U.S. District Court Strikes New York Climate Change Superfund Act

Update: Since this article was published, a second federal court has ruled against New York’s Climate Change Superfund Act (the “Climate Superfund Act”). On September 23, 2026, in a parallel challenge brought by the U.S. Department of Justice and U.S. Environmental Protection Agency (EPA), Judge P. Kevin Castel of the U.S. District Court for the Southern District of New York held that the Act is preempted by the Clean Air Act (CAA) and separately invalid under the foreign affairs doctrine.

On September 14, 2026, attorneys for New York State and plaintiffs challenging the Climate Superfund Act jointly asked the U.S. District Court for the Northern District of New York to enter final judgment on the plaintiffs’ two preemption claims. The request follows the court’s August 31 Memorandum-Decision and Order granting summary judgment on those preemption claims and would set the stage for an immediate appeal to the Second Circuit. Any appeal could be significantly affected by the Supreme