Last year, the US Court of Appeals (D.C. Circuit) upheld a series of findings, interpretations, and regulations that the Environmental Protection Agency (EPA) had issued as its first steps to limit the emissions of greenhouse gases under the Clean Air Act. First, EPA had made a finding that emissions of greenhouse gases from motor vehicles cause or contribute to an endangerment to the public health or welfare. Second, to address this endangerment, EPA together with the Department of Transportation, promulgated greenhouse gas emission and fuel efficiency standards for cars and light trucks for model years 2012 through 2016. EPA estimates that these standards will reduce greenhouse gas emissions by approximately 960 million metric tons of CO2 equivalent over the life of these model years. Third, EPA formally reaffirmed its interpretation that the motor vehicle emission standards - by regulating greenhouse gases under the Act - would trigger permitting requirements for greenhouse gas emissions from stationary facilities. These permitting requirements include the installation of best available control technology to reduce greenhouse gas emissions from new or modified facilities. Fourth, EPA issued regulations phasing in these permitting requirements over several years. Rejecting a multitude of challenges, the court upheld all these actions, thus paving the way for EPA to significantly regulate and limit greenhouse gas emissions from motor vehicles and stationary facilities.
On 26 June 2012, the prominent US Court of Appeals for the District of Columbia Circuit handed the Barak Obama Administration a decisive, quadruple victory in its efforts to limit greenhouse gas emissions through regulations. The court upheld the finding of the US Environmental Protection Agency (EPA) that greenhouse gas emissions are reasonably anticipated to endanger public health and welfare. The court also upheld EPA regulations and interpretations that will require reductions in greenhouse gas emissions from motor vehicles and large stationary sources. The court reaffirmed its decision, denying a petition for rehearing, on 20 December 2012. The decision paves the way for significant mandatory reductions of greenhouse gas emissions in the US.European Energy and Environmental Law Review