Cars, Trucks, and Climate: EPA Regulation of Greenhouse Gases from Mobile Sources

As Congress and the Administration considered new legislation to reduce the greenhouse gas (GHG) emissions that contribute to climate change over the last year and a half (a process that has now stalled), the Environmental Protection Agency simultaneously began to exercise its existing authority under the Clean Air Act to set standards for GHG emissions. The Administration has made clear that its preference would be for Congress to address the climate issue through new legislation. Nevertheless, it is moving forward on several fronts to define how the Clean Air Act will be used and to promulgate regulations. This report covers the steps that the Administration is taking on this topic