07/25/2016 US EPA
“United States Environmental Protection Agency”
“EPA has already set effective GHG standards for cars and trucks and any future aircraft engine standards will also provide important climate and public health benefits.”
“The agency is not issuing emissions standards for aircraft engines in this action…”
“The EPA determination applies specifically to the six well-mixed GHGs in the atmosphere: carbon dioxide (CO2), methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Two of these six gases, CO2 and nitrous oxide, are emitted by aircraft engines.