Wednesday, June 10, 2015
The U.S. Environmental Protection Agency (EPA) announced today that it is proposing to find that greenhouse gas emissions from aircraft engines contribute to air pollution that endangers public health and welfare. In doing so, the EPA is acting under the authority provided it by Section 231 of the Clean Air Act, which directs the agency to study emissions from aircraft and to issue standards to control emissions "which may reasonably be anticipated to endanger public health or welfare." Such a finding has long been seen as inevitable. In 2007, the Supreme Court held in Massachusetts v. EPA that greenhouse gas emissions were covered air pollutants under the Clean Air Act. Subsequently, the EPA has found that greenhouse gases endangered public health and welfare when emitted by motor vehicles, leaving little basis to assert that these gases would not endanger public health and welfare when emitted by aircraft.
The EPA has, however, held off on issuing an endangerment finding until now, choosing to first act on emissions from other sectors such as motor vehicles, trucking, and power plants. This delay in addressing aircraft emissions, which has been challenged in court by environmental groups, is likely primarily attributable to the airline industry's relatively minor contributions to total greenhouse gas emissions compared to those other sectors. But a secondary reason for the timing of today's announcement is readily apparent from reading the text of the EPA's statement, a desire not to get ahead of ICAO. The EPA has joined the FAA in representing the U.S. at ICAO's deliberations over the development of international standards for greenhouse gas emissions from aircraft, which are scheduled for release next year. An endangerment finding is just a preliminary step the EPA must take before developing and issuing rules restricting aircraft emissions. The EPA's announcement today made clear that this endangerment finding is intended to lay the groundwork for the EPA to issue domestic rules conforming to the international standards agreed upon within ICAO. There is no indication at this point that the EPA intends to go any further in restricting aircraft emissions than the eventual international standards. A detailed account of the EPA's reasoning and analysis can be found here.