from zero + or low-carbon sources in 2050, such as renewables or fossil fuels with CO2 capture + and storage, combined with increased electrification of energy demand. Such pathways + meet energy service demand with relatively low energy use, through e.g., enhanced + energy efficiency and behavioural changes and increased electrification of energy + end use. Modelled global pathways limiting global warming to 1.5°C with no or + limited overshoot generally implement such changes faster than pathways limiting + global warming to 2°C. AFOLU mitigation options, when sustainably implemented, + can deliver large-scale GHG emission reductions and enhanced CO2 removal; however, + barriers to implementation and trade-offs may result from the impacts of climate + change, competing demands on land, conflicts with food security and livelihoods, + the complexity of land ownership and management systems, and cultural aspects. + All assessed modelled pathways that limit warming to 2°C or lower by 2100 include + land-based mitigation and land-use change, with most including different combinations + of reforestation, afforestation, reduced deforestation, and bioenergy. However, + accumulated carbon in vegetation and soils is at risk from future loss triggered + by climate change and disturbances such as flood, drought, fire, or pest outbreaks, + or future poor management. In addition to deep, rapid, and sustained emission + reductions, CDR can fulfil three complementary roles: lowering net CO2 or net + GHG emissions in the near term; counterbalancing ‘hard-to-abate’ residual emissions to + help reach net zero CO2 or GHG emissions, and achieving net negative CO 2 or GHG + emissions if deployed at levels exceeding annual residual emissions. CDR methods + vary in terms of their maturity, removal process, time scale of carbon storage, + storage medium, mitigation potential, cost, co-benefits, impacts and risks, and + governance requirements. Specifically, maturity ranges from lower maturity to + higher maturity; removal and storage potential ranges from lower potential to + higher potential; costs range from lower cost to higher cost . Estimated storage + timescales vary from decades to centuries for methods that store carbon in vegetation + and through soil carbon management, to ten thousand years or more for methods + that store carbon in geological formations . Afforestation, reforestation, improved + forest management, agroforestry and soil carbon sequestration are currently the + only widely practiced CDR methods. Methods and levels of CDR deployment in global + modelled mitigation pathways vary depending on assumptions about costs, availability + and constraints.' + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - 'Near-Term Risks Many changes in the climate system, including extreme events, + will become larger in the near term with increasing global warming. Multiple climatic + and non-climatic risks will interact, resulting in increased compounding and cascading + impacts becoming more difficult to manage. Losses and damages will increase with + increasing global warming, while strongly concentrated among the poorest vulnerable + populations. Continuing with current unsustainable development patterns would + increase exposure and vulnerability of ecosystems and people to climate hazards. + Global warming will continue to increase in the near term mainly due to increased + cumulative CO 2 emissions in nearly all considered scenarios and pathways. In + the near term, every region in the world is projected to face further increases + in climate hazards , increasing multiple risks to ecosystems and humans. In the + near term, natural variability will modulate human-caused changes, either attenuating + or amplifying projected changes, especially at regional scales, with little effect + on centennial global warming. Those modulations are important to consider in adaptation + planning. Global surface temperature in any single year can vary above or below + the long-term human-induced trend, due to natural variability. By 2030, global + surface temperature in any individual year could exceed 1.5°C relative to 1850–1900 + with a probability between 40% and 60%, across the five scenarios assessed in + WGI. The occurrence of individual years with global surface temperature change + above a certain level does not imply that this global warming level has been reached. + If a large explosive volcanic eruption were to occur in the near term 150, it + would temporarily and partially mask human-caused climate change by reducing global + surface temperature and precipitation, especially over land, for one to three + years. The level of risk for humans and ecosystems will depend on near-term trends + in vulnerability, exposure, level of socio-economic development and adaptation. + In the near term, many climate-associated risks to natural and human systems depend + more strongly on changes in these systems’ vulnerability and exposure than on + differences in climate hazards between emissions scenarios . Future exposure to + climatic hazards is increasing globally due to socio-economic development trends + including growing inequality, and when urbanisation or migration increase exposure + . Urbanisation increases hot extremes and precipitation runoff intensity. Increasing + urbanisation in low-lying and coastal zones will be a major driver of increasing + exposure to extreme riverflow events and sea level rise hazards, increasing risks. + Vulnerability will also rise rapidly in low-lying Small Island Developing States + and atolls in the context of sea level rise . Human vulnerability will concentrate + in informal settlements and rapidly growing smaller settlements; and vulnerability + in rural areas will be heightened by reduced habitability and high reliance on + climate-sensitive livelihoods. Human and ecosystem vulnerability are interdependent. + Vulnerability to climate change for ecosystems will be strongly influenced by + past, present, and future patterns of human development, including from unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Several near-term risks can be moderated + with adaptation. Principal hazards and associated risks expected in the near + term are: • Increased intensity and frequency of hot extremes and dangerous heat-humidity + conditions, with increased human mortality, morbidity, and labour productivity + loss. • Increasing frequency of marine heatwaves will increase risks of biodiversity + loss in the oceans, including from mass mortality events. • Near-term risks for + biodiversity loss are moderate to high in forest ecosystems and kelp and seagrass + ecosystems and are high to very high in Arctic sea-ice and terrestrial ecosystems + and warm-water coral reefs. • More intense and frequent extreme rainfall and + associated flooding in many regions including coastal and other low-lying cities + , and increased proportion of and peak wind speeds of intense tropical cyclones. • + High risks from dryland water scarcity, wildfire damage, and permafrost degradation. • + Continued sea level rise and increased frequency and magnitude of extreme sea + level events encroaching on coastal human settlements and damaging coastal infrastructure + , committing low-lying coastal ecosystems to submergence and loss, expanding land + salinization, with cascading to risks to livelihoods, health, well-being, cultural + values, food and water security. • Climate change will significantly increase + ill health and premature deaths from the near to long term. Further warming will + increase climate-sensitive food-borne, water-borne, and vector-borne disease risks, + and mental health challenges including anxiety and stress. Cryosphere-related + changes in floods, landslides, and water availability have the potential to lead + to severe consequences for people, infrastructure and the economy in most mountain + regions . • The projected increase in frequency and intensity of heavy precipitation + will increase rain-generated local flooding. Multiple climate change risks will + increasingly compound and cascade in the near term. Many regions are projected + to experience an increase in the probability of compound events with higher global + warming including concurrent heatwaves and drought. Risks to health and food production + will be made more severe from the interaction of sudden food production losses + from heat and drought, exacerbated by heatinduced labour productivity losses. + These interacting impacts will increase food prices, reduce household incomes, + and lead to health risks of malnutrition and climate-related mortality with no + or low levels of adaptation, especially in tropical regions . Concurrent and cascading + risks from climate change to food systems, human settlements, infrastructure and + health will make these risks more severe and more difficult to manage, including + when interacting with non-climatic risk drivers such as competition for land between + urban expansion and food production, and pandemics . Loss of ecosystems and their + services has cascading and long-term impacts on people globally, especially for + Indigenous Peoples and local communities who are directly dependent on ecosystems, + to meet basic needs. Increasing transboundary risks are projected across the food, + energy and water sectors as impacts from weather and climate extremes propagate + through supply-chains, markets, and natural resource flows and may interact with + impacts from other crises such as pandemics. Risks also arise from some responses + intended to reduce the risks of climate change, including risks from maladaptation + and adverse side effects of some emissions reduction and carbon dioxide removal + measures, such as afforestation of naturally unforested land or poorly implemented + bioenergy compounding climate-related risks to biodiversity, food and water security, + and livelihoods. With every increment of global warming losses and damages will + increase, become increasingly difficult to avoid and be strongly concentrated + among the poorest vulnerable populations. Adaptation does not prevent all losses + and damages, even with effective adaptation and before reaching soft and hard + limits. Losses and damages will be unequally distributed across systems, regions + and sectors and are not comprehensively addressed by current financial, governance + and institutional arrangements, particularly in vulnerable developing countries. + .' + C.2.3: + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - Land, Ocean, Food, and Water There is substantial mitigation and adaptation potential + from options in agriculture, forestry and other land use, and in the oceans, that + could be upscaled in the near term across most regions. Conservation, improved + management, and restoration of forests and other ecosystems offer the largest + share of economic mitigation potential, with reduced deforestation in tropical + regions having the highest total mitigation potential. Ecosystem restoration, + reforestation, and afforestation can lead to trade-offs due to competing demands + on land. Minimizing trade-offs requires integrated approaches to meet multiple + objectives including food security. Demand-side measures and sustainable agricultural + intensification can reduce ecosystem conversion and CH4 and N2 O emissions, and + free up land for reforestation and ecosystem restoration. Sustainably sourced + agriculture and forest products, including long-lived wood products, can be used + instead of more GHG-intensive products in other sectors. Effective adaptation + options include cultivar improvements, agroforestry, community-based adaptation, + farm and landscape diversification, and urban agriculture. These AFOLU response + options require integration of biophysical, socioeconomic and other enabling factors. + The effectiveness of ecosystem-based adaptation and most water-related adaptation + options declines with increasing warming. Some options, such as conservation + of high-carbon ecosystems , have immediate impacts while others, such as restoration + of high-carbon ecosystems, reclamation of degraded soils or afforestation, take + decades to deliver measurable results. Many sustainable land management technologies + and practices are financially profitable in three to ten years. Maintaining the + resilience of biodiversity and ecosystem services at a global scale depends on + effective and equitable conservation of approximately 30–50% of Earth’s land, + freshwater and ocean areas, including currently near-natural ecosystems. The services + and options provided by terrestrial, freshwater, coastal and ocean ecosystems + can be supported by protection, restoration, precautionary ecosystem-based management + of renewable resource use, and the reduction of pollution and other stressors. Large-scale + land conversion for bioenergy, biochar, or afforestation can increase risks to + biodiversity, water and food security. In contrast, restoring natural forests + and drained peatlands, and improving sustainability of managed forests enhances + the resilience of carbon stocks and sinks and reduces ecosystem vulnerability + to climate change. Cooperation, and inclusive decision making, with local communities + and Indigenous Peoples, as well as recognition of inherent rights of Indigenous + Peoples, is integral to successful adaptation across forests and other ecosystems. Natural + rivers, wetlands and upstream forests reduce flood risk in most circumstances. + Enhancing natural water retention such as by restoring wetlands and rivers, land + use planning such as no build zones or upstream forest management, can further + reduce flood risk . For inland flooding, combinations of non-structural measures + like early warning systems and structural measures like levees have reduced loss + of lives, but hard defences against flooding or sea level rise can also be maladaptive + . Protection and restoration of coastal ‘blue carbon’ ecosystems could reduce + emissions and/or increase carbon uptake and storage . Coastal wetlands protect + against coastal erosion and flooding. Strengthening precautionary approaches, + such as rebuilding overexploited or depleted fisheries, and responsiveness of + existing fisheries management strategies reduces negative climate change impacts + on fisheries, with benefits for regional economies and livelihoods. Ecosystem-based + management in fisheries and aquaculture supports food security, biodiversity, + human health and well-being. + - Health and Nutrition Human health will benefit from integrated mitigation and + adaptation options that mainstream health into food, infrastructure, social protection, + and water policies . Balanced and sustainable healthy diets and reduced food loss + and waste present important opportunities for adaptation and mitigation while + generating significant co-benefits in terms of biodiversity and human health. + Public health policies to improve nutrition, such as increasing the diversity + of food sources in public procurement, health insurance, financial incentives, + and awareness-raising campaigns, can potentially influence food demand, reduce + food waste, reduce healthcare costs, contribute to lower GHG emissions and enhance + adaptive capacity. Improved access to clean energy sources and technologies, and + shifts to active mobility and public transport can deliver socioeconomic, air + quality and health benefits, especially for women and children. Effective adaptation + options exist to help protect human health and well-being. Health Action Plans + that include early warning and response systems are effective for extreme heat + . Effective options for water-borne and food-borne diseases include improving + access to potable water, reducing exposure of water and sanitation systems to + flooding and extreme weather events, and improved early warning systems. For vector-borne + diseases, effective adaptation options include surveillance, early warning systems, + and vaccine development. Effective adaptation options for reducing mental health + risks under climate change include improving surveillance and access to mental + health care, and monitoring of psychosocial impacts from extreme weather events. + A key pathway to climate resilience in the health sector is universal access to + healthcare. + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals Mitigation + and adaptation actions have more synergies than trade-offs with Sustainable Development + Goals . Synergies and trade-offs depend on context and scale of implementation. + Potential trade-offs can be compensated or avoided with additional policies, investments + and financial partnerships. Many mitigation and adaptation actions have multiple + synergies with Sustainable Development Goals, but some actions can also have trade-offs. + Potential synergies with SDGs exceed potential trade-offs. Synergies and trade-offs + are context specific and depend on: means and scale of implementation, intra- + and inter-sectoral interactions, cooperation between countries and regions, the + sequencing, timing and stringency of actions, governance, and policy design. Eradicating + extreme poverty, energy poverty, and providing decent living standards to all, + consistent with nearterm sustainable development objectives, can be achieved without + significant global emissions growth. Several mitigation and adaptation options + can harness nearterm synergies and reduce trade-offs to advance sustainable development + in energy, urban and land systems . Clean energy supply systems have multiple + co-benefits, including improvements in air quality and health. Heat Health Action + Plans that include early warning and response systems, approaches that mainstream + health into food, livelihoods, social protection, water and sanitation benefit + health and wellbeing. There are potential synergies between multiple Sustainable + Development Goals and sustainable land use and urban planning with more green + spaces, reduced air pollution, and demand-side mitigation including shifts to + balanced, sustainable healthy diets. Electrification combined with low-GHG energy, + and shifts to public transport can enhance health, employment, and can contribute + to energy security and deliver equity. Conservation, protection and restoration + of terrestrial, freshwater, coastal and ocean ecosystems, together with targeted + management to adapt to unavoidable impacts of climate change can generate multiple + additional benefits, such as agricultural productivity, food security, and biodiversity + conservation. When implementing mitigation and adaptation together, and taking + trade-offs into account, multiple co-benefits and synergies for human well-being + as well as ecosystem and planetary health can be realised. There is a strong link + between sustainable development, vulnerability and climate risks. Social safety + nets that support climate change adaptation have strong co-benefits with development + goals such as education, poverty alleviation, gender inclusion and food security. + Land restoration contributes to mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Trade-offs can be evaluated and minimised + by giving emphasis to capacity building, finance, technology transfer, investments; + governance, development, context specific gender-based and other social equity + considerations with meaningful participation of Indigenous Peoples, local communities + and vulnerable populations. . Context relevant design and implementation requires + considering people’s needs, biodiversity, and other sustainable development dimensions. + Countries at all stages of economic development seek to improve the well-being + of people, and their development priorities reflect different starting points + and contexts. Different contexts include but are not limited to social, economic, + environmental, cultural, or political circumstances, resource endowment, capabilities, + international environment, and prior development. n regions with high dependency + on fossil fuels for, among other things, revenue and employment generation, mitigating + risks for sustainable development requires policies that promote economic and + energy sector diversification and considerations of just transitions principles, + processes and practices. For individuals and households in low-lying coastal areas, + in Small Islands, and smallholder farmers transitioning from incremental to transformational + adaptation can help overcome soft adaptation limits. Effective governance is needed + to limit trade-offs of some mitigation options such as large scale afforestation + and bioenergy options due to risks from their deployment for food systems, biodiversity, + other ecosystem functions and services, and livelihoods. Effective governance + requires adequate institutional capacity at all levels .' + C.2.4: + - Synergies and trade-offs, costs and benefits Mitigation and adaptation options + can lead to synergies and trade-offs with other aspects of sustainable development + . Synergies and trade-offs depend on the pace and magnitude of changes and the + development context including inequalities, with consideration of climate justice. + The potential or effectiveness of some adaptation and mitigation options decreases + as climate change intensifies . In the energy sector, transitions to low-emission + systems will have multiple co-benefits, including improvements in air quality + and health. There are potential synergies between sustainable development and, + for instance, energy efficiency and renewable energy. For agriculture, land, + and food systems, many land management options and demand-side response options can + contribute to eradicating poverty and eliminating hunger while promoting good + health and well-being, clean water and sanitation, and life on land . In contrast, + certain adaptation options that promote intensification of production, such as + irrigation, may have negative effects on sustainability . Reforestation, improved + forest management, soil carbon sequestration, peatland restoration and coastal + blue carbon management are examples of CDR methods that can enhance biodiversity + and ecosystem functions, employment and local livelihoods, depending on context + . However, afforestation or production of biomass crops for bioenergy with carbon + dioxide capture and storage or biochar can have adverse socio-economic and environmental + impacts, including on biodiversity, food and water security, local livelihoods + and the rights of Indigenous Peoples, especially if implemented at large scales + and where land tenure is insecure. Modelled pathways that assume using resources + more efficiently or shift global development towards sustainability include fewer + challenges, such as dependence on CDR and pressure on land and biodiversity, and + have the most pronounced synergies with respect to sustainable development . Strengthening + climate change mitigation action entails more rapid transitions and higher up-front + investments, but brings benefits from avoiding damages from climate change and + reduced adaptation costs. The aggregate effects of climate change mitigation on + global GDP are small compared to global projected GDP growth. Projected estimates + of global aggregate net economic damages and the costs of adaptation generally + increase with global warming level. Cost-benefit analysis remains limited in + its ability to represent all damages from climate change, including non-monetary + damages, or to capture the heterogeneous nature of damages and the risk of catastrophic + damages. Even without accounting for these factors or for the co-benefits of mitigation, + the global benefits of limiting warming to 2°C exceed the cost of mitigation . + This finding is robust against a wide range of assumptions about social preferences + on inequalities and discounting over time . Limiting global warming to 1.5°C instead + of 2°C would increase the costs of mitigation, but also increase the benefits + in terms of reduced impacts and related risks and reduced adaptation needs 140. Considering + other sustainable development dimensions, such as the potentially strong economic + benefits on human health from air quality improvement, may enhance the estimated + benefits of mitigation . The economic effects of strengthened mitigation action + vary across regions and countries, depending notably on economic structure, regional + emissions reductions, policy design and level of international cooperation. Ambitious + mitigation pathways imply large and sometimes disruptive changes in economic structure, + with implications for near-term actions, equity , sustainability, and finance + . + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + C.2.5: + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + - Finance for Mitigation and Adaptation Actions Improved availability and access + to finance will enable accelerated climate action. Addressing needs and gaps and + broadening equitable access to domestic and international finance, when combined + with other supportive actions, can act as a catalyst for accelerating mitigation + and shifting development pathways. Climate resilient development is enabled by + increased international cooperation including improved access to financial resources, + particularly for vulnerable regions, sectors and groups, and inclusive governance + and coordinated policies . Accelerated international financial cooperation is + a critical enabler of low-GHG and just transitions, and can address inequities + in access to finance and the costs of, and vulnerability to, the impacts of climate + change. Both adaptation and mitigation finance need to increase many-fold, to + address rising climate risks and to accelerate investments in emissions reduction. + Increased finance would address soft limits to adaptation and rising climate risks + while also averting some related losses and damages, particularly in vulnerable + developing countries. Enhanced mobilisation of and access to finance, together + with building capacity, are essential for implementation of adaptation actions + and to reduce adaptation gaps given rising risks and costs, especially for the + most vulnerable groups, regions and sectors . Public finance is an important enabler + of adaptation and mitigation, and can also leverage private finance. Adaptation + funding predominately comes from public sources, and public mechanisms and finance + can leverage private sector finance by addressing real and perceived regulatory, + cost and market barriers, for instance via public-private partnerships. Financial + and technological resources enable effective and ongoing implementation of adaptation, + especially when supported by institutions with a strong understanding of adaptation + needs and capacity. Average annual modelled mitigation investment requirements + for 2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a factor + of three to six greater than current levels, and total mitigation investments + would need to increase across all sectors and regions. Even if extensive global + mitigation efforts are implemented, there will be a large need for financial, + technical, and human resources for adaptation . + C.3.1: + - 'The Timing and Urgency of Climate Action The magnitude and rate of climate change + and associated risks depend strongly on near-term mitigation and adaptation actions + . Global warming is more likely than not to reach 1.5°C between 2021 and 2040 + even under the very low GHG emission scenarios, and likely or very likely to exceed + 1.5°C under higher emissions scenarios 141. Many adaptation options have medium + or high feasibility up to 1.5°C , but hard limits to adaptation have already been + reached in some ecosystems and the effectiveness of adaptation to reduce climate + risk will decrease with increasing warming. Societal choices and actions implemented + in this decade determine the extent to which medium- and long-term pathways will + deliver higher or lower climate resilient development. Climate resilient development + prospects are increasingly limited if current greenhouse gas emissions do not + rapidly decline, especially if 1.5°C global warming is exceeded in the near term. + Without urgent, effective and equitable adaptation and mitigation actions, climate + change increasingly threatens the health and livelihoods of people around the + globe, ecosystem health, and biodiversity, with severe adverse consequences for + current and future generations. . In modelled pathways that limit warming to + 1.5°C with no or limited overshoot and in those that limit warming to 2°C, assuming + immediate actions, global GHG emissions are projected to peak in the early 2020s + followed by rapid and deep GHG emissions reductions 142 . In pathways that limit + warming to 1.5°C with no or limited overshoot, net global GHG emissions are projected + to fall by 43 [34 to 60]%143 below 2019 levels by 2030, 60 [49 to 77]% by 2035, + 69 [58 to 90]% by 2040 and 84 [73 to 98]% by 2050 144. Global modelled pathways + that limit warming to 2°C have reductions in GHG emissions below 2019 levels of + 21 [1 to 42]% by 2030, 35 [22 to 55] % by 2035, 46 [34 to 63] % by 2040 and 64 + [53 to 77]% by 2050145. Global GHG emissions associated with NDCs announced prior + to COP26 would make it likely that warming would exceed 1.5°C and limiting warming + to 2°C would then imply a rapid acceleration of emission reductions during 2030–2050, + around 70% faster than in pathways where immediate action is taken to limit warming + to 2°C Continued investments in unabated high-emitting infrastructure and limited + development and deployment of low-emitting alternatives prior to 2030 would act + as barriers to this acceleration and increase feasibility risks. All global modelled + pathways that limit warming to 2°C or lower by 2100 involve reductions in both + net CO 2 emissions and non-CO 2 emissions. For example, in pathways that limit + warming to 1.5°C with no or limited overshoot, global CH4 emissions are reduced + by 34 [21 to 57]% below 2019 levels by 2030 and by 44 [31 to 63]% in 2040. Global + CH 4 emissions are reduced by 24 [9 to 53]% below 2019 levels by 2030 and by 37 + [20 to 60]% in 2040 in modelled pathways that limit warming to 2°C with action + starting in 2020. All global modelled pathways that limit warming to 2°C or lower + by 2100 involve GHG emission reductions in all sectors . The contributions of + different sectors vary across modelled mitigation pathways. In most global modelled + mitigation pathways, emissions from land-use, land-use change and forestry, via + reforestation and reduced deforestation, and from the energy supply sector reach + net zero CO2 emissions earlier than the buildings, industry and transport sectors. + Strategies can rely on combinations of different options, but doing less in one + sector needs to be compensated by further reductions in other sectors if warming + is to be limited. Without rapid, deep and sustained mitigation and accelerated + adaptation actions, losses and damages will continue to increase, including projected + adverse impacts in Africa, LDCs, SIDS, Central and South America , Asia and the + Arctic, and will disproportionately affect the most vulnerable populations . ' + - 'Energy Systems Rapid and deep reductions in GHG emissions require major energy + system transitions. Adaptation options can help reduce climate-related risks to + the energy system . Net zero CO2 energy systems entail: a substantial reduction + in overall fossil fuel use, minimal use of unabated fossil fuels 153, and use + of Carbon Capture and Storage in the remaining fossil fuel systems; electricity + systems that emit no net CO 2; widespread electrification; alternative energy + carriers in applications less amenable to electrification; energy conservation + and efficiency; and greater integration across the energy system . Large contributions + to emissions reductions can come from options costing less than USD 20 tCO 2 -eq + –1, including solar and wind energy, energy efficiency improvements, and CH4 emissions + reductions . 154 Many of these response options are technically viable and are + supported by the public. Maintaining emission-intensive systems may, in some regions + and sectors, be more expensive than transitioning to low emission systems. Climate + change and related extreme events will affect future energy systems, including + hydropower production, bioenergy yields, thermal power plant efficiencies, and + demands for heating and cooling . The most feasible energy system adaptation options + support infrastructure resilience, reliable power systems and efficient water + use for existing and new energy generation systems . Adaptations for hydropower + and thermo-electric power generation are effective in most regions up to 1.5°C + to 2°C, with decreasing effectiveness at higher levels of warming . Energy generation + diversification and demand side management can increase energy reliability and + reduce vulnerabilities to climate change, especially in rural populations . Climate + responsive energy markets, updated design standards on energy assets according + to current and projected climate change, smart-grid technologies, robust transmission + systems and improved capacity to respond to supply deficits have high feasibility + in the medium- to long-term, with mitigation co-benefits .' + - Society, Livelihoods, and Economies Enhancing knowledge on risks and available + adaptation options promotes societal responses, and behaviour and lifestyle changes + supported by policies, infrastructure and technology can help reduce global GHG + emissions. Climate literacy and information provided through climate services + and community approaches, including those that are informed by Indigenous Knowledge + and local knowledge, can accelerate behavioural changes and planning . Educational + and information programmes, using the arts, participatory modelling and citizen + science can facilitate awareness, heighten risk perception, and influence behaviours + . The way choices are presented can enable adoption of low GHG intensive socio-cultural + options, such as shifts to balanced, sustainable healthy diets, reduced food waste, + and active mobility. Judicious labelling, framing, and communication of social + norms can increase the effect of mandates, subsidies, or taxes. A range of adaptation + options, such as disaster risk management, early warning systems, climate services + and risk spreading and sharing approaches, have broad applicability across sectors + and provide greater risk reduction benefits when combined . Climate services that + are demand-driven and inclusive of different users and providers can improve agricultural + practices, inform better water use and efficiency, and enable resilient infrastructure + planning. Policy mixes that include weather and health insurance, social protection + and adaptive safety nets, contingent finance and reserve funds, and universal + access to early warning systems combined with effective contingency plans, can + reduce vulnerability and exposure of human systems. Integrating climate adaptation + into social protection programs, including cash transfers and public works programs, + is highly feasible and increases resilience to climate change, especially when + supported by basic services and infrastructure. Social safety nets can build adaptive + capacities, reduce socioeconomic vulnerability, and reduce risk linked to hazards. Reducing + future risks of involuntary migration and displacement due to climate change is + possible through cooperative, international efforts to enhance institutional adaptive + capacity and sustainable development. Increasing adaptive capacity minimises risk + associated with involuntary migration and immobility and improves the degree of + choice under which migration decisions are made, while policy interventions can + remove barriers and expand the alternatives for safe, orderly and regular migration + that allows vulnerable people to adapt to climate change. Accelerating commitment + and follow-through by the private sector is promoted for instance by building + business cases for adaptation, accountability and transparency mechanisms, and + monitoring and evaluation of adaptation progress . Integrated pathways for managing + climate risks will be most suitable when so-called ‘low-regret’ anticipatory options + are established jointly across sectors in a timely manner and are feasible and + effective in their local context, and when path dependencies and maladaptations + across sectors are avoided. Sustained adaptation actions are strengthened by mainstreaming + adaptation into institutional budget and policy planning cycles, statutory planning, + monitoring and evaluation frameworks and into recovery efforts from disaster events. + Instruments that incorporate adaptation such as policy and legal frameworks, behavioural + incentives, and economic instruments that address market failures, such as climate + risk disclosure, inclusive and deliberative processes strengthen adaptation actions + by public and private actors. + - Industry There are several options to reduce industrial emissions that differ + by type of industry; many industries are disrupted by climate change, especially + from extreme events . Reducing industry emissions will entail coordinated action + throughout value chains to promote all mitigation options, including demand management, + energy and materials efficiency, circular material flows, as well as abatement + technologies and transformational changes in production processes. Light industry + and manufacturing can be largely decarbonized through available abatement technologies, + electrification, and switching to low- and zero-GHG emitting fuels , while deep + reduction of cement process emissions will rely on cementitious material substitution + and the availability of Carbon Capture and Storage until new chemistries are mastered. + Reducing emissions from the production and use of chemicals would need to rely + on a life cycle approach, including increased plastics recycling, fuel and feedstock + switching, and carbon sourced through biogenic sources, and, depending on availability, + Carbon Capture and Utilisation, direct air CO2 capture, as well as CCS. Action + to reduce industry sector emissions may change the location of GHG-intensive industries + and the organisation of value chains, with distributional effects on employment + and economic structure. Many industrial and service sectors are negatively affected + by climate change through supply and operational disruptions, especially from + extreme events, and will require adaptation efforts. Water intensive industries + can undertake measures to reduce water stress, such as water recycling and reuse, + using brackish or saline sources, working to improve water use efficiency. However, + residual risks will remain, especially at higher levels of warming . + - 'Cities, Settlements and Infrastructure Urban systems are critical for achieving + deep emissions reductions and advancing climate resilient development, particularly + when this involves integrated planning that incorporates physical, natural and + social infrastructure . Deep emissions reductions and integrated adaptation actions + are advanced by: integrated, inclusive land use planning and decision-making; + compact urban form by co-locating jobs and housing; reducing or changing urban + energy and material consumption; electrification in combination with low emissions + sources; improved water and waste management infrastructure; and enhancing carbon + uptake and storage in the urban environment . Cities can achieve net zero emissions + if emissions are reduced within and outside of their administrative boundaries + through supply chains, creating beneficial cascading effects across other sectors. Considering + climate change impacts and risks in the design and planning of urban and rural + settlements and infrastructure is critical for resilience and enhancing human + well-being. Effective mitigation can be advanced at each of the design, construction, + retrofit, use and disposal stages for buildings. Mitigation interventions for + buildings include: at the construction phase, lowemission construction materials, + highly efficient building envelope and the integration of renewable energy solutions; + at the use phase, highly efficient appliances/equipment, the optimisation of the + use of buildings and their supply with low-emission energy sources; and at the + disposal phase, recycling and re-using construction materials. Sufficiency 155 + measures can limit the demand for energy and materials over the lifecycle of buildings + and appliances. Transport-related GHG emissions can be reduced by demand-side + options and low-GHG emissions technologies. Changes in urban form, reallocation + of street space for cycling and walking, digitalisation and programs that encourage + changes in consumer behaviour can reduce demand for transport services and support + the shift to more energy efficient transport modes. Electric vehicles powered + by low-emissions electricity offer the largest decarbonisation potential for land-based + transport, on a life cycle basis. Costs of electrified vehicles are decreasing + and their adoption is accelerating, but they require continued investments in + supporting infrastructure to increase scale of deployment. The environmental footprint + of battery production and growing concerns about critical minerals can be addressed + by material and supply diversification strategies, energy and material efficiency + improvements, and circular material flows . Advances in battery technologies could + facilitate the electrification of heavy-duty trucks and compliment conventional + electric rail systems. Sustainable biofuels can offer additional mitigation benefits + in land-based transport in the short and medium term. Sustainable biofuels, low-emissions + hydrogen, and derivatives can support mitigation of CO2 emissions from shipping, + aviation, and heavy-duty land transport but require production process improvements + and cost reductions. Key infrastructure systems including sanitation, water, health, + transport, communications and energy will be increasingly vulnerable if design + standards do not account for changing climate conditions. Green/natural and blue + infrastructure such as urban forestry, green roofs, ponds and lakes, and river + restoration can mitigate climate change through carbon uptake and storage, avoided + emissions, and reduced energy use while reducing risk from extreme events such + as heatwaves, heavy precipitation and droughts, and advancing co-benefits for + health, well-being and livelihoods. Urban greening can provide local cooling. + Combining green/natural and grey/physical infrastructure adaptation responses + has potential to reduce adaptation costs and contribute to flood control, sanitation, + water resources management, landslide prevention and coastal protection. Globally, + more financing is directed at grey/physical infrastructure than green/natural + infrastructure and social infrastructure, and there is limited evidence of investment + in informal settlements . The greatest gains in well-being in urban areas can + be achieved by prioritising finance to reduce climate risk for low-income and + marginalised communities including people living in informal settlements. Responses + to ongoing sea level rise and land subsidence in low-lying coastal cities and + settlements and small islands include protection, accommodation, advance and planned + relocation. These responses are more effective if combined and/or sequenced, planned + well ahead, aligned with sociocultural values and development priorities, and + underpinned by inclusive community engagement processes. ' + - Land, Ocean, Food, and Water There is substantial mitigation and adaptation potential + from options in agriculture, forestry and other land use, and in the oceans, that + could be upscaled in the near term across most regions. Conservation, improved + management, and restoration of forests and other ecosystems offer the largest + share of economic mitigation potential, with reduced deforestation in tropical + regions having the highest total mitigation potential. Ecosystem restoration, + reforestation, and afforestation can lead to trade-offs due to competing demands + on land. Minimizing trade-offs requires integrated approaches to meet multiple + objectives including food security. Demand-side measures and sustainable agricultural + intensification can reduce ecosystem conversion and CH4 and N2 O emissions, and + free up land for reforestation and ecosystem restoration. Sustainably sourced + agriculture and forest products, including long-lived wood products, can be used + instead of more GHG-intensive products in other sectors. Effective adaptation + options include cultivar improvements, agroforestry, community-based adaptation, + farm and landscape diversification, and urban agriculture. These AFOLU response + options require integration of biophysical, socioeconomic and other enabling factors. + The effectiveness of ecosystem-based adaptation and most water-related adaptation + options declines with increasing warming. Some options, such as conservation + of high-carbon ecosystems , have immediate impacts while others, such as restoration + of high-carbon ecosystems, reclamation of degraded soils or afforestation, take + decades to deliver measurable results. Many sustainable land management technologies + and practices are financially profitable in three to ten years. Maintaining the + resilience of biodiversity and ecosystem services at a global scale depends on + effective and equitable conservation of approximately 30–50% of Earth’s land, + freshwater and ocean areas, including currently near-natural ecosystems. The services + and options provided by terrestrial, freshwater, coastal and ocean ecosystems + can be supported by protection, restoration, precautionary ecosystem-based management + of renewable resource use, and the reduction of pollution and other stressors. Large-scale + land conversion for bioenergy, biochar, or afforestation can increase risks to + biodiversity, water and food security. In contrast, restoring natural forests + and drained peatlands, and improving sustainability of managed forests enhances + the resilience of carbon stocks and sinks and reduces ecosystem vulnerability + to climate change. Cooperation, and inclusive decision making, with local communities + and Indigenous Peoples, as well as recognition of inherent rights of Indigenous + Peoples, is integral to successful adaptation across forests and other ecosystems. Natural + rivers, wetlands and upstream forests reduce flood risk in most circumstances. + Enhancing natural water retention such as by restoring wetlands and rivers, land + use planning such as no build zones or upstream forest management, can further + reduce flood risk . For inland flooding, combinations of non-structural measures + like early warning systems and structural measures like levees have reduced loss + of lives, but hard defences against flooding or sea level rise can also be maladaptive + . Protection and restoration of coastal ‘blue carbon’ ecosystems could reduce + emissions and/or increase carbon uptake and storage . Coastal wetlands protect + against coastal erosion and flooding. Strengthening precautionary approaches, + such as rebuilding overexploited or depleted fisheries, and responsiveness of + existing fisheries management strategies reduces negative climate change impacts + on fisheries, with benefits for regional economies and livelihoods. Ecosystem-based + management in fisheries and aquaculture supports food security, biodiversity, + human health and well-being. + - Health and Nutrition Human health will benefit from integrated mitigation and + adaptation options that mainstream health into food, infrastructure, social protection, + and water policies . Balanced and sustainable healthy diets and reduced food loss + and waste present important opportunities for adaptation and mitigation while + generating significant co-benefits in terms of biodiversity and human health. + Public health policies to improve nutrition, such as increasing the diversity + of food sources in public procurement, health insurance, financial incentives, + and awareness-raising campaigns, can potentially influence food demand, reduce + food waste, reduce healthcare costs, contribute to lower GHG emissions and enhance + adaptive capacity. Improved access to clean energy sources and technologies, and + shifts to active mobility and public transport can deliver socioeconomic, air + quality and health benefits, especially for women and children. Effective adaptation + options exist to help protect human health and well-being. Health Action Plans + that include early warning and response systems are effective for extreme heat + . Effective options for water-borne and food-borne diseases include improving + access to potable water, reducing exposure of water and sanitation systems to + flooding and extreme weather events, and improved early warning systems. For vector-borne + diseases, effective adaptation options include surveillance, early warning systems, + and vaccine development. Effective adaptation options for reducing mental health + risks under climate change include improving surveillance and access to mental + health care, and monitoring of psychosocial impacts from extreme weather events. + A key pathway to climate resilience in the health sector is universal access to + healthcare. + C.3.2: + - 'Energy Systems Rapid and deep reductions in GHG emissions require major energy + system transitions. Adaptation options can help reduce climate-related risks to + the energy system . Net zero CO2 energy systems entail: a substantial reduction + in overall fossil fuel use, minimal use of unabated fossil fuels 153, and use + of Carbon Capture and Storage in the remaining fossil fuel systems; electricity + systems that emit no net CO 2; widespread electrification; alternative energy + carriers in applications less amenable to electrification; energy conservation + and efficiency; and greater integration across the energy system . Large contributions + to emissions reductions can come from options costing less than USD 20 tCO 2 -eq + –1, including solar and wind energy, energy efficiency improvements, and CH4 emissions + reductions . 154 Many of these response options are technically viable and are + supported by the public. Maintaining emission-intensive systems may, in some regions + and sectors, be more expensive than transitioning to low emission systems. Climate + change and related extreme events will affect future energy systems, including + hydropower production, bioenergy yields, thermal power plant efficiencies, and + demands for heating and cooling . The most feasible energy system adaptation options + support infrastructure resilience, reliable power systems and efficient water + use for existing and new energy generation systems . Adaptations for hydropower + and thermo-electric power generation are effective in most regions up to 1.5°C + to 2°C, with decreasing effectiveness at higher levels of warming . Energy generation + diversification and demand side management can increase energy reliability and + reduce vulnerabilities to climate change, especially in rural populations . Climate + responsive energy markets, updated design standards on energy assets according + to current and projected climate change, smart-grid technologies, robust transmission + systems and improved capacity to respond to supply deficits have high feasibility + in the medium- to long-term, with mitigation co-benefits .' + C.3.3: + - Industry There are several options to reduce industrial emissions that differ + by type of industry; many industries are disrupted by climate change, especially + from extreme events . Reducing industry emissions will entail coordinated action + throughout value chains to promote all mitigation options, including demand management, + energy and materials efficiency, circular material flows, as well as abatement + technologies and transformational changes in production processes. Light industry + and manufacturing can be largely decarbonized through available abatement technologies, + electrification, and switching to low- and zero-GHG emitting fuels , while deep + reduction of cement process emissions will rely on cementitious material substitution + and the availability of Carbon Capture and Storage until new chemistries are mastered. + Reducing emissions from the production and use of chemicals would need to rely + on a life cycle approach, including increased plastics recycling, fuel and feedstock + switching, and carbon sourced through biogenic sources, and, depending on availability, + Carbon Capture and Utilisation, direct air CO2 capture, as well as CCS. Action + to reduce industry sector emissions may change the location of GHG-intensive industries + and the organisation of value chains, with distributional effects on employment + and economic structure. Many industrial and service sectors are negatively affected + by climate change through supply and operational disruptions, especially from + extreme events, and will require adaptation efforts. Water intensive industries + can undertake measures to reduce water stress, such as water recycling and reuse, + using brackish or saline sources, working to improve water use efficiency. However, + residual risks will remain, especially at higher levels of warming . + - 'Cities, Settlements and Infrastructure Urban systems are critical for achieving + deep emissions reductions and advancing climate resilient development, particularly + when this involves integrated planning that incorporates physical, natural and + social infrastructure . Deep emissions reductions and integrated adaptation actions + are advanced by: integrated, inclusive land use planning and decision-making; + compact urban form by co-locating jobs and housing; reducing or changing urban + energy and material consumption; electrification in combination with low emissions + sources; improved water and waste management infrastructure; and enhancing carbon + uptake and storage in the urban environment . Cities can achieve net zero emissions + if emissions are reduced within and outside of their administrative boundaries + through supply chains, creating beneficial cascading effects across other sectors. Considering + climate change impacts and risks in the design and planning of urban and rural + settlements and infrastructure is critical for resilience and enhancing human + well-being. Effective mitigation can be advanced at each of the design, construction, + retrofit, use and disposal stages for buildings. Mitigation interventions for + buildings include: at the construction phase, lowemission construction materials, + highly efficient building envelope and the integration of renewable energy solutions; + at the use phase, highly efficient appliances/equipment, the optimisation of the + use of buildings and their supply with low-emission energy sources; and at the + disposal phase, recycling and re-using construction materials. Sufficiency 155 + measures can limit the demand for energy and materials over the lifecycle of buildings + and appliances. Transport-related GHG emissions can be reduced by demand-side + options and low-GHG emissions technologies. Changes in urban form, reallocation + of street space for cycling and walking, digitalisation and programs that encourage + changes in consumer behaviour can reduce demand for transport services and support + the shift to more energy efficient transport modes. Electric vehicles powered + by low-emissions electricity offer the largest decarbonisation potential for land-based + transport, on a life cycle basis. Costs of electrified vehicles are decreasing + and their adoption is accelerating, but they require continued investments in + supporting infrastructure to increase scale of deployment. The environmental footprint + of battery production and growing concerns about critical minerals can be addressed + by material and supply diversification strategies, energy and material efficiency + improvements, and circular material flows . Advances in battery technologies could + facilitate the electrification of heavy-duty trucks and compliment conventional + electric rail systems. Sustainable biofuels can offer additional mitigation benefits + in land-based transport in the short and medium term. Sustainable biofuels, low-emissions + hydrogen, and derivatives can support mitigation of CO2 emissions from shipping, + aviation, and heavy-duty land transport but require production process improvements + and cost reductions. Key infrastructure systems including sanitation, water, health, + transport, communications and energy will be increasingly vulnerable if design + standards do not account for changing climate conditions. Green/natural and blue + infrastructure such as urban forestry, green roofs, ponds and lakes, and river + restoration can mitigate climate change through carbon uptake and storage, avoided + emissions, and reduced energy use while reducing risk from extreme events such + as heatwaves, heavy precipitation and droughts, and advancing co-benefits for + health, well-being and livelihoods. Urban greening can provide local cooling. + Combining green/natural and grey/physical infrastructure adaptation responses + has potential to reduce adaptation costs and contribute to flood control, sanitation, + water resources management, landslide prevention and coastal protection. Globally, + more financing is directed at grey/physical infrastructure than green/natural + infrastructure and social infrastructure, and there is limited evidence of investment + in informal settlements . The greatest gains in well-being in urban areas can + be achieved by prioritising finance to reduce climate risk for low-income and + marginalised communities including people living in informal settlements. Responses + to ongoing sea level rise and land subsidence in low-lying coastal cities and + settlements and small islands include protection, accommodation, advance and planned + relocation. These responses are more effective if combined and/or sequenced, planned + well ahead, aligned with sociocultural values and development priorities, and + underpinned by inclusive community engagement processes. ' + C.3.4: + - 'Cities, Settlements and Infrastructure Urban systems are critical for achieving + deep emissions reductions and advancing climate resilient development, particularly + when this involves integrated planning that incorporates physical, natural and + social infrastructure . Deep emissions reductions and integrated adaptation actions + are advanced by: integrated, inclusive land use planning and decision-making; + compact urban form by co-locating jobs and housing; reducing or changing urban + energy and material consumption; electrification in combination with low emissions + sources; improved water and waste management infrastructure; and enhancing carbon + uptake and storage in the urban environment . Cities can achieve net zero emissions + if emissions are reduced within and outside of their administrative boundaries + through supply chains, creating beneficial cascading effects across other sectors. Considering + climate change impacts and risks in the design and planning of urban and rural + settlements and infrastructure is critical for resilience and enhancing human + well-being. Effective mitigation can be advanced at each of the design, construction, + retrofit, use and disposal stages for buildings. Mitigation interventions for + buildings include: at the construction phase, lowemission construction materials, + highly efficient building envelope and the integration of renewable energy solutions; + at the use phase, highly efficient appliances/equipment, the optimisation of the + use of buildings and their supply with low-emission energy sources; and at the + disposal phase, recycling and re-using construction materials. Sufficiency 155 + measures can limit the demand for energy and materials over the lifecycle of buildings + and appliances. Transport-related GHG emissions can be reduced by demand-side + options and low-GHG emissions technologies. Changes in urban form, reallocation + of street space for cycling and walking, digitalisation and programs that encourage + changes in consumer behaviour can reduce demand for transport services and support + the shift to more energy efficient transport modes. Electric vehicles powered + by low-emissions electricity offer the largest decarbonisation potential for land-based + transport, on a life cycle basis. Costs of electrified vehicles are decreasing + and their adoption is accelerating, but they require continued investments in + supporting infrastructure to increase scale of deployment. The environmental footprint + of battery production and growing concerns about critical minerals can be addressed + by material and supply diversification strategies, energy and material efficiency + improvements, and circular material flows . Advances in battery technologies could + facilitate the electrification of heavy-duty trucks and compliment conventional + electric rail systems. Sustainable biofuels can offer additional mitigation benefits + in land-based transport in the short and medium term. Sustainable biofuels, low-emissions + hydrogen, and derivatives can support mitigation of CO2 emissions from shipping, + aviation, and heavy-duty land transport but require production process improvements + and cost reductions. Key infrastructure systems including sanitation, water, health, + transport, communications and energy will be increasingly vulnerable if design + standards do not account for changing climate conditions. Green/natural and blue + infrastructure such as urban forestry, green roofs, ponds and lakes, and river + restoration can mitigate climate change through carbon uptake and storage, avoided + emissions, and reduced energy use while reducing risk from extreme events such + as heatwaves, heavy precipitation and droughts, and advancing co-benefits for + health, well-being and livelihoods. Urban greening can provide local cooling. + Combining green/natural and grey/physical infrastructure adaptation responses + has potential to reduce adaptation costs and contribute to flood control, sanitation, + water resources management, landslide prevention and coastal protection. Globally, + more financing is directed at grey/physical infrastructure than green/natural + infrastructure and social infrastructure, and there is limited evidence of investment + in informal settlements . The greatest gains in well-being in urban areas can + be achieved by prioritising finance to reduce climate risk for low-income and + marginalised communities including people living in informal settlements. Responses + to ongoing sea level rise and land subsidence in low-lying coastal cities and + settlements and small islands include protection, accommodation, advance and planned + relocation. These responses are more effective if combined and/or sequenced, planned + well ahead, aligned with sociocultural values and development priorities, and + underpinned by inclusive community engagement processes. ' + C.3.5: + - Land, Ocean, Food, and Water There is substantial mitigation and adaptation potential + from options in agriculture, forestry and other land use, and in the oceans, that + could be upscaled in the near term across most regions. Conservation, improved + management, and restoration of forests and other ecosystems offer the largest + share of economic mitigation potential, with reduced deforestation in tropical + regions having the highest total mitigation potential. Ecosystem restoration, + reforestation, and afforestation can lead to trade-offs due to competing demands + on land. Minimizing trade-offs requires integrated approaches to meet multiple + objectives including food security. Demand-side measures and sustainable agricultural + intensification can reduce ecosystem conversion and CH4 and N2 O emissions, and + free up land for reforestation and ecosystem restoration. Sustainably sourced + agriculture and forest products, including long-lived wood products, can be used + instead of more GHG-intensive products in other sectors. Effective adaptation + options include cultivar improvements, agroforestry, community-based adaptation, + farm and landscape diversification, and urban agriculture. These AFOLU response + options require integration of biophysical, socioeconomic and other enabling factors. + The effectiveness of ecosystem-based adaptation and most water-related adaptation + options declines with increasing warming. Some options, such as conservation + of high-carbon ecosystems , have immediate impacts while others, such as restoration + of high-carbon ecosystems, reclamation of degraded soils or afforestation, take + decades to deliver measurable results. Many sustainable land management technologies + and practices are financially profitable in three to ten years. Maintaining the + resilience of biodiversity and ecosystem services at a global scale depends on + effective and equitable conservation of approximately 30–50% of Earth’s land, + freshwater and ocean areas, including currently near-natural ecosystems. The services + and options provided by terrestrial, freshwater, coastal and ocean ecosystems + can be supported by protection, restoration, precautionary ecosystem-based management + of renewable resource use, and the reduction of pollution and other stressors. Large-scale + land conversion for bioenergy, biochar, or afforestation can increase risks to + biodiversity, water and food security. In contrast, restoring natural forests + and drained peatlands, and improving sustainability of managed forests enhances + the resilience of carbon stocks and sinks and reduces ecosystem vulnerability + to climate change. Cooperation, and inclusive decision making, with local communities + and Indigenous Peoples, as well as recognition of inherent rights of Indigenous + Peoples, is integral to successful adaptation across forests and other ecosystems. Natural + rivers, wetlands and upstream forests reduce flood risk in most circumstances. + Enhancing natural water retention such as by restoring wetlands and rivers, land + use planning such as no build zones or upstream forest management, can further + reduce flood risk . For inland flooding, combinations of non-structural measures + like early warning systems and structural measures like levees have reduced loss + of lives, but hard defences against flooding or sea level rise can also be maladaptive + . Protection and restoration of coastal ‘blue carbon’ ecosystems could reduce + emissions and/or increase carbon uptake and storage . Coastal wetlands protect + against coastal erosion and flooding. Strengthening precautionary approaches, + such as rebuilding overexploited or depleted fisheries, and responsiveness of + existing fisheries management strategies reduces negative climate change impacts + on fisheries, with benefits for regional economies and livelihoods. Ecosystem-based + management in fisheries and aquaculture supports food security, biodiversity, + human health and well-being. + C.3.6: + - Land, Ocean, Food, and Water There is substantial mitigation and adaptation potential + from options in agriculture, forestry and other land use, and in the oceans, that + could be upscaled in the near term across most regions. Conservation, improved + management, and restoration of forests and other ecosystems offer the largest + share of economic mitigation potential, with reduced deforestation in tropical + regions having the highest total mitigation potential. Ecosystem restoration, + reforestation, and afforestation can lead to trade-offs due to competing demands + on land. Minimizing trade-offs requires integrated approaches to meet multiple + objectives including food security. Demand-side measures and sustainable agricultural + intensification can reduce ecosystem conversion and CH4 and N2 O emissions, and + free up land for reforestation and ecosystem restoration. Sustainably sourced + agriculture and forest products, including long-lived wood products, can be used + instead of more GHG-intensive products in other sectors. Effective adaptation + options include cultivar improvements, agroforestry, community-based adaptation, + farm and landscape diversification, and urban agriculture. These AFOLU response + options require integration of biophysical, socioeconomic and other enabling factors. + The effectiveness of ecosystem-based adaptation and most water-related adaptation + options declines with increasing warming. Some options, such as conservation + of high-carbon ecosystems , have immediate impacts while others, such as restoration + of high-carbon ecosystems, reclamation of degraded soils or afforestation, take + decades to deliver measurable results. Many sustainable land management technologies + and practices are financially profitable in three to ten years. Maintaining the + resilience of biodiversity and ecosystem services at a global scale depends on + effective and equitable conservation of approximately 30–50% of Earth’s land, + freshwater and ocean areas, including currently near-natural ecosystems. The services + and options provided by terrestrial, freshwater, coastal and ocean ecosystems + can be supported by protection, restoration, precautionary ecosystem-based management + of renewable resource use, and the reduction of pollution and other stressors. Large-scale + land conversion for bioenergy, biochar, or afforestation can increase risks to + biodiversity, water and food security. In contrast, restoring natural forests + and drained peatlands, and improving sustainability of managed forests enhances + the resilience of carbon stocks and sinks and reduces ecosystem vulnerability + to climate change. Cooperation, and inclusive decision making, with local communities + and Indigenous Peoples, as well as recognition of inherent rights of Indigenous + Peoples, is integral to successful adaptation across forests and other ecosystems. Natural + rivers, wetlands and upstream forests reduce flood risk in most circumstances. + Enhancing natural water retention such as by restoring wetlands and rivers, land + use planning such as no build zones or upstream forest management, can further + reduce flood risk . For inland flooding, combinations of non-structural measures + like early warning systems and structural measures like levees have reduced loss + of lives, but hard defences against flooding or sea level rise can also be maladaptive + . Protection and restoration of coastal ‘blue carbon’ ecosystems could reduce + emissions and/or increase carbon uptake and storage . Coastal wetlands protect + against coastal erosion and flooding. Strengthening precautionary approaches, + such as rebuilding overexploited or depleted fisheries, and responsiveness of + existing fisheries management strategies reduces negative climate change impacts + on fisheries, with benefits for regional economies and livelihoods. Ecosystem-based + management in fisheries and aquaculture supports food security, biodiversity, + human health and well-being. + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals Mitigation + and adaptation actions have more synergies than trade-offs with Sustainable Development + Goals . Synergies and trade-offs depend on context and scale of implementation. + Potential trade-offs can be compensated or avoided with additional policies, investments + and financial partnerships. Many mitigation and adaptation actions have multiple + synergies with Sustainable Development Goals, but some actions can also have trade-offs. + Potential synergies with SDGs exceed potential trade-offs. Synergies and trade-offs + are context specific and depend on: means and scale of implementation, intra- + and inter-sectoral interactions, cooperation between countries and regions, the + sequencing, timing and stringency of actions, governance, and policy design. Eradicating + extreme poverty, energy poverty, and providing decent living standards to all, + consistent with nearterm sustainable development objectives, can be achieved without + significant global emissions growth. Several mitigation and adaptation options + can harness nearterm synergies and reduce trade-offs to advance sustainable development + in energy, urban and land systems . Clean energy supply systems have multiple + co-benefits, including improvements in air quality and health. Heat Health Action + Plans that include early warning and response systems, approaches that mainstream + health into food, livelihoods, social protection, water and sanitation benefit + health and wellbeing. There are potential synergies between multiple Sustainable + Development Goals and sustainable land use and urban planning with more green + spaces, reduced air pollution, and demand-side mitigation including shifts to + balanced, sustainable healthy diets. Electrification combined with low-GHG energy, + and shifts to public transport can enhance health, employment, and can contribute + to energy security and deliver equity. Conservation, protection and restoration + of terrestrial, freshwater, coastal and ocean ecosystems, together with targeted + management to adapt to unavoidable impacts of climate change can generate multiple + additional benefits, such as agricultural productivity, food security, and biodiversity + conservation. When implementing mitigation and adaptation together, and taking + trade-offs into account, multiple co-benefits and synergies for human well-being + as well as ecosystem and planetary health can be realised. There is a strong link + between sustainable development, vulnerability and climate risks. Social safety + nets that support climate change adaptation have strong co-benefits with development + goals such as education, poverty alleviation, gender inclusion and food security. + Land restoration contributes to mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Trade-offs can be evaluated and minimised + by giving emphasis to capacity building, finance, technology transfer, investments; + governance, development, context specific gender-based and other social equity + considerations with meaningful participation of Indigenous Peoples, local communities + and vulnerable populations. . Context relevant design and implementation requires + considering people’s needs, biodiversity, and other sustainable development dimensions. + Countries at all stages of economic development seek to improve the well-being + of people, and their development priorities reflect different starting points + and contexts. Different contexts include but are not limited to social, economic, + environmental, cultural, or political circumstances, resource endowment, capabilities, + international environment, and prior development. n regions with high dependency + on fossil fuels for, among other things, revenue and employment generation, mitigating + risks for sustainable development requires policies that promote economic and + energy sector diversification and considerations of just transitions principles, + processes and practices. For individuals and households in low-lying coastal areas, + in Small Islands, and smallholder farmers transitioning from incremental to transformational + adaptation can help overcome soft adaptation limits. Effective governance is needed + to limit trade-offs of some mitigation options such as large scale afforestation + and bioenergy options due to risks from their deployment for food systems, biodiversity, + other ecosystem functions and services, and livelihoods. Effective governance + requires adequate institutional capacity at all levels .' + C.3.7: + - Health and Nutrition Human health will benefit from integrated mitigation and + adaptation options that mainstream health into food, infrastructure, social protection, + and water policies . Balanced and sustainable healthy diets and reduced food loss + and waste present important opportunities for adaptation and mitigation while + generating significant co-benefits in terms of biodiversity and human health. + Public health policies to improve nutrition, such as increasing the diversity + of food sources in public procurement, health insurance, financial incentives, + and awareness-raising campaigns, can potentially influence food demand, reduce + food waste, reduce healthcare costs, contribute to lower GHG emissions and enhance + adaptive capacity. Improved access to clean energy sources and technologies, and + shifts to active mobility and public transport can deliver socioeconomic, air + quality and health benefits, especially for women and children. Effective adaptation + options exist to help protect human health and well-being. Health Action Plans + that include early warning and response systems are effective for extreme heat + . Effective options for water-borne and food-borne diseases include improving + access to potable water, reducing exposure of water and sanitation systems to + flooding and extreme weather events, and improved early warning systems. For vector-borne + diseases, effective adaptation options include surveillance, early warning systems, + and vaccine development. Effective adaptation options for reducing mental health + risks under climate change include improving surveillance and access to mental + health care, and monitoring of psychosocial impacts from extreme weather events. + A key pathway to climate resilience in the health sector is universal access to + healthcare. + C.3.8: + - Society, Livelihoods, and Economies Enhancing knowledge on risks and available + adaptation options promotes societal responses, and behaviour and lifestyle changes + supported by policies, infrastructure and technology can help reduce global GHG + emissions. Climate literacy and information provided through climate services + and community approaches, including those that are informed by Indigenous Knowledge + and local knowledge, can accelerate behavioural changes and planning . Educational + and information programmes, using the arts, participatory modelling and citizen + science can facilitate awareness, heighten risk perception, and influence behaviours + . The way choices are presented can enable adoption of low GHG intensive socio-cultural + options, such as shifts to balanced, sustainable healthy diets, reduced food waste, + and active mobility. Judicious labelling, framing, and communication of social + norms can increase the effect of mandates, subsidies, or taxes. A range of adaptation + options, such as disaster risk management, early warning systems, climate services + and risk spreading and sharing approaches, have broad applicability across sectors + and provide greater risk reduction benefits when combined . Climate services that + are demand-driven and inclusive of different users and providers can improve agricultural + practices, inform better water use and efficiency, and enable resilient infrastructure + planning. Policy mixes that include weather and health insurance, social protection + and adaptive safety nets, contingent finance and reserve funds, and universal + access to early warning systems combined with effective contingency plans, can + reduce vulnerability and exposure of human systems. Integrating climate adaptation + into social protection programs, including cash transfers and public works programs, + is highly feasible and increases resilience to climate change, especially when + supported by basic services and infrastructure. Social safety nets can build adaptive + capacities, reduce socioeconomic vulnerability, and reduce risk linked to hazards. Reducing + future risks of involuntary migration and displacement due to climate change is + possible through cooperative, international efforts to enhance institutional adaptive + capacity and sustainable development. Increasing adaptive capacity minimises risk + associated with involuntary migration and immobility and improves the degree of + choice under which migration decisions are made, while policy interventions can + remove barriers and expand the alternatives for safe, orderly and regular migration + that allows vulnerable people to adapt to climate change. Accelerating commitment + and follow-through by the private sector is promoted for instance by building + business cases for adaptation, accountability and transparency mechanisms, and + monitoring and evaluation of adaptation progress . Integrated pathways for managing + climate risks will be most suitable when so-called ‘low-regret’ anticipatory options + are established jointly across sectors in a timely manner and are feasible and + effective in their local context, and when path dependencies and maladaptations + across sectors are avoided. Sustained adaptation actions are strengthened by mainstreaming + adaptation into institutional budget and policy planning cycles, statutory planning, + monitoring and evaluation frameworks and into recovery efforts from disaster events. + Instruments that incorporate adaptation such as policy and legal frameworks, behavioural + incentives, and economic instruments that address market failures, such as climate + risk disclosure, inclusive and deliberative processes strengthen adaptation actions + by public and private actors. + C.4.1: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals Mitigation + and adaptation actions have more synergies than trade-offs with Sustainable Development + Goals . Synergies and trade-offs depend on context and scale of implementation. + Potential trade-offs can be compensated or avoided with additional policies, investments + and financial partnerships. Many mitigation and adaptation actions have multiple + synergies with Sustainable Development Goals, but some actions can also have trade-offs. + Potential synergies with SDGs exceed potential trade-offs. Synergies and trade-offs + are context specific and depend on: means and scale of implementation, intra- + and inter-sectoral interactions, cooperation between countries and regions, the + sequencing, timing and stringency of actions, governance, and policy design. Eradicating + extreme poverty, energy poverty, and providing decent living standards to all, + consistent with nearterm sustainable development objectives, can be achieved without + significant global emissions growth. Several mitigation and adaptation options + can harness nearterm synergies and reduce trade-offs to advance sustainable development + in energy, urban and land systems . Clean energy supply systems have multiple + co-benefits, including improvements in air quality and health. Heat Health Action + Plans that include early warning and response systems, approaches that mainstream + health into food, livelihoods, social protection, water and sanitation benefit + health and wellbeing. There are potential synergies between multiple Sustainable + Development Goals and sustainable land use and urban planning with more green + spaces, reduced air pollution, and demand-side mitigation including shifts to + balanced, sustainable healthy diets. Electrification combined with low-GHG energy, + and shifts to public transport can enhance health, employment, and can contribute + to energy security and deliver equity. Conservation, protection and restoration + of terrestrial, freshwater, coastal and ocean ecosystems, together with targeted + management to adapt to unavoidable impacts of climate change can generate multiple + additional benefits, such as agricultural productivity, food security, and biodiversity + conservation. When implementing mitigation and adaptation together, and taking + trade-offs into account, multiple co-benefits and synergies for human well-being + as well as ecosystem and planetary health can be realised. There is a strong link + between sustainable development, vulnerability and climate risks. Social safety + nets that support climate change adaptation have strong co-benefits with development + goals such as education, poverty alleviation, gender inclusion and food security. + Land restoration contributes to mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Trade-offs can be evaluated and minimised + by giving emphasis to capacity building, finance, technology transfer, investments; + governance, development, context specific gender-based and other social equity + considerations with meaningful participation of Indigenous Peoples, local communities + and vulnerable populations. . Context relevant design and implementation requires + considering people’s needs, biodiversity, and other sustainable development dimensions. + Countries at all stages of economic development seek to improve the well-being + of people, and their development priorities reflect different starting points + and contexts. Different contexts include but are not limited to social, economic, + environmental, cultural, or political circumstances, resource endowment, capabilities, + international environment, and prior development. n regions with high dependency + on fossil fuels for, among other things, revenue and employment generation, mitigating + risks for sustainable development requires policies that promote economic and + energy sector diversification and considerations of just transitions principles, + processes and practices. For individuals and households in low-lying coastal areas, + in Small Islands, and smallholder farmers transitioning from incremental to transformational + adaptation can help overcome soft adaptation limits. Effective governance is needed + to limit trade-offs of some mitigation options such as large scale afforestation + and bioenergy options due to risks from their deployment for food systems, biodiversity, + other ecosystem functions and services, and livelihoods. Effective governance + requires adequate institutional capacity at all levels .' + C.4.2: + - Synergies and trade-offs, costs and benefits Mitigation and adaptation options + can lead to synergies and trade-offs with other aspects of sustainable development + . Synergies and trade-offs depend on the pace and magnitude of changes and the + development context including inequalities, with consideration of climate justice. + The potential or effectiveness of some adaptation and mitigation options decreases + as climate change intensifies . In the energy sector, transitions to low-emission + systems will have multiple co-benefits, including improvements in air quality + and health. There are potential synergies between sustainable development and, + for instance, energy efficiency and renewable energy. For agriculture, land, + and food systems, many land management options and demand-side response options can + contribute to eradicating poverty and eliminating hunger while promoting good + health and well-being, clean water and sanitation, and life on land . In contrast, + certain adaptation options that promote intensification of production, such as + irrigation, may have negative effects on sustainability . Reforestation, improved + forest management, soil carbon sequestration, peatland restoration and coastal + blue carbon management are examples of CDR methods that can enhance biodiversity + and ecosystem functions, employment and local livelihoods, depending on context + . However, afforestation or production of biomass crops for bioenergy with carbon + dioxide capture and storage or biochar can have adverse socio-economic and environmental + impacts, including on biodiversity, food and water security, local livelihoods + and the rights of Indigenous Peoples, especially if implemented at large scales + and where land tenure is insecure. Modelled pathways that assume using resources + more efficiently or shift global development towards sustainability include fewer + challenges, such as dependence on CDR and pressure on land and biodiversity, and + have the most pronounced synergies with respect to sustainable development . Strengthening + climate change mitigation action entails more rapid transitions and higher up-front + investments, but brings benefits from avoiding damages from climate change and + reduced adaptation costs. The aggregate effects of climate change mitigation on + global GDP are small compared to global projected GDP growth. Projected estimates + of global aggregate net economic damages and the costs of adaptation generally + increase with global warming level. Cost-benefit analysis remains limited in + its ability to represent all damages from climate change, including non-monetary + damages, or to capture the heterogeneous nature of damages and the risk of catastrophic + damages. Even without accounting for these factors or for the co-benefits of mitigation, + the global benefits of limiting warming to 2°C exceed the cost of mitigation . + This finding is robust against a wide range of assumptions about social preferences + on inequalities and discounting over time . Limiting global warming to 1.5°C instead + of 2°C would increase the costs of mitigation, but also increase the benefits + in terms of reduced impacts and related risks and reduced adaptation needs 140. Considering + other sustainable development dimensions, such as the potentially strong economic + benefits on human health from air quality improvement, may enhance the estimated + benefits of mitigation . The economic effects of strengthened mitigation action + vary across regions and countries, depending notably on economic structure, regional + emissions reductions, policy design and level of international cooperation. Ambitious + mitigation pathways imply large and sometimes disruptive changes in economic structure, + with implications for near-term actions, equity , sustainability, and finance + . + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals Mitigation + and adaptation actions have more synergies than trade-offs with Sustainable Development + Goals . Synergies and trade-offs depend on context and scale of implementation. + Potential trade-offs can be compensated or avoided with additional policies, investments + and financial partnerships. Many mitigation and adaptation actions have multiple + synergies with Sustainable Development Goals, but some actions can also have trade-offs. + Potential synergies with SDGs exceed potential trade-offs. Synergies and trade-offs + are context specific and depend on: means and scale of implementation, intra- + and inter-sectoral interactions, cooperation between countries and regions, the + sequencing, timing and stringency of actions, governance, and policy design. Eradicating + extreme poverty, energy poverty, and providing decent living standards to all, + consistent with nearterm sustainable development objectives, can be achieved without + significant global emissions growth. Several mitigation and adaptation options + can harness nearterm synergies and reduce trade-offs to advance sustainable development + in energy, urban and land systems . Clean energy supply systems have multiple + co-benefits, including improvements in air quality and health. Heat Health Action + Plans that include early warning and response systems, approaches that mainstream + health into food, livelihoods, social protection, water and sanitation benefit + health and wellbeing. There are potential synergies between multiple Sustainable + Development Goals and sustainable land use and urban planning with more green + spaces, reduced air pollution, and demand-side mitigation including shifts to + balanced, sustainable healthy diets. Electrification combined with low-GHG energy, + and shifts to public transport can enhance health, employment, and can contribute + to energy security and deliver equity. Conservation, protection and restoration + of terrestrial, freshwater, coastal and ocean ecosystems, together with targeted + management to adapt to unavoidable impacts of climate change can generate multiple + additional benefits, such as agricultural productivity, food security, and biodiversity + conservation. When implementing mitigation and adaptation together, and taking + trade-offs into account, multiple co-benefits and synergies for human well-being + as well as ecosystem and planetary health can be realised. There is a strong link + between sustainable development, vulnerability and climate risks. Social safety + nets that support climate change adaptation have strong co-benefits with development + goals such as education, poverty alleviation, gender inclusion and food security. + Land restoration contributes to mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Trade-offs can be evaluated and minimised + by giving emphasis to capacity building, finance, technology transfer, investments; + governance, development, context specific gender-based and other social equity + considerations with meaningful participation of Indigenous Peoples, local communities + and vulnerable populations. . Context relevant design and implementation requires + considering people’s needs, biodiversity, and other sustainable development dimensions. + Countries at all stages of economic development seek to improve the well-being + of people, and their development priorities reflect different starting points + and contexts. Different contexts include but are not limited to social, economic, + environmental, cultural, or political circumstances, resource endowment, capabilities, + international environment, and prior development. n regions with high dependency + on fossil fuels for, among other things, revenue and employment generation, mitigating + risks for sustainable development requires policies that promote economic and + energy sector diversification and considerations of just transitions principles, + processes and practices. For individuals and households in low-lying coastal areas, + in Small Islands, and smallholder farmers transitioning from incremental to transformational + adaptation can help overcome soft adaptation limits. Effective governance is needed + to limit trade-offs of some mitigation options such as large scale afforestation + and bioenergy options due to risks from their deployment for food systems, biodiversity, + other ecosystem functions and services, and livelihoods. Effective governance + requires adequate institutional capacity at all levels .' + - Integration of Near-Term Actions Across Sectors and Systems The feasibility, + effectiveness and benefits of mitigation and adaptation actions are increased + when multi-sectoral solutions are undertaken that cut across systems. When such + options are combined with broader sustainable development objectives, they can + yield greater benefits for human well-being, social equity and justice, and ecosystem + and planetary health. Climate resilient development strategies that treat climate, + ecosystems and biodiversity, and human society as parts of an integrated system + are the most effective. Human and ecosystem vulnerability are interdependent. + Climate resilient development is enabled when decision-making processes and actions + are integrated across sectors. Synergies with and progress towards the Sustainable + Development Goals enhance prospects for climate resilient development. Choices + and actions that treat humans and ecosystems as an integrated system build on + diverse knowledge about climate risk, equitable, just and inclusive approaches, + and ecosystem stewardship. Approaches that align goals and actions across sectors + provide opportunities for multiple and large-scale benefits and avoided damages + in the near term. Such measures can also achieve greater benefits through cascading + effects across sectors . For example, the feasibility of using land for both agriculture + and centralised solar production can increase when such options are combined. + Similarly, integrated transport and energy infrastructure planning and operations + can together reduce the environmental, social, and economic impacts of decarbonising + the transport and energy sectors. The implementation of packages of multiple city-scale + mitigation strategies can have cascading effects across sectors and reduce GHG + emissions both within and outside a city’s administrative boundaries . Integrated + design approaches to the construction and retrofit of buildings provide increasing + examples of zero energy or zero carbon buildings in several regions. To minimise + maladaptation, multi-sectoral, multi-actor and inclusive planning with flexible + pathways encourages low-regret and timely actions that keep options open, ensure + benefits in multiple sectors and systems and suggest the available solution space + for adapting to long-term climate change . Trade-offs in terms of employment, + water use, land-use competition and biodiversity, as well as access to, and the + affordability of, energy, food, and water can be avoided by well-implemented land-based + mitigation options, especially those that do not threaten existing sustainable + land uses and land rights, with frameworks for integrated policy implementation. Mitigation + and adaptation when implemented together, and combined with broader sustainable + development objectives, would yield multiple benefits for human well-being as + well as ecosystem and planetary health. The range of such positive interactions + is significant in the landscape of near-term climate policies across regions, + sectors and systems. For example, AFOLU mitigation actions in land-use change + and forestry, when sustainably implemented, can provide large-scale GHG emission + reductions and removals that simultaneously benefit biodiversity, food security, + wood supply and other ecosystem services but cannot fully compensate for delayed + mitigation action in other sectors. Adaptation measures in land, ocean and ecosystems + similarly can have widespread benefits for food security, nutrition, health and + well-being, ecosystems and biodiversity. Equally, urban systems are critical, + interconnected sites for climate resilient development; urban policies that implement + multiple interventions can yield adaptation or mitigation gains with equity and + human well-being. Integrated policy packages can improve the ability to integrate + considerations of equity, gender equality and justice. Coordinated cross-sectoral + policies and planning can maximise synergies and avoid or reduce trade-offs between + mitigation and adaptation. Effective action in all of the above areas will require + near-term political commitment and follow-through, social cooperation, finance, + and more integrated cross-sectoral policies and support and actions. . + C.4.3: + - 'Benefits of Strengthening Near-Term Action Accelerated implementation of adaptation + will improve well-being by reducing losses and damages, especially for vulnerable + populations. Deep, rapid, and sustained mitigation actions would reduce future + adaptation costs and losses and damages, enhance sustainable development co-benefits, + avoid locking-in emission sources, and reduce stranded assets and irreversible + climate changes. These near-term actions involve higher up-front investments and + disruptive changes, which can be moderated by a range of enabling conditions and + removal or reduction of barriers to feasibility. Accelerated implementation of + adaptation responses will bring benefits to human well-being. As adaptation options + often have long implementation times, long-term planning and accelerated implementation, + particularly in this decade, is important to close adaptation gaps, recognising + that constraints remain for some regions. The benefits to vulnerable populations + would be high . Near-term actions that limit global warming to close to 1.5°C + would substantially reduce projected losses and damages related to climate change + in human systems and ecosystems, compared to higher warming levels, but cannot + eliminate them all . The magnitude and rate of climate change and associated risks + depend strongly on near-term mitigation and adaptation actions, and projected + adverse impacts and related losses and damages escalate with every increment of + global warming. Delayed mitigation action will further increase global warming + which will decrease the effectiveness of many adaptation options, including Ecosystem-based + Adaptation and many water-related options, as well as increasing mitigation feasibility + risks, such as for options based on ecosystems. Comprehensive, effective, and + innovative responses integrating adaptation and mitigation can harness synergies + and reduce trade-offs between adaptation and mitigation, as well as in meeting + requirements for financing . Mitigation actions will have other sustainable development + co-benefits. Mitigation will improve air quality and human health in the near + term notably because many air pollutants are co-emitted by GHG emitting sectors + and because methane emissions leads to surface ozone formation. The benefits from + air quality improvement include prevention of air pollution-related premature + deaths, chronic diseases and damages to ecosystems and crops. The economic benefits + for human health from air quality improvement arising from mitigation action can + be of the same order of magnitude as mitigation costs, and potentially even larger + . As methane has a short lifetime but is a potent GHG, strong, rapid and sustained + reductions in methane emissions can limit near-term warming and improve air quality + by reducing global surface ozone. Challenges from delayed adaptation and mitigation + actions include the risk of cost escalation, lock-in of infrastructure, stranded + assets, and reduced feasibility and effectiveness of adaptation and mitigation + options. The continued installation of unabated fossil fuel infrastructure will + ‘lock-in’ GHG emissions. Limiting global warming to 2°C or below will leave a + substantial amount of fossil fuels unburned and could strand considerable fossil + fuel infrastructure , with globally discounted value projected to be around USD + 1 to 4 trillion from 2015 to 2050. Early actions would limit the size of these + stranded assets, whereas delayed actions with continued investments in unabated + high-emitting infrastructure and limited development and deployment of low-emitting + alternatives prior to 2030 would raise future stranded assets to the higher end + of the range – thereby acting as barriers and increasing political economy feasibility + risks that may jeopardise efforts to limit global warming. . Scaling-up near-term + climate actions will mobilise a mix of low-cost and high-cost options. High-cost + options, as in energy and infrastructure, are needed to avoid future lock-ins, + foster innovation and initiate transformational changes. Climate resilient development + pathways in support of sustainable development for all are shaped by equity, and + social and climate justice. Embedding effective and equitable adaptation and mitigation + in development planning can reduce vulnerability, conserve and restore ecosystems, + and enable climate resilient development. This is especially challenging in localities + with persistent development gaps and limited resources. Scaling-up climate action + may generate disruptive changes in economic structure with distributional consequences + and need to reconcile divergent interests, values and worldviews, within and between + countries. Deeper fiscal, financial, institutional and regulatory reforms can + offset such adverse effects and unlock mitigation potentials. Societal choices + and actions implemented in this decade will determine the extent to which medium + and long-term development pathways will deliver higher or lower climate resilient + development outcomes. Enabling conditions would need to be strengthened in the + nearterm and barriers reduced or removed to realise opportunities for deep and + rapid adaptation and mitigation actions and climate resilient development. These + enabling conditions are differentiated by national, regional and local circumstances + and geographies, according to capabilities, and include: equity and inclusion + in climate action, rapid and far-reaching transitions in sectors and system , + measures to achieve synergies and reduce tradeoffs with sustainable development + goals, governance and policy improvements, access to finance, improved international + cooperation and technology improvements, and integration of near-term actions + across sectors, systems and regions. Barriers to feasibility would need to be + reduced or removed to deploy mitigation and adaptation options at scale. Many + limits to feasibility and effectiveness of responses can be overcome by addressing + a range of barriers, including economic, technological, institutional, social, + environmental and geophysical barriers. The feasibility and effectiveness of options + increase with integrated, multi-sectoral solutions that differentiate responses + based on climate risk, cut across systems and address social inequities. Strengthened + near-term actions in modelled cost-effective pathways that limit global warming + to 2°C or lower, reduce the overall risk to the feasibility of the system transitions, + compared to modelled pathways with delayed or uncoordinated action. Integrating + ambitious climate actions with macroeconomic policies under global uncertainty + would provide benefits . This encompasses three main directions: economy-wide + mainstreaming packages supporting options to improved sustainable low-emission + economic recovery, development and job creation programs safety nets and social + protection in the transition; and broadened access to finance, technology and + capacity-building and coordinated support to low-emission infrastructure , especially + in developing regions, and under debt stress .' + - 'Cities, Settlements and Infrastructure Urban systems are critical for achieving + deep emissions reductions and advancing climate resilient development, particularly + when this involves integrated planning that incorporates physical, natural and + social infrastructure . Deep emissions reductions and integrated adaptation actions + are advanced by: integrated, inclusive land use planning and decision-making; + compact urban form by co-locating jobs and housing; reducing or changing urban + energy and material consumption; electrification in combination with low emissions + sources; improved water and waste management infrastructure; and enhancing carbon + uptake and storage in the urban environment . Cities can achieve net zero emissions + if emissions are reduced within and outside of their administrative boundaries + through supply chains, creating beneficial cascading effects across other sectors. Considering + climate change impacts and risks in the design and planning of urban and rural + settlements and infrastructure is critical for resilience and enhancing human + well-being. Effective mitigation can be advanced at each of the design, construction, + retrofit, use and disposal stages for buildings. Mitigation interventions for + buildings include: at the construction phase, lowemission construction materials, + highly efficient building envelope and the integration of renewable energy solutions; + at the use phase, highly efficient appliances/equipment, the optimisation of the + use of buildings and their supply with low-emission energy sources; and at the + disposal phase, recycling and re-using construction materials. Sufficiency 155 + measures can limit the demand for energy and materials over the lifecycle of buildings + and appliances. Transport-related GHG emissions can be reduced by demand-side + options and low-GHG emissions technologies. Changes in urban form, reallocation + of street space for cycling and walking, digitalisation and programs that encourage + changes in consumer behaviour can reduce demand for transport services and support + the shift to more energy efficient transport modes. Electric vehicles powered + by low-emissions electricity offer the largest decarbonisation potential for land-based + transport, on a life cycle basis. Costs of electrified vehicles are decreasing + and their adoption is accelerating, but they require continued investments in + supporting infrastructure to increase scale of deployment. The environmental footprint + of battery production and growing concerns about critical minerals can be addressed + by material and supply diversification strategies, energy and material efficiency + improvements, and circular material flows . Advances in battery technologies could + facilitate the electrification of heavy-duty trucks and compliment conventional + electric rail systems. Sustainable biofuels can offer additional mitigation benefits + in land-based transport in the short and medium term. Sustainable biofuels, low-emissions + hydrogen, and derivatives can support mitigation of CO2 emissions from shipping, + aviation, and heavy-duty land transport but require production process improvements + and cost reductions. Key infrastructure systems including sanitation, water, health, + transport, communications and energy will be increasingly vulnerable if design + standards do not account for changing climate conditions. Green/natural and blue + infrastructure such as urban forestry, green roofs, ponds and lakes, and river + restoration can mitigate climate change through carbon uptake and storage, avoided + emissions, and reduced energy use while reducing risk from extreme events such + as heatwaves, heavy precipitation and droughts, and advancing co-benefits for + health, well-being and livelihoods. Urban greening can provide local cooling. + Combining green/natural and grey/physical infrastructure adaptation responses + has potential to reduce adaptation costs and contribute to flood control, sanitation, + water resources management, landslide prevention and coastal protection. Globally, + more financing is directed at grey/physical infrastructure than green/natural + infrastructure and social infrastructure, and there is limited evidence of investment + in informal settlements . The greatest gains in well-being in urban areas can + be achieved by prioritising finance to reduce climate risk for low-income and + marginalised communities including people living in informal settlements. Responses + to ongoing sea level rise and land subsidence in low-lying coastal cities and + settlements and small islands include protection, accommodation, advance and planned + relocation. These responses are more effective if combined and/or sequenced, planned + well ahead, aligned with sociocultural values and development priorities, and + underpinned by inclusive community engagement processes. ' + - Health and Nutrition Human health will benefit from integrated mitigation and + adaptation options that mainstream health into food, infrastructure, social protection, + and water policies . Balanced and sustainable healthy diets and reduced food loss + and waste present important opportunities for adaptation and mitigation while + generating significant co-benefits in terms of biodiversity and human health. + Public health policies to improve nutrition, such as increasing the diversity + of food sources in public procurement, health insurance, financial incentives, + and awareness-raising campaigns, can potentially influence food demand, reduce + food waste, reduce healthcare costs, contribute to lower GHG emissions and enhance + adaptive capacity. Improved access to clean energy sources and technologies, and + shifts to active mobility and public transport can deliver socioeconomic, air + quality and health benefits, especially for women and children. Effective adaptation + options exist to help protect human health and well-being. Health Action Plans + that include early warning and response systems are effective for extreme heat + . Effective options for water-borne and food-borne diseases include improving + access to potable water, reducing exposure of water and sanitation systems to + flooding and extreme weather events, and improved early warning systems. For vector-borne + diseases, effective adaptation options include surveillance, early warning systems, + and vaccine development. Effective adaptation options for reducing mental health + risks under climate change include improving surveillance and access to mental + health care, and monitoring of psychosocial impacts from extreme weather events. + A key pathway to climate resilience in the health sector is universal access to + healthcare. + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals Mitigation + and adaptation actions have more synergies than trade-offs with Sustainable Development + Goals . Synergies and trade-offs depend on context and scale of implementation. + Potential trade-offs can be compensated or avoided with additional policies, investments + and financial partnerships. Many mitigation and adaptation actions have multiple + synergies with Sustainable Development Goals, but some actions can also have trade-offs. + Potential synergies with SDGs exceed potential trade-offs. Synergies and trade-offs + are context specific and depend on: means and scale of implementation, intra- + and inter-sectoral interactions, cooperation between countries and regions, the + sequencing, timing and stringency of actions, governance, and policy design. Eradicating + extreme poverty, energy poverty, and providing decent living standards to all, + consistent with nearterm sustainable development objectives, can be achieved without + significant global emissions growth. Several mitigation and adaptation options + can harness nearterm synergies and reduce trade-offs to advance sustainable development + in energy, urban and land systems . Clean energy supply systems have multiple + co-benefits, including improvements in air quality and health. Heat Health Action + Plans that include early warning and response systems, approaches that mainstream + health into food, livelihoods, social protection, water and sanitation benefit + health and wellbeing. There are potential synergies between multiple Sustainable + Development Goals and sustainable land use and urban planning with more green + spaces, reduced air pollution, and demand-side mitigation including shifts to + balanced, sustainable healthy diets. Electrification combined with low-GHG energy, + and shifts to public transport can enhance health, employment, and can contribute + to energy security and deliver equity. Conservation, protection and restoration + of terrestrial, freshwater, coastal and ocean ecosystems, together with targeted + management to adapt to unavoidable impacts of climate change can generate multiple + additional benefits, such as agricultural productivity, food security, and biodiversity + conservation. When implementing mitigation and adaptation together, and taking + trade-offs into account, multiple co-benefits and synergies for human well-being + as well as ecosystem and planetary health can be realised. There is a strong link + between sustainable development, vulnerability and climate risks. Social safety + nets that support climate change adaptation have strong co-benefits with development + goals such as education, poverty alleviation, gender inclusion and food security. + Land restoration contributes to mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Trade-offs can be evaluated and minimised + by giving emphasis to capacity building, finance, technology transfer, investments; + governance, development, context specific gender-based and other social equity + considerations with meaningful participation of Indigenous Peoples, local communities + and vulnerable populations. . Context relevant design and implementation requires + considering people’s needs, biodiversity, and other sustainable development dimensions. + Countries at all stages of economic development seek to improve the well-being + of people, and their development priorities reflect different starting points + and contexts. Different contexts include but are not limited to social, economic, + environmental, cultural, or political circumstances, resource endowment, capabilities, + international environment, and prior development. n regions with high dependency + on fossil fuels for, among other things, revenue and employment generation, mitigating + risks for sustainable development requires policies that promote economic and + energy sector diversification and considerations of just transitions principles, + processes and practices. For individuals and households in low-lying coastal areas, + in Small Islands, and smallholder farmers transitioning from incremental to transformational + adaptation can help overcome soft adaptation limits. Effective governance is needed + to limit trade-offs of some mitigation options such as large scale afforestation + and bioenergy options due to risks from their deployment for food systems, biodiversity, + other ecosystem functions and services, and livelihoods. Effective governance + requires adequate institutional capacity at all levels .' + - Integration of Near-Term Actions Across Sectors and Systems The feasibility, + effectiveness and benefits of mitigation and adaptation actions are increased + when multi-sectoral solutions are undertaken that cut across systems. When such + options are combined with broader sustainable development objectives, they can + yield greater benefits for human well-being, social equity and justice, and ecosystem + and planetary health. Climate resilient development strategies that treat climate, + ecosystems and biodiversity, and human society as parts of an integrated system + are the most effective. Human and ecosystem vulnerability are interdependent. + Climate resilient development is enabled when decision-making processes and actions + are integrated across sectors. Synergies with and progress towards the Sustainable + Development Goals enhance prospects for climate resilient development. Choices + and actions that treat humans and ecosystems as an integrated system build on + diverse knowledge about climate risk, equitable, just and inclusive approaches, + and ecosystem stewardship. Approaches that align goals and actions across sectors + provide opportunities for multiple and large-scale benefits and avoided damages + in the near term. Such measures can also achieve greater benefits through cascading + effects across sectors . For example, the feasibility of using land for both agriculture + and centralised solar production can increase when such options are combined. + Similarly, integrated transport and energy infrastructure planning and operations + can together reduce the environmental, social, and economic impacts of decarbonising + the transport and energy sectors. The implementation of packages of multiple city-scale + mitigation strategies can have cascading effects across sectors and reduce GHG + emissions both within and outside a city’s administrative boundaries . Integrated + design approaches to the construction and retrofit of buildings provide increasing + examples of zero energy or zero carbon buildings in several regions. To minimise + maladaptation, multi-sectoral, multi-actor and inclusive planning with flexible + pathways encourages low-regret and timely actions that keep options open, ensure + benefits in multiple sectors and systems and suggest the available solution space + for adapting to long-term climate change . Trade-offs in terms of employment, + water use, land-use competition and biodiversity, as well as access to, and the + affordability of, energy, food, and water can be avoided by well-implemented land-based + mitigation options, especially those that do not threaten existing sustainable + land uses and land rights, with frameworks for integrated policy implementation. Mitigation + and adaptation when implemented together, and combined with broader sustainable + development objectives, would yield multiple benefits for human well-being as + well as ecosystem and planetary health. The range of such positive interactions + is significant in the landscape of near-term climate policies across regions, + sectors and systems. For example, AFOLU mitigation actions in land-use change + and forestry, when sustainably implemented, can provide large-scale GHG emission + reductions and removals that simultaneously benefit biodiversity, food security, + wood supply and other ecosystem services but cannot fully compensate for delayed + mitigation action in other sectors. Adaptation measures in land, ocean and ecosystems + similarly can have widespread benefits for food security, nutrition, health and + well-being, ecosystems and biodiversity. Equally, urban systems are critical, + interconnected sites for climate resilient development; urban policies that implement + multiple interventions can yield adaptation or mitigation gains with equity and + human well-being. Integrated policy packages can improve the ability to integrate + considerations of equity, gender equality and justice. Coordinated cross-sectoral + policies and planning can maximise synergies and avoid or reduce trade-offs between + mitigation and adaptation. Effective action in all of the above areas will require + near-term political commitment and follow-through, social cooperation, finance, + and more integrated cross-sectoral policies and support and actions. . + C.5.1: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + C.5.2: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + C.5.3: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - 'Cities, Settlements and Infrastructure Urban systems are critical for achieving + deep emissions reductions and advancing climate resilient development, particularly + when this involves integrated planning that incorporates physical, natural and + social infrastructure . Deep emissions reductions and integrated adaptation actions + are advanced by: integrated, inclusive land use planning and decision-making; + compact urban form by co-locating jobs and housing; reducing or changing urban + energy and material consumption; electrification in combination with low emissions + sources; improved water and waste management infrastructure; and enhancing carbon + uptake and storage in the urban environment . Cities can achieve net zero emissions + if emissions are reduced within and outside of their administrative boundaries + through supply chains, creating beneficial cascading effects across other sectors. Considering + climate change impacts and risks in the design and planning of urban and rural + settlements and infrastructure is critical for resilience and enhancing human + well-being. Effective mitigation can be advanced at each of the design, construction, + retrofit, use and disposal stages for buildings. Mitigation interventions for + buildings include: at the construction phase, lowemission construction materials, + highly efficient building envelope and the integration of renewable energy solutions; + at the use phase, highly efficient appliances/equipment, the optimisation of the + use of buildings and their supply with low-emission energy sources; and at the + disposal phase, recycling and re-using construction materials. Sufficiency 155 + measures can limit the demand for energy and materials over the lifecycle of buildings + and appliances. Transport-related GHG emissions can be reduced by demand-side + options and low-GHG emissions technologies. Changes in urban form, reallocation + of street space for cycling and walking, digitalisation and programs that encourage + changes in consumer behaviour can reduce demand for transport services and support + the shift to more energy efficient transport modes. Electric vehicles powered + by low-emissions electricity offer the largest decarbonisation potential for land-based + transport, on a life cycle basis. Costs of electrified vehicles are decreasing + and their adoption is accelerating, but they require continued investments in + supporting infrastructure to increase scale of deployment. The environmental footprint + of battery production and growing concerns about critical minerals can be addressed + by material and supply diversification strategies, energy and material efficiency + improvements, and circular material flows . Advances in battery technologies could + facilitate the electrification of heavy-duty trucks and compliment conventional + electric rail systems. Sustainable biofuels can offer additional mitigation benefits + in land-based transport in the short and medium term. Sustainable biofuels, low-emissions + hydrogen, and derivatives can support mitigation of CO2 emissions from shipping, + aviation, and heavy-duty land transport but require production process improvements + and cost reductions. Key infrastructure systems including sanitation, water, health, + transport, communications and energy will be increasingly vulnerable if design + standards do not account for changing climate conditions. Green/natural and blue + infrastructure such as urban forestry, green roofs, ponds and lakes, and river + restoration can mitigate climate change through carbon uptake and storage, avoided + emissions, and reduced energy use while reducing risk from extreme events such + as heatwaves, heavy precipitation and droughts, and advancing co-benefits for + health, well-being and livelihoods. Urban greening can provide local cooling. + Combining green/natural and grey/physical infrastructure adaptation responses + has potential to reduce adaptation costs and contribute to flood control, sanitation, + water resources management, landslide prevention and coastal protection. Globally, + more financing is directed at grey/physical infrastructure than green/natural + infrastructure and social infrastructure, and there is limited evidence of investment + in informal settlements . The greatest gains in well-being in urban areas can + be achieved by prioritising finance to reduce climate risk for low-income and + marginalised communities including people living in informal settlements. Responses + to ongoing sea level rise and land subsidence in low-lying coastal cities and + settlements and small islands include protection, accommodation, advance and planned + relocation. These responses are more effective if combined and/or sequenced, planned + well ahead, aligned with sociocultural values and development priorities, and + underpinned by inclusive community engagement processes. ' + - Health and Nutrition Human health will benefit from integrated mitigation and + adaptation options that mainstream health into food, infrastructure, social protection, + and water policies . Balanced and sustainable healthy diets and reduced food loss + and waste present important opportunities for adaptation and mitigation while + generating significant co-benefits in terms of biodiversity and human health. + Public health policies to improve nutrition, such as increasing the diversity + of food sources in public procurement, health insurance, financial incentives, + and awareness-raising campaigns, can potentially influence food demand, reduce + food waste, reduce healthcare costs, contribute to lower GHG emissions and enhance + adaptive capacity. Improved access to clean energy sources and technologies, and + shifts to active mobility and public transport can deliver socioeconomic, air + quality and health benefits, especially for women and children. Effective adaptation + options exist to help protect human health and well-being. Health Action Plans + that include early warning and response systems are effective for extreme heat + . Effective options for water-borne and food-borne diseases include improving + access to potable water, reducing exposure of water and sanitation systems to + flooding and extreme weather events, and improved early warning systems. For vector-borne + diseases, effective adaptation options include surveillance, early warning systems, + and vaccine development. Effective adaptation options for reducing mental health + risks under climate change include improving surveillance and access to mental + health care, and monitoring of psychosocial impacts from extreme weather events. + A key pathway to climate resilience in the health sector is universal access to + healthcare. + - Society, Livelihoods, and Economies Enhancing knowledge on risks and available + adaptation options promotes societal responses, and behaviour and lifestyle changes + supported by policies, infrastructure and technology can help reduce global GHG + emissions. Climate literacy and information provided through climate services + and community approaches, including those that are informed by Indigenous Knowledge + and local knowledge, can accelerate behavioural changes and planning . Educational + and information programmes, using the arts, participatory modelling and citizen + science can facilitate awareness, heighten risk perception, and influence behaviours + . The way choices are presented can enable adoption of low GHG intensive socio-cultural + options, such as shifts to balanced, sustainable healthy diets, reduced food waste, + and active mobility. Judicious labelling, framing, and communication of social + norms can increase the effect of mandates, subsidies, or taxes. A range of adaptation + options, such as disaster risk management, early warning systems, climate services + and risk spreading and sharing approaches, have broad applicability across sectors + and provide greater risk reduction benefits when combined . Climate services that + are demand-driven and inclusive of different users and providers can improve agricultural + practices, inform better water use and efficiency, and enable resilient infrastructure + planning. Policy mixes that include weather and health insurance, social protection + and adaptive safety nets, contingent finance and reserve funds, and universal + access to early warning systems combined with effective contingency plans, can + reduce vulnerability and exposure of human systems. Integrating climate adaptation + into social protection programs, including cash transfers and public works programs, + is highly feasible and increases resilience to climate change, especially when + supported by basic services and infrastructure. Social safety nets can build adaptive + capacities, reduce socioeconomic vulnerability, and reduce risk linked to hazards. Reducing + future risks of involuntary migration and displacement due to climate change is + possible through cooperative, international efforts to enhance institutional adaptive + capacity and sustainable development. Increasing adaptive capacity minimises risk + associated with involuntary migration and immobility and improves the degree of + choice under which migration decisions are made, while policy interventions can + remove barriers and expand the alternatives for safe, orderly and regular migration + that allows vulnerable people to adapt to climate change. Accelerating commitment + and follow-through by the private sector is promoted for instance by building + business cases for adaptation, accountability and transparency mechanisms, and + monitoring and evaluation of adaptation progress . Integrated pathways for managing + climate risks will be most suitable when so-called ‘low-regret’ anticipatory options + are established jointly across sectors in a timely manner and are feasible and + effective in their local context, and when path dependencies and maladaptations + across sectors are avoided. Sustained adaptation actions are strengthened by mainstreaming + adaptation into institutional budget and policy planning cycles, statutory planning, + monitoring and evaluation frameworks and into recovery efforts from disaster events. + Instruments that incorporate adaptation such as policy and legal frameworks, behavioural + incentives, and economic instruments that address market failures, such as climate + risk disclosure, inclusive and deliberative processes strengthen adaptation actions + by public and private actors. + C.5.4: + - Observed Changes, Impacts and Attribution Human activities, principally through + emissions of greenhouse gases, have unequivocally caused global warming, with + global surface temperature reaching 1.1°C above 1850–1900 in 2011–2020. Global + greenhouse gas emissions have continued to increase over 2010–2019, with unequal + historical and ongoing contributions arising from unsustainable energy use, land + use and land-use change, lifestyles and patterns of consumption and production + across regions, between and within countries, and between individuals. Human-caused + climate change is already affecting many weather and climate extremes in every + region across the globe. This has led to widespread adverse impacts on food and + water security, human health and on economies and society and related losses and + damages to nature and people. Vulnerable communities who have historically contributed + the least to current climate change are disproportionately affected. + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + C.6.1: + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + C.6.2: + - Responses Undertaken to Date International climate agreements, rising national + ambitions for climate action, along with rising public awareness are accelerating + efforts to address climate change at multiple levels of governance. Mitigation + policies have contributed to a decrease in global energy and carbon intensity, + with several countries achieving GHG emission reductions for over a decade. Low-emission + technologies are becoming more affordable, with many low or zero emissions options + now available for energy, buildings, transport, and industry. Adaptation planning + and implementation progress has generated multiple benefits, with effective adaptation + options having the potential to reduce climate risks and contribute to sustainable + development. Global tracked finance for mitigation and adaptation has seen an + upward trend since AR5, but falls short of needs. + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + C.6.3: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + C.6.4: + - Mitigation Actions to Date There has been a consistent expansion of policies + and laws addressing mitigation since AR5. Climate governance supports mitigation + by providing frameworks through which diverse actors interact, and a basis for + policy development and implementation. Many regulatory and economic instruments + have already been deployed successfully. By 2020, laws primarily focussed on reducing + GHG emissions existed in 56 countries covering 53% of global emissions. The application + of diverse policy instruments for mitigation at the national and sub-national + levels has grown consistently across a range of sectors. Policy coverage is uneven + across sectors and remains limited for emissions from agriculture, and from industrial + materials and feedstocks. Practical experience has informed economic instrument + design and helped to improve predictability, environmental effectiveness, economic + efficiency, alignment with distributional goals, and social acceptance. Low-emission + technological innovation is strengthened through the combination of technology-push + policies, together with policies that create incentives for behaviour change and + market opportunities. Comprehensive and consistent policy packages have been found + to be more effective than single policies. Combining mitigation with policies + to shift development pathways, policies that induce lifestyle or behaviour changes, + for example, measures promoting walkable urban areas combined with electrification + and renewable energy can create health co-benefits from cleaner air and enhanced + active mobility . Climate governance enables mitigation by providing an overall + direction, setting targets, mainstreaming climate action across policy domains + and levels, based on national circumstances and in the context of international + cooperation. Effective governance enhances regulatory certainty, creating specialised + organisations and creating the context to mobilise finance. These functions can + be promoted by climate-relevant laws, which are growing in number, or climate + strategies, among others, based on national and sub-national context. Effective + and equitable climate governance builds on engagement with civil society actors, + political actors, businesses, youth, labour, media, Indigenous Peoples and local + communities. The unit costs of several low-emission technologies, including solar, + wind and lithium-ion batteries, have fallen consistently since 2010. Design and + process innovations in combination with the use of digital technologies have led + to near-commercial availability of many low or zero emissions options in buildings, + transport and industry. From 2010-2019, there have been sustained decreases in + the unit costs of solar energy , wind energy, and lithium-ion batteries, and large + increases in their deployment, e.g., >10× for solar and >100× for electric vehicles, + albeit varying widely across regions. Electricity from PV and wind is now cheaper + than electricity from fossil sources in many regions, electric vehicles are increasingly + competitive with internal combustion engines, and large-scale battery storage + on electricity grids is increasingly viable. In comparison to modular small-unit + size technologies, the empirical record shows that multiple large-scale mitigation + technologies, with fewer opportunities for learning, have seen minimal cost reductions + and their adoption has grown slowly. Maintaining emission-intensive systems may, + in some regions and sectors, be more expensive than transitioning to low emission + systems. For almost all basic materials – primary metals, building materials + and chemicals – many low- to zero-GHG intensity production processes are at the + pilot to near-commercial and in some cases commercial stage but they are not yet + established industrial practice. Integrated design in construction and retrofit + of buildings has led to increasing examples of zero energy or zero carbon buildings. + Technological innovation made possible the widespread adoption of LED lighting. + Digital technologies including sensors, the internet of things, robotics, and + artificial intelligence can improve energy management in all sectors; they can + increase energy efficiency, and promote the adoption of many low-emission technologies, + including decentralised renewable energy, while creating economic opportunities. + However, some of these climate change mitigation gains can be reduced or counterbalanced + by growth in demand for goods and services due to the use of digital devices. + Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand side management, + improved forest- and crop/grassland management, and reduced food waste and loss, + are technically viable, are becoming increasingly cost effective and are generally + supported by the public, and this enables expanded deployment in many regions. The + magnitude of global climate finance flows has increased and financing channels + have broadened. Annual tracked total financial flows for climate mitigation and + adaptation increased by up to 60% between 2013/14 and 2019/20, but average growth + has slowed since 2018 and most climate finance stays within national borders. + Markets for green bonds, environmental, social and governance and sustainable + finance products have expanded significantly since AR5 . Investors, central banks, + and financial regulators are driving increased awareness of climate risk to support + climate policy development and implementation. Accelerated international financial + cooperation is a critical enabler of low-GHG and just transitions. Economic instruments + have been effective in reducing emissions, complemented by regulatory instruments + mainly at the national and also sub-national and regional level. By 2020, over + 20% of global GHG emissions were covered by carbon taxes or emissions trading + systems, although coverage and prices have been insufficient to achieve deep reductions. + Equity and distributional impacts of carbon pricing instruments can be addressed + by using revenue from carbon taxes or emissions trading to support low-income + households, among other approaches. The mix of policy instruments which reduced + costs and stimulated adoption of solar energy, wind energy and lithium-ion batteries + includes public R&D, funding for demonstration and pilot projects, and demand-pull + instruments such as deployment subsidies to attain scale . Mitigation actions, + supported by policies, have contributed to a decrease in global energy and carbon + intensity between 2010 and 2019, with a growing number of countries achieving + absolute GHG emission reductions for more than a decade . While global net GHG + emissions have increased since 2010, global energy intensity decreased by 2% yr + –1 between 2010 and 2019. Global carbon intensity also decreased by 0.3% yr –1 + , mainly due to fuel switching from coal to gas, reduced expansion of coal capacity, + and increased use of renewables, and with large regional variations over the same + period. In many countries, policies have enhanced energy efficiency, reduced rates + of deforestation and accelerated technology deployment, leading to avoided and + in some cases reduced or removed emissions. At least 18 countries have sustained + production-based CO2 and GHG and consumption-based CO2 absolute emission reductions + for longer than 10 years since 2005 through energy supply decarbonization, energy + efficiency gains, and energy demand reduction, which resulted from both policies + and changes in economic structure. Some countries have reduced production-based + GHG emissions by a third or more since peaking, and some have achieved reduction + rates of around 4% yr–1 for several years consecutively. Multiple lines of evidence + suggest that mitigation policies have led to avoided global emissions of several + GtCO 2-eq yr–1. At least 1.8 GtCO2-eq yr–1 of avoided emissions can be accounted + for by aggregating separate estimates for the effects of economic and regulatory + instruments. Growing numbers of laws and executive orders have impacted global + emissions and are estimated to have resulted in 5.9 GtCO2 -eq yr–1 of avoided + emissions in 2016. These reductions have only partly offset global emissions growth. + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + C.6.5: + - Equity and Inclusion in Climate Change Action Actions that prioritise equity, + climate justice, social justice and inclusion lead to more sustainable outcomes, + co-benefits, reduce trade-offs, support transformative change and advance climate + resilient development. Adaptation responses are immediately needed to reduce rising + climate risks, especially for the most vulnerable. Equity, inclusion and just + transitions are key to progress on adaptation and deeper societal ambitions for + accelerated mitigation. Adaptation and mitigation actions, across scales, sectors + and regions, that prioritise equity, climate justice, rights-based approaches, + social justice and inclusivity, lead to more sustainable outcomes, reduce trade-offs, + support transformative change and advance climate resilient development . Redistributive + policies across sectors and regions that shield the poor and vulnerable, social + safety nets, equity, inclusion and just transitions, at all scales can enable + deeper societal ambitions and resolve trade-offs with sustainable development + goals., particularly education, hunger, poverty, gender and energy access . Mitigation + efforts embedded within the wider development context can increase the pace, depth + and breadth of emission reductions . Equity, inclusion and just transitions at + all scales enable deeper societal ambitions for accelerated mitigation, and climate + action more broadly. The complexity in risk of rising food prices, reduced household + incomes, and health and climate-related malnutrition and mortality increases + with little or low levels of adaptation. Regions and people with considerable + development constraints have high vulnerability to climatic hazards. Adaptation + outcomes for the most vulnerable within and across countries and regions are enhanced + through approaches focusing on equity, inclusivity, and rights-based approaches, + including 3.3 to 3.6 billion people living in contexts that are highly vulnerable + to climate change. Vulnerability is higher in locations with poverty, governance + challenges and limited access to basic services and resources, violent conflict + and high levels of climate-sensitive livelihoods . Several risks can be moderated + with adaptation. The largest adaptation gaps exist among lower income population + groups and adaptation progress is unevenly distributed with observed adaptation + gaps. Present development challenges causing high vulnerability are influenced + by historical and ongoing patterns of inequity such as colonialism, especially + for many Indigenous Peoples and local communities. Vulnerability is exacerbated + by inequity and marginalisation linked to gender, ethnicity, low income or combinations + thereof, especially for many Indigenous Peoples and local communities. Meaningful + participation and inclusive planning, informed by cultural values, Indigenous + Knowledge, local knowledge, and scientific knowledge can help address adaptation + gaps and avoid maladaptation. Such actions with flexible pathways may encourage + low-regret and timely actions . Integrating climate adaptation into social protection + programmes, including cash transfers and public works programmes, would increase + resilience to climate change, especially when supported by basic services and + infrastructure. Equity, inclusion, just transitions, broad and meaningful participation + of all relevant actors in decision making at all scales enable deeper societal + ambitions for accelerated mitigation, and climate action more broadly, and build + social trust, support transformative changes and an equitable sharing of benefits + and burdens. Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries, including shifting of income and employment during the + transition from high to low emissions activities. While some jobs may be lost, + low-emissions development can also open up opportunities to enhance skills and + create jobs. Broadening equitable access to finance, technologies and governance + that facilitate mitigation, and consideration of climate justice can help equitable + sharing of benefits and burdens, especially for vulnerable countries and communities. Development + priorities among countries also reflect different starting points and contexts, + and enabling conditions for shifting development pathways towards increased sustainability + will therefore differ, giving rise to different needs . Implementing just transition + principles through collective and participatory decision-making processes is an + effective way of integrating equity principles into policies at all scales depending + on national circumstances, while in several countries just transition commissions, + task forces and national policies have been established . Many economic and regulatory + instruments have been effective in reducing emissions and practical experience + has informed instrument design to improve them while addressing distributional + goals and social acceptance. The design of behavioural interventions, including + the way that choices are presented to consumers work synergistically with price + signals, making the combination more effective. Individuals with high socio-economic + status contribute disproportionately to emissions, and have the highest potential + for emissions reductions, e.g., as citizens, investors, consumers, role models, + and professionals . There are options on design of instruments such as taxes, + subsidies, prices, and consumption-based approaches, complemented by regulatory + instruments to reduce high-emissions consumption while improving equity and societal + well-being. Behaviour and lifestyle changes to help end-users adopt low-GHG-intensive + options can be supported by policies, infrastructure and technology with multiple + co-benefits for societal well-being. Broadening equitable access to domestic and + international finance, technologies and capacity can also act as a catalyst for + accelerating mitigation and shifting development pathways in low-income contexts + . Eradicating extreme poverty, energy poverty, and providing decent living standards + to all in these regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + Technology development, transfer, capacity building and financing can support + developing countries/ regions leapfrogging or transitioning to low-emissions transport + systems thereby providing multiple co-benefits . Climate resilient development + is advanced when actors work in equitable, just and enabling ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes + . + - Society, Livelihoods, and Economies Enhancing knowledge on risks and available + adaptation options promotes societal responses, and behaviour and lifestyle changes + supported by policies, infrastructure and technology can help reduce global GHG + emissions. Climate literacy and information provided through climate services + and community approaches, including those that are informed by Indigenous Knowledge + and local knowledge, can accelerate behavioural changes and planning . Educational + and information programmes, using the arts, participatory modelling and citizen + science can facilitate awareness, heighten risk perception, and influence behaviours + . The way choices are presented can enable adoption of low GHG intensive socio-cultural + options, such as shifts to balanced, sustainable healthy diets, reduced food waste, + and active mobility. Judicious labelling, framing, and communication of social + norms can increase the effect of mandates, subsidies, or taxes. A range of adaptation + options, such as disaster risk management, early warning systems, climate services + and risk spreading and sharing approaches, have broad applicability across sectors + and provide greater risk reduction benefits when combined . Climate services that + are demand-driven and inclusive of different users and providers can improve agricultural + practices, inform better water use and efficiency, and enable resilient infrastructure + planning. Policy mixes that include weather and health insurance, social protection + and adaptive safety nets, contingent finance and reserve funds, and universal + access to early warning systems combined with effective contingency plans, can + reduce vulnerability and exposure of human systems. Integrating climate adaptation + into social protection programs, including cash transfers and public works programs, + is highly feasible and increases resilience to climate change, especially when + supported by basic services and infrastructure. Social safety nets can build adaptive + capacities, reduce socioeconomic vulnerability, and reduce risk linked to hazards. Reducing + future risks of involuntary migration and displacement due to climate change is + possible through cooperative, international efforts to enhance institutional adaptive + capacity and sustainable development. Increasing adaptive capacity minimises risk + associated with involuntary migration and immobility and improves the degree of + choice under which migration decisions are made, while policy interventions can + remove barriers and expand the alternatives for safe, orderly and regular migration + that allows vulnerable people to adapt to climate change. Accelerating commitment + and follow-through by the private sector is promoted for instance by building + business cases for adaptation, accountability and transparency mechanisms, and + monitoring and evaluation of adaptation progress . Integrated pathways for managing + climate risks will be most suitable when so-called ‘low-regret’ anticipatory options + are established jointly across sectors in a timely manner and are feasible and + effective in their local context, and when path dependencies and maladaptations + across sectors are avoided. Sustained adaptation actions are strengthened by mainstreaming + adaptation into institutional budget and policy planning cycles, statutory planning, + monitoring and evaluation frameworks and into recovery efforts from disaster events. + Instruments that incorporate adaptation such as policy and legal frameworks, behavioural + incentives, and economic instruments that address market failures, such as climate + risk disclosure, inclusive and deliberative processes strengthen adaptation actions + by public and private actors. + - Governance and Policy for Near-Term Climate Change Action Effective climate action + requires political commitment, well-aligned multi-level governance and institutional + frameworks, laws, policies and strategies. It needs clear goals, adequate finance + and financing tools, coordination across multiple policy domains, and inclusive + governance processes. Many mitigation and adaptation policy instruments have been + deployed successfully, and could support deep emissions reductions and climate + resilience if scaled up and applied widely, depending on national circumstances. + Adaptation and mitigation action benefits from drawing on diverse knowledge. Effective + climate governance enables mitigation and adaptation by providing overall direction + based on national circumstances, setting targets and priorities, mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. Effective governance enhances + monitoring and evaluation and regulatory certainty, prioritising inclusive, transparent + and equitable decision-making, and improves access to finance and technology. + These functions can be promoted by climate-relevant laws and plans, which are + growing in number across sectors and regions, advancing mitigation outcomes and + adaptation benefits . Climate laws have been growing in number and have helped + deliver mitigation and adaptation outcomes . Effective municipal, national and + sub-national climate institutions, such as expert and co-ordinating bodies, enable + co-produced, multi-scale decision-processes, build consensus for action among + diverse interests, and inform strategy settings . This requires adequate institutional + capacity at all levels. Vulnerabilities and climate risks are often reduced through + carefully designed and implemented laws, policies, participatory processes, and + interventions that address context specific inequities such as based on gender, + ethnicity, disability, age, location and income. Policy support is influenced + by Indigenous Peoples, businesses, and actors in civil society, including, youth, + labour, media, and local communities, and effectiveness is enhanced by partnerships + between many different groups in society . Climate-related litigation is growing, + with a large number of cases in some developed countries and with a much smaller + number in some developing countries, and in some cases has influenced the outcome + and ambition of climate governance. Effective climate governance is enabled by + inclusive decision processes, allocation of appropriate resources, and institutional + review, monitoring and evaluation. Multi-level, hybrid and cross-sector governance + facilitates appropriate consideration for co-benefits and trade-offs, particularly + in land sectors where decision processes range from farm level to national scale. + Consideration of climate justice can help to facilitate shifting development pathways + towards sustainability. Drawing on diverse knowledge and partnerships, including + with women, youth, Indigenous Peoples, local communities, and ethnic minorities + can facilitate climate resilient development and has allowed locally appropriate + and socially acceptable solutions. Many regulatory and economic instruments have + already been deployed successfully. These instruments could support deep emissions + reductions if scaled up and applied more widely. Practical experience has informed + instrument design and helped to improve predictability, environmental effectiveness, + economic efficiency, and equity. Scaling up and enhancing the use of regulatory + instruments, consistent with national circumstances, can improve mitigation outcomes + in sectoral applications, and regulatory instruments that include flexibility + mechanisms can reduce costs of cutting emissions. Where implemented, carbon pricing + instruments have incentivized low-cost emissions reduction measures, but have + been less effective, on their own and at prevailing prices during the assessment + period, to promote higher-cost measures necessary for further reductions. Revenue + from carbon taxes or emissions trading can be used for equity and distributional + goals, for example to support low-income households, among other approaches. There + is no consistent evidence that current emission trading systems have led to significant + emissions leakage. Removing fossil fuel subsidies would reduce emissions, improve + public revenue and macroeconomic performance, and yield other environmental and + sustainable development benefits such as improved public revenue, macroeconomic + and sustainability performance; subsidy removal can have adverse distributional + impacts especially on the most economically vulnerable groups which, in some cases, + can be mitigated by measures such as re-distributing revenue saved, and depend + on national circumstances. Fossil fuel subsidy removal is projected by various + studies to reduce global CO 2 emissions by 1–4%, and GHG emissions by up to 10% + by 2030, varying across regions . National policies to support technology development, + and participation in international markets for emission reduction, can bring positive + spillover effects for other countries , although reduced demand for fossil fuels + as a result of climate policy could result in costs to exporting countries . Economy-wide + packages can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Examples are public spending commitments; + pricing reforms; and investment in education and training, R&D and infrastructure. + Effective policy packages would be comprehensive in coverage, harnessed to a clear + vision for change, balanced across objectives, aligned with specific technology + and system needs, consistent in terms of design and tailored to national circumstances + . + C.7.1: + - Finance for Mitigation and Adaptation Actions Improved availability and access + to finance will enable accelerated climate action. Addressing needs and gaps and + broadening equitable access to domestic and international finance, when combined + with other supportive actions, can act as a catalyst for accelerating mitigation + and shifting development pathways. Climate resilient development is enabled by + increased international cooperation including improved access to financial resources, + particularly for vulnerable regions, sectors and groups, and inclusive governance + and coordinated policies . Accelerated international financial cooperation is + a critical enabler of low-GHG and just transitions, and can address inequities + in access to finance and the costs of, and vulnerability to, the impacts of climate + change. Both adaptation and mitigation finance need to increase many-fold, to + address rising climate risks and to accelerate investments in emissions reduction. + Increased finance would address soft limits to adaptation and rising climate risks + while also averting some related losses and damages, particularly in vulnerable + developing countries. Enhanced mobilisation of and access to finance, together + with building capacity, are essential for implementation of adaptation actions + and to reduce adaptation gaps given rising risks and costs, especially for the + most vulnerable groups, regions and sectors . Public finance is an important enabler + of adaptation and mitigation, and can also leverage private finance. Adaptation + funding predominately comes from public sources, and public mechanisms and finance + can leverage private sector finance by addressing real and perceived regulatory, + cost and market barriers, for instance via public-private partnerships. Financial + and technological resources enable effective and ongoing implementation of adaptation, + especially when supported by institutions with a strong understanding of adaptation + needs and capacity. Average annual modelled mitigation investment requirements + for 2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a factor + of three to six greater than current levels, and total mitigation investments + would need to increase across all sectors and regions. Even if extensive global + mitigation efforts are implemented, there will be a large need for financial, + technical, and human resources for adaptation . + C.7.3: + - Finance for Mitigation and Adaptation Actions Improved availability and access + to finance will enable accelerated climate action. Addressing needs and gaps and + broadening equitable access to domestic and international finance, when combined + with other supportive actions, can act as a catalyst for accelerating mitigation + and shifting development pathways. Climate resilient development is enabled by + increased international cooperation including improved access to financial resources, + particularly for vulnerable regions, sectors and groups, and inclusive governance + and coordinated policies . Accelerated international financial cooperation is + a critical enabler of low-GHG and just transitions, and can address inequities + in access to finance and the costs of, and vulnerability to, the impacts of climate + change. Both adaptation and mitigation finance need to increase many-fold, to + address rising climate risks and to accelerate investments in emissions reduction. + Increased finance would address soft limits to adaptation and rising climate risks + while also averting some related losses and damages, particularly in vulnerable + developing countries. Enhanced mobilisation of and access to finance, together + with building capacity, are essential for implementation of adaptation actions + and to reduce adaptation gaps given rising risks and costs, especially for the + most vulnerable groups, regions and sectors . Public finance is an important enabler + of adaptation and mitigation, and can also leverage private finance. Adaptation + funding predominately comes from public sources, and public mechanisms and finance + can leverage private sector finance by addressing real and perceived regulatory, + cost and market barriers, for instance via public-private partnerships. Financial + and technological resources enable effective and ongoing implementation of adaptation, + especially when supported by institutions with a strong understanding of adaptation + needs and capacity. Average annual modelled mitigation investment requirements + for 2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a factor + of three to six greater than current levels, and total mitigation investments + would need to increase across all sectors and regions. Even if extensive global + mitigation efforts are implemented, there will be a large need for financial, + technical, and human resources for adaptation . + C.7.4: + - Finance for Mitigation and Adaptation Actions Improved availability and access + to finance will enable accelerated climate action. Addressing needs and gaps and + broadening equitable access to domestic and international finance, when combined + with other supportive actions, can act as a catalyst for accelerating mitigation + and shifting development pathways. Climate resilient development is enabled by + increased international cooperation including improved access to financial resources, + particularly for vulnerable regions, sectors and groups, and inclusive governance + and coordinated policies . Accelerated international financial cooperation is + a critical enabler of low-GHG and just transitions, and can address inequities + in access to finance and the costs of, and vulnerability to, the impacts of climate + change. Both adaptation and mitigation finance need to increase many-fold, to + address rising climate risks and to accelerate investments in emissions reduction. + Increased finance would address soft limits to adaptation and rising climate risks + while also averting some related losses and damages, particularly in vulnerable + developing countries. Enhanced mobilisation of and access to finance, together + with building capacity, are essential for implementation of adaptation actions + and to reduce adaptation gaps given rising risks and costs, especially for the + most vulnerable groups, regions and sectors . Public finance is an important enabler + of adaptation and mitigation, and can also leverage private finance. Adaptation + funding predominately comes from public sources, and public mechanisms and finance + can leverage private sector finance by addressing real and perceived regulatory, + cost and market barriers, for instance via public-private partnerships. Financial + and technological resources enable effective and ongoing implementation of adaptation, + especially when supported by institutions with a strong understanding of adaptation + needs and capacity. Average annual modelled mitigation investment requirements + for 2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a factor + of three to six greater than current levels, and total mitigation investments + would need to increase across all sectors and regions. Even if extensive global + mitigation efforts are implemented, there will be a large need for financial, + technical, and human resources for adaptation . + C.7.5: + - 'Technology Innovation, Adoption, Diffusion and Transfer Enhancing technology + innovation systems can provide opportunities to lower emissions growth and create + social and environmental co-benefits. Policy packages tailored to national contexts + and technological characteristics have been effective in supporting low-emission + innovation and technology diffusion. Support for successful low-carbon technological + innovation includes public policies such as training and R&D, complemented by + regulatory and market-based instruments that create incentives and market opportunities + such as appliance performance standards and building codes. International cooperation + on innovation systems and technology development and transfer, accompanied by + capacity building, knowledge sharing, and technical and financial support can + accelerate the global diffusion of mitigation technologies, practices and policies + and align these with other development objectives. Choice architecture can help + end-users adopt technology and low-GHG-intensive options. Adoption of low-emission + technologies lags in most developing countries, particularly least developed ones, + due in part to weaker enabling conditions, including limited finance, technology + development and transfer, and capacity building. International cooperation on + innovation works best when tailored to and beneficial for local value chains, + when partners collaborate on an equal footing, and when capacity building is an + integral part of the effort. Technological innovation can have trade-offs that + include externalities such as new and greater environmental impacts and social + inequalities; rebound effects leading to lower net emission reductions or even + emission increases; and overdependence on foreign knowledge and providers. Appropriately + designed policies and governance have helped address distributional impacts and + rebound effects. For example, digital technologies can promote large increases + in energy efficiency through coordination and an economic shift to services. However, + societal digitalization can induce greater consumption of goods and energy and + increased electronic waste as well as negatively impacting labour markets and + worsening inequalities between and within countries. Digitalisation requires appropriate + governance and policies in order to enhance mitigation potential. Effective policy + packages can help to realise synergies, avoid trade-offs and/or reduce rebound + effects: these might include a mix of efficiency targets, performance standards, + information provision, carbon pricing, finance and technical assistance . Technology + transfer to expand use of digital technologies for land use monitoring, sustainable + land management, and improved agricultural productivity supports reduced emissions + from deforestation and land use change while also improving GHG accounting and + standardisation .' +paragraph_topics: + A.1.1: Observed Warming and its Causes + A.1.3: Observed Warming and its Causes + A.1.5: Observed Warming and its Causes + A.2.1: Observed Changes and Impacts + A.2.2: Observed Changes and Impacts + A.2.3: Observed Changes and Impacts + A.2.4: Observed Changes and Impacts + A.2.5: Observed Changes and Impacts + A.2.6: Observed Changes and Impacts + A.2.7: Observed Changes and Impacts + A.3.1: Current Progress in Adaptation and Gaps and Challenges + A.3.2: Current Progress in Adaptation and Gaps and Challenges + A.3.3: Current Progress in Adaptation and Gaps and Challenges + A.3.6: Current Progress in Adaptation and Gaps and Challenges + A.4.1: Current Mitigation Progress, Gaps and Challenges + A.4.2: Current Mitigation Progress, Gaps and Challenges + A.4.3: Current Mitigation Progress, Gaps and Challenges + A.4.4: Current Mitigation Progress, Gaps and Challenges + A.4.5: Current Mitigation Progress, Gaps and Challenges + B.1.1: Future Climate Change + B.1.4: Future Climate Change + B.1.5: Future Climate Change + B.2.1: Climate Change Impacts and Climate-Related Risks + B.2.2: Climate Change Impacts and Climate-Related Risks + B.3.1: Likelihood and Risks of Unavoidable, Irreversible or Abrupt Changes + B.3.2: Likelihood and Risks of Unavoidable, Irreversible or Abrupt Changes + B.4.1: Adaptation Options and their Limits in a Warmer World + B.4.2: Adaptation Options and their Limits in a Warmer World + B.4.3: Adaptation Options and their Limits in a Warmer World + B.5.1: Carbon Budgets and Net Zero Emissions + B.5.3: Carbon Budgets and Net Zero Emissions + B.6.1: Mitigation Pathways + B.6.2: Mitigation Pathways + B.6.3: Mitigation Pathways + B.6.4: Mitigation Pathways + B.7.1: 'Overshoot: Exceeding a Warming Level and Returning' + B.7.2: 'Overshoot: Exceeding a Warming Level and Returning' + B.7.3: 'Overshoot: Exceeding a Warming Level and Returning' + C.1.1: Urgency of Near-Term Integrated Climate Action + C.1.2: Urgency of Near-Term Integrated Climate Action + C.1.3: Urgency of Near-Term Integrated Climate Action + C.2.1: The Benefits of Near-Term Action + C.2.2: The Benefits of Near-Term Action + C.2.3: The Benefits of Near-Term Action + C.2.4: The Benefits of Near-Term Action + C.2.5: The Benefits of Near-Term Action + C.3.1: Mitigation and Adaptation Options across Systems + C.3.2: Mitigation and Adaptation Options across Systems + C.3.3: Mitigation and Adaptation Options across Systems + C.3.4: Mitigation and Adaptation Options across Systems + C.3.5: Mitigation and Adaptation Options across Systems + C.3.6: Mitigation and Adaptation Options across Systems + C.3.7: Mitigation and Adaptation Options across Systems + C.3.8: Mitigation and Adaptation Options across Systems + C.4.1: Synergies and Trade-Offs with Sustainable Development + C.4.2: Synergies and Trade-Offs with Sustainable Development + C.4.3: Synergies and Trade-Offs with Sustainable Development + C.5.1: Equity and Inclusion + C.5.2: Equity and Inclusion + C.5.3: Equity and Inclusion + C.5.4: Equity and Inclusion + C.6.1: Governance and Policies + C.6.2: Governance and Policies + C.6.3: Governance and Policies + C.6.4: Governance and Policies + C.6.5: Governance and Policies + C.7.1: Finance, Technology and International Cooperation + C.7.3: Finance, Technology and International Cooperation + C.7.4: Finance, Technology and International Cooperation + C.7.5: Finance, Technology and International Cooperation +pointers: + A.1.1: + - 2.1.1 + A.1.3: + - 2.1.1 + A.1.5: + - 2.1.1 + A.2.1: + - 2.1.2 + A.2.2: + - 2.1.2 + - '4.4' + A.2.3: + - 2.1.2 + A.2.4: + - 2.1.2 + A.2.5: + - 2.1.2 + A.2.6: + - 2.1.2 + A.2.7: + - 2.1.2 + A.3.1: + - 2.2.3 + A.3.2: + - 2.2.3 + A.3.3: + - 2.3.2 + A.3.6: + - 2.3.2 + - 2.3.3 + A.4.1: + - 2.2.1 + - 2.2.2 + A.4.2: + - 2.2.2 + A.4.3: + - 2.3.1 + - '4.1' + A.4.4: + - 2.2.2 + - 2.3.1 + - 3.1.1 + A.4.5: + - 2.2.2 + - 2.3.1 + - 2.3.3 + B.1.1: + - 3.1.1 + - 3.3.4 + - '4.3' + B.1.4: + - 3.1.1 + - 3.1.3 + B.1.5: + - '4.3' + B.2.1: + - '4.3' + B.2.2: + - 3.1.2 + - 3.1.3 + B.3.1: + - 3.1.3 + B.3.2: + - 3.1.2 + - 3.1.3 + B.4.1: + - '3.2' + - '4.1' + - '4.2' + B.4.2: + - 2.3.2 + - '3.2' + - '4.3' + B.4.3: + - 2.3.2 + - '3.2' + B.5.1: + - 3.1.1 + - 3.3.1 + - 3.3.2 + - 3.3.3 + B.5.3: + - 2.3.1 + - 3.3.1 + B.6.1: + - 3.3.2 + - 3.3.4 + - '4.1' + B.6.2: + - 3.3.2 + - 3.3.3 + B.6.3: + - 3.3.3 + - '4.1' + - '4.5' + B.6.4: + - 3.4.1 + B.7.1: + - 3.3.2 + - 3.3.4 + B.7.2: + - 3.1.2 + - 3.3.4 + B.7.3: + - 3.3.3 + - 3.3.4 + - 3.4.1 + C.1.1: + - '3.4' + - 3.4.2 + - '4.1' + C.1.2: + - '3.4' + - '4.2' + - '4.4' + - '4.5' + - '4.7' + - '4.8' + C.1.3: + - 3.1.3 + - 3.3.3 + - 3.4.1 + - '4.1' + - '4.2' + - '4.3' + - '4.4' + C.2.1: + - '4.1' + - '4.2' + - '4.3' + C.2.2: + - 2.1.2 + - 3.1.2 + - '3.2' + - 3.3.1 + - 3.3.3 + - '4.1' + - '4.2' + - '4.3' + C.2.3: + - '4.2' + - 4.5.4 + - 4.5.5 + - '4.6' + C.2.4: + - 3.4.1 + - '4.2' + C.2.5: + - '4.2' + - '4.4' + - '4.7' + - 4.8.1 + C.3.1: + - '4.1' + - 4.5.1 + - 4.5.6 + - 4.5.2 + - 4.5.3 + - 4.5.4 + - 4.5.5 + C.3.2: + - 4.5.1 + C.3.3: + - 4.5.2 + - 4.5.3 + C.3.4: + - 4.5.3 + C.3.5: + - 4.5.4 + C.3.6: + - 4.5.4 + - '4.6' + C.3.7: + - 4.5.5 + C.3.8: + - 4.5.6 + C.4.1: + - '4.4' + - '4.6' + C.4.2: + - 3.4.1 + - '4.6' + - '4.9' + C.4.3: + - '4.2' + - 4.5.3 + - 4.5.5 + - '4.6' + - '4.9' + C.5.1: + - '4.4' + C.5.2: + - '4.4' + C.5.3: + - '4.4' + - 4.5.3 + - 4.5.5 + - 4.5.6 + C.5.4: + - '2.1' + - '4.4' + C.6.1: + - 2.2.2 + - '4.7' + C.6.2: + - '2.2' + - '4.7' + C.6.3: + - '4.4' + - '4.7' + C.6.4: + - 2.2.2 + - '4.7' + C.6.5: + - '4.4' + - 4.5.6 + - '4.7' + C.7.1: + - 4.8.1 + C.7.3: + - 4.8.1 + C.7.4: + - 4.8.1 + C.7.5: + - 4.8.3 +section_topics: + A.1.1: Current Status and Trends + A.1.3: Current Status and Trends + A.1.5: Current Status and Trends + A.2.1: Current Status and Trends + A.2.2: Current Status and Trends + A.2.3: Current Status and Trends + A.2.4: Current Status and Trends + A.2.5: Current Status and Trends + A.2.6: Current Status and Trends + A.2.7: Current Status and Trends + A.3.1: Current Status and Trends + A.3.2: Current Status and Trends + A.3.3: Current Status and Trends + A.3.6: Current Status and Trends + A.4.1: Current Status and Trends + A.4.2: Current Status and Trends + A.4.3: Current Status and Trends + A.4.4: Current Status and Trends + A.4.5: Current Status and Trends + B.1.1: Future Climate Change, Risks, and Long-Term Responses + B.1.4: Future Climate Change, Risks, and Long-Term Responses + B.1.5: Future Climate Change, Risks, and Long-Term Responses + B.2.1: Future Climate Change, Risks, and Long-Term Responses + B.2.2: Future Climate Change, Risks, and Long-Term Responses + B.3.1: Future Climate Change, Risks, and Long-Term Responses + B.3.2: Future Climate Change, Risks, and Long-Term Responses + B.4.1: Future Climate Change, Risks, and Long-Term Responses + B.4.2: Future Climate Change, Risks, and Long-Term Responses + B.4.3: Future Climate Change, Risks, and Long-Term Responses + B.5.1: Future Climate Change, Risks, and Long-Term Responses + B.5.3: Future Climate Change, Risks, and Long-Term Responses + B.6.1: Future Climate Change, Risks, and Long-Term Responses + B.6.2: Future Climate Change, Risks, and Long-Term Responses + B.6.3: Future Climate Change, Risks, and Long-Term Responses + B.6.4: Future Climate Change, Risks, and Long-Term Responses + B.7.1: Future Climate Change, Risks, and Long-Term Responses + B.7.2: Future Climate Change, Risks, and Long-Term Responses + B.7.3: Future Climate Change, Risks, and Long-Term Responses + C.1.1: Responses in the Near Term + C.1.2: Responses in the Near Term + C.1.3: Responses in the Near Term + C.2.1: Responses in the Near Term + C.2.2: Responses in the Near Term + C.2.3: Responses in the Near Term + C.2.4: Responses in the Near Term + C.2.5: Responses in the Near Term + C.3.1: Responses in the Near Term + C.3.2: Responses in the Near Term + C.3.3: Responses in the Near Term + C.3.4: Responses in the Near Term + C.3.5: Responses in the Near Term + C.3.6: Responses in the Near Term + C.3.7: Responses in the Near Term + C.3.8: Responses in the Near Term + C.4.1: Responses in the Near Term + C.4.2: Responses in the Near Term + C.4.3: Responses in the Near Term + C.5.1: Responses in the Near Term + C.5.2: Responses in the Near Term + C.5.3: Responses in the Near Term + C.5.4: Responses in the Near Term + C.6.1: Responses in the Near Term + C.6.2: Responses in the Near Term + C.6.3: Responses in the Near Term + C.6.4: Responses in the Near Term + C.6.5: Responses in the Near Term + C.7.1: Responses in the Near Term + C.7.3: Responses in the Near Term + C.7.4: Responses in the Near Term + C.7.5: Responses in the Near Term +summaries: + A.1.1: Global surface temperature was 1.09 [0.95 to 1.20]°C5 higher in 2011–2020 + than 1850–19006, with larger increases over land than over the ocean. Global + surface temperature in the first two decades of the 21st century was 0.99 [0.84 + to 1.10]°C higher than 1850–1900. Global surface temperature has increased faster + since 1970 than in any other 50-year period over at least the last 2000 years. + The likely range of total human-caused global surface temperature increase from + 1850–1900 to 2010–20197 is 0.8°C to 1.3°C, with a best estimate of 1.07°C. Over + this period, it is likely that well-mixed greenhouse gases contributed a warming + of 1.0°C to 2.0°C8, and other human drivers contributed a cooling of 0.0°C to + 0.8°C, natural drivers changed global surface temperature by –0.1°C to +0.1°C, + and internal variability changed it by –0.2°C to +0.2°C. + A.1.3: Observed increases in well-mixed GHG concentrations since around 1750 are + unequivocally caused by GHG emissions from human activities over this period. + Historical cumulative net CO2 emissions from 1850 to 2019 were 2400 ± 240 GtCO2 + of which more than half occurred between 1850 and 1989, and about 42% occurred + between 1990 and 2019 . In 2019, atmospheric CO2 concentrations were higher than + at any time in at least 2 million years, and concentrations of methane and nitrous + oxide were higher than at any time in at least 800, years. Global net anthropogenic + GHG emissions have been estimated to be 59 ± 6.6 GtCO2-eq9 in 2019, about 12% higher + than in 2010 and 54% higher than in 1990, with the largest share and growth in + gross GHG emissions occurring in CO2 from fossil fuels combustion and industrial + processes followed by methane, whereas the highest relative growth occurred in + fluorinated gases, starting from low levels in 1990. Average annual GHG emissions + during 2010–2019 were higher than in any previous decade on record, while the + rate of growth between 2010 and 2019 was lower than that between 2000 and 2009. + In 2019, approximately 79% of global GHG emissions came from the sectors of energy, + industry, transport, and buildings together and 22%10 from agriculture, forestry + and other land use. Emissions reductions in CO2-FFI due to improvements in energy + intensity of GDP and carbon intensity of energy, have been less than emissions + increases from rising global activity levels in industry, energy supply, transport, + agriculture and buildings. + A.1.5: Historical contributions of CO2 emissions vary substantially across regions + in terms of total magnitude, but also in terms of contributions to CO2-FFI and + net CO2 emissions from land use, land-use change and forestry. In 2019, around + 35% of the global population live in countries emitting more than 9 tCO2-eq per + capita while 41% live in countries emitting less than 3 tCO2-eq per capita; of + the latter a substantial share lacks access to modern energy services. Least Developed + Countries and Small Island Developing States have much lower per capita emissions + than the global average, excluding CO2-LULUCF. The 10% of households with the + highest per capita emissions contribute 34–45% of global consumption-based household + GHG emissions, while the bottom 50% contribute 13–15%. + A.2.1: It is unequivocal that human influence has warmed the atmosphere, ocean and + land. Global mean sea level increased by 0.20 [0.15 to 0.25] m between 1901 and + 2018. The average rate of sea level rise was 1.3 [0.6 to 2.1] mm yr-1 between + 1901 and 1971, increasing to 1.9 [0.8 to 2.9] mm yr-1 between 1971 and 2006, and + further increasing to 3.7 [3.2 to 4.2] mm yr-1 between 2006 and 2018. Human influence + was very likely the main driver of these increases since at least 1971. Evidence + of observed changes in extremes such as heatwaves, heavy precipitation, droughts, + and tropical cyclones, and, in particular, their attribution to human influence, + has further strengthened since AR5. Human influence has likely increased the chance + of compound extreme events since the 1950s, including increases in the frequency + of concurrent heatwaves and droughts. + A.2.2: Approximately 3.3 to 3.6 billion people live in contexts that are highly + vulnerable to climate change. Human and ecosystem vulnerability are interdependent. + Regions and people with considerable development constraints have high vulnerability + to climatic hazards. Increasing weather and climate extreme events have exposed + millions of people to acute food insecurity and reduced water security, with the + largest adverse impacts observed in many locations and/or communities in Africa, + Asia, Central and South America, LDCs, Small Islands and the Arctic, and globally + for Indigenous Peoples, small-scale food producers and low-income households. + Between 2010 and 2020, human mortality from floods, droughts and storms was 15 + times higher in highly vulnerable regions, compared to regions with very low vulnerability. + A.2.3: Climate change has caused substantial damages, and increasingly irreversible + losses, in terrestrial, freshwater, cryospheric, and coastal and open ocean ecosystems. + Hundreds of local losses of species have been driven by increases in the magnitude + of heat extremes with mass mortality events recorded on land and in the ocean. + Impacts on some ecosystems are approaching irreversibility such as the impacts + of hydrological changes resulting from the retreat of glaciers, or the changes + in some mountain and Arctic ecosystems driven by permafrost thaw. + A.2.4: Climate change has reduced food security and affected water security, hindering + efforts to meet Sustainable Development Goals. Although overall agricultural + productivity has increased, climate change has slowed this growth over the past + 50 years globally, with related negative impacts mainly in midand low latitude + regions but positive impacts in some high latitude regions. Ocean warming and + ocean acidification have adversely affected food production from fisheries and + shellfish aquaculture in some oceanic regions. Roughly half of the world’s population + currently experience severe water scarcity for at least part of the year due to + a combination of climatic and non-climatic drivers. + A.2.5: In all regions increases in extreme heat events have resulted in human mortality + and morbidity . The occurrence of climate-related food-borne and water-borne + diseases and the incidence of vector-borne diseases have increased. In assessed + regions, some mental health challenges are associated with increasing temperatures, + trauma from extreme events, and loss of livelihoods and culture. Climate and weather + extremes are increasingly driving displacement in Africa, Asia, North America, + and Central and South America, with small island states in the Caribbean and South + Pacific being disproportionately affected relative to their small population size + . + A.2.6: Climate change has caused widespread adverse impacts and related losses and + damages to nature and people that are unequally distributed across systems, regions + and sectors. Economic damages from climate change have been detected in climate-exposed + sectors, such as agriculture, forestry, fishery, energy, and tourism. Individual + livelihoods have been affected through, for example, destruction of homes and + infrastructure, and loss of property and income, human health and food security, + with adverse effects on gender and social equity. + A.2.7: In urban areas, observed climate change has caused adverse impacts on human + health, livelihoods and key infrastructure. Hot extremes have intensified in + cities. Urban infrastructure, including transportation, water, sanitation and + energy systems have been compromised by extreme and slow-onset events, with resulting + economic losses, disruptions of services and negative impacts to well-being. Observed + adverse impacts are concentrated amongst economically and socially marginalised + urban residents. + A.3.1: Progress in adaptation planning and implementation has been observed across + all sectors and regions, generating multiple benefits. Growing public and political + awareness of climate impacts and risks has resulted in at least 170 countries + and many cities including adaptation in their climate policies and planning processes + . + A.3.2: 'Effectiveness of adaptation in reducing climate risks16 is documented for + specific contexts, sectors and regions . Examples of effective adaptation options + include: cultivar improvements, on-farm water management and storage, soil moisture + conservation, irrigation, agroforestry, community-based adaptation, farm and landscape + level diversification in agriculture, sustainable land management approaches, + use of agroecological principles and practices and other approaches that work + with natural processes. Ecosystem-based adaptation approaches such as urban greening, + restoration of wetlands and upstream forest ecosystems have been effective in + reducing flood risks and urban heat. Combinations of non-structural measures like + early warning systems and structural measures like levees have reduced loss of + lives in case of inland flooding. Adaptation options such as disaster risk management, + early warning systems, climate services and social safety nets have broad applicability + across multiple sectors.' + A.3.3: Most observed adaptation responses are fragmented, incremental, sector-specific + and unequally distributed across regions. Despite progress, adaptation gaps exist + across sectors and regions, and will continue to grow under current levels of + implementation, with the largest adaptation gaps among lower income groups. There + is increased evidence of maladaptation in various sectors and regions. Maladaptation + especially affects marginalised and vulnerable groups adversely. Soft limits + to adaptation are currently being experienced by small-scale farmers and households + along some low- lying coastal areas resulting from financial, governance, institutional + and policy constraints . Some tropical, coastal, polar and mountain ecosystems + have reached hard adaptation limits . Adaptation does not prevent all losses and + damages, even with effective adaptation and before reaching soft and hard limits. + A.3.6: Key barriers to adaptation are limited resources, lack of private sector + and citizen engagement, insufficient mobilization of finance, low climate literacy, + lack of political commitment, limited research and/or slow and low uptake of adaptation + science, and low sense of urgency. There are widening disparities between the + estimated costs of adaptation and the finance allocated to adaptation. Adaptation + finance has come predominantly from public sources, and a small proportion of + global tracked climate finance was targeted to adaptation and an overwhelming + majority to mitigation. Although global tracked climate finance has shown an upward + trend since AR5, current global financial flows for adaptation, including from + public and private finance sources, are insufficient and constrain implementation + of adaptation options, especially in developing countries . Adverse climate impacts + can reduce the availability of financial resources by incurring losses and damages + and through impeding national economic growth, thereby further increasing financial + constraints for adaptation, particularly for developing and least developed countries. + A.4.1: The UNFCCC, Kyoto Protocol, and the Paris Agreement are supporting rising + levels of national ambition. The Paris Agreement, adopted under the UNFCCC, with + near universal participation, has led to policy development and target-setting + at national and sub-national levels, in particular in relation to mitigation, + as well as enhanced transparency of climate action and support. Many regulatory + and economic instruments have already been deployed successfully . In many countries, + policies have enhanced energy efficiency, reduced rates of deforestation and accelerated + technology deployment, leading to avoided and in some cases reduced or removed + emissions . Multiple lines of evidence suggest that mitigation policies have led + to several Gt CO2-eq yr-1 of avoided global emissions. At least 18 countries have + sustained absolute production-based GHG and consumption-based CO2 reductions for + longer than 10 years. These reductions have only partly offset global emissions + growth. + A.4.2: Several mitigation options, notably solar energy, wind energy, electrification + of urban systems, urban green infrastructure, energy efficiency, demand-side + management, improved forest and crop/grassland management, and reduced food waste + and loss, are technically viable, are becoming increasingly cost effective and + are generally supported by the public. From 2010 to 2019 there have been sustained + decreases in the unit costs of solar energy, wind energy , and lithium-ion batteries, + and large increases in their deployment, e.g., >10× for solar and >100× for electric + vehicles, varying widely across regions. The mix of policy instruments that reduced + costs and stimulated adoption includes public R&D, funding for demonstration and + pilot projects, and demand-pull instruments such as deployment subsidies to attain + scale. Maintaining emission-intensive systems may, in some regions and sectors, + be more expensive than transitioning to low emission systems. + A.4.3: A substantial ‘emissions gap’ exists between global GHG emissions in 2030 + associated with the implementation of NDCs announced prior to COP2626 and those + associated with modelled mitigation pathways that limit warming to 1.5°C with + no or limited overshoot or limit warming to 2°C assuming immediate action. This + would make it likely that warming will exceed 1.5°C during the 21st century. Global + modelled mitigation pathways that limit warming to 1.5°C with no or limited overshoot + or limit warming to 2°C assuming immediate action imply deep global GHG emissions + reductions this decade 27. Modelled pathways that are consistent with NDCs announced + prior to COP26 until 2030 and assume no increase in ambition thereafter have higher + emissions, leading to a median global warming of 2.8 [2.1 to 3.4] °C by 2100 . + Many countries have signalled an intention to achieve net zero GHG or net zero + CO2 by around mid-century but pledges differ across countries in terms of scope + and specificity, and limited policies are to date in place to deliver on them. + A.4.4: Policy coverage is uneven across sectors . Policies implemented by the end + of 2020 are projected to result in higher global GHG emissions in 2030 than emissions + implied by NDCs, indicating an ‘implementation gap’ . Without a strengthening + of policies, global warming of 3.2 [2.2 to 3.5] °C is projected by 2100 . + A.4.5: The adoption of low-emission technologies lags in most developing countries, + particularly least developed ones, due in part to limited finance, technology + development and transfer, and capacity. The magnitude of climate finance flows + has increased over the last decade and financing channels have broadened but growth + has slowed since 2018. Financial flows have developed heterogeneously across regions + and sectors . Public and private finance flows for fossil fuels are still greater + than those for climate adaptation and mitigation. The overwhelming majority of + tracked climate finance is directed towards mitigation, but nevertheless falls + short of the levels needed to limit warming to below 2°C or to 1.5°C across all + sectors and regions. In 2018, public and publicly mobilised private climate finance + flows from developed to developing countries were below the collective goal under + the UNFCCC and Paris Agreement to mobilise USD 100 billion per year by 2020 in + the context of meaningful mitigation action and transparency on implementation + . + B.1.1: Global warming will continue to increase in the near term mainly due to + increased cumulative CO2 emissions in nearly all considered scenarios and modelled + pathways. In the near term, global warming is more likely than not to reach 1.5°C + even under the very low GHG emission scenario and likely or very likely to exceed + 1.5°C under higher emissions scenarios. In the considered scenarios and modelled + pathways, the best estimates of the time when the level of global warming of 1.5°C + is reached lie in the near term. Global warming declines back to below 1.5°C by + the end of the 21st century in some scenarios and modelled pathways. The assessed + climate response to GHG emissions scenarios results in a best estimate of warming + for 2081–2100 that spans a range from 1.4°C for a very low GHG emissions scenario + to 2.7°C for an intermediate GHG emissions scenario and 4.4°C for a very high + GHG emissions scenario 30, with narrower uncertainty ranges than for corresponding + scenarios in AR5. Discernible differences in trends of global surface temperature + between contrasting GHG emissions scenarios would begin to emerge from natural + variability within around 20 years. Under these contrasting scenarios, discernible + effects would emerge within years for GHG concentrations, and sooner for air quality + improvements, due to the combined targeted air pollution controls and strong and + sustained methane emissions reductions. Targeted reductions of air pollutant emissions + lead to more rapid improvements in air quality within years compared to reductions + in GHG emissions only, but in the long term, further improvements are projected + in scenarios that combine efforts to reduce air pollutants as well as GHG emissions. + Continued emissions will further affect all major climate system components. With + every additional increment of global warming, changes in extremes continue to + become larger. Continued global warming is projected to further intensify the + global water cycle, including its variability, global monsoon precipitation, and + very wet and very dry weather and climate events and seasons. In scenarios with + increasing CO2 emissions, natural land and ocean carbon sinks are projected to + take up a decreasing proportion of these emissions. Other projected changes include + further reduced extents and/or volumes of almost all cryospheric elements, further + global mean sea level rise, and increased ocean acidification and deoxygenation + . + B.1.4: With further warming, every region is projected to increasingly experience + concurrent and multiple changes in climatic impact-drivers. Compound heatwaves + and droughts are projected to become more frequent, including concurrent events + across multiple locations. Due to relative sea level rise, current 1-in-100 year + extreme sea level events are projected to occur at least annually in more than + half of all tide gauge locations by 2100 under all considered scenarios. Other + projected regional changes include intensification of tropical cyclones and/or + extratropical storms, and increases in aridity and fire weather. + B.1.5: Natural variability will continue to modulate human-caused climate changes, + either attenuating or amplifying projected changes, with little effect on centennial-scale + global warming. These modulations are important to consider in adaptation planning, + especially at the regional scale and in the near term. If a large explosive volcanic + eruption were to occur, it would temporarily and partially mask human-caused climate + change by reducing global surface temperature and precipitation for one to three + years. + B.2.1: In the near term, every region in the world is projected to face further + increases in climate hazards , increasing multiple risks to ecosystems and humans + . Hazards and associated risks expected in the near term include an increase in + heat-related human mortality and morbidity, food-borne, water-borne, and vector-borne + diseases, and mental health challenges, flooding in coastal and other low-lying + cities and regions, biodiversity loss in land, freshwater and ocean ecosystems, + and a decrease in food production in some regions. Cryosphere-related changes + in floods, landslides, and water availability have the potential to lead to severe + consequences for people, infrastructure and the economy in most mountain regions. + The projected increase in frequency and intensity of heavy precipitation will + increase rain-generated local flooding. + B.2.2: Risks and projected adverse impacts and related losses and damages from climate + change will escalate with every increment of global warming. They are higher + for global warming of 1.5°C than at present, and even higher at 2°C. Compared + to the AR5, global aggregated risk levels are assessed to become high to very + high at lower levels of global warming due to recent evidence of observed impacts, + improved process understanding, and new knowledge on exposure and vulnerability + of human and natural systems, including limits to adaptation. Due to unavoidable + sea level rise, risks for coastal ecosystems, people and infrastructure will continue + to increase beyond 2100. With further warming, climate change risks will become + increasingly complex and more difficult to manage. Multiple climatic and non-climatic + risk drivers will interact, resulting in compounding overall risk and risks cascading + across sectors and regions. Climate-driven food insecurity and supply instability, + for example, are projected to increase with increasing global warming, interacting + with non-climatic risk drivers such as competition for land between urban expansion + and food production, pandemics and conflict. For any given warming level, the + level of risk will also depend on trends in vulnerability and exposure of humans + and ecosystems. Future exposure to climatic hazards is increasing globally due + to socio-economic development trends including migration, growing inequality and + urbanisation. Human vulnerability will concentrate in informal settlements and + rapidly growing smaller settlements. In rural areas vulnerability will be heightened + by high reliance on climatesensitive livelihoods. Vulnerability of ecosystems + will be strongly influenced by past, present, and future patterns of unsustainable + consumption and production, increasing demographic pressures, and persistent unsustainable + use and management of land, ocean, and water. Loss of ecosystems and their services + has cascading and long-term impacts on people globally, especially for Indigenous + Peoples and local communities who are directly dependent on ecosystems to meet + basic needs. + B.3.1: Limiting global surface temperature does not prevent continued changes in + climate system components that have multi-decadal or longer timescales of response. + Sea level rise is unavoidable for centuries to millennia due to continuing deep + ocean warming and ice sheet melt, and sea levels will remain elevated for thousands + of years . However, deep, rapid, and sustained GHG emissions reductions would + limit further sea level rise acceleration and projected long-term sea level rise + commitment. Relative to 1995–2014, the likely global mean sea level rise under + the SSP1-1.9 GHG emissions scenario is 0.15–0.23 m by 2050 and 0.28–0.55 m by + 2100; while for the SSP5-8.5 GHG emissions scenario it is 0.20–0.29 m by 2050 + and 0.63–1.01 m by 2100. Over the next 2000 years, global mean sea level will + rise by about 2–3 m if warming is limited to 1.5°C and 2–6 m if limited to 2°C. + B.3.2: The likelihood and impacts of abrupt and/or irreversible changes in the climate + system, including changes triggered when tipping points are reached, increase + with further global warming. As warming levels increase, so do the risks of species + extinction or irreversible loss of biodiversity in ecosystems including forests, + coral reefs and in Arctic regions. At sustained warming levels between 2°C and + 3°C, the Greenland and West Antarctic ice sheets will be lost almost completely + and irreversibly over multiple millennia, causing several metres of sea level + rise. The probability and rate of ice mass loss increase with higher global surface + temperatures. The probability of low-likelihood outcomes associated with potentially + very large impacts increases with higher global warming levels. Due to deep uncertainty + linked to ice-sheet processes, global mean sea level rise above the likely range + – approaching 2 m by 2100 and in excess of 15 m by 2300 under the very high GHG + emissions scenario – cannot be excluded. There is medium confidence that the + Atlantic Meridional Overturning Circulation will not collapse abruptly before + 2100, but if it were to occur, it would very likely cause abrupt shifts in regional + weather patterns, and large impacts on ecosystems and human activities. + B.4.1: The effectiveness of adaptation, including ecosystem-based and most water-related + options, will decrease with increasing warming. The feasibility and effectiveness + of options increase with integrated, multi-sectoral solutions that differentiate + responses based on climate risk, cut across systems and address social inequities. + As adaptation options often have long implementation times, long-term planning + increases their efficiency. + B.4.2: With additional global warming, limits to adaptation and losses and damages, + strongly concentrated among vulnerable populations, will become increasingly + difficult to avoid. Above 1.5°C of global warming, limited freshwater resources + pose potential hard adaptation limits for small islands and for regions dependent + on glacier and snow melt. Above that level, ecosystems such as some warm-water + coral reefs, coastal wetlands, rainforests, and polar and mountain ecosystems + will have reached or surpassed hard adaptation limits and as a consequence, some + Ecosystem-based Adaptation measures will also lose their effectiveness. + B.4.3: Actions that focus on sectors and risks in isolation and on short-term gains + often lead to maladaptation over the long term, creating lock-ins of vulnerability, + exposure and risks that are difficult to change. For example, seawalls effectively + reduce impacts to people and assets in the short term but can also result in lock-ins + and increase exposure to climate risks in the long term unless they are integrated + into a long-term adaptive plan. Maladaptive responses can worsen existing inequities + especially for Indigenous Peoples and marginalised groups and decrease ecosystem + and biodiversity resilience. Maladaptation can be avoided by flexible, multi-sectoral, + inclusive, long-term planning and implementation of adaptation actions, with co-benefits + to many sectors and systems. + B.5.1: From a physical science perspective, limiting human-caused global warming + to a specific level requires limiting cumulative CO2 emissions, reaching at least + net zero CO2 emissions, along with strong reductions in other greenhouse gas emissions. + Reaching net zero GHG emissions primarily requires deep reductions in CO2, methane, + and other GHG emissions, and implies net negative CO2 emissions. Carbon dioxide + removal will be necessary to achieve net negative CO2 emissions. Net zero GHG + emissions, if sustained, are projected to result in a gradual decline in global + surface temperatures after an earlier peak. For every 1000 GtCO2 emitted by human + activity, global surface temperature rises by 0.45°C . The best estimates of the + remaining carbon budgets from the beginning of 2020 are 500 GtCO2 for a 50% likelihood + of limiting global warming to 1.5°C and 1150 GtCO2 for a 67% likelihood of limiting + warming to 2°C40. The stronger the reductions in non-CO2 emissions, the lower + the resulting temperatures are for a given remaining carbon budget or the larger + remaining carbon budget for the same level of temperature change. + B.5.3: If the annual CO2 emissions between 2020–2030 stayed, on average, at the + same level as 2019, the resulting cumulative emissions would almost exhaust the + remaining carbon budget for 1.5°C, and deplete more than a third of the remaining + carbon budget for 2°C. Estimates of future CO2 emissions from existing fossil + fuel infrastructures without additional abatement already exceed the remaining + carbon budget for limiting warming to 1.5°C . Projected cumulative future CO2 + emissions over the lifetime of existing and planned fossil fuel infrastructure, + if historical operating patterns are maintained and without additional abatement, + are approximately equal to the remaining carbon budget for limiting warming to + 2°C with a likelihood of 83%44. + B.6.1: 'Global modelled pathways provide information on limiting warming to different + levels; these pathways, particularly their sectoral and regional aspects, depend + on the assumptions described in Box SPM.1. Global modelled pathways that limit + warming to 1.5°C with no or limited overshoot or limit warming to 2°C are characterized + by deep, rapid, and, in most cases, immediate GHG emissions reductions. Pathways + that limit warming to 1.5 °C with no or limited overshoot reach net zero CO2 in + the early 2050s, followed by net negative CO2 emissions. Those pathways that reach + net zero GHG emissions do so around the 2070s. Pathways that limit warming to + 2 °C reach net zero CO2 emissions in the early 2070s. Global GHG emissions are + projected to peak between 2020 and at the latest before 2025 in global modelled + pathways that limit warming to 1.5°C with no or limited overshoot and in those + that limit warming to 2°C and assume immediate action. ' + B.6.2: Reaching net zero CO2 or GHG emissions primarily requires deep and rapid + reductions in gross emissions of CO2, as well as substantial reductions of non-CO2 + GHG emissions. For example, in modelled pathways that limit warming to 1.5°C with + no or limited overshoot, global methane emissions are reduced by 34 [21–57] % + by 2030 relative to 2019. However, some hard-to-abate residual GHG emissions remain + and would need to be counterbalanced by deployment of CDR methods to achieve net + zero CO2 or GHG emissions. As a result, net zero CO2 is reached earlier than net + zero GHGs. + B.6.3: Global modelled mitigation pathways reaching net zero CO2 and GHG emissions + include transitioning from fossil fuels without carbon capture and storage to + very low- or zero-carbon energy sources, such as renewables or fossil fuels with + CCS, demand-side measures and improving efficiency, reducing non-CO2 GHG emissions, + and CDR47. In most global modelled pathways, land-use change and forestry and + the energy supply sector reach net zero CO2 emissions earlier than the buildings, + industry and transport sectors. + B.6.4: Mitigation options often have synergies with other aspects of sustainable + development, but some options can also have trade-offs. There are potential synergies + between sustainable development and, for instance, energy efficiency and renewable + energy. Similarly, depending on the context, biological CDR methods like reforestation, + improved forest management, soil carbon sequestration, peatland restoration and + coastal blue carbon management can enhance biodiversity and ecosystem functions, + employment and local livelihoods. However, afforestation or production of biomass + crops can have adverse socio-economic and environmental impacts, including on + biodiversity, food and water security, local livelihoods and the rights of Indigenous + Peoples, especially if implemented at large scales and where land tenure is insecure. + Modelled pathways that assume using resources more efficiently or that shift global + development towards sustainability include fewer challenges, such as less dependence + on CDR and pressure on land and biodiversity. + B.7.1: Only a small number of the most ambitious global modelled pathways limit + global warming to 1.5°C by 2100 without exceeding this level temporarily. Achieving + and sustaining net negative global CO2 emissions, with annual rates of CDR greater + than residual CO2 emissions, would gradually reduce the warming level again. Adverse + impacts that occur during this period of overshoot and cause additional warming + via feedback mechanisms, such as increased wildfires, mass mortality of trees, + drying of peatlands, and permafrost thawing, weakening natural land carbon sinks + and increasing releases of GHGs would make the return more challenging. + B.7.2: The higher the magnitude and the longer the duration of overshoot, the more + ecosystems and societies are exposed to greater and more widespread changes in + climatic impact-drivers, increasing risks for many natural and human systems. + Compared to pathways without overshoot, societies would face higher risks to infrastructure, + low-lying coastal settlements, and associated livelihoods. Overshooting 1.5°C + will result in irreversible adverse impacts on certain ecosystems with low resilience, + such as polar, mountain, and coastal ecosystems, impacted by ice-sheet melt, glacier + melt, or by accelerating and higher committed sea level rise. + B.7.3: 'The larger the overshoot, the more net negative CO2 emissions would be needed + to return to 1.5°C by 2100. Transitioning towards net zero CO2 emissions faster + and reducing non-CO2 emissions such as methane more rapidly would limit peak warming + levels and reduce the requirement for net negative CO2 emissions, thereby reducing + feasibility and sustainability concerns, and social and environmental risks associated + with CDR deployment at large scales. ' + C.1.1: Evidence of observed adverse impacts and related losses and damages, projected + risks, levels and trends in vulnerability and adaptation limits, demonstrate + that worldwide climate resilient development action is more urgent than previously + assessed in AR5. Climate resilient development integrates adaptation and GHG mitigation + to advance sustainable development for all. Climate resilient development pathways + have been constrained by past development, emissions and climate change and are + progressively constrained by every increment of warming, in particular beyond + 1.5°C. + C.1.2: 'Government actions at sub-national, national and international levels, with + civil society and the private sector, play a crucial role in enabling and accelerating + shifts in development pathways towards sustainability and climate resilient development. + Climate resilient development is enabled when governments, civil society and the + private sector make inclusive development choices that prioritize risk reduction, + equity and justice, and when decision-making processes, finance and actions are + integrated across governance levels, sectors, and timeframes . Enabling conditions + are differentiated by national, regional and local circumstances and geographies, + according to capabilities, and include: political commitment and follow-through, + coordinated policies, social and international cooperation, ecosystem stewardship, + inclusive governance, knowledge diversity, technological innovation, monitoring + and evaluation, and improved access to adequate financial resources, especially + for vulnerable regions, sectors and communities.' + C.1.3: Continued emissions will further affect all major climate system components, + and many changes will be irreversible on centennial to millennial time scales + and become larger with increasing global warming. Without urgent, effective, and + equitable mitigation and adaptation actions, climate change increasingly threatens + ecosystems, biodiversity, and the livelihoods, health and well-being of current + and future generations. + C.2.1: Deep, rapid, and sustained mitigation and accelerated implementation of adaptation + actions in this decade would reduce future losses and damages related to climate + change for humans and ecosystems. As adaptation options often have long implementation + times, accelerated implementation of adaptation in this decade is important to + close adaptation gaps. Comprehensive, effective, and innovative responses integrating + adaptation and mitigation can harness synergies and reduce trade-offs between + adaptation and mitigation . + C.2.2: Delayed mitigation action will further increase global warming and losses + and damages will rise and additional human and natural systems will reach adaptation + limits. Challenges from delayed adaptation and mitigation actions include the + risk of cost escalation, lock-in of infrastructure, stranded assets, and reduced + feasibility and effectiveness of adaptation and mitigation options. Without rapid, + deep and sustained mitigation and accelerated adaptation actions, losses and damages + will continue to increase, including projected adverse impacts in Africa, LDCs, + SIDS, Central and South America, Asia and the Arctic, and will disproportionately + affect the most vulnerable populations. + C.2.3: Accelerated climate action can also provide co-benefits . Many mitigation + actions would have benefits for health through lower air pollution, active mobility, + and shifts to sustainable healthy diets. Strong, rapid and sustained reductions + in methane emissions can limit near-term warming and improve air quality by reducing + global surface ozone. Adaptation can generate multiple additional benefits such + as improving agricultural productivity, innovation, health and well-being, food + security, livelihood, and biodiversity conservation. + C.2.4: Cost-benefit analysis remains limited in its ability to represent all avoided + damages from climate change . The economic benefits for human health from air + quality improvement arising from mitigation action can be of the same order of + magnitude as mitigation costs, and potentially even larger. Even without accounting + for all the benefits of avoiding potential damages, the global economic and social + benefit of limiting global warming to 2°C exceeds the cost of mitigation in most + of the assessed literature 50. More rapid climate change mitigation, with emissions + peaking earlier, increases co-benefits and reduces feasibility risks and costs + in the long-term, but requires higher up-front investments. + C.2.5: Ambitious mitigation pathways imply large and sometimes disruptive changes + in existing economic structures, with significant distributional consequences + within and between countries. To accelerate climate action, the adverse consequences + of these changes can be moderated by fiscal, financial, institutional and regulatory + reforms and by integrating climate actions with macroeconomic policies through + economy-wide packages, consistent with national circumstances, supporting sustainable + low-emission growth paths; climate resilient safety nets and social protection; + and improved access to finance for low-emissions infrastructure and technologies, + especially in developing countries. + C.3.1: 'The systemic change required to achieve rapid and deep emissions reductions + and transformative adaptation to climate change is unprecedented in terms of + scale, but not necessarily in terms of speed. Systems transitions include: deployment + of low- or zero-emission technologies; reducing and changing demand through infrastructure + design and access, socio-cultural and behavioural changes, and increased technological + efficiency and adoption; social protection, climate services or other services; + and protecting and restoring ecosystems. Feasible, effective, and low-cost options + for mitigation and adaptation are already available. The availability, feasibility + and potential of mitigation and adaptation options in the near term differs across + systems and regions .' + C.3.2: 'Net zero CO2 energy systems entail: a substantial reduction in overall fossil + fuel use, minimal use of unabated fossil fuels, and use of carbon capture and + storage in the remaining fossil fuel systems; electricity systems that emit no + net CO2; widespread electrification; alternative energy carriers in applications + less amenable to electrification; energy conservation and efficiency; and greater + integration across the energy system. Large contributions to emissions reductions + with costs less than USD 20 tCO2-eq-1 come from solar and wind energy, energy + efficiency improvements, and methane emissions reductions. There are feasible + adaptation options that support infrastructure resilience, reliable power systems + and efficient water use for existing and new energy generation systems. Energy + generation diversification and demand-side management can increase energy reliability + and reduce vulnerabilities to climate change. Climate responsive energy markets, + updated design standards on energy assets according to current and projected climate + change, smart-grid technologies, robust transmission systems and improved capacity + to respond to supply deficits have high feasibility in the medium to long term, + with mitigation co-benefits.' + C.3.3: Reducing industry GHG emissions entails coordinated action throughout value + chains to promote all mitigation options, including demand management, energy + and materials efficiency, circular material flows, as well as abatement technologies + and transformational changes in production processes. In transport, sustainable + biofuels, low-emissions hydrogen, and derivatives can support mitigation of CO2 + emissions from shipping, aviation, and heavy-duty land transport but require production + process improvements and cost reductions. Sustainable biofuels can offer additional + mitigation benefits in land-based transport in the short and medium term. Electric + vehicles powered by low-GHG emissions electricity have large potential to reduce + land-based transport GHG emissions, on a life cycle basis. Advances in battery + technologies could facilitate the electrification of heavy-duty trucks and compliment + conventional electric rail systems. The environmental footprint of battery production + and growing concerns about critical minerals can be addressed by material and + supply diversification strategies, energy and material efficiency improvements, + and circular material flows. + C.3.4: Urban systems are critical for achieving deep emissions reductions and advancing + climate resilient development . Key adaptation and mitigation elements in cities + include considering climate change impacts and risks in the design and planning + of settlements and infrastructure; land use planning to achieve compact urban + form, co-location of jobs and housing; supporting public transport and active + mobility ; the efficient design, construction, retrofit, and use of buildings; + reducing and changing energy and material consumption; sufficiency; material substitution; + and electrification in combination with low emissions sources. Urban transitions + that offer benefits for mitigation, adaptation, human health and wellbeing, ecosystem + services, and vulnerability reduction for low-income communities are fostered + by inclusive long-term planning that takes an integrated approach to physical, + natural and social infrastructure. Green/ natural and blue infrastructure supports + carbon uptake and storage and either singly or when combined with grey infrastructure + can reduce energy use and risk from extreme events such as heatwaves, flooding, + heavy precipitation and droughts, while generating co-benefits for health, well-being + and livelihoods. + C.3.5: Many agriculture, forestry, and other land use options provide adaptation + and mitigation benefits that could be upscaled in the near term across most regions. + Conservation, improved management, and restoration of forests and other ecosystems + offer the largest share of economic mitigation potential, with reduced deforestation + in tropical regions having the highest total mitigation potential. Ecosystem restoration, + reforestation, and afforestation can lead to trade-offs due to competing demands + on land. Minimizing trade-offs requires integrated approaches to meet multiple + objectives including food security. Demand-side measures and sustainable agricultural + intensification can reduce ecosystem conversion, and methane and nitrous oxide + emissions, and free up land for reforestation and ecosystem restoration. Sustainably + sourced agricultural and forest products, including long-lived wood products, + can be used instead of more GHG-intensive products in other sectors. Effective + adaptation options include cultivar improvements, agroforestry, community-based + adaptation, farm and landscape diversification, and urban agriculture. These AFOLU + response options require integration of biophysical, socioeconomic and other enabling + factors. Some options, such as conservation of high-carbon ecosystems , deliver + immediate benefits, while others, such as restoration of high-carbon ecosystems, + take decades to deliver measurable results. + C.3.6: Maintaining the resilience of biodiversity and ecosystem services at a global + scale depends on effective and equitable conservation of approximately 30% to + 50% of Earth’s land, freshwater and ocean areas, including currently nearnatural + ecosystems. Conservation, protection and restoration of terrestrial, freshwater, + coastal and ocean ecosystems, together with targeted management to adapt to unavoidable + impacts of climate change reduces the vulnerability of biodiversity and ecosystem + services to climate change, reduces coastal erosion and flooding, and could increase + carbon uptake and storage if global warming is limited . Rebuilding overexploited + or depleted fisheries reduces negative climate change impacts on fisheries and + supports food security, biodiversity, human health and well-being. Land restoration + contributes to climate change mitigation and adaptation with synergies via enhanced + ecosystem services and with economically positive returns and co-benefits for + poverty reduction and improved livelihoods. Cooperation, and inclusive decision + making, with Indigenous Peoples and local communities, as well as recognition + of inherent rights of Indigenous Peoples, is integral to successful adaptation + and mitigation across forests and other ecosystems. + C.3.7: 'Human health will benefit from integrated mitigation and adaptation options + that mainstream health into food, infrastructure, social protection, and water + policies. Effective adaptation options exist to help protect human health and + well-being, including: strengthening public health programs related to climate-sensitive + diseases, increasing health systems resilience, improving ecosystem health, improving + access to potable water, reducing exposure of water and sanitation systems to + flooding, improving surveillance and early warning systems, vaccine development, + improving access to mental healthcare, and Heat Health Action Plans that include + early warning and response systems. Adaptation strategies which reduce food loss + and waste or support balanced, sustainable healthy diets contribute to nutrition, + health, biodiversity and other environmental benefits.' + C.3.8: Policy mixes that include weather and health insurance, social protection + and adaptive social safety nets, contingent finance and reserve funds, and universal + access to early warning systems combined with effective contingency plans, can + reduce vulnerability and exposure of human systems. Disaster risk management, + early warning systems, climate services and risk spreading and sharing approaches + have broad applicability across sectors. Increasing education including capacity + building, climate literacy, and information provided through climate services + and community approaches can facilitate heightened risk perception and accelerate + behavioural changes and planning. + C.4.1: Mitigation efforts embedded within the wider development context can increase + the pace, depth and breadth of emission reductions. Countries at all stages of + economic development seek to improve the well-being of people, and their development + priorities reflect different starting points and contexts. Different contexts + include but are not limited to social, economic, environmental, cultural, political + circumstances, resource endowment, capabilities, international environment, and + prior development. In regions with high dependency on fossil fuels for, among + other things, revenue and employment generation, mitigating risk for sustainable + development requires policies that promote economic and energy sector diversification + and considerations of just transitions principles, processes and practices. Eradicating + extreme poverty, energy poverty, and providing decent living standards in low-emitting + countries / regions in the context of achieving sustainable development objectives, + in the near term, can be achieved without significant global emissions growth. + C.4.2: Many mitigation and adaptation actions have multiple synergies with Sustainable + Development Goals and sustainable development generally, but some actions can + also have trade-offs. Potential synergies with SDGs exceed potential trade-offs; + synergies and trade-offs depend on the pace and magnitude of change and the development + context including inequalities with consideration of climate justice. Trade-offs + can be evaluated and minimised by giving emphasis to capacity building, finance, + governance, technology transfer, investments, development, context specific gender-based + and other social equity considerations with meaningful participation of Indigenous + Peoples, local communities and vulnerable populations. + C.4.3: Implementing both mitigation and adaptation actions together and taking trade-offs + into account supports co-benefits and synergies for human health and well-being. + For example, improved access to clean energy sources and technologies generates + health benefits especially for women and children; electrification combined with + low-GHG energy, and shifts to active mobility and public transport can enhance + air quality, health, employment, and can elicit energy security and deliver equity. + C.5.1: Equity remains a central element in the UN climate regime, notwithstanding + shifts in differentiation between states over time and challenges in assessing + fair shares. Ambitious mitigation pathways imply large and sometimes disruptive + changes in economic structure, with significant distributional consequences, within + and between countries. Distributional consequences within and between countries + include shifting of income and employment during the transition from high- to + low-emissions activities. + C.5.2: Adaptation and mitigation actions that prioritise equity, social justice, + climate justice, rights-based approaches, and inclusivity, lead to more sustainable + outcomes, reduce trade-offs, support transformative change and advance climate + resilient development. Redistributive policies across sectors and regions that + shield the poor and vulnerable, social safety nets, equity, inclusion and just + transitions, at all scales can enable deeper societal ambitions and resolve tradeoffs + with sustainable development goals. Attention to equity and broad and meaningful + participation of all relevant actors in decision making at all scales can build + social trust which builds on equitable sharing of benefits and burdens of mitigation + that deepen and widen support for transformative changes. + C.5.3: 'Regions and people with considerable development constraints have high + vulnerability to climatic hazards. Adaptation outcomes for the most vulnerable + within and across countries and regions are enhanced through approaches focusing + on equity, inclusivity and rights-based approaches. Vulnerability is exacerbated + by inequity and marginalisation linked to e.g., gender, ethnicity, low incomes, + informal settlements, disability, age, and historical and ongoing patterns of + inequity such as colonialism, especially for many Indigenous Peoples and local + communities. Integrating climate adaptation into social protection programs, including + cash transfers and public works programs, is highly feasible and increases resilience + to climate change, especially when supported by basic services and infrastructure. + The greatest gains in well-being in urban areas can be achieved by prioritising + access to finance to reduce climate risk for low-income and marginalised communities + including people living in informal settlements. ' + C.5.4: The design of regulatory instruments and economic instruments and consumption-based + approaches, can advance equity. Individuals with high socio-economic status contribute + disproportionately to emissions, and have the highest potential for emissions + reductions. Many options are available for reducing emission-intensive consumption + while improving societal well-being. Socio-cultural options, behaviour and lifestyle + changes supported by policies, infrastructure, and technology can help end-users + shift to low-emissions-intensive consumption, with multiple co-benefits. A substantial + share of the population in low-emitting countries lack access to modern energy + services. Technology development, transfer, capacity building and financing can + support developing countries / regions leapfrogging or transitioning to low-emissions + transport systems thereby providing multiple co-benefits. Climate resilient development + is advanced when actors work in equitable, just and inclusive ways to reconcile + divergent interests, values and worldviews, toward equitable and just outcomes. + C.6.1: Effective climate governance enables mitigation and adaptation. Effective + governance provides overall direction on setting targets and priorities and mainstreaming + climate action across policy domains and levels, based on national circumstances + and in the context of international cooperation. It enhances monitoring and evaluation + and regulatory certainty, prioritising inclusive, transparent and equitable decision-making, + and improves access to finance and technology. + C.6.2: Effective local, municipal, national and subnational institutions build consensus + for climate action among diverse interests, enable coordination and inform strategy + setting but require adequate institutional capacity. Policy support is influenced + by actors in civil society, including businesses, youth, women, labour, media, + Indigenous Peoples, and local communities. Effectiveness is enhanced by political + commitment and partnerships between different groups in society. + C.6.3: 'Effective multilevel governence for mitigation, adaptation, risk management, + and climate resilient development is enabled by inclusive decision processes + that prioritise equity and justice in planning and implementation, allocation + of appropriate resources, institutional review, and monitoring and evaluation. + Vulnerabilities and climate risks are often reduced through carefully designed + and implemented laws, policies, participatory processes, and interventions that + address context specific inequities such as those based on gender, ethnicity, + disability, age, location and income. ' + C.6.4: Regulatory and economic instruments could support deep emissions reductions + if scaled up and applied more widely . Scaling up and enhancing the use of regulatory + instruments can improve mitigation outcomes in sectoral applications, consistent + with national circumstances. Where implemented, carbon pricing instruments have + incentivized low-cost emissions reduction measures but have been less effective, + on their own and at prevailing prices during the assessment period, to promote + higher-cost measures necessary for further reductions . Equity and distributional + impacts of such carbon pricing instruments, e.g., carbon taxes and emissions trading, + can be addressed by using revenue to support low-income households, among other + approaches. Removing fossil fuel subsidies would reduce emissions and yield benefits + such as improved public revenue, macroeconomic and sustainability performance; + subsidy removal can have adverse distributional impacts, especially on the most + economically vulnerable groups which, in some cases can be mitigated by measures + such as redistributing revenue saved, all of which depend on national circumstances. + Economy-wide policy packages, such as public spending commitments and pricing + reforms, can meet short-term economic goals while reducing emissions and shifting + development pathways towards sustainability. Effective policy packages would be + comprehensive, consistent, balanced across objectives, and tailored to national + circumstances. + C.6.5: Drawing on diverse knowledges and cultural values, meaningful participation + and inclusive engagement processes— including Indigenous Knowledge, local knowledge, + and scientific knowledge—facilitates climate resilient development, builds capacity + and allows locally appropriate and socially acceptable solutions. + C.7.1: Improved availability of and access to finance55 would enable accelerated + climate action . Addressing needs and gaps and broadening equitable access to + domestic and international finance, when combined with other supportive actions, + can act as a catalyst for accelerating adaptation and mitigation, and enabling + climate resilient development. If climate goals are to be achieved, and to address + rising risks and accelerate investments in emissions reductions, both adaptation + and mitigation finance would need to increase many-fold . Increased access to + finance can build capacity and address soft limits to adaptation and avert rising + risks, especially for developing countries, vulnerable groups, regions and sectors. + Public finance is an important enabler of adaptation and mitigation, and can also + leverage private finance. Average annual modelled mitigation investment requirements + for 2020 to 2030 in scenarios that limit warming to 2°C or 1.5°C are a factor + of three to six greater than current levels, and total mitigation investments + would need to increase across all sectors and regions. Even if extensive global + mitigation efforts are implemented, there will be a need for financial, technical, + and human resources for adaptation. + C.7.3: 'There is sufficient global capital and liquidity to close global investment + gaps, given the size of the global financial system, but there are barriers to + redirect capital to climate action both within and outside the global financial + sector and in the context of economic vulnerabilities and indebtedness facing + developing countries. Reducing financing barriers for scaling up financial flows + would require clear signalling and support by governments, including a stronger + alignment of public finances in order to lower real and perceived regulatory, + cost and market barriers and risks and improving the risk-return profile of investments. + At the same time, depending on national contexts, financial actors, including + investors, financial intermediaries, central banks and financial regulators can + shift the systemic underpricing of climaterelated risks, and reduce sectoral and + regional mismatches between available capital and investment needs. ' + C.7.4: 'Tracked financial flows fall short of the levels needed for adaptation and + to achieve mitigation goals across all sectors and regions. These gaps create + many opportunities and the challenge of closing gaps is largest in developing + countries. Accelerated financial support for developing countries from developed + countries and other sources is a critical enabler to enhance adaptation and mitigation + actions and address inequities in access to finance, including its costs, terms + and conditions, and economic vulnerability to climate change for developing countries. + Scaled-up public grants for mitigation and adaptation funding for vulnerable regions, + especially in Sub-Saharan Africa, would be cost-effective and have high social + returns in terms of access to basic energy. Options for scaling up mitigation + in developing countries include: increased levels of public finance and publicly + mobilised private finance flows from developed to developing countries in the + context of the USD 100 billion-a-year goal; increased use of public guarantees + to reduce risks and leverage private flows at lower cost; local capital markets + development; and building greater trust in international cooperation processes. + A coordinated effort to make the post-pandemic recovery sustainable over the longer-term + can accelerate climate action, including in developing regions and countries facing + high debt costs, debt distress and macroeconomic uncertainty.' + C.7.5: 'Enhancing technology innovation systems can provide opportunities to lower + emissions growth, create social and environmental co-benefits, and achieve other + SDGs. Policy packages tailored to national contexts and technological characteristics + have been effective in supporting low-emission innovation and technology diffusion. + Public policies can support training and R&D, complemented by both regulatory + and market-based instruments that create incentives and market opportunities. + Technological innovation can have trade-offs such as new and greater environmental + impacts, social inequalities, overdependence on foreign knowledge and providers, + distributional impacts and rebound effects, requiring appropriate governance and + policies to enhance potential and reduce trade-offs. Innovation and adoption of + low-emission technologies lags in most developing countries, particularly least + developed ones, due in part to weaker enabling conditions, including limited finance, + technology development and transfer, and capacity building. ' +summary_topics: + A.1.1: Global Surface Temperature + A.1.3: GHG Emissions + A.1.5: CO2 Emissions + A.2.1: Human Influence + A.2.2: Vulnerability + A.2.3: Damages + A.2.4: Food Security + A.2.5: Mortality and Disease + A.2.6: Damage Distribution + A.2.7: Urban Environment + A.3.1: Progress in Adaptation + A.3.2: Effectiveness of Adaptation + A.3.3: Gaps and Limits in Adaptation + A.3.6: Barriers to Adaptation + A.4.1: International Agreements + A.4.2: Mitigation Options + A.4.3: Emission Gap + A.4.4: Policy Coverage + A.4.5: Adoption of Technology + B.1.1: Global Warming Projections + B.1.4: Future Effects of Global Warming + B.1.5: Natural Variability + B.2.1: Climate Hazards + B.2.2: Risks and Impact + B.3.1: Unavoidable Changes + B.3.2: Likelihood of Unavoidable Changes + B.4.1: Decrease in Effectiveness of Adaptation + B.4.2: Limits to Adaptation + B.4.3: Maladaptation + B.5.1: Reasons to Limit CO2 + B.5.3: Effects of Not Limiting CO2 + B.6.1: Pathways for Limiting Warming + B.6.2: Reacing Net Zero Emissions + B.6.3: Transitioning from Fossil Fuel + B.6.4: Mitigation Synergies + B.7.1: Likelihood of Overshoot + B.7.2: Degree of Overshoot + B.7.3: Returning after Overshoot + C.1.1: Urgency of Action + C.1.2: Insitutional Action + C.1.3: Risks of Continued Emissions + C.2.1: Benefits of Adaptation and Mitigation + C.2.2: Risks of Delayed Mitigation + C.2.3: Co-Benefits + C.2.4: Cost-benefit Analysis + C.2.5: Economic Changes + C.3.1: Scale of Change Required + C.3.2: Reaching Net Zero CO2 + C.3.3: Reducing GHG Emissions + C.3.4: Urban Systems + C.3.5: Agricolture, Forestry and Land Use + C.3.6: Conservation of Ecosystems and Biodiversity + C.3.7: Human Health + C.3.8: Policies + C.4.1: Synergies with Different National Contexts + C.4.2: Synergies with Sustainable Development Goals + C.4.3: Co-benefits + C.5.1: Equity + C.5.2: Sustainable outcomes + C.5.3: Vulnerable Regions and People + C.5.4: Regulations + C.6.1: Governance + C.6.2: Insitutions + C.6.3: Decision Processes + C.6.4: Policy and Economic Instruments + C.6.5: Diversity and Local Knowledge + C.7.1: Financing + C.7.3: Investment Gaps + C.7.4: Gaps in Financing + C.7.5: Technological Innovation +titles: + A.1.1: + - 'Observed Warming and its Causes + + ' + A.1.3: + - 'Observed Warming and its Causes + + ' + A.1.5: + - 'Observed Warming and its Causes + + ' + A.2.1: + - 'Observed Climate System Changes and Impacts to + + ' + A.2.2: + - 'Observed Climate System Changes and Impacts to + + ' + - 'Equity and Inclusion in Climate Change Action + + ' + A.2.3: + - 'Observed Climate System Changes and Impacts to + + ' + A.2.4: + - 'Observed Climate System Changes and Impacts to + + ' + A.2.5: + - 'Observed Climate System Changes and Impacts to + + ' + A.2.6: + - 'Observed Climate System Changes and Impacts to + + ' + A.2.7: + - 'Observed Climate System Changes and Impacts to + + ' + A.3.1: + - 'Adaptation Actions to Date + + ' + A.3.2: + - 'Adaptation Actions to Date + + ' + A.3.3: + - 'Adaptation Gaps and Barriers + + ' + A.3.6: + - 'Adaptation Gaps and Barriers + + ' + - 'Lack of Finance as a Barrier to Climate Action + + ' + A.4.1: + - 'Global Policy Setting + + ' + - 'Mitigation Actions to Date + + ' + A.4.2: + - 'Mitigation Actions to Date + + ' + A.4.3: + - 'The Gap Between Mitigation Policies, Pledges and + + ' + - 'The Timing and Urgency of Climate Action + + ' + A.4.4: + - 'Mitigation Actions to Date + + ' + - 'The Gap Between Mitigation Policies, Pledges and + + ' + - 'Long-term Climate Change + + ' + A.4.5: + - 'Mitigation Actions to Date + + ' + - 'The Gap Between Mitigation Policies, Pledges and + + ' + - 'Lack of Finance as a Barrier to Climate Action + + ' + B.1.1: + - 'Long-term Climate Change + + ' + - 'Overshoot Pathways: Increased Risks and Other + + ' + - 'Near-Term Risks + + ' + B.1.4: + - 'Long-term Climate Change + + ' + - 'The Likelihood and Risks of Abrupt and Irreversible + + ' + B.1.5: + - 'Near-Term Risks + + ' + B.2.1: + - 'Near-Term Risks + + ' + B.2.2: + - 'Impacts and Related Risks + + ' + - 'The Likelihood and Risks of Abrupt and Irreversible + + ' + B.3.1: + - 'The Likelihood and Risks of Abrupt and Irreversible + + ' + B.3.2: + - 'Impacts and Related Risks + + ' + - 'The Likelihood and Risks of Abrupt and Irreversible + + ' + B.4.1: + - 'Long-term Adaptation Options and Limits + + ' + - 'The Timing and Urgency of Climate Action + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + B.4.2: + - 'Adaptation Gaps and Barriers + + ' + - 'Long-term Adaptation Options and Limits + + ' + - 'Near-Term Risks + + ' + B.4.3: + - 'Adaptation Gaps and Barriers + + ' + - 'Long-term Adaptation Options and Limits + + ' + B.5.1: + - 'Long-term Climate Change + + ' + - 'Remaining Carbon Budgets + + ' + - 'Net Zero Emissions: Timing and Implications + + ' + - 'Sectoral Contributions to Mitigation + + ' + B.5.3: + - 'The Gap Between Mitigation Policies, Pledges and + + ' + - 'Remaining Carbon Budgets + + ' + B.6.1: + - 'Net Zero Emissions: Timing and Implications + + ' + - 'Overshoot Pathways: Increased Risks and Other + + ' + - 'The Timing and Urgency of Climate Action + + ' + B.6.2: + - 'Net Zero Emissions: Timing and Implications + + ' + - 'Sectoral Contributions to Mitigation + + ' + B.6.3: + - 'Sectoral Contributions to Mitigation + + ' + - 'The Timing and Urgency of Climate Action + + ' + - 'Near-Term Mitigation and Adaptation Actions + + ' + B.6.4: + - 'Synergies and trade-offs, costs and benefits + + ' + B.7.1: + - 'Net Zero Emissions: Timing and Implications + + ' + - 'Overshoot Pathways: Increased Risks and Other + + ' + B.7.2: + - 'Impacts and Related Risks + + ' + - 'Overshoot Pathways: Increased Risks and Other + + ' + B.7.3: + - 'Sectoral Contributions to Mitigation + + ' + - 'Overshoot Pathways: Increased Risks and Other + + ' + - 'Synergies and trade-offs, costs and benefits + + ' + C.1.1: + - 'Long-Term Interactions Between Adaptation, Mitigation and Sustainable Development + + ' + - 'Advancing Integrated Climate Action for Sustainable + + ' + - 'The Timing and Urgency of Climate Action + + ' + C.1.2: + - 'Long-Term Interactions Between Adaptation, Mitigation and Sustainable Development + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Near-Term Mitigation and Adaptation Actions + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + - 'Strengthening the Response: Finance, International Cooperation and Technology + + ' + C.1.3: + - 'The Likelihood and Risks of Abrupt and Irreversible + + ' + - 'Sectoral Contributions to Mitigation + + ' + - 'Synergies and trade-offs, costs and benefits + + ' + - 'The Timing and Urgency of Climate Action + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Near-Term Risks + + ' + - 'Equity and Inclusion in Climate Change Action + + ' + C.2.1: + - 'The Timing and Urgency of Climate Action + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Near-Term Risks + + ' + C.2.2: + - 'Observed Climate System Changes and Impacts to + + ' + - 'Impacts and Related Risks + + ' + - 'Long-term Adaptation Options and Limits + + ' + - 'Remaining Carbon Budgets + + ' + - 'Sectoral Contributions to Mitigation + + ' + - 'The Timing and Urgency of Climate Action + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Near-Term Risks + + ' + C.2.3: + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Land, Ocean, Food, and Water + + ' + - 'Health and Nutrition + + ' + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals + + ' + C.2.4: + - 'Synergies and trade-offs, costs and benefits + + ' + - 'Benefits of Strengthening Near-Term Action + + ' + C.2.5: + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + - 'Finance for Mitigation and Adaptation Actions + + ' + C.3.1: + - 'The Timing and Urgency of Climate Action + + ' + - 'Energy Systems + + ' + - 'Society, Livelihoods, and Economies + + ' + - 'Industry + + ' + - 'Cities, Settlements and Infrastructure + + ' + - 'Land, Ocean, Food, and Water + + ' + - 'Health and Nutrition + + ' + C.3.2: + - 'Energy Systems + + ' + C.3.3: + - 'Industry + + ' + - 'Cities, Settlements and Infrastructure + + ' + C.3.4: + - 'Cities, Settlements and Infrastructure + + ' + C.3.5: + - 'Land, Ocean, Food, and Water + + ' + C.3.6: + - 'Land, Ocean, Food, and Water + + ' + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals + + ' + C.3.7: + - 'Health and Nutrition + + ' + C.3.8: + - 'Society, Livelihoods, and Economies + + ' + C.4.1: + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals + + ' + C.4.2: + - 'Synergies and trade-offs, costs and benefits + + ' + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals + + ' + - 'Integration of Near-Term Actions Across Sectors and Systems + + ' + C.4.3: + - 'Benefits of Strengthening Near-Term Action + + ' + - 'Cities, Settlements and Infrastructure + + ' + - 'Health and Nutrition + + ' + - 'Co-Benefits of Adaptation and Mitigation for Sustainable Development Goals + + ' + - 'Integration of Near-Term Actions Across Sectors and Systems + + ' + C.5.1: + - 'Equity and Inclusion in Climate Change Action + + ' + C.5.2: + - 'Equity and Inclusion in Climate Change Action + + ' + C.5.3: + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Cities, Settlements and Infrastructure + + ' + - 'Health and Nutrition + + ' + - 'Society, Livelihoods, and Economies + + ' + C.5.4: + - 'Observed Changes, Impacts and Attribution + + ' + - 'Equity and Inclusion in Climate Change Action + + ' + C.6.1: + - 'Mitigation Actions to Date + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + C.6.2: + - 'Responses Undertaken to Date + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + C.6.3: + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + C.6.4: + - 'Mitigation Actions to Date + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + C.6.5: + - 'Equity and Inclusion in Climate Change Action + + ' + - 'Society, Livelihoods, and Economies + + ' + - 'Governance and Policy for Near-Term Climate Change Action + + ' + C.7.1: + - 'Finance for Mitigation and Adaptation Actions + + ' + C.7.3: + - 'Finance for Mitigation and Adaptation Actions + + ' + C.7.4: + - 'Finance for Mitigation and Adaptation Actions + + ' + C.7.5: + - 'Technology Innovation, Adoption, Diffusion and + + '