Repeal of EPA’s endangerment finding on greenhouse gases faces hurdles and would threaten regulatory instability.
Calling it “the greatest day of deregulation our nation has seen,” Lee Zeldin, the administrator of the U.S. Environmental Protection Agency (EPA), announced on March 12, EPA’s plans to repeal 31 agency rules—an action he said would “drive a dagger straight into the heart of the climate change religion.” Among the rules targeted for repeal is EPA’s 2009 “endangerment finding,” which determined that “six greenhouse gases taken in combination endanger both the public health and the public welfare of current and future generations.” But can EPA repeal this endangerment finding and—as important—should it?
The short answer to the first question is that an agency generally has the authority to repeal regulations that themselves were not mandated by Congress, but there are significant procedural hurdles under the Administrative Procedure Act (APA) to doing so. In the case of the endangerment finding, the hurdles are particularly steep.
EPA’s 2009 endangerment finding was the outgrowth of the U.S. Supreme Court’s 2007 decision in Massachusetts v. EPA. The petitioners in the case—several states and environmental groups—challenged EPA’s denial of a petition for a rulemaking. The proposed rule would have required EPA to conclude that carbon dioxide was an “air pollutant” under the Clean Air Act and that automobile emissions of this and other greenhouse gases must be regulated because they “may reasonably be anticipated to endanger public health or welfare.” The Court rejected EPA’s challenges to the states’ standing, EPA’s argument that greenhouse gases were not air pollutants, and EPA’s claimed discretion whether to make an endangerment finding, remanding the case to the agency. In rejecting EPA’s claim of discretion, the Court reasoned that “if EPA makes a finding of endangerment, the Clean Air Act requires the Agency to regulate emissions of the deleterious pollutant from new motor vehicles.”
EPA’s subsequent 2009 endangerment finding was the product of an extensive notice-and-comment rulemaking proceeding that followed the Court’s decision. The fact that the endangerment finding was the product of a notice-and-comment process is important for several reasons.
First, before an agency may repeal a rule issued using notice-and-comment procedures, it must use those same procedures. That can be a lengthy process. The agency must consider and address adequately all significant comments to avoid the taint of arbitrariness. That is no small feat. A rule that alters a major agency policy such as the endangerment finding is likely to engender thousands of comments. For example, the Federal Communications Commission’s proposal to end its “net neutrality” policy prompted several million comments. The process of review will also almost surely be made harder—and more prone to error—in light of the EPA administrator’s announced plans to cut the agency’s spending by 65 percent. Budgetary cuts, coupled with plans to repeal 31 rules, are sure to strain the agency’s resources.
Second, if the original rule was centered on the agency’s fact finding—which was the case with what the agency termed its endangerment finding—the agency is not writing on a “blank slate.” In such cases, it must demonstrate either that the facts underlying the original rule have changed or, if not, why repeal is nonetheless appropriate. That too will likely be difficult for EPA. In the years since the endangerment finding, the climate change impacts of greenhouse gas emissions have gotten worse, as the United Nations (U.N.) has warned.
Finally, in repealing a rule, the agency must consider any “reliance interests” that the original rule may have created. In Department of Homeland Security v. Regents of University of California, for example, the Supreme Court struck down the first Trump Administration’s attempt to repeal the Deferred Action for Childhood Arrivals (DACA) rule protecting “dreamers”—undocumented immigrants brought to the United States as children—because the U.S. Department of Homeland Security had failed to consider the reliance interests of universities and others that had planned their affairs based on the rule. The existence of reliance interests is not a bar to repeal, but the agency must demonstrate that those interests have not been ignored and are outweighed by the benefits of the rule. Again, this task will be a hefty lift for EPA. The endangerment finding has been in effect for nearly a generation—undisturbed by Congress. During that time, utilities across the United States have retooled their generation fleets to reduce carbon emissions, car manufacturers—reliant on tax credits—have restructured their organizations to produce more hybrid and all-electric vehicles, and other major industries have promoted their own efforts to secure green energy.
Beyond these hurdles, the Supreme Court’s 2024 decision in Loper Bright Enterprises v. Raimondo—which overturned the Chevron doctrine, under which a court must defer to a reasonable agency interpretation of an ambiguous statute—may not cut in a deregulatory direction, contrary to conventional wisdom. It is one thing when private parties are challenging government statutory overreach—the lack of agency deference helps the challengers. It is quite another thing when the government seeks to undo its own existing statutory interpretation.
Even before Chevron’s demise, an agency’s statutory interpretation was not entitled to judicial deference when the courts themselves had previously found the statutory term at issue to be unambiguous. In the case of EPA’s endangerment finding, one thing that is not at issue is whether greenhouse gases are air pollutants. “Carbon dioxide, methane, nitrous oxide, and hydrofluorocarbons,” the Court concluded in Massachusetts v. EPA, “are without a doubt ‘physical and chemical … substances which are emitted into … the ambient air.’ The statute is unambiguous.”
In Massachusetts v. EPA, the Court suggested that the question of whether these pollutants “may reasonably be anticipated to endanger public health or welfare” may present a legal rather than a factual issue. Citing Chevron v. Natural Resources Defense Council, the Court stated that it need not and does not “reach the question whether on remand EPA must make an endangerment finding, or whether policy concerns can inform EPA’s actions in the event that it makes such a finding.” Even assuming there is a meaningful question of law remaining, under Loper Bright, EPA would have to convince a reviewing court that reversing its endangerment finding is the “best reading” of the statute. That task seems like a tall order given the Supreme Court’s observation in Massachusetts v. EPA that “judged by any standard, U.S. motor-vehicle emissions make a meaningful contribution to greenhouse gas concentrations.”
Far more likely, though, reviewing courts would view any reversal of EPA’s endangerment finding as a factual question subject to traditional arbitrary and capricious review under the APA. As the Supreme Court noted in Loper Bright:
When the best reading of a statute is that it delegates discretionary authority to an agency, the role of the reviewing court under the APA is, as always, to independently interpret the statute and effectuate the will of Congress subject to constitutional limits. The court fulfills that role by recognizing constitutional delegations, “fixing the boundaries of the delegated authority,” and ensuring the agency has engaged in “reasoned decisionmaking” within those boundaries. By doing so, a court upholds the traditional conception of the judicial function that the APA adopts.
More specifically, can EPA support with “substantial evidence” a finding that greenhouse gas pollutants cannot “reasonably be anticipated to endanger public health or welfare?” Eighteen years ago, in Massachusetts v. EPA, the Supreme Court observed when remanding the challenged EPA action that “if the scientific uncertainty is so profound that it precludes EPA from making a reasoned judgment as to whether greenhouse gases contribute to global warming, EPA must say so.” Of course, EPA had said the opposite. In the ensuing years, the evidence of climate change risks has only mounted. The 1998 rulemaking petition that led to Massachusetts v. EPA cited the fact that 1998 was then the hottest year on record. We have had many more hottest years on record since then, the last, according to the National Oceanic and Atmospheric Administration, in 2024. And U.S. and U.N. assessments suggest that we are past the tipping point and that climate impacts will only get worse.
Putting these legal issues aside, repealing the endangerment finding is simply a terrible idea—creating the same risks of regulatory instability posed by the Trump Administration’s erratic, grievance-driven tariff policies, which have provoked retaliatory tariffs by Canada, Mexico, and the European Union. I have already mentioned the considerable reliance interests engendered by this now 16-year-old endangerment finding. Undoing the finding will affect scores of federal regulations around which businesses have been planning their operations for years. It will also create needless conflicts with many state governments that have been pushing companies to adopt climate resilience measures. But it is not only that: Climate risks are real, and perhaps more importantly, are perceived as real by the marketplace. This reality is reflected in the rising rates of insurance carriers to both homeowners and businesses, not to mention their withdrawal from climate risk-prone markets. Rating agencies, which greatly influence borrowing costs for businesses, are sending the same message. An agency rule to turn back the clock in the face of these realities will do far more harm than good.
