Mitigation involves the reduction in emissions of any greenhouse gases that contribute to climate change. Carbon dioxide is generally used as the base case to which all other gases are compared, as is the case with carbon offset programmes. However, methane, for example, contributes to climate change much more per molecule than carbon dioxide. Adaptation involves responding to the changes induced as a result of climate change. Adaptation can be reactive or anticipatory. Where possible, anticipatory actions will provide the most cost-effective response to reduce risk. Impact assessment can play an important role in identifying both potential contributions to greenhouse gas emissions and possible adaptation responses to climate change.
The contributions to and effects of climate change are by no means evenly distributed around the world. Prosperous countries are major contributors to greenhouse gas emissions, particularly through transportation and energy production, whereas the impacts of climate change are frequently felt more strongly in developing countries which may have less ability to respond to the changes. The magnitude of change also differs geographically with polar regions experiencing the greatest amount of change in the physical environment.
EIA, both project-related and strategic, and HIA are used globally as tools to assess climate impacts on projects and policy/programmes, as well as the effects on climate on populations and communities. They represent one of the few standardized global tools available to incorporate the effects of climate change into design of projects, programmes and policies by forecasting the resulting changes of baseline and future conditions. At the same time, the methodology of the impact assessment process must evolve to better incorporate these climate change-related environmental impacts.
Historically, environmental health concerns have focused on toxicological or microbiological risks to health from local exposures. However, the scale of environmental health problems is increasing as a result of climate change, and various larger-scale environmental hazards to human population health have begun to appear. Changes in the IA methodology to incorporate climate change need to begin within different jurisdictions and different climate regimes in a consistent way. At the same time regulatory bodies, governments and IFIs need to support and monitor these evaluations and be ready to incorporate them in their assessment and evaluation processes. Revision to and evaluation of IA methodology should include key risk analysts from, for example, real estate, bank and insurance industries to ensure that risk assessment methodologies conform to industry standards.
The IA methodology can be summarized generically into:
- issue scoping,
- selection of valued environmental/socio-economic components and indicators,
- assessment of impacts,
- quantification of significant impacts,
- development of mitigation and effects monitoring plans,
- reporting of residual impacts and conclusions.
Terminology may differ but these basic elements, including the quantification of impacts and determination of significance, are common world-wide. This provides a consistent framework for the evaluation of environmental and socio-economic impacts associated with environmental change.
To date, incorporating climate change into the EIA process has focused on identification of mitigation elements within the project or programme scope and potential effects of climate change on the physical foundation of the project or programme. Since mitigation has been an accepted requirement for policy and project review globally following the general adoption of the Kyoto Protocol, most EIA jurisdictions require some identification of how the project or programme will affect GHG emissions. A number of guides are available to assist in formulation of GHG contributions from various types of projects, with the UK and Australia providing good templates. However, the requirement for adaptation to climate change as a current reality is a mo