The petitioners challenging the Environmental Protection Agency’s (EPA) Clean Power Plan (CPP) in the U.S. Court of Appeals for the D.C. Circuit filed their joint opening briefs on February 19, 2016. The Opening Briefs of Petitioners on Core Legal Issues (“Core Legal Issues Brief”) is available here. The Opening Brief of Petitioners on Procedural and Record-Based Issues (“Procedural Issues Brief”) is available here.

The briefs present withering attacks on EPA’s legal authority to promulgate the CPP and on numerous challenges to the procedures EPA followed and the issues it considered, offering the D.C. Circuit an array of avenues on which to vacate the rule. EPA and parties that intervened in support of the CPP will file their responsive arguments by March 28, 2016. Petitioners’ reply briefs are to be filed on April 15, 2016. Oral argument is scheduled for June 2, 2016.

Until briefing is completed and oral argument heard, predicting how the Court will rule is a “fool’s errand.” Nevertheless, the briefs lay out options for the Court to vacate the CPP, ranging from an argument that would significantly cabin EPA’s power under the Clean Air Act (CAA) to detailed technical attacks on the process EPA followed in promulgating the rule:

First, relying heavily on the Supreme Court’s decision in UARG v. EPA, petitioners characterize the CPP as an effort by EPA to make “decisions of vast ‘economic and political significance’” that would “‘bring about an enormous and transformative expansion’ in its authority under a ‘long-extant statute.’” Core Legal Issues Brief at 32 (citations omitted). Petitioners assert that EPA’s statutory authority is limited to actions available to a source “Within the fence line.”

Second, petitioners argue that Section 111(d) of the CAA expressly prohibits EPA’s use of Section 111 to require states to regulate “any air pollutant . . . emitted from a source category which is regulated under section [1]12.” CAA § 111(d)(1)(A). Since EPA has promulgated the Mercury and Air Toxic Standards for Power Plants (MATS) pursuant to Section 112, petitioners assert that EPA is barred from promulgating the CPP under Section 111. Core Legal Issues Brief at 61-74.

Third, petitioners identify an array of flaws in EPA’s rulemaking process, including that the final rule differed so significantly from the proposed rule that there was inadequate opportunity to comment and that several aspects of EPA’s technical and economic analyses were not supported and/or addressed issues outside EPA’s expertise. Procedural Issues Brief at 13-17, 22-49, 53-55.

The first option would provide the broadest victory to those parties opposed to EPA regulation of greenhouse gases (GHG). The third option would require lengthy, time-consuming evaluation by the Court of complex and highly fact-specific procedural challenges. The second option seems the likeliest basis for the Court to rule in petitioners’ favor. Here is why.

The CPP has become highly politicized, and the D.C. Circuit’s decision will likely be issued during the last weeks of a presidential election campaign marked by unprecedented levels of hostility and animosity. If that were not enough, the vacancy on the Supreme Court, and the potential for a 4-to-4 deadlock were the challenges to the CPP to reach the Court before the vacancy is filled, produce more intense scrutiny of whatever decision the D.C. Circuit reaches.

Should the D.C. Circuit conclude that the CPP is unlawful and must be vacated, a ruling that EPA cannot regulate under Section 111 of the CAA sources already regulated under Section 112 leaves for another day whether the current CAA provides EPA with the authority to regulate GHGs emitted by fossil-fuel electricity generators. The Supreme Court has already struck down the MATS Rule. While EPA has promulgated a new MATS Rule addressing the issues on which the Supreme Court ruled, the validity of the new MATS Rule remains uncertain. Irrespective of how the new MATS Rule fares, EPA would be able to choose whether to regulate power plants under Section 111 or Section 112.

A new president and a new Congress would also have a clean slate on which to develop a comprehensive program to address climate change.