The US Environmental Protection Agency is expected to issue a rollback of the 2009 “endangerment finding” that enables greenhouse-gas regulation under the Clean Air Act.

If finalized, the rollback would undercut the legal foundation for most federal climate rules on vehicles, power plants, and other major emitters, forcing regulators to rebuild authority through new rulemaking or litigation. It also sets up a high-stakes court path that is likely to reach the US Supreme Court, creating a multi-year period where compliance planning and capital allocation assumptions for automakers, utilities, and oil & gas face shifting federal requirements. Companies involved in state and local climate litigation would see the federal regulatory posture change, affecting legal strategy and settlement leverage tied to federal standards.