Untangling the Attack on the Scientific Foundation of Climate Change Regulation

You may have heard that the Trump Administration recently repealed the landmark Endangerment Finding, which served as the foundation for regulating greenhouse gas (GHG) emissions in the U.S. What you may not have heard, however, is that this move marks the largest step yet in a systematic effort to unravel climate change regulation, involving a major debate within the scientific community about the validity of the underlying evidence.

Legal Basis of the Endangerment Finding

The Endangerment Finding is not itself a rule that limits GHG emissions, but rather the legal key that unlocks the EPA’s authority to do so. In 1970, Nixon signed the Clean Air Act (CAA), which broadly defined air pollutants: the act grants the EPA Administrator the authority to regulate any “air pollution which may reasonably be anticipated to endanger public health or welfare.” In essence, the EPA must first establish that a pollutant is harmful before imposing limits on it. In 2007, the Supreme Court ruled in Massachusetts v. EPA that GHGs qualify as air pollutants, triggering a requirement for the EPA to prove whether they meet this standard of harm.

That obligation was met in 2009, when the EPA issued two key findings: the Endangerment Finding, which identified that six GHGs (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride) “threaten the public health and welfare of current and future generations,” and the Cause or Contribute Finding, stating new motor vehicle GHG emissions contribute to this harmful pollution. Together, these mandated that the EPA regulate GHG emissions for vehicles, a directive later expanded in 2015, when the EPA issued standards limiting power plant emissions.

Repeal of the Finding Invokes Scientific and Legal Scrutiny

In July 2025, this bedrock of regulation officially crumbled when Trump’s EPA proposed its repeal of the Endangerment Finding, a move finalized on February 12. Far from a standalone development, the repeal marks the latest advance in a trajectory of deregulation that, at its core, challenges the scientific foundation upon which climate regulation rests. Yet, the process for this challenge has not come without legal scrutiny.

In early 2025, Department of Energy (DOE) Secretary Chris Wright commissioned 5 climate contrarian scientists from outside the DOE to draft a report questioning the basic tenets of climate science. The report claims to review the “scientific uncertainties” in the effects of anthropogenic GHG emissions on climate, extreme weather, and wellbeing. Its central findings include that elevated concentrations of CO2 enhance agricultural productivity, that widely cited climate change projections overstate emission trends, and that excessively aggressive emissions mitigation policies could prove more harmful than beneficial. The EPA cited this DOE report—published after less than 5 months of work—at least 16 times in its notice to reconsider the Endangerment Finding.

Since being released, the report has faced pushback from both the scientific and environmental communities. Eighty-five DOE scientists came together to review the report and submit a rebuttal to the EPA, stating that the report “misrepresents the state of climate science by cherry-picking evidence, exaggerating uncertainties, and ignoring decades of peer-reviewed research,” calling many of its claims “misleading or outright wrong.” Not only that, but the Environmental Defense Fund (EDF) and the Union of Concerned Scientists sued the DOE for allegedly violating public disclosure laws in assembling the Climate Working Group (CWG) that wrote the report. On January 30, a U.S. Federal Court sided with the EDF, citing that the existence of the CWG had not been publicly disclosed at the time of the draft’s release in July of 2025.

Furthermore, now-public emails reveal an underlying motivation to purposefully tailor the report. DOE advisor Travis Fisher wrote in an email to the group that he could help with “targeting your work” to focus on the “areas of inquiry that are most relevant to the policymaking process.” This is critical: if the report was written with the intent to influence policy rather than to objectively review the science, its scientific and legal value is drastically diminished.

The Future of Regulation

The repeal of the landmark Endangerment Finding, while not an end to all GHG regulation in the U.S., means that regulation is no longer required, paving the way for the elimination of emissions limits, grant programs, and additional tools to curb emissions. The effects of climate change, which have already been amplifying, impacting people’s health and financial well-being, will only intensify further. Furthermore, by attempting to undo decades of research and well-established science, the U.S. is sending a signal to the world that its policy is not grounded in fact.

Anya Draves

Research Assistant

Anya Draves is an undergraduate student majoring in physics. She is a research assistant with the Kleinman Center and was a 2025 fall undergraduate fellow.