The Environmental Protection Agency (EPA) and other agencies have responded to concerns that the Endangered Species Act (ESA) might be used to prevent projects that would emit greenhouse gases (GHG). Some critics have feared that the recent addition of the polar bear as a "threatened species" would enable opponents to argue that a project’s GHG emissions and resulting climate change would jeopardize the critical habitat of the polar bear and other species.

The EPA released documents finding that ESA reviews would not be necessary for facilities seeking Clean Air Act permits to increase GHG emissions. Current technology cannot trace a causal relationship between the actual emissions and specific impact upon a critical habitat.

Department of the Interior Solicitor David Bernhardt released a memorandum reiterating the EPA’s conclusion. Bernhardt explained that the proposed action would only be subject to ESA review if it "directly or indirectly" poses any effect upon a listed species or critical habitat. GHG emissions would fail this test and therefore would not require review because "the requisite causal connections cannot be made between the emissions of GHGs from a proposed agency action and specific localized climate change as it impacts listed species or critical habitat."

In addition, James Lecky, Director of the National Oceanic and Atmospheric Administration’s Office of Protected Species, responded to the EPA’s finding, saying that "NOAA agrees that current models do not allow us to trace a link between individual actions that contribute to atmospheric carbon levels and localized climate impacts relevant to a consultation." He concluded that the risk of harm would not require an ESA review.

Public Employees for Environmental Responsibility (PEER) responded to the agencies’ conclusions, accusing them of "cling[ing] to circular legalisms to justify continued inaction."