CSIU has submitted a detailed comment refuting the claims made by the Environmental Protection Agency (EPA) in their August 1, 2025 proposal to rescind their own 2009 Endangerment Finding. That ruling was originally made by the EPA in response to scientific evidence amassed documenting the impacts of greenhouse gas emissions on the health and welfare of American citizens.
The Endangerment Finding is the basis for all EPA standards and regulations of greenhouse gas emissions from new U.S. vehicles. It was adopted by using the authority delegated to EPA by the U.S. Congress in the 1970 Clean Air Act to regulate air pollutants. The Endangerment Finding declared carbon dioxide, methane, and other greenhouse gases to be air pollutants jeopardizing the health and welfare of Americans by their contribution to climate change. The danger of greenhouse gas emissions and the EPA’s authority and responsibility to regulate them were further reinforced by Congress in the 2022 Inflation Reduction Act. Since 2015 the transportation sector has been the largest emitter of carbon dioxide in the U.S., overtaking the electric power generation sector.
As part of the Trump administration’s overall efforts to disregard the scientific evidence and the well-documented dangers of climate change, the EPA has now proposed legal, scientific, and technical arguments for rescinding the Endangerment Finding. The proposal is open for public comment until September 22, 2025. The CSIU comment urges rejection of the proposal by documenting in detail why each of the EPA’s arguments is unsound and “at odds with the clear language of the Clean Air Act and of the Inflation Reduction Act, the SCOTUS [U.S. Supreme Court 2007] ruling in Massachusetts v. EPA, the vast majority of international global warming and climate change research, and the efforts being pursued in most other industrialized countries to reduce vehicular emissions of greenhouse gases.”
The EPA’s flawed scientific arguments have been drawn from a new Department of Energy (DOE) climate report released in July 2025. That report was drafted by five scientists from the tiny contrarian wing of the international climate science community, who were hand-picked by the Secretary of Energy to cast doubt on the existence and urgency of climate change impacts on human health and welfare. A recent review of that DOE report, written by more than 85 climate experts, has judged the report to be “a mockery of science,” finding it “biased, full of errors, and not fit to inform policymaking.”
The CSIU comment finds that “The scientific rationale offered in this [EPA] proposal for rescinding the Endangerment Finding is shallow, sloppy, unsubstantiated, and ultimately unable to meet the legal standard laid out by SCOTUS” in Massachusetts v. EPA. Furthermore, CSIU labels as “ridiculous” the EPA’s argument that regulating greenhouse gas (GHG) emissions is unimportant because even if all U.S. vehicle GHG emissions were reduced to zero, that would only reduce global warming trends by about 3%. Climate change is a serious cumulative global environmental problem caused primarily by human activities in many countries. Efforts to mitigate the most severe impacts will require greenhouse gas emission reductions from many countries and from many sources. CSIU notes that “if each of those countries decides that a mere 3% reduction is not worth pursuing, as the EPA is doing here, then humans would have committed themselves to doing nothing to address the problem. Incremental efforts not only matter, but they are essential.”
The CSIU comment was submitted to the Regulations.gov portal on Sept. 9, 2025. By federal law, this proposed regulatory policy change requires the EPA to post a public comment period and address all comments received before the policy can be implemented. The full CSIU comment can be read here.
