Trump Administration Repeals the 2009 Endangerment Finding, Dismantling the Greenhouse Gas Regulation Framework
On February 12, the Trump Administration took its most significant step yet in overhauling federal climate policy by formally repealing the Environmental Protection Agency’s (EPA) 2009 Endangerment Finding, the basis for federal greenhouse gas (GHG) regulation under the Clean Air Act. The Administration described this move as the "single largest deregulatory action in U.S. history."
This action, coupled with the immediate rollback of emission standards and GHG reporting requirements for motor vehicles and proposed changes to GHG reporting requirements for stationary sources, signals a shift toward a hands-off approach to climate change on the federal level by removing the EPA’s authority to regulate most sources of GHGs, such as emissions from chemical and power plants.
The Endangerment Finding
The Endangerment Finding emerged from the U.S. Supreme Court's 2007 ruling in Massachusetts v. EPA. In that case, a coalition of states and environmental organizations challenged the EPA's refusal to grant a petition for rulemaking. This proposed rule would have compelled the EPA to classify carbon dioxide as an "air pollutant" under the Clean Air Act. Furthermore, it sought to mandate the regulation of automobile emissions of carbon dioxide and other greenhouse gases, based on the premise that they "may reasonably be anticipated to endanger public health or welfare."
The Supreme Court sided with the petitioners, rejecting the EPA's assertion that greenhouse gases were not air pollutants, and dismissing the agency's claim that it had discretion on whether to issue an endangerment finding. Consequently, the case was sent back to the EPA for further action. In its decision, the Court clarified that if the EPA determines that an endangerment exists, the Clean Air Act obligates the agency to regulate the emissions of harmful pollutants from new motor vehicles. However, that finding would have impacts far beyond just motor vehicle emissions.
Following subsequent extensive notice-and-comment rulemaking, the EPA issued the 2009 Endangerment Finding, concluding that a mix of six key greenhouse gases in the atmosphere, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), threaten public health and welfare pursuant to Section 202(a) of the Clean Air Act.
The Trump Administration’s Repeal of the Endangerment Finding
On his first day in office, President Trump issued an Executive Order titled "Unleashing American Energy," which directed EPA to review the "legality and continued applicability" of the Endangerment Finding. This process culminated on February 12, when EPA Administrator Lee Zeldin finalized the repeal, which is scheduled to become effective on April 20.
While earlier reports suggested the EPA might rely on a controversial climate science review produced by the Department of Energy (DOE), the EPA’s justification for the repeal appears to have pivoted from pure scientific disagreement to strict statutory interpretation. Specifically, the agency argues that Section 202(a) of the Clean Air Act does not grant the EPA authority to enact emissions regulations specifically to address global climate change.
Relying on the “major questions doctrine,” which holds that Congress must speak clearly if it wishes to assign agencies vast political and economic powers, the EPA asserts that the Endangerment Finding exceeded the agency’s delegated authority. Furthermore, the EPA maintains that regulating GHG emissions is not necessary to fulfill its core mission of protecting human health and the environment because it argues that eliminating U.S. vehicle emissions would have “no material impact” on global temperatures.
By framing the issue as one of lack of statutory authority, rather than a lack of scientific support, it appears that the Trump Administration aims to insulate the repeal from scientific challenges and force a re-evaluation of Massachusetts v. EPA before the Supreme Court.
Proposed Overhaul of Greenhouse Gas Reporting Requirements
Alongside the focus on the Endangerment Finding, the Trump Administration is also targeting the Greenhouse Gas Reporting Program (GHGRP). Although the repeal of the Endangerment Finding immediately eliminates GHG reporting obligations for all motor vehicles, the GHGRP for stationary sources (like power plants and refineries) has not yet been fully abolished. However, the EPA has proposed a separate rule eliminating reporting requirements for 46 of the 47 industries covered. The only sources not targeted by this proposed rule are petroleum and natural gas systems, which the Trump Administration argues is due to the “waste emissions charge,” a methane fee established by the Inflation Reduction Act.
Notably, this proposal has faced resistance, not just from environmental groups, but also from segments of the oil and gas industry. While trade groups like the Independent Petroleum Association of America (IPAA) have applauded the repeal of the Endangerment Finding itself, they have simultaneously signaled concern regarding the durability and clarity of the remaining GHG regulations.
Rollback of Specific Greenhouse Gas Regulations
The Trump Administration is also pursuing rollbacks of other specific climate-related rules. For example, the Department of Transportation has rescinded a rule requiring states to measure and set declining CO2 emission targets for federally funded highways, purportedly to reduce project costs and increase state autonomy. In addition, the EPA has signaled its intent to reconsider various regulations limiting air emissions from power plants and other industrial sources, including GHG emissions.
Why Some Emitters Are Concerned about These Rollbacks
The primary concern for many emitters is that eliminating the federal standards will create a regulatory vacuum that individual states could rush to fill. If the federal framework disappears, emitters face the risk of navigating a "patchwork" of 50 different state-level regulatory regimes, significantly increasing compliance costs compared to preemptive federal standards. In addition to these new potential regulatory headaches, the lack of a preemptive federal framework could lead to a rise in common law nuisance lawsuits against emitters. See City of New York v. Chevron Corp., 993 F.3d 81 (2d Cir. 2021).
On the other hand, the Trump Administration’s Executive Order, "Protecting American Energy from State Overreach" aims to counter state and local laws that penalize energy companies for GHG emissions or otherwise burden domestic energy production, which may deter state and local governments from taking action for the remainder of the Trump Administration.
What Comes Next?
The repeal of the Endangerment Finding, coupled with changes to GHG reporting and specific regulations, marks a massive shift in U.S. climate policy. The ultimate impact will be decided in the courts. Health and environmental groups have already filed suit against the EPA to challenge the repeal, arguing that it violates the Clean Air Act’s requirement to follow scientific evidence regarding human health, and the states of California, Massachusetts, and Colorado have vowed to bring similar challenges.
Businesses, industry groups, and other stakeholders should closely follow these developments, as they could significantly alter the regulatory landscape for greenhouse gas emissions in the United States.
If you have any questions about current or future regulations of air emissions, please reach out to Blake Donewar, Steve Levine, Phillip Dupré, Sophie Gray or any member of the Phelps Environmental team.