U.S. Sues States Over Planned Climate Change Litigation

On April 30, 2025, the United States of America, represented by the Environment and Natural Resources Division of the U.S. Department of Justice (DOJ), sued the State of Hawaii and the State of Michigan (collectively, the States). The United States alleges that potential lawsuits by Hawaii and Michigan against various fossil fuel companies are preempted by the Clean Air Act and would be unconstitutional.

The lawsuit comes in apparent response to the States’ indications that they intend to sue fossil fuel companies for their contribution to greenhouse gas emissions. Both Hawaii and Michigan have indicated that their intent to join the ranks of the municipalities and other States — including Minnesota — that have already filed such claims. See Sabin Center, Climate Case Chart, Common Law Claims. While the specific theories that Hawaii or Michigan would use are unknown, the United States’ complaint nonetheless alleges that: “the goal of the lawsuit is clear — to exact large sums of money from fossil fuel companies for purportedly causing climate change impacts.”

Relying on a series of U.S. Supreme Court cases about the Clean Air Act’s cooperative federalism model, the United States asserts that the Clean Air Act’s nationwide program for regulating air pollution displaces the States’ regulation of greenhouse gas emissions, thereby preempting claims by Michigan or Hawaii, regardless of what claims the States might ultimately bring.

The United States further alleges that the suits would be unconstitutional because they violate the extraterritoriality doctrine of the Due Process clause by regulating conduct outside of the States’ borders.

Relatedly, the United States alleges that the lawsuits violate the interstate and foreign commerce clause. The United States alleges that the States’ claims will discriminate against interstate commerce because fossil fuel extraction and refining occur primarily outside of Hawaii and Michigan — in states like Texas, New Mexico, Louisiana, Wyoming, Pennsylvania, Oklahoma, and North Dakota. The United States also asserts that the burden imposed by the lawsuits would be “clearly excessive in relationship to the putative local benefits,” because the suits would disrupt the national market for fossil fuels.

Finally, the United States asserts “Foreign Affairs Preemption,” alleging that authority over foreign affairs and foreign policy are vested in the president, and the States’ claims over climate change “fall outside the area of any traditional state interest,” because they seek to regulate “a uniquely international problem,” by regulating climate change.

On May 1, 2025, the United States also sued Vermont and New York, raising similar arguments. The United States challenged these states’ Climate Superfund Acts.

These lawsuits appear to be the first lawsuits under E.O. 14260 “Protecting American Energy from State Overreach,” which directed the Department of Justice to “identify all State and local laws, regulations, causes of action, policies, and practices (collectively, State laws) burdening the identification, development, siting, production, or use of domestic energy resources that are or may be unconstitutional, preempted by Federal law, or otherwise unenforceable,” and to “expeditiously take all appropriate action to stop the enforcement of State laws.”

These lawsuits come amid a backdrop of nearly 40 claims brought by other states and municipalities, including Minnesota. In Minnesota, a Ramsey County District Court recently rejected many of the arguments now raised by the DOJ. In Minnesota v. American Petroleum Institute, the court held that the Clean Air Act did not preempt Minnesota’s claims against fossil fuel companies, that the Minnesota’s claims and requested relief in the case would not violate the Commerce Clause, and that the Foreign Affairs Doctrine does not preempt the States’ claims. The Minnesota court did not directly consider the Due Process Clause or the Foreign Commerce Clause.