U.S. Court of Appeals Upholds EPA’s Aircraft GHG Emissions Rules

Originally published in the September 2023 issue of Bench & Bar of Minnesota Environmental Law Update, Minnesota State Bar Association.

In a recent ruling, the United States Court of Appeals for the D.C. Circuit upheld the 2021 EPA standards regulating greenhouse gas (GHG) emissions from domestic aircraft. California v. Environmental Protection Agency, 72 F.4th 308 (D.D.C. 2023). The EPA’s standards aligned with those adopted by the International Civil Aviation Organization (ICAO). Petitioners, made up of twelve states, the District of Columbia, and three environmental groups, challenged the EPA’s regulations, claiming they should have been more stringent than those promulgated by ICAO in an effort to combat climate change. 

Petitioners first asserted that the EPA failed to apply factors required by Section 231 of the Clean Air Act. The court rejected this argument, citing to the language of Section 231 which provides that “[t]he Administrator shall, from time to time, issue proposed emission standards applicable to the emission of any air pollutant from any class or classes of aircraft engines which in his judgment causes, or contributes to, air pollution which may reasonably be anticipated to endanger public health or welfare.” The court, examining the plain language of Section 231, explained that the statute is “relatively simple,” and does not mandate consideration of certain factors (i.e., a “latest-technology” approach), nor contemplation of substantive content of aircraft emissions standards. The EPA relied upon an earlier 2016 endangerment finding related to emissions of GHG from aircraft over a certain size. The EPA concluded that “elevated concentrations of these substances were reasonably anticipated to endanger the public health and welfare by contributing to climate change.” Having made the endangerment finding, the EPA was within its authority under Section 231 to “issue proposed emissions standards” related to GHG emissions from aircraft. 

Petitioners next contended that the EPA acted arbitrarily and capriciously in passing the aircraft emissions standards. They asserted three prongs to this argument: (1) by aligning domestic aircraft standards with ICAO, the EPA did not account for harms of climate change; (2) the EPA failed to consider alternatives which would reduce GHG emissions; and (3) the EPA did not consider effects of the emissions standards on minority and low-income populations as required by executive orders. The court rejected all three prongs. First, the court found it beneficial to align domestic emissions standards with global ICAO standards, citing to a history of consistent harmonization between the EPA and ICAO. Next, the court held that the EPA reasonably concluded that implementing alternative standards like those proposed by petitioners would result in delay and undue hardship to American aircraft manufacturers, which the court recognized already “navigate lengthy timelines for the certification and sale of new aircraft.”  Finally, the court rejected the third claim, explaining that petitioners’ claim was foreclosed by the executive orders, and not subject to judicial review. 

The court concluded that the EPA has substantial discretion to regulate GHG emissions from aircraft under Section 231 and acted properly in aligning domestic standards with those of ICAO.