Recently the Supreme Court, for the first time, halted the implementation of an EPA rule before review by the Court of Appeals. As reported on this blog, in August the EPA adopted rules under the Clean Air Act to ensure that by 2030, carbon dioxide emissions from existing power plants would be 32 percent below 2005 levels. The rules are an important part of the Obama administration’s efforts to combat climate change in the face of congressional recalcitrance. Adoption of the rules was also instrumental in facilitating the Paris climate deal, negotiated in December and due to be ratified by the countries on April 22.

Upon adoption, the rules were immediately challenged by a coalition of industry and states (none from the Pacific Northwest). The case is before the U.S. Court of Appeals for the D.C. Circuit, which refused to halt implementation of the rules during the legal proceedings. A three-judge panel will hear oral argument on June 2. It should be before the Supreme Court later this year or early next year. The immediate regulatory impact of the Supreme Court’s action is that states will not have to submit plans for how they intend to comply with the rules in September.