Finding That Greenhouse Gas Emissions From Aircraft Cause or Contribute to Air Pollution That May Reasonably Be Anticipated To Endanger Public Health and Welfare

In this action, the Administrator finds that elevated concentrations of greenhouse gases in the atmosphere endanger the public health and welfare of current and future generations within the meaning of section 231(a)(2)(A) of the Clean Air Act (CAA, or Act). She makes this finding specifically with respect to the same six well-mixed greenhouse gases--carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride-- that together were defined as the air pollution in the 2009 Endangerment Finding under section 202(a) of the CAA and that together constitute the primary cause of the climate change problem. The Administrator also finds that emissions of those six well-mixed greenhouse gases from certain classes of engines used in certain aircraft are contributing to the air pollution--the aggregate group of the same six greenhouse gases--that endangers public health and welfare under CAA section 231(a)(2)(A).