Policies & Analysis

The 2009 Endangerment Finding determined that six greenhouse gases (GHG) are air pollutants that endanger public health and welfare, and subsequently allowed EPA to regulate GHG emissions from motor vehicles under section 202(a) of the Clean Air Act. Specifically, EPA is proposing to repeal all greenhouse gas emission standards for most vehicles. In part, EPA is basing its reconsideration on an argument that climate change is a "major question" that Congress could not have intended the agency to regulate. The 2009 Endangerment Finding serves as the foundation for several subsequent environmental regulations, including regulations of methane, airplane emissions, and carbon pollution from fossil fuel-fired power plants. Its rescission could ultimately undermine multiple EPA regulations, making people and communities less safe and healthy.