In a key ruling on the limits of the Environmental Protection Agency (EPA) to enact regulations under the Clean Air Act, the U.S. Supreme Court ruled the agency had exceeded its authority when it promulgated the Clean Power Plan.

The decision pits the proponents of administrative agencies' authority to enact regulations that impact climate change against the proponents of restricting agencies' authority to regulate the industry and the economy and shrink the federal government's role in such regulation.

The majority, led by Chief Justice John Roberts, wrote that the EPA's Clean Power Plan required the states to regulate power plant carbon dioxide emissions more stringently and that the Clean Air Act did not give the agency such authority.

The EPA's Clean Power Plan, issued in 2015 during then-President Obama's administration, shifted power generation away from fossil fuel plants to cleaner sources.

To do so, the Court ruled that a "decision of such magnitude and consequence rests with Congress itself, or a clear delegation from that representative body." In the 6-3 opinion, Chief Justice John Roberts was joined by Justices Thomas, Alito, Gorsuch, Kavanaugh, and Barrett.

Justice Elena Kagan wrote the dissent and was joined by Justices Breyer and Sotomayor. In the dissent, Kagan wrote that the Court's decision "stripped the [EPA] of the power that Congress gave it to respond to 'the most pressing environmental challenge of our time.'… The court appoints itself – instead of Congress or the expert agency – the decisionmaker on climate policy. I cannot think of many things more frightening."

The impact of the decision will likely result in more pressure on state and local governments to control air emissions. It may also signal a move toward restricting the EPA's rule-making authority in other areas and, more generally, restricting other administrative agencies' authority to regulate.

The full opinion of the Court in W. Virginia v. Env't Prot. Agency, No. 20-1530, ___ S.Ct.___ (U.S. June 30, 2022), is available at: https://www.supremecourt.gov/opinions/21pdf/20-1530_n758.pdf.