The Inflation Reduction Act (IRA) of 2022 added seven new sections to the Clean Air Act (CAA) and provided the U.S. Environmental Protection Agency (EPA) with substantial new authorities and resources. This Article examines these new amendments and the EPA-related provisions of the IRA, and explains the major implications of this historic legislation. It describes how the IRA confirms that reduction of greenhouse gases (GHGs) is a core goal of the CAA, that the funding provided should allow EPA to increase the ambition of its CAA rulemakings, and that the IRA confirms applicability of the CAA to GHGs in three important, specific areas: California’s ability to regulate GHG emissions from vehicles; EPA’s authority to regulate methane emissions from oil and gas facilities; and EPA’s authority to regulate GHG emissions from power plants.

On October 29, 2021, the U.S. Supreme Court granted certiorari in West Virginia v. Environmental Protection Agency, a petition filed by several states and coal companies attacking the U.S. Environmental Protection Agency's (EPA’s) regulatory authority under the Clean Air Act (CAA). The Court’s holding in this case would determine EPA’s continued ability to use the CAA—including the national ambient air quality standard (NAAQS) program—as a climate change tool. The Court saved its ruling until June 30, 2022, the last day of a drama-filled term. This Comment summarizes the Court's ruling and examines how its specific and more general analyses apply to NAAQS and other CAA provisions, concluding that NAAQS and several other regulatory options—particularly EPA’s proposed methane regulations—remain viable. It also explores the relevance of regulatory options in light of the newly enacted Inflation Reduction Act, adopted just a month and a half after the Court’s ruling.