Tomorrow the Environmental Protection Agency (EPA) is expected to release its final rule rescinding the "endangerment finding" for greenhouse gases. By taking this step, the Trump Administration is hoping to undercut the federal regulation of greenhouse gases and deprive the EPA of any authority to adopt such rules under the Clean Air Act.

I am on record arguing that this is a risky move. As a legal matter, attempting to undo the endangerment finding is not as simple or straightforward as many political commentators seem to think. The rule will immediately be subject to legal challenge, initially in the U.S Court of Appeals for the D.C. Circuit, which is not the most friendly venue for aggressive deregulatory moves. As the New York Times reported, the Administration is nonetheless hoping that it can get this issue before the Supreme Court before the end of the Trump Administration, lest a new administration undercuts the defense of the rule.

It is hard to handicap any prospective legal challenge to the final rule rescinding the endangerment finding until it is released, as much will depend on the specific strategy the EPA has adopted, and how well that strategy is executed.

For background on the legal issues and what may be in store, here are some of my posts on the subject:

• Can the EPA Rescind the Endangerment Finding? Should It Even Try?, May 10, 2025;
• Can the EPA Finesse the Greenhouse Gas Endangerment Finding?, May 16, 2025;
• NYT: EPA Embarking on Endangerment Finding Fool's Errand, July 23, 2025;
• Why Trying to Undo the Endangerment Finding Is A High-Risk (and Low-Reward) Deregulatory Strategy, September 15, 2025.

More to come!