Litigation over the Clean Power Plan of the U.S. Environmental Protection Agency (EPA) has proceeded at a fevered pitch since petitions for review before the D.C. Circuit were filed beginning on October 23, 2015, the day the rule was published in the Federal Register. The agency’s controversial effort to regulate carbon dioxide emissions from existing power plants ultimately generated 42 petitions for review filed by 159 petitioners. Petitioners include 32 states and state agencies and a broad array of American industry, including notable representation of the electric utility industry, mining interests, labor, and manufacturing. The D.C. Circuit consolidated all of these petitions for review, although three petitions were later severed and placed in abeyance to allow the EPA time to reconsider particular issues related to the combustion of biomass.
The litigation also attracted 7 intervenors supporting petitioners and 52 intervenors—composed primarily of states, cities, and environmental organizations—filing briefs in support of the EPA, as well as 418 amici for petitioners and 401 amici for respondents, representing a wide range of current and former federal officials, climate scientists, and various advocacy organizations, among others, who also filed briefs in the cases. Despite the enormous number of parties, briefing in these cases—which began on February 19, 2016, with the filing of opening briefs by the petitioners—was completed just under two months later, when reply briefs were filed on April 15, 2016. Given the number of parties and the number of issues to be addressed, the efforts expended over this compressed period are, if not unprecedented, then at least highly unusual in the area of federal environmental law.