A decision today by the United States Supreme Court has restricted the Environmental Protection Agency’s (EPA) purview to regulate carbon emissions from power plants. The ruling is a major setback for the Biden administration and wider efforts to combat climate change, which collectively call for more stringent regulation of the energy sector.

The final vote was 6 to 3, with liberal-leaning judges Elena Kagan, Stephen G. Breyer, and Sonia Sotomayor dissenting. The decision comes in response to the case West Virginia v. Environmental Protection Agency, No. 20-1530, presented to the court in February. In this case, coal producers were upset over the regulations and emission caps determined by the EPA in the Clean Power Plan and Clean Air Act. The issue at hand asks legislators to clarify the authoritative power agencies, such as the EPA, have in “decisions of vast economic and political significance.”

“For authority,” the EPA cited provision Section 111(d) of the Clean Air Act which says States have jurisdiction over “existing sources” such as power plants with the EPA determining the “emissions limit with which they will have to comply.” While this ruling specifically focuses on the EPA and its jurisdiction over energy production, the implications for other issues are far reaching; potential impacts could extend beyond environmental policy and challenge the power that can be exerted by administrative agencies in charge of other pressing national issues, such as health and immigration.

The verdict comes at a time when warnings about global warming, climate change, and natural disasters are omnipresent. The United Nations’ Intergovernmental Report on Climate Change, most recently issued in February, found that even an ambitious attempt to limit warming to 2.7 º F (1.5º C) would, in the near-term, “cause unavoidable increases in multiple climate hazards and present multiple risks to ecosystems and humans.”

The Clean Power Plan, proposed during Obama’s presidency, was rejected by the Supreme Court in 2016 and replaced by a different Section 111(d) regulation–the Affordable Clean Energy (ACE) Rule, which asked for “small reductions” in carbon emissions, angering coal producers from West Virginia, North Dakota, Westmoreland Mining Holdings LLC, and The North American Coal Corporation (NACC), all of whom filed lawsuits which were decided in this ruling.

The Opinion of the Court statements drafted by the Supreme Court acknowledge that capping carbon emissions across the country “may be a sensible solution,” but goes on to cite it is “not plausible” that Congress authorize the EPA “to adopt on its own such a regulatory scheme in Section 111(d).”

Judge Elena Kagan wrote the dissent, advancing her and her liberal colleagues’ disappointment in the ruling. Her reprimand was direct: “Whatever else this Court may know about, it does not have a clue about how to address climate change.”

She continues and concludes:

“And let’s say the obvious: The stakes here are high. Yet the Court today prevents congressionally authorized agency action to curb power plants’ carbon dioxide emissions. The Court appoints itself—instead of Congress or the expert agency—the decisionmaker on climate policy. I cannot think of many things more frightening. Respectfully, I dissent.”

The decision arrives towards the end of a week in which the Supreme Court offered rulings on other controversial topics: the authority of states to prosecute non-Indigenous people for crimes which take place on tribal land, the ability to pray publicly, the capacity for states to regulate open-carry laws, and the overturning of Roe v. Wade, which federally protected a woman’s right to an abortion.

In other news, Associate Justice Stephen Breyer retired as of noon today, and Justice Ketanji Brown Jackson has been sworn in. She is the first Black woman to serve on the Supreme Court.

While the decision most immediately impacts efforts to reduce carbon emissions from American energy producers, it remains to be seen how this ruling might affect the disciplines that design and construct the built environment.

The full decision is available online and can be read here.