On June 10, EPA took two major steps toward eventually adopting an international standard for greenhouse gas (GHG) emissions from aircraft, mostly including commercial aircraft, the last transportation sector to be subject to such limits.  

In pertinent part:

  • EPA proposed making an "endangerment determination," or an agency finding that greenhouse gases emitted from certain classes of aircraft engines cause or contribute to air pollution, which may reasonably be anticipated to endanger public health or welfare. This finding (after it is made final) renders those aircraft GHGs eligible for regulation under the Clean Air Act.
  • In the same package, EPA also issued an Advance Notice of Proposed Rulemaking (ANPR) soliciting comments on a variety of issues currently being debated within the International Civil Aviation Organization (ICAO) (a specialized body of the United Nations comprising 191 member states that focuses on international aircraft emission standards), including on ICAO's progress in establishing standards that achieve meaningful GHG reductions; and the use of the Clean Air Act to adopt and implement domestic aircraft engine GHG emission standards. The U.S. ICAO participant (consisting of EPA and FAA representatives) is awaiting stakeholder input to inform the U.S. position before the ICAO through this ANPR.

The saga began in April 2007 with the U.S. Supreme Court's landmark Massachusetts v. EPA decision, which found that GHGs are air pollutants that can be regulated under the Clean Air Act and ordered EPA to determine whether GHG emissions from new motor vehicles pose an endangerment. Environmental groups petitioned EPA in December 2007 to issue an endangerment determination regarding aircraft GHG emissions, seeking a domestic GHG limit that would drive ICAO's international standard. They then sued EPA in 2010, claiming unreasonable delay. In 2011, the D.C. District Court ruled in Center for Biological Diversity, et al. v. EPA that EPA must issue an endangerment determination, but that it had not unreasonably delayed in so doing. In last week's release, EPA maintains its preference for adopting an international standard, which environmentalists fear would be too weak, or would apply to too few engines. ICAO is expected to finalize its standard in February 2016; EPA expects it will finalize its endangerment determination in the spring of 2016 and, thereafter, propose and finalize a rule to adopt the international standard. As an ICAO standard is not self-implementing, it requires domestic legislation or regulation.  

Although EPA's June 10 announcement makes it clear that "[t]he EPA is not at this time proposing aircraft engine GHG emission standards," potentially impacted parties should consider keeping track of developments and submitting comments on the proposed endangerment determination and in response to the ANPR. Comments on both are due 60 days from their publication in the Federal Register (which, as of the date of this writing, has not yet happened). EPA's publication did announce that, if requested, it will hold a public hearing on August 11, 2015 at 10:00 a.m. ET. The last day to pre-register to speak at the hearing is August 6.

  • EPA is proposing to find that GHG emissions from engines used in U.S. subsonic jet aircraft with a maximum takeoff mass (MTOM) greater than 5,700 kilograms and in subsonic propeller-driven (e.g., turboprop) aircraft with a MTOM greater than 8,618 kilograms contribute to GHG air pollution that endangers public health and welfare. Examples of covered aircraft would include smaller jet aircraft, such as the Cessna Citation CJ2+ and the Embraer E170; the largest jet aircraft, such as the Airbus A380 and the Boeing 747; and the larger turboprop aircraft, such as the ATR72 and the Bombardier Q400.
  • In its ANPR, EPA is soliciting comments on issues pertaining to aircraft GHG standards, including whether an international standard should apply to new aircraft, as well as to new aircraft in production; the appropriate stringency levels for the standard; and the appropriate effective dates for the standard.

Given the present limits in technology, and the time required to establish whether it is safe for use in aircraft, compliance will likely focus mainly on the use of low-carbon fuel alternatives such as biofuel.