U.S. Court of Appeals—D.C. Circuit Upholds EPA's Action to Reduce Greenhouse Gases under the Clean Air Act

On June 26, 2012, the U.S. Court of Appeals- D.C. Circuit upheld EPA's Endangerment Finding and greenhouse gas regulations issued under the Clean Air Act (CAA) for passenger vehicles and CAA permitting for stationary sources.

In 2007 the Supreme Court ruled in Massachusetts v. EPA that greenhouse gases are covered by the CAA's definition of air pollutant and that EPA must determine whether or not emissions of greenhouse gases from new motor vehicles cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.

EPA was challenged through a group of lawsuits over its actions resulting from the Supreme Court decision to address greenhouse gases, including:

1. The 2009 Endangerment Finding, in which EPA determined that greenhouse gases endanger the health and welfare of Americans
2. The Light Duty Vehicle Rule, in which EPA coordinated with the National Highway Traffic Safety Administration to develop harmonized regulations to reduce greenhouse gas emissions and improve the fuel economy of light-duty vehicles.
3. The Tailoring Rule, in which EPA set greenhouse gas emission thresholds to define when permits under the New Source Review Prevention Significant Deterioration (PSD) and title V Operating Permit programs are required for new and existing industrial facilities.

See the Greenhouse Gas Court Decision.

The U.S. Chamber of Commerce and the National Association of Manufacturers (with others) filed petitions to the U.S. Court of Appeals-D.C. Circuit to rehear the case. The Department of Justice and EPA provided a response on Friday, October 12, 2012.