The US Environmental Protection Agency (EPA) finalized a determination under the Clean Air Act that greenhouse gas (GHG) emissions from certain types of aircraft engines contribute to the pollution that causes climate change and endangers Americans’ health and the environment.
The findings are for CO2, methane, nitrous oxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). These particular GHGs come primarily from engines used on large commercial jets.
Aircraft are the third largest contributor to GHG emissions in the US transportation sector, and these emissions are expected to increase in the future. 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.—Janet McCabe, EPA’s Acting Assistant Administrator for Air and Radiation
The agency is not issuing emissions standards for aircraft engines in this action. The final endangerment and contribution findings for aircraft engine GHG emissions are an important step that EPA must take prior to adopting domestic GHG engine standards.
EPA anticipates that the International Civil Aviation Organization (ICAO) will formally adopt its environmental committee’s February 2016 agreement on international aircraft CO2 standards in March 2017. EPA anticipates moving forward on standards that would be at least as stringent as ICAO’s standards.
The rulemaking process for aircraft GHG emissions will provide opportunities for industry, NGOs and other interested parties to provide their input through public review and comment.
US aircraft emit roughly 12% of GHG emissions from the US transportation sector and 29% of GHG emissions from all aircraft globally. Under the Clean Air Act, EPA consults with the Federal Aviation Administration as it develops aircraft engine emissions standards. By law, any standards EPA sets must not cause a significant increase in noise or adversely affect safety.
The endangerment findings do not apply to small piston-engine planes (the type of plane often used for recreational purposes), or to military aircraft.