United States v. Michigan

One day after the Michigan Attorney General filed a lawsuit alleging that energy industry defendants engaged in a conspiracy to delay the transition to low-carbon transportation and energy (see below under “New Cases and Filings”), the federal district court for the Western District of Michigan dismissed the United States’ lawsuit seeking to block the State of Michigan from filing a lawsuit seeking damages from fossil fuel companies for climate change harms. The court ruled that at the time the U.S.’s amended complaint was filed, the case was not ripe for judicial review and the United States did not have standing. Regarding ripeness, the court found that the case turned on “contingent future events” and that deferring review would not “impose significant practical harm” on the United States. With respect to standing, the court found that the federal government failed to establish an “existing” or “certainly impending” injury and, moreover, that the U.S. failed to establish a causal connection between its alleged injuries and the State of Michigan’s alleged conduct.

On April 30, 2025, the Trump administration filed a lawsuit against the State of Michigan seeking to block the State from pursuing a climate change lawsuit against fossil fuel companies. On the same day, the United States also filed a <a href="https://climatecasechart.com/case/united-states-v-hawaii/">similar lawsuit</a> against the State of Hawaii. The complaint cited a news article reporting on Michigan’s intention to file such a lawsuit. The complaint alleged that the United States was bringing the lawsuits “to vindicate its sovereign, proprietary, and parens patriae interests.” The alleged sovereign interests included ensuring that states do not interfere with federal law such as the Clean Air Act or the federal government’s “exclusive authority over interstate and foreign commerce”; the alleged proprietary interests included the U.S.’s economic interests in revenue from fossil fuel leasing on federal lands and in costs for purchasing fossil fuels; and its parens patriae interests related to protecting “the economic well-being of its citizens and the national energy market” from the “nationwide economic and constitutional injuries” allegedly caused by state lawsuits against fossil fuel companies. The United States asserted that the claims in the lawsuit Michigan intended to file were preempted by the Clean Air Act “because they impermissibly regulate out-of-state greenhouse gas emissions and obstruct the Clean Air Act’s comprehensive federal-state framework and EPA’s regulatory discretion.” The U.S. also claimed that the claims against fossil fuel companies were preempted under the Foreign Affairs Doctrine. In addition, the U.S. asserted that the anticipated lawsuit constituted unconstitutional extraterritorial regulation, in violation of due process and concepts of state sovereignty and federalism. The complaint also asserted violations of the Interstate and Foreign Commerce Clauses. The United States requested that the court declare the State's claims unconstitutional and permanently enjoin the State “from taking actions to assert … state law claims.”