Executive Summary
Since 1970, the EPA has executed its statutory authority under the Clean Air Act (CAA) to mitigate pollution from both stationary and mobile sources deemed to endanger public health, welfare, and the environment. For decades, the EPA has adopted science-based standards under this authority to reduce harmful tailpipe pollution. These standards have grown stronger over time, driving U.S. automotive sector innovation while providing consumers with safer, cleaner, and more efficient transportation options. They have strengthened the economy and cleaned the air while saving consumers money and creating jobs.
In August 2025, however, the EPA issued a proposed rule, Reconsideration of the Endangerment Finding and Greenhouse Gas Vehicle Standards, to rescind their 2009 Endangerment Finding and repeal greenhouse gas emission standards from all new vehicles. The 2009 Endangerment Finding underpins the federal government’s ability to regulate greenhouse gas (GHG) emissions, while also repealing certain vehicle tailpipe emissions standards promulgated under this authority.
Repealing these standards threatens the budgets, public health, and economic opportunity of Americans: It would force households to pay $310 billion more in energy costs, cause 700 premature pollution related deaths annually, cut cumulative U.S. GDP by $710 billion and cost the domestic labor force an average of 110,000 jobs annually, all between 2026 and 2050.
Higher energy spending is not offset by lower upfront vehicle costs since EV prices have fallen as deployment surges and battery costs decline, while the average new gasoline car price has increased over time through inflation and consumers choosing larger vehicles.
After the 2007 U.S. Supreme Court decision in Massachusetts v. EPA determined GHGs are air pollutants covered by the CAA, the EPA signed the Final Endangerment and Cause or Contribute findings for six GHG pollutants from new motor vehicles. They concluded these pollutants cause or contribute to air pollution that endangers public health or welfare[1]—a finding backed by resounding consensus in the global scientific community.[2] Since 2010, the EPA has adopted updated standards to reduce GHGs from new models of light-, medium-, and heavy-duty vehicles. The EPA’s 2024 standards, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and Medium-Duty Vehicles and Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles – Phase 3 (“existing standards”), were designed to further reduce harmful air pollutant emissions while benefiting society.
We used the open-source Energy Policy Simulator to model the impacts of this proposed rule, finding that repealing GHG tailpipe emission standards would significantly harm America’s families, economy, public health, and welfare. Simultaneously, by reducing investment in more efficient vehicles and increasing demand for gasoline, the EPA’s proposal would cause U.S. households to pay $310 billion more on energy, for an average $83 per household per year over the next 25 years. The Proposed Reconsideration conflicts with the EPA’s responsibility to protect public health and welfare.
[1] U.S. EPA, “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act,” Climate Change, February 27, 2025, https://www.epa.gov/climate-change/endangerment-and-cause-or-contributefindings-greenhouse-gases-under-section-202a.
[2] National Academies of Sciences, Engineering, and Medicine, “Effects of Human-Caused Greenhouse Gas Emissions on U.S. Climate, Health, and Welfare,” National Academies Press, ahead of print, 2025, https://doi.org/10.17226/29239.