Endangerment and Cause or Contribute Findings under the Clean Air Act

GHG Emissions from Aircrafts

Before regulating a new pollutant under certain Clean Air Act programs, EPA must make a finding that the pollutant endangers public health or welfare, and that emissions targeted by the regulations cause or contribute to such pollution. In Massachusetts v. EPA, 549 U.S. 497 (2007), the Supreme Court concluded that greenhouse gases (GHGs) are air pollutants under the Clean Air Act, and that EPA must determine under section 202(a) of the Clean Air Act whether or not GHG emissions from new motor vehicles cause or contribute to air pollution that would endanger public health or welfare.

Obama Administration (2009-2016)

On August 15, 2016, EPA published a final rule under section 231(a) of the Clean Air Act finding that GHG emissions from certain aircraft engines contribute to air pollution that endangers public health and welfare. 81 Fed. Reg. 54,422 (Aug. 15, 2016). Aircraft covered by the rule include small jet aircraft such as the Cessna Citation CJ2+ and the Embraer E170, up to and including the largest commercial jet aircrafts—the Airbus A380 and the Boeing 747. On December 30, 2016, EPA denied a petition for reconsideration of the aircraft endangerment finding. 81 Fed. Reg. 96,413 (Dec. 30, 2016).