On Feb. 12, the U.S. Environmental Protection Agency (EPA) announced a final rule to rescind the 2009 Obama-era Endangerment Finding issued under Section 202(a)(1) of the Clean Air Act (CAA). The Endangerment Finding determined that emissions of greenhouse gases (GHGs), including carbon dioxide and methane, from new motor vehicles and engines contributed to air pollution that threatens public health and welfare. The Endangerment Finding had been the basis for EPA to establish federal GHG emission standards for motor vehicles and engines and push toward electric vehicle (EV) mandates. In rescinding the Endangerment Finding, EPA also repealed all federal GHG emission standards for all light-duty, medium-duty, and heavy-duty vehicles and engines of model years 2012 to 2027 and beyond. The final rule was published Feb. 18, and legal challenges have already been filed.

Legal Rationale For Action

EPA has taken the position that Section 202(a)(1) of the CAA does not authorize the agency to prescribe motor vehicle emission standards to address “global” climate change concerns. CAA Section 202(a)(1) requires EPA to regulate emissions of any “air pollutant” from motor vehicles if the emissions “cause or contribute” to air pollution that can “reasonably be anticipated to endanger public health or welfare.” EPA has concluded that CAA Section 202(a)(1) should be read as only authorizing regulation of emissions from motor vehicles and engines based on air pollution that endangers public health or welfare “through local or regional exposure,” finding that there must be more than some “attenuated chain of causation” linking the GHG emissions to the endangerment.

EPA also concludes that rescission of the Endangerment Finding is consistent with recent Supreme Court case law. In the 2007 decision, Massachusetts v. EPA, the U.S. Supreme Court held that GHGs may be regulated as an “air pollutant” under the CAA and that EPA must determine if they pose a danger to public health or welfare. Directly following the Supreme Court’s directive, EPA issued the Endangerment Finding, and the federal GHG motor vehicle emission standards followed.

The U.S. Supreme Court has never directly ruled on the Endangerment Finding, but since the Massachusetts decision, it has issued decisions limiting agency discretion in Loper Bright v. Raimondo and invoking the major questions doctrine in West Virginia v. EPA, in which it vacated the Clean Power Plan regulations. Commenters have noted that the Massachusetts opinion was a 5-4 decision and may be ripe for overturning, with all five justices in the majority having left the bench, while three of the dissenters remain.

Vehicle GHG Rules Impacted By The Action

The rule rescinds only EPA GHG emission standards and related regulatory provisions for light-duty, medium-duty, and heavy-duty vehicles and engines that were promulgated following the Endangerment Finding. Specifically, EPA has removed regulations in 40 CFR Parts 85, 86, 600, 1036, 1037, and 1039 pertaining to the control of GHG emissions, including measurement, control, and reporting of GHG emissions.

Expected Environmental Impacts From The Action

EPA determined not to finalize a scientific rationale for its action or issue a new finding. EPA does, however, note that the GHG emissions standards on motor vehicles and engines have had “no material impact on global climate change concerns.” Based on “climate impact modeling” submitted to EPA during the rulemaking proceeding, EPA has further concluded that eliminating all GHG emissions from vehicles in the U.S. would only have de minimis impact on global temperature, and therefore, it would be unreasonable to retain the GHG emission standards due to their “futility.”

Legal Challenges To The Action

Petitions to review EPA’s rescission of the Endangerment Finding and related vehicle GHG emission standards have already been filed with the U.S. Court of Appeals for the D.C. Circuit, and more petitions are expected. Petitions must be filed within 60 days after the rule was published in the Federal Register, or by April 20. Taft will continue to follow the litigation.