May 19, 2026

EPA Finalizes GHG Rescission, States Regulating GHGs is “Futile”

Effective April 20, 2026, EPA’s 2009 greenhouse gas (GHG) endangerment finding [74 FR 66496] and GHG emission standards for light-, medium-, and heavy-duty vehicles and engines have been rescinded. [91 FR 7686] The agency’s rule was finalized mostly as proposed, citing the same tenuous logic, as discussed in a previous article. Ultimately, the agency believes any one of three main arguments is sufficient to eliminate GHG regulation:

CAA Section 202(a) [42 U.S.C. Section 7521(a)] can’t be used to address climate change because the term “air pollution” only extends to pollution with local or regional effects. Additionally, the statutory terms “cause” or “contribute” require an endangerment finding before a pollutant may be regulated, and GHG emissions have only a de minimis connection to climate change and thus warrant no finding.
Clear congressional authorization to regulate vehicle emissions to address climate change is absent per the major questions doctrine (see West Virginia vs. EPA; U.S. Supreme Court; Docket No. 20-1530; June 30, 2022).
Addressing climate change through GHG regulation is “futile,” and the costs are too high for such little health and welfare benefits.

Yet, the Supreme Court said GHGs are unambiguously air pollutants under the CAA and EPA must use “scientific judgment,” without considering policy or cost in making an endangerment finding. [Massachusetts et al. vs. EPA et al.; U.S. Supreme Court; Docket No. 05-1120; April 2, 2007] In its rescission, EPA has chosen to reject its previous scientific judgment in favor of a controversial Department of Energy (DOE) report authored by a panel of climate change deniers, where DOE was found to have violated federal law. [Environmental Defense Fund, Inc. et al. vs. Wright et al.; United States District Court District of Massachusetts; Civil Action No. 25-12249-WGY; September 17, 2025]

A coalition of dozens of state and local governments has already filed suit against EPA for rejecting legal requirements and betraying its mission. Unless the courts deem otherwise and stay the final rule, two primary changes are in effect. First, all GHG emission standards for light-, medium-, and heavy-duty motor vehicles and engines for model years 2012 and forward have been eliminated. Second, the removal of certain test procedures, averaging/banking/trading requirements, reporting provisions, and fleet-average emission requirements found in 40 CFR Parts 85, 86, 600, 1036, and 1037, have been removed.

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