The Earth's climate system has demonstrably changed on both global and regional scales over the past century. An increasing body of observations gives a collective picture of a warming world and other climate system changes. There is now new and stronger evidence that most of the warming observed over the past 50 years is attributable to human activities such as the burning of fossil fuels for industrial use, transportation, electricity generation and land clearing, which have resulted in increased atmospheric concentrations of greenhouse gases (GHGs).

EA is a comprehensive and systematic planning process designed to identify, analyze and evaluate the environmental effects of proposed projects and ensure that these considerations are factored into project decision making. This is an effective means for governments and project proponents to advance an agenda of sustainable development and environmental protection. Climate change described in this guidance document is one of several factors to be considered in EAs. Information collected through the EA process relating to GHG emissions and the impacts of climate change on a project can:

• help proponents manage or reduce the potential risk posed by the impacts of climate change to their projects and contribute to climate change action;
• provide assurance to the public that climate change implications are being appropriately considered in the assessment of proposed projects;
• provide environmental managers with information that will assist their broader climate change action; and
• help decision makers to address climate change implications in a risk management context.

Like other environmental considerations factored into the EA process, climate change parameters are not explicitly identified in Canadian EA legislation and there remains a lack of legally binding federal, provincial or territorial regulations or targets for GHG emission reductions. However, governments are developing policies and plans for managing GHG emissions, which, in the future, will provide thresholds or limits relevant to project EAs. For example, Alberta has established a target to cut emissions in the province relative to Gross Domestic Product by 50 % below 1990 levels by 2020. The federal government released the Climate Change Plan for Canada in November 2002, establishing that covenants will be used with large emitters for achieving GHG emissions reductions in industrial sectors (thermal electricity, oil and gas, and mining and manufacturing). When put in place by jurisdictions, and applied to entities and facilities, such covenants, targets and/or regulations, should constitute the mitigation required of practitioners subject to these provisions.

EA is an effective means to incorporate climate change considerations in project planning, yet challenges remain. The EA process cannot consider the bulk of GHG emitted from already existing developments. Furthermore, unlike most project-related environmental effects, the contribution of an individual project to climate change cannot be measured.

Nevertheless, the environmental importance of a particular project can be assessed by placing it in the context of the policy objectives or regulations of the relevant jurisdictions, and if applicable, by the use of additional tools such as the strategic environmental assessment (SEA) of jurisdictional policies, plans or priorities. This would enable practitioners and decision makers to place the predicted GHG emissions associated with an individual project within a regional or jurisdictional context. Likewise, jurisdictions are uniquely situated to consider the cumulative effects associated with projects in a given industry or region. As such, when incorporating climate change considerations in a project EA, practitioners should consult with jurisdictional authorities on relevant climate change and EA-related policies, knowledge and practices.

Similar challenges confront the consideration of climate change impacts on individual projects. While research is ongoing, sufficiently detailed information may not be available on local changes in climatic factors, to be able to accurately predict climate change impacts on a specific project. However, scenarios based on climate model projections, existing climate data, local experiences and traditional ecological knowledge (TEK), can contribute to the identification of climate change considerations, and assist risk-based decisions. Although climate change projections are still developing, they can represent an improvement over the use of historical climate data, which in many cases, may not be representative of future climate conditions. Practitioners should draw upon expert authorities as necessary.

In spite of the challenges, some Canadian jurisdictions, such as Alberta and British Columbia, have already incorporated climate change considerations in selected EAs (see Annex C for selected case studies). Although not explicitly or consistently incorporated into the current EA process, changes in precipitation, snowmelt, wind, temperature, and other climatic and atmospheric parameters over time, have often been elements considered in EAs.