EPA’s Plan to Rescind GHG Endangerment Finding Sets Up Legal Showdown

On July 29, the Trump EPA unveiled a controversial proposal to rescind the agency’s 2009 endangerment finding for greenhouse gases (GHGs) under the Clean Air Act — the foundational determination that has underpinned U.S. climate regulation for over a decade.

EPA Administrator Lee Zeldin called EPA’s proposal “the largest deregulatory action in the history of the United States.” But environmental groups are already preparing legal challenges, calling the move legally and scientifically indefensible.

What’s in the Proposal?

The proposal stakes out several novel legal theories:

• Statutory Authority: EPA now argues that Clean Air Act section 202(a) does not authorize EPA to regulate GHGs from vehicles to address global climate concerns — a direct rebuke of the agency’s longstanding interpretation affirmed by the Supreme Court in Massachusetts v. EPA (2007).

• Scientific Skepticism: The proposal claims the 2009 finding involved “mental leaps” in connecting GHG emissions (including gases not emitted by vehicles) to climate impacts and public health harms.

• Cost Burdens: EPA claims the original finding failed to consider the downstream economic burdens of regulations that flowed from it.

• Alternative Findings: The agency offers several fallback arguments, including that available vehicle technology cannot address climate concerns without causing greater harms — a rationale likely to invite scrutiny under the arbitrary and capricious standard.

The Legal Landscape

Administrator Zeldin argues the endangerment finding is inconsistent with Michigan v. EPA, West Virginia v. EPA, and Loper Bright v. Raimondo. But critics say those cases are inapplicable or misinterpreted. Indeed, Massachusetts v. EPA remains binding precedent affirming both EPA’s authority and obligation to regulate GHGs if they endanger public health and welfare.

The proposal’s legal durability will hinge on whether the agency can overcome the deferential but still demanding standards of the Administrative Procedure Act. Critics have already called the reasoning speculative and the evidentiary record lacking.

What Comes Next?

A public hearing is scheduled for August 19–20, and written comments are due by September 21. Given the scope of the rollback, this rulemaking will likely eventually end up before the Supreme Court with the outcome potentially redefining the federal government’s role in climate policy for years to come.

Final Thoughts - The Pendulum Swings: Navigating GHG Regulatory Uncertainty

This new proposal, whether viewed as a principled reinterpretation of the EPA's authority or a move to dismantle climate protections, will undoubtedly have far-reaching effects. The unfortunate reality is that we're likely facing years of regulatory uncertainty. This "pendulum swing" between administrations, from aggressive environmental policies to deregulation, creates an unpredictable landscape for businesses. The ideal scenario for industry would be the emergence of a middle ground, where greenhouse gas regulations and similar environmental issues transcend this cycle of extreme policy shifts.