What is the 2009 Endangerment Finding?
Established by the U.S. Environmental Protection Agency (EPA), the 2009 Endangerment Finding is a scientific finding that concludes six well-mixed greenhouse gases (GHGs) endanger public health and the welfare of current and future generations. GHGs are gases that trap heat in the atmosphere and warm Earth’s surface. Some GHGs remain in the atmosphere for hundreds of years, and their concentrations can alter the Earth’s radiative balance and affect climate and weather patterns.
First signed during former President Barack Obama’s administration, the 2009 Endangerment Finding has served as a framework for the EPA’s regulation of GHG emissions from passenger cars and trucks, fossil fuel-fired power plants, and the other facilities in the oil and natural gas sector. To respond to the EPA’s GHG emission standards, some American auto makers have equipped vehicles with start-stop ignition systems, which automatically shut off a vehicle’s engine when the vehicle is idling in order to reduce emissions. Many states have also established laws and incentives for electric vehicles (EVs), with California leading the country with 98 EV policies.
How Did Massachusetts v. EPA (2007) Influence the 2009 Endangerment Finding?
Before the institution of the 2009 Endangerment Finding, Massachusetts v. EPA (2007) acted as a catalyst for the scientific finding that determined a combination of six GHGs harm public health and welfare. The Supreme Court’s decision in Massachusetts came in response to the EPA’s denial of a special request made by 19 private organizations, who urged the EPA to regulate GHG emissions from new motor vehicles under Section 202(a)(1) of the Clean Air Act (CAA). This request is often called a petition of rulemaking and is allowed under the Administrative Procedure (APA) any time a party wants an agency to “issue, amend, or repeal a rule.” At the time of its denial of the request, the EPA argued that the agency lacked statutory authority to regulate GHG emissions because GHGs were not recognized as “air pollutants” under the CAA and that potential regulation would cause a number of policy concerns.
In a 5-4 decision, the Court ruled that, because the CAA’s definition of “air pollutant” was intentionally broad, the six GHGs in question—carbon dioxide, hydrofluorocarbons, methane, nitrous oxide, perfluorocarbons, and sulfur hexafluoride—fell under the CAA’s definition. The Court then instructed the EPA to respond to the petition for rulemaking and determine whether GHGs contribute to climate change. If the EPA made such a determination as Justice John Paul Stevens wrote in the Court’s majority opinion, the agency would be required under the CAA to regulate GHG emissions from new motor vehicles. Two years after the Court’s decision, the EPA adopted the 2009 Endangerment Finding after collecting a large body of scientific evidence and hosting a 60-day public comment period to weigh the finding. Since 2009, the Endangerment Finding has been reaffirmed with additional evidence and has been upheld by the Court following its rejection to hear petitions for reconsideration in 2017 and 2019.
Why is the 2009 Endangerment Finding Being Revoked?
On February 12th, 2026, the EPA revoked the 2009 Endangerment Finding, referencing its own lack of statutory authority under the CAA to set standards for GHG emissions in its decision. The EPA’s walk back followed Executive Order No. 14154. The order, signed by President Donald Trump on January 20th, 2025, had directed the Administrator of the EPA to reconsider the “legality and continuing applicability” of the 2009 Endangerment Finding. In its official rule summary, the EPA said that this latest revocation realigns the EPA’s regulatory powers with the “best reading of the CAA” and will save American families and businesses over $1.3 trillion from regulations.
Who Supports the Revocation of the 2009 Endangerment Finding?
Supporters of the revocation of the 2009 Endangerment Finding include President Donald Trump, who has praised the revocation for being “the single largest deregulatory action in American history.” Lee Zeldin, the Administrator of the EPA, has also voiced his support for the move, arguing that the regulations imposed under the 2009 Endangerment Finding have “strangled” the economy and the American auto industry and have harmed affordability and consumer choice. The Heritage Foundation, a conservative think tank, has repeated President Trump and Zeplin’s praises, applauding the revocation for saving Americans money and for no longer giving the EPA “the power of a central planner of the economy.”
The revocation of the Endangering Finding has gained support from some auto makers too, with the Alliance for Automotive Innovation President and CEO John Bozzella calling the previous regulation standards “unachievable.” Will Otero, a representative at Chrysler’s parent company, has said that the EPA’s decision will allow Chrysler to offer Americans vehicles that “they want, need, and can afford,” especially since Zeldin announced the end to emission credits for manufacturers who install start-stop ignition systems along with the Endangerment Finding revocation.
Who Opposes the Revocation of the 2009 Endangerment Finding?
Former EPA officials like Dr. Lynn Goldman, who led the Office of Chemical Safety and Pollution Prevention at the EPA during the Clinton administration, have criticized the revocation, asserting that it will put people’s lives at risk from air pollution and increase premature deaths and health care costs. Margo T. Oge, who was the Director of the Office of Transportation and Air Quality (OTAQ) at the EPA for 18 years, has warned that the EPA’s move will increase fuel prices and eliminate jobs as companies cancel or downsize clean energy projects, like electric vehicle (EV) programs. Former President Barack Obama, whose administration adopted the Endangerment Finding, has pushed back against the move as well, writing in an Instagram post that has since gained over 2 million likes that the revocation will make Americans “less safe, less healthy, and less able to fight climate change.”
Scientists have also spoken out against the revocation, with some worrying that the EPA’s decision to no longer regulate GHG emissions will raise the atmospheric total of GHG emissions, thus impacting economies, ecosystems, and human health worldwide. Other opponents like Michael B. Gerrard, a professor at Columbia University, have argued that the U.S is “abdicating its responsibility” to regulate its emissions as the largest GHG emitter with the EPA’s revocation.
What Are the Future Implications?
With mixed reactions to the EPA’s move to revoke the 2009 Endangerment Founding, many anticipate legal challenges. As of February 18th, the revocation has already been met with a lawsuit from a coalition of public health and environmental organizations, who believe the EPA’s actions are at “complete odds with public interest and the best available science.” Yet before the EPA can respond to any judicial proceedings, the agency must comply with Section 307(d) of the CAA, which requires the agency to share evidence in support of the rule change and participate in a comment period, known as the “notice-and-comment rulemaking.” Over 570,000 public comments have been submitted since the EPA’s revocation so far, and it is only after the EPA has responded to every comment that the agency can submit its rule change for judicial review.
Although the current Supreme Court has recently reined in the EPA’s regulatory powers under the CAA with cases like West Virginia v. EPA (2022), uncertainties remain on whether the Court will find the EPA’s evidence substantial enough to revoke the 2009 Endangerment Finding. A response from Congress could also have a sizable impact on the permanence of the EPA’s revocation, with some Republican lawmakers recently sharing interest in codifying the revocation. For Americans, the economic impact of the revocation is projected to be a mix of costs and savings, as drivers could save $2,400 for new vehicles at the time of the initial purchase but spend $6,000 more in fuel and maintenance costs over the lifetimes of their vehicles. The revocation could also have significant effects on the environment, as it will eliminate a 2024 program endorsed by former President Joe Biden that would have cut 7 billion tons of emissions and combatted climate change, signaling an unknown road ahead for advocates of more robust climate policies in the U.S.