US EPA finalizes endangerment finding for GHG emissions from aircraft

25 July 2016

The US Environmental Protection Agency (EPA) today 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 carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF₆), all of which contribute to GHG pollution. These particular GHGs come primarily from engines used on large commercial jets, noted the EPA. The endangerment finding follows a proposal of June 2015.

The final endangerment and contribution findings for aircraft engine GHG emissions are an important step that the EPA must take prior to adopting domestic GHG engine standards. The EPA said it 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. The EPA anticipates moving forward on US standards that would be at least as stringent as ICAO’s standards.

The endangerment finding is not applicable to small piston-engine planes (the type of plane often used for recreational purposes), or to military aircraft.

In 2009, EPA issued similar findings regarding GHG emissions from new cars and light trucks. The agency determined that those vehicles contribute to GHG pollution that threatens Americans' health and welfare by leading to long-lasting changes in our climate. Following the 2009 findings, the agency has issued a number of rules to reduce GHG emissions from light- and heavy-duty vehicles.

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.

The US EPA has been also working in cooperation with the ICAO to develop emission standards for particulate matter, including the mass and number emissions of non-volatile particles from commercial aircraft.

Source: US EPA