As discussed previously in this blog, in 2012, the United States District Court for the District of Columbia required the Environmental Protection Agency (EPA) to review and respond to an administrative petition filed by several environmental groups, including the Center for Biological Diversity and Friends of the Earth, regarding their request that the agency issue an endangerment finding for greenhouse gas (GHG) emissions from aircraft. (Ctr. for Biological Diversity et al. v. EPA et al., No. 1:10-cv-00985). Section 231 (a)(2)(A) of the Clean Air Act, 42 U.S.C. § 7401 et seq., requires EPA to determine whether GHG emissions from aircraft endanger public health and the environment, and thus should be regulated. EPA reviewed the petition and responded that the agency would need 22 months to complete the rulemaking process.

On August 5, 2014, the Center for Biological Diversity and Friends of the Earth filed a notice of intent to sue EPA for unreasonable delay because, after two years, the agency has failed to begin the rulemaking process to determine if an endangerment finding is necessary. According to the groups, the aviation sector is one of the fastest-growing sources of carbon dioxide pollution, contributing 3% of the U.S. GHG emissions in 2006 and emissions were growing by 5% annually by 2008.