Trump's plan to end EPA endangerment finding would weaken climate change regulations

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The Environmental Protection Agency’s endangerment finding is one of the most consequential environmental regulations in recent U.S. history. President Donald Trump’s administration this week proposed revoking the finding, with EPA Administrator Lee Zeldin calling it “the largest deregulation action in the history of America.”

Issued in 2009, this scientific and legal determination found that greenhouse gases, like carbon dioxide and methane, pose a significant threat to public health and welfare [1][2][3][4]. The potential revocation of the finding sets the stage for a dramatic shift in America’s approach to climate change regulation.

The foundation of federal climate authority

The endangerment finding emerged from the Supreme Court’s 2007 Massachusetts v. EPA ruling, which required the EPA to evaluate whether greenhouse gases endanger public health and welfare [1][2][3][4]. After extensive scientific review, the agency concluded that human-caused emissions are driving climate change and thereby increasing risks such as extreme weather, heat waves, floods and wildfires [1][3].

This determination provides the crucial legal foundation for the EPA’s authority under the Clean Air Act to regulate greenhouse gas emissions from power plants, vehicles and other major pollution sources [1][2][3][4]. The finding is backed by extensive scientific consensus linking human activities to climate change and its associated health risks.

The push for revocation

The Trump administration has proposed revoking the endangerment finding, claiming there is “insufficient reliable information” supporting the conclusion that greenhouse gas emissions from U.S. sources endanger public health and welfare [1][5][6]. This move represents part of a broader campaign to dismantle federal climate regulations issued under previous administrations.

Current EPA leadership has characterized the endangerment finding as a barrier to economic growth and energy independence [5][7][6]. Proponents of revocation argue that repealing it would save Americans money and jobs by removing or reducing costly regulations, particularly those affecting vehicles and power plants.

Sweeping policy implications

Revoking the EPA’s endangerment finding would fundamentally undermine the federal government’s ability to regulate greenhouse gas emissions under the Clean Air Act [11][12]. The elimination of legal authority would mean the EPA could no longer enforce limits on emissions from vehicles, power plants, factories and other industrial sources [11][12]. Current rules that reduce emissions from the largest polluters — including automotive fuel efficiency standards and power plant regulations — would be rescinded [13][14].

Perhaps most critically, future administrations would be unable to introduce new, science-based national rules limiting greenhouse gas emissions unless they restored or replaced the endangerment finding [11][12]. This would leave only state-level or voluntary measures as regulatory tools, shifting responsibility to individual states and creating a fragmented, less effective national response [15].

Enforcement, regulatory impact

The impact on emissions enforcement would be severe and immediate. Without the endangerment finding, the EPA cannot legally classify greenhouse gases as pollutants that endanger public health and welfare, effectively halting or rolling back federal regulations [30][31]. Existing rules such as fuel efficiency standards for cars and trucks, power plant emission limits and methane controls on oil and gas operations could be rescinded or relaxed [30][31][32].

Reports indicate that EPA staff have already been instructed to reduce enforcement actions on fossil fuel emissions violations, which weakens compliance and may lead to increased pollution levels in practice, beyond just formal rule changes [31]. This relaxed enforcement policy creates greater regulatory uncertainty and litigation, particularly affecting states like California that adopt their own stringent mobile source emission standards via Clean Air Act waivers [30][33].

Nevada at risk

Nevada provides a stark example of how revoking the endangerment finding could affect public health at the state level. Nevada ranks among the worst states for ozone (smog) and particle pollution, with over 93% of Nevadans living in areas with unhealthy air quality [18][19]. Major sources include vehicle emissions and heat-driven ozone formation, which trigger asthma, lung disease, heart attacks and strokes.

Extreme heat poses a particularly severe threat in Nevada. In 2024, Southern Nevada recorded 526 heat-related fatalities, surpassing both homicides and traffic deaths [20]. Las Vegas alone reported a 39% increase in heat-associated deaths among unhoused individuals [21]. Without nationwide efforts to curb greenhouse emissions, heat waves will become more intense and frequent, endangering outdoor workers, the elderly, residents without air conditioning and people experiencing homelessness.

Nevada also faces rising wildfire risks due to drought and increasing temperatures, exposing residents to hazardous particle pollution that leads to more asthma attacks, emergency visits and premature deaths [22].

Vulnerable populations in Nevada — including people with low income, communities of color, seniors, children, the unhoused and those with preexisting health conditions — face disproportionate exposure to poor air quality and climate-related hazards [25][26][27]. These populations tend to live in areas with higher pollution and limited green space, and are more likely to lack resources such as reliable air conditioning, safe housing and access to health care [25][27][26][28]. Without strong federal policies, these health threats would cluster with other social stresses such as poverty, limited access to transportation and underresourced health services, likely widening existing disparities [26][27][29].

State authority to act

While federal rollbacks create significant challenges, states retain important authority to maintain stricter emissions limits. California has historically had the power under the Clean Air Act to set stricter vehicle emissions standards than the federal government, an authority that extends to other states adopting its rules [36][37]. However, this waiver system has been targeted by federal rollbacks and Congressional Review Act resolutions.

Despite federal resistance, California and several other states have pledged to continue enforcing or strengthen their own regulations. California Gov. Gavin Newsom has directed his state’s air quality board to develop replacement or even more stringent vehicle emissions rules following federal rollbacks [36]. States can generally enact and enforce environmental regulations that exceed federal standards, as federal laws typically allow states to adopt stricter measures covering air quality, vehicle emissions and other climate-related protections [38][39].

States are forming coalitions and interstate compacts to bolster environmental protections and fill gaps left by federal deregulation [38][40]. In large markets like California and states that adopt its standards, stricter state emissions limits could persist and influence national vehicle manufacturing and emissions trends, though legal battles and federal resistance may complicate these efforts [36][37][41]. This creates a patchwork regulatory environment where key states drive more ambitious climate and pollution controls despite federal retrenchment [34][35].

The proposal to revoke the endangerment finding faces significant opposition from multiple quarters. Critics, including former EPA leaders and environmental groups, warn that revoking the finding would undermine all existing and future climate protections, jeopardizing public health, increasing climate change impacts and making it much harder for future administrations to address greenhouse gas emissions [8][2][9][6][10].

The move is expected to trigger extensive legal challenges and has been widely criticized by environmental groups, public health advocates and scientists as contrary to decades of climate research and U.S. legal precedents [13][17][16]. Any proposal to rescind must undergo a lengthy review and public comment process and would likely face robust court challenges [13][11].

The EPA’s endangerment finding represents more than just a regulatory tool — it embodies the federal government’s commitment to protecting public health from the growing threats of climate change. Revoking this finding would effectively dismantle the main legal mechanism for federal climate action in the United States, severely weakening existing policies and blocking future efforts to control greenhouse gas emissions nationwide [12][17][11].

While state and local efforts to address climate change would still be possible, national coordination and effectiveness would be heavily reduced [15]. For states like Nevada, which already face severe environmental health challenges, the loss of federal climate leadership could prove particularly devastating for vulnerable populations who can least afford to bear the costs of inaction.

The debate over the endangerment finding ultimately reflects broader questions about the federal government’s role in addressing climate change and protecting public health. As this policy faces potential revocation, the stakes could not be higher for both current and future generations of Americans.

Sources

[1] https://thehill.com/policy/energy-environment/5426546-trump-epa-zeldin-endangerment-finding-climate-change-greenhouse-gases/

[2] https://apnews.com/article/trump-climate-epa-endangerment-zeldin-5cba0871c880e23d044ef40a398c57b2

[3] https://www.momscleanairforce.org/what-to-know-about-the-endangerment-finding/

[4] https://www.epa.gov/climate-change/endangerment-and-cause-or-contribute-findings-greenhouse-gases-under-section-202a

[5] https://www.npr.org/2025/07/29/nx-s1-5482966/trump-climate-change-epa

[6] https://www.cbsnews.com/news/epa-revoke-endangerment-finding-regulating-greenhouse-gases/

[7] https://www.reuters.com/legal/litigation/trumps-epa-targets-basis-all-us-greenhouse-gas-rules-2025-07-29/

[8] https://www.cnn.com/2025/07/29/climate/trump-epa-endangerment-finding

[9] https://abcnews.go.com/US/wireStory/trump-epa-moves-repeal-landmark-finding-allows-climate-124173885

[10] https://www.nytimes.com/2025/07/29/climate/epa-endangerment-finding-repeal-proposal.html

[11] https://coloradosun.com/2025/07/29/epa-climate-regulation-repeal-greenhouse-gas-emissions-climate-change/

[12] https://www.nytimes.com/2025/07/29/climate/epa-endangerment-finding-repeal-proposal.html

[13] https://www.politico.com/news/2025/07/29/epa-to-revoke-2009-finding-that-climate-pollution-endangers-humans-00476166

[14] https://www.cbsnews.com/news/epa-revoke-endangerment-finding-regulating-greenhouse-gases/

[15] https://www.governing.com/resilience/epa-proposal-would-gut-climate-rule-long-used-to-limit-emissions

[16] https://www.npr.org/2025/07/29/nx-s1-5482966/trump-climate-change-epa

[17] https://www.cnn.com/2025/07/29/climate/trump-epa-endangerment-finding

[18] https://www.lung.org/getmedia/b0003c18-46f2-4d2b-ad5a-2558d7450e33/nevada-sota-2025-fact-sheet.pdf

[19] https://www.lung.org/media/press-releases/nv-sota-2025-lasvegas-release

[20] https://www.rtcsnv.com/projects-initiatives/projects/current-projects/southern-nevada-urban-heat-mapping-project-v2/

[21] https://www.woodwellclimate.org/risks-and-realities-in-las-vegas-nv/

[22] https://climateintegrity.org/uploads/media/CCI_Nevada_Impacts_Costs_2023.pdf

[23] https://www.aspenpublicradio.org/health-and-wellness/2025-07-14/how-tribes-in-nevada-are-working-to-limit-climate-changes-health-impacts

[25] https://www.ehn.org/nevada-residents-press-lawmakers-to-act-on-deadly-heat-and-air-quality-risks

[26] https://dpbh.nv.gov/uploadedFiles/dpbhnvgov/content/About/2023-28-SSHIP-23-28-Final2.pdf

[27] https://www.psehealthyenergy.org/wp-content/uploads/2021/08/Equity-Focused-Climate-Strategies_NV_Report-1.pdf

[28] https://www.rtcsnv.com/projects-initiatives/wp-content/uploads/sites/4/2021/10/Southern-Nevada-Extreme-Heat-Vulnerability-Analysis-RTC-of-Southern-Nevada-2021-1.pdf

[30] https://natlawreview.com/article/pumping-brakes-outlook-state-and-federal-vehicle-engine-and-equipment-emissions

[31] https://www.scrippsnews.com/science-and-tech/environment/epa-staffers-are-reportedly-instructed-to-relax-enforcement-of-fossil-fuel-emissions-rules

[32] https://www.georgetownclimate.org/articles/u-s-epa-to-revise-ghg-emissions-standards-for-model-year-2022-2025-cars-and-light-trucks.html

[33] https://www.hklaw.com/en/insights/publications/2025/01/the-impact-of-a-trump-epa-on-californias-mobile-source-rules

[34] https://blogs.law.columbia.edu/climatechange/2025/04/08/new-executive-order-tees-up-challenges-to-state-and-local-climate-laws/

[35] https://www.whitehouse.gov/presidential-actions/2025/04/protecting-american-energy-from-state-overreach/

[36] https://www.ccjdigital.com/alternative-power/article/15750300/how-trumps-rollback-of-emissions-rules-affects-trucking-fleets

[37] https://www.clearbluemarkets.com/knowledge-base/evolving-u.s.-climate-policy-californias-waiver-and-the-endangerment-finding

[38] https://www.fairobserver.com/more/environment/how-us-states-can-protect-the-environment-from-federal-rollbacks-and-intervention/

[39] https://abc7news.com/post/epa-considering-rollback-key-climate-change-tools-regulate-greenhouse-gas-emissions-report-says/17265772/

[40] https://climate-xchange.org/2025/04/webinar-recap-epas-climate-rollbacks-and-how-states-can-fill-the-gaps/

[41] https://www.npr.org/2025/07/29/nx-s1-5463771/epa-greenhouse-gas-regulations-cars-pollution