EPA’s rescission of the Endangerment Finding and the vehicle greenhouse gas standards that extend from it relies on a set of legal arguments that are aimed at eliminating EPA’s ability to use the Clean Air Act to regulate greenhouse gas emissions. The final rule blurs the scientific and legal analysis required by statute and misapplies Supreme Court precedent. Although EPA dropped the science-based alternative rationale that was part of its proposal, EPA’s justification for ending regulation of greenhouse gas emissions from new vehicles rests on a scientific conclusion that those emissions are too insignificant to matter.

This analysis breaks down each argument offered by the EPA in the final rule, explores the potential tension with the Supreme Court’s decision in Massachusetts v. EPA and additional legal vulnerabilities we anticipate will be raised in the litigation, and evaluates what EPA’s legal arguments, if successful, will mean for regulating greenhouse gas emissions from motor vehicles and other sectors by the Trump administration and any future administration.

For a brief overview of the legal issues in the rule, see EELP’s Salata Institute Climate Brief. As challenges to EPA’s Endangerment Finding rescission progress, we will be watching how the D.C. Circuit, and likely ultimately the Supreme Court, evaluate each part of EPA’s reasoning for this reversal and will assess what the rescission means for GHG rulemakings for the power and oil and gas sectors, nuisance lawsuits, and state climate policies. To stay up to date on this rule and ensuing litigation, see EELP’s Endangerment Finding tracker page.