In the United States, federal agencies that license, permit or finance energy and infrastructure projects must, with some limited exceptions, analyze the environmental impacts of those projects before they approve them, pursuant to the National Environmental Policy Act of 1969 (NEPA). But to what extent must those agencies consider climate change impacts as part of their NEPA reviews? The President’s Council on Environmental Quality (CEQ) has just issued a guidance document that addresses that question.

CEQ’s guidance document—an August 1 memorandum addressed to the heads of all federal departments and agencies—urges federal agencies to consider two climate change-related topics when conducting NEPA reviews.

The first topic is the impact of a proposed project on climate change, and the memorandum urges federal agencies to approach that topic by focusing on the project’s direct, and indirect, greenhouse gas (GHG) emissions. Agencies are encouraged to calculate a project’s anticipated emissions using existing government resources and calculators, and to draw upon existing government literature on the impacts of such emissions. The memorandum acknowledges that “the totality of climate change impacts is not attributable to any single action,” but concludes that climate-related impacts are exacerbated by some government actions and encourages agencies to compare the level of emissions expected from a proposed project to the level expected under alternative project scenarios. The memorandum provides scant details on how to calculate “indirect” GHG emissions but does suggest that for projects involving fossil fuel extraction, the indirect impacts turn, at least in part, on the anticipated ultimate use of the extracted fuel.

The second topic is the impact of climate change on the project, and on the project’s impacts.Here, CEQ’s memorandum encourages federal agencies to consider a proposed project’s impacts not simply on environmental conditions as they currently exist but as they will exist in the future and reflecting any changes that are expected as a result of climate change. Thus, if a project will draw water from a river that is already being, or that will be, diminished because of changing snowfall or rainfall patterns, that is an impact that should be acknowledged. The memorandum also encourages agencies to incorporate climate change resiliency and adaptation planning into their NEPA reviews, especially when analyzing project alternatives and potential mitigation measures. The memorandum suggests, for example, that agencies consider whether a proposed project’s design makes it more vulnerable to changing climate conditions (such as, in some areas of the country, increased risk of wildfires) than alternative projects.

CEQ’s memorandum applies to all new NEPA reviews and states that agencies “should exercise judgment” when considering whether to apply the guidance to currently ongoing reviews. CEQ states in the memorandum that it “does not expect agencies to apply” the guidance to projects for which a final environmental impact statement or environmental assessment has already been issued.