Twenty AGs Petitioned EPA to Reconsider Clean Air Act Greenhouse Gas Threshold Rule

California Attorney General Xavier Becerra led a coalition of 20 attorneys general in filing a petition for reconsideration of the Environmental Protection Agency’s (EPA) “significant contribution” rule that set an arbitrary, three percent sector-by-sector threshold for regulation of greenhouse gas (GHG) emissions from stationary sources under Section 111 of the Clean Air Act. The petition warned that the EPA’s "new, artificially constrained interpretation of its own authority" would prohibit the agency from using Section 111 to regulate sectors collectively responsible for more than half of all U.S. GHG emissions from stationary sources, “[d]espite the clear danger posed by climate change.” The petition stressed that the final rule “dramatically departed from” the EPA’s original proposal, and noted that the agency’s new interpretations of its Section 111 authority “were not even mentioned” in said proposal. The petition also noted that in its January 2021 decision vacating the Trump administration's Affordable Clean Energy (ACE) rule, the U.S. Court of Appeals for the D.C. Circuit rejected assertions that the EPA’s “significant contribution” findings must “be measured by a ‘simple percentage criterion’ or another metric.”