Tackling global challenges
Over the years, we have made significant developments in agriculture, energy and health that have contributed to human well-being. However, some of these improvements in our lives have resulted in changes to the environment around us.
Our environment is a hugely complex system that includes the air we breathe, the land we live on, the water we drink and the climate around us. We must work to ensure that our developments in some areas do not adversely affect our environment whilst also ensuring that we mitigate any damage that has occurred. Work by some researchers has shown that we are already at a tipping point that might lead to "non-linear, abrupt environmental change within continental- to planetary-scale systems".
The good news is that politicians globally are looking at how to solve this. The UN's Sustainable Development Goals include universal calls to action to protect life on land and in water, producing clean water and tackling climate change. Meanwhile, the EU's Environmental Action Plan includes nine priority objectives that aim to ensure "we live well, within the planet's ecological limits".
As we strive towards a better world, we work to ensure chemistry's contributions are realised. Chemistry can help us to understand, monitor, protect and improve the environment around us. Chemists are developing tools and techniques to make sure that we can see and measure air and water pollution. They have helped to build the evidence that shows how our climate has changed over time. And they can be part of the effort to understand and address new problems that we face like microplastics and the potential effects of the different chemicals that we are exposed to.
Chemical scientists have an important role to play in reducing air pollution (sometimes in unexpected ways), as well as in helping us to understand and monitor it.
The World Health Organisation reported that around 7 million people died as a result of air pollution in 2012. According to the Organisation for Economic Co-operation and Development, poor ambient air quality is set to be the world's leading environmental cause of premature death by 2050 if we maintain current policies. By improving air quality, we can save millions of lives and improve our quality of living.
Cleaner air will also help us to protect the environment and preserve cultural heritage sites. Pollutants such as sulfur dioxide and nitrogen oxides can form acid rain, which pollutes soil and water and damages buildings such as the Acropolis and the Taj Mahal.
Other pollutants, such as ground level ozone, affect vegetation and so reduce agricultural yields.
Air pollution is a concern for the whole world as pollutants can be carried long distances, even across countries. However, scientists and engineers worldwide are tackling this issue, and we aim to support chemistry's vital role in understanding air pollution and developing solutions to reduce it.
How chemistry helps
Chemistry of air pollution
Air is a mixture of gases and particles, some of which are reactive and undergo complex chemical reactions in the atmosphere to form air pollutants such as ozone. Other air pollutants are emitted directly - for example, sulfur dioxide. Air pollutants can be solid, liquid or gas and come from natural and man-made sources; the biggest contributors to air pollution today are power stations, road transport, industry and residential burning of fuels.
A detailed understanding of pollutants and their chemistry is important for interpreting health effects, regulating emissions, and developing pollution-reducing technologies. For example, chemists have created a "master chemical mechanism" that describes the chemical reactions involved in degradation of volatile organic compounds in the lower atmosphere. This helps policy makers to "test" how effective a piece of proposed regulation or legislation would be. In another example, chemists identified trees as the source of high levels of organic pollutants during heatwaves. This unexpected result has improved the air quality forecasts provided to the public in the UK by taking into account natural emissions.
Monitoring air pollution
Accurate measurements of pollutants are vital for checking that we comply with national and international air quality directives. In addition, measurements can help us to understand correlations between health problems and air pollution - for example, the relationship between different types of particulate matter and cardiovascular problems.
The UK has around 300 air quality monitoring sites measuring a variety of pollutants, including ozone, nitrogen oxides, sulfur dioxide, carbon monoxide and particulates. One such site is next to a busy road in central Cambridge and measures the concentration of nitrogen oxides from the traffic in real time using chemiluminescence.
The graph below shows the output from one such measurement. The UK and EU air quality target for nitrogen dioxide is an annual mean of 40 micrograms per cubic metre, and the hourly concentration should not exceed 200 micrograms per cubic metre more than 18 times in a year.
Nitrogen dioxide concentrations in Cambridge, UK during the first week of February 2015 Picture: Royal Society of Chemistry 2015
Tackling air pollution
Tackling air pollution takes a combination of approaches, including regulation, land use planning, technological solutions (such as vehicle engine design), and consumer behaviour. Chemistry plays a role in developing technological solutions.
Chemists help to decrease emissions from transport in a variety of ways, ranging from developing cleaner fuels (such as low sulfur fuels) to increasing the efficiency of engines. Chemists are also working to enable new transport technologies – for example, batteries for electric vehicles and fuel cells for hydrogen vehicles, as well as systems to produce fuels from renewable energy sources rather than from fossil fuels.
Another way to reduce pollutant emissions is by fitting pollution control devices to the vehicle exhaust. For example, most petrol engines have three-way catalytic converters to reduce carbon monoxide, unburnt hydrocarbons and nitrogen oxides from the exhaust.
Platinum or palladium catalysts oxidise carbon monoxide and hydrocarbons to produce carbon dioxide and water, while rhodium catalysts reduce nitrogen oxides to produce nitrogen and oxygen. Chemists, materials scientists, and engineers develop and improve the catalysts, absorbers, and particulate filters that reduce pollutant emissions.
In the future, even the clothes you wear and our buildings could purify the air. Photocatalytic clothing can break down nitrogen oxides and volatile organic compounds using just oxygen and light. The same technology has been used in paint and cement, allowing buildings to clean the air around them.
In 2013 we brought together atmospheric chemists to discuss the role of aerosols in the atmosphere at our Faraday Discussion: Tropospheric Aerosol - Formation, Transformation, Fate and Impacts. You can read the papers published alongside the discussion in the Faraday Discussions journal.
Many of our members are actively engaged in understanding, monitoring and tackling air pollution. Our Automation and Analytical Management Interest Group hold an annual meeting on monitoring ambient air.
We awarded a blue plaque to Johnson Matthey PLC in recognition of the 40th anniversary of the world's first commercial catalytic converters being manufactured on this site, and the subsequent development of catalysts and filters for gasoline and diesel vehicles that have cleaned billions of tonnes of pollutants from the environment worldwide. You can read more about the evolution of catalytic converters in Education in Chemistry, our magazine for teachers.
You can also see our public lecture given by Professor Alastair Lewis of the University of York, entitled 'Air pollution past, present and future'.
In December 2015, nations around the world gathered in Paris to develop a new international climate change agreement.
In the lead-up to this important conference, we supported the chemical sciences community to discuss and contribute to our understanding of climate change (for example, through the Faraday Discussions series of conferences and publications) as well as its causes and impacts.
You can read more about causes and impacts of climate change in our special collection of research papers, review articles and themed collections. You can also read more about the role of atmospheric chemists in climate change research in Education in Chemistry.
We have also held scientific meetings and wider community engagement activities focused on the many ways in which chemistry will contribute to mitigating and adapting to climate change (for example, see our work on energy, food and water).
You can read more about how chemistry contributes to tackling global challenges in RSC News.
We have joined with the Institution of Chemical Engineers to reaffirm our own position on climate change. Read our joint statement below.
UK science communiqué on climate change
We are one of 24 of the UK's professional and learned societies that have endorsed a communiqué on climate change calling for government action. The organisations involved represent a diverse range of expertise from across the sciences, social sciences, arts, humanities, medicine and engineering.
Together, we launched this statement in July 2015, which was covered in the Guardian and Telegraph newspapers.
Download the full communiqué text.
Our statement on climate change
The overwhelming weight of scientific evidence indicates that human activity is the predominant cause of recent climate change. It is clear that the increase in carbon dioxide and other greenhouse gas emissions since the industrial revolution is the chief cause of observed global warming. Regional and year-on-year variations are expected within climate systems, but the evidence shows warming over the last half-century that cannot be explained by natural causes.
Carbon dioxide is already at levels much higher than at any time in the last 800,000 years, and continued emissions are expected to lead to significant further warming. Moreover, the speed of warming will be faster than during past natural climate change events, making adaptation more difficult. This change in climate is expected to bring changes in regional temperature and precipitation and to increase the frequency of heat waves, heavy rainfall, and some other types of extreme weather events. These will have a serious adverse effect on human wellbeing and the natural world.
The choices we make now will have far-reaching consequences. We need to develop mitigation and adaptation strategies to address the challenges that climate change poses. These strategies include developing and deploying low carbon technologies, improving energy efficiency, and changing behaviours to enable sustainable development.
The Royal Society of Chemistry and the Institution of Chemical Engineers are committed to supporting the chemical sciences community in their contributions to tackling climate change. The chemical sciences help us to understand, mitigate, and adapt to climate change. The best evidence based on the best science is essential to inform the right policy decisions on all three fronts. Already, chemists and chemical engineers contribute in a variety of ways, such as improving our understanding of atmospheric and ocean chemistry, investigating the consequences of climate change, developing new energy and carbon mitigation solutions, and helping crops to tolerate the changing conditions.
Institution of Chemical Engineers
Dominic Tildesley CBE
President Geoffrey Maitland
Lesley Yellowlees CBE
Immediate Past President Judith Hackitt CBE
David Phillips CBE
Past President Russell Scott
For more information read the Royal Society and National Academy of Sciences report Climate Change: Evidence and Causes.