The Legal Case Against EPA: The Rescission of the Endangerment Finding

According to EPA statistics, the U.S. vehicle sector produces enough emissions annually that, if it were a separate country, it would be the fifth-largest source of greenhouse gases in the world. [1] For nearly two decades, the EPA’s 2009 Endangerment Finding has served as the legal and scientific foundation for regulating these emissions through the Clean Air Act. However, under the second Trump Administration, the agency has recently reversed course, rescinding the Endangerment Finding, directly contradicting its own data, and allowing these emissions to continue unchecked. In light of this stark departure from the scientific consensus and past regulatory practice, this article will evaluate the merits of the legal reasoning the EPA used to rescind the Endangerment Finding. It argues that the EPA’s final rule raises serious questions about consistency with statutory text in the Clean Air Act, divergence from established legal precedent, and disregard for scientific evidence supporting greenhouse gas regulations. Moreover, if the EPA rule is brought to the Supreme Court, the rescission would likely face significant legal challenges, even against the current conservative-majority Court.

The Endangerment Finding is a formal EPA ruling issued in 2009 determining that greenhouse gases (GHGs) pose a threat to the public health and welfare of current and future generations, and that emissions from new motor vehicles and new motor vehicle engines contribute to that threat. [2] The ruling followed the Supreme Court case Massachusetts v. EPA (2007), in which the court determined that GHGs qualify as air pollutants under section 202(a)(1) of the Clean Air Act (CAA) and are subject to regulation. [3] In its ruling, the Court also directed the EPA to determine whether GHGs endanger public health, leading to the issuance of the Endangerment Finding two years later. This ruling provided a clear agency conclusion that GHGs may reasonably be anticipated to endanger public health, thereby triggering the EPA’s statutory obligation under 202(a)(1) of CAA to develop emission standards for new motor vehicles or engines to control air pollution from GHGs. [4] Historically, the EPA has interpreted this provision as requiring a purely scientific judgment regarding the dangers of air pollution on public health, as the statute does not authorize consideration of other factors and instead defers economic, safety, and related concerns to later stages of the rule-making process. [5] As such, the Endangerment Finding has served as the legal and scientific foundation for all federal regulations of GHGs.

Under the second Trump Administration, the EPA has gradually withdrawn from its regulatory responsibilities, all in the name of “energy dominance.” [6] In an effort to promote American fossil fuel interests, the agency has adopted a more permissive regulatory approach toward greenhouse gas emissions; for example, in January 2026, the EPA issued a rule halting its longstanding practice of calculating health-related monetary benefits of air pollution regulation. [7] This shift has culminated in the rescission of the Endangerment Finding, hailed by the EPA as “Single Largest Deregulatory Action in U.S. History.” [8] Lee Zeldin first announced the agency’s plans to rescind the Endangerment Finding in July 2025, and the initial rule proposal was published a month later. The proposed rule primarily relied on a report prepared for the Department of Energy by five scientists known for their contrarian views on climate change. Relying on the scientific findings of this report, the EPA established its preliminary rationale for the rescission: there is “insufficient reliable information” on climate science to conclude that GHG emissions from new motor vehicles and engines contribute to the endangerment of public health. [9] However, the EPA’s final rule, issued on February 18, 2026, notably omits any discussion of climate science. Instead, the EPA backtracks on its science-based attacks and instead shifts to a repeal based purely on legal considerations. The legal rationale consists of three principal arguments. The first adopts a narrow reinterpretation of the CAA's statutory text, excluding GHGs from the category of “pollutants” subject to regulation. [10] Second, it invokes the Major Questions Doctrine, arguing that the economic impacts of the Endangerment Finding and its related regulations exceed the authority granted to the EPA by Congress. [11] Third, it contends that emissions from new motor vehicles and engines contribute so minimally to overall impacts of climate change that, in light of the “immense burdens” imposed, the Endangerment Finding is unnecessary. [12] 

The first claim declassifying GHGs as pollutants in the recent EPA ruling takes a narrow textual analysis of section 202(a)(1) of the Clean Air Act, which conflicts with prior judicial interpretations of the CAA and departs from the statutory text. Under the EPA’s new interpretation of the clause, the CAA limits the EPA to regulate only the emissions that domestic new motor vehicles and engines “cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.” [13] The EPA argues that, when read in the statutory context and historical practice, Congress intended this provision to target air pollution that threatens public health or welfare through local or regional exposure. [14] Accordingly, the agency reasons that regulation must be limited only to pollutants that can be meaningfully addressed through domesticated motor vehicle standards. Because GHGs are defined by reference to global atmospheric concentrations and worldwide emissions, the EPA contends that they do not fit within the contextual understanding of “air pollution” under (202)(a)(1). Through this reading of 202(a)(1), “air pollution” is limited to geographically bounded harms. Thus, GHGs cannot satisfy the statutory endangerment standard, and the 2009 Endangerment Finding exceeds the EPA’s authority and must be rescinded. This reasoning was heavily based on interpretations of the CAA prior to 2009, which historically addressed geographically bounded pollution problems, such as localized issues related to smog and air toxins. [15] The weakness of this argument lies in its reliance on pre-2009 historical interpretation of the act rather than clear statutory text. The EPA emphasizes the historical application of the act to local and regional air pollution; however, historical agency practice does not control statutory meaning. The Supreme Court already made clear in their decision in Massachusetts v. EPA (2007) that GHGs “unambiguous[ly]” qualify as “air pollutants” under section 202(a)(1), and thus “EPA has statutory authority to regulate emission of such gases from new motor vehicles.” [16] Furthermore, when the Supreme Court denied certiorari in Coalition for Responsible Regulation, Inc. v. EPA (2012), it left in place the DC Circuit’s holding that the EPA’s interpretation of the governing CAA provisions to authorize GHG regulation was unambiguously correct, reinforcing a reading of the CAA that permits comprehensive GHG regulation. In addition to legal precedent conflicting with this new interpretation, the EPA’s argument also depends on a narrowed reading of the statute that does not appear in the text itself. Section 202(a)(1) contains no explicit geographic limitation. Conversely, in 202(a)(1) of the CAA actually provides that “The Administrator shall by regulation prescribe… standards applicable to the emission of any air pollutant… which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare,” and “welfare” is expressly defined as including “climate” in the definition section 302(h). [17] Read together, these provisions make clear that Congress contemplated regulation of pollutants with climate-related impacts and imposed no locally-bound limitation on that authority. Thus, the EPA’s “best reading” of the CAA conflicts with the statute’s plain language, and any argument imposing a geographic limitation on GHG regulation is unpersuasive. Both the statutory text and controlling precedent strongly support the conclusion that GHGs fall within the scope of the EPA’s congressionally delegated authority. Accordingly, the Endangerment Finding should be upheld, and the EPA must regulate GHGs as required by law.

The second claim that the EPA makes is that they lack “clear congressional authorization” required under the major questions octrine—which says that federal agencies cannot regulate matters of “economic and political significance” without clear Congressional authorization—to be the sole deciding factor for the nation’s response to global climate change. [18] However, the precedent the EPA relies on to support its major questions claim, upon closer examination, does not substantiate this conclusion, as it addresses the limits of specific regulatory mechanisms of GHGs rather than a denial of the agency’s underlying authority to regulate GHGs in the first place. The Endangerment Finding triggers mandatory regulation of GHGs, impacting the automobile industry, energy markets, and the broader national economy. In their argument, the EPA cites two main applications of the major questions doctrine. In West Virginia v. EPA (2022), the Supreme Court held that the EPA lacked clear Congressional authorization to regulate GHG emissions by mandating power plants to transition to renewable energy sources because it would effectively restructure the nation’s grid. [19] In Utility Air Regulatory Group v. EPA (2014), the court rejected the EPA’s attempt to expand its regulatory authority over GHGs in a way that would have dramatically increased the scope of its regulatory programs without clear statutory support. [20] In the major questions claim, the EPA contends that the impacts of the Endangerment Finding provide a “reason to hesitate” and that agencies must point to clear congressional authorization when asserting authority over issues of such magnitude. The ruling references multiple examples, but most prominently likens the emission regulatory laws to a forced shift to EVs, and argues that “mandating a shift in the national vehicle fleet from one type of vehicle to another is indistinguishable from the emission guidelines at issue in West Virginia” and thus constitutes a major question. [21] Because the CAA does not explicitly authorize the EPA to direct such a large-scale transformation of the national vehicle market, the agency concludes that the Endangerment Finding triggers regulatory consequences beyond what Congress delegated in the CAA. Similar to the first claim, this argument seems to cherry-pick its evidence by selectively elevating recent major questions doctrine cases while minimizing the binding precedent from Massachusetts. A closer examination of West Virginia and UARG also reveals key differences in the scope of the former cases and the current rule. In West Virginia and UARG, the courts examined whether regulatory mechanisms, such as mandating renewable energy use in power plants or requiring GHG emission data to issue certain permits, were exceeding EPA authority. In contrast, the new EPA rule examines a much larger question of whether or not the EPA can regulate GHGs as a whole, rather than the scope of regulation. Put in context with the major questions doctrine, the “major question” considered in cited cases was whether the EPA’s choice of regulatory mechanism exceeded their authority granted by Congress, not whether the agency could regulate greenhouse gases at all. [22] In fact, the decisions of both cases were premised on the understanding that EPA did have the authority to regulate GHG emissions and upheld the agency’s regulatory ability. [23]

The EPA’s final claim for the repeal is built on a “separate but complementary basis,” arguing that there is no need for the Endangerment Finding because GHG standards impose immense burdens but have a de minimis impact on the identified dangers of global climate change. This claim is both scientifically incorrect and undermines the explicit precedent from Massachusetts that ruled against a similar de minimis argument in 2007. [24] In the recission’s de minimis claim, the EPA circumvents addressing the overwhelming amount of climate science in support of the Endangerment Finding by taking a purely legal approach based solely on statutory analysis. [25] This approach was adopted to avoid the scientific evidentiary requirements that the EPA has interpreted as central to its “judgment” in determining whether greenhouse gases pose a risk to public health under CAA 202(a). [26] There are two main problems with this assessment of the impacts of GHGs on public health and welfare effects. First, as their reluctance to engage with the scientific evidence suggests, their factual conclusion that GHG standards have “no material impact” on global climate change is highly disputable. They attempt to minimize the effects of climate change by selectively examining the projected global mean surface temperature change by 2050 (0.013 °C) and comparing it to the natural variability in global temperature from 2016 to 2025 (0.14 °C). [27] However, according to statistics reported by the EPA in 2023 under the Biden Administration, US on-road motor vehicles will cost $415 billion in annual climate damages and generate 1,630 million tons of CO2 in 2027, or approximately 4% of global emissions—ranking above the total emissions of nearly every nation except the United States, China, India, and Russia. [28] In addition to issues in the factual conclusion, the EPA’s de minimis argument is inconsistent with the legal precedent established by the Supreme Court in Massachusetts v. EPA. In the opinion of the Court written by Justice Stevens, the court explicitly dismissed a nearly identical de minimis argument made by the EPA, arguing that US motor vehicle emissions are “meaningful” enough that “a reduction in domestic emissions would slow the pace of global emissions increases, no matter what happens elsewhere.” [29] Unless the case were to reach the Supreme Court and the Court were willing to undermine its own precedent in Massachusetts by permitting the EPA to disregard contributions it has already deemed legally significant, this argument would be unlikely to succeed. Lastly, adoption of this rule and its supporting de minimis argumentation by other agencies would establish a framework where no contributing factor to climate change would be “material” enough to be regulated. Agencies could argue that any effort they take to mitigate the effects of climate change would only have a small impact on the global temperature increase, but would unduly burden regulated parties, consumers, and the economy. If the Supreme Court were to rule in favor of the rescission and accept their de minimis argument, it would effectively establish a doctrinal basis for declining to regulate climate-related harms altogether. In the post-Loper Bright era, following the overruling of Chevron deference and the corresponding elimination of mandatory judicial deference to agency statutory interpretations, such a decision would provide an especially strong justification for agencies seeking to avoid engaging with climate change in their regulatory frameworks.

Looking ahead, significant questions remain regarding the ultimate trajectory of this litigation and its implications for federal climate regulation. The case must first proceed through the D.C. Circuit, a process that could take months or even years, unless the EPA forces an expedited review through emergency relief on the Supreme Court’s shadow docket. Recent changes in SCOTUS have led to a considerably conservative shift that may influence a potential SCOTUS decision on the issue. Of the justices who were present for the 2007 decision, none of those who voted in favor are still on the court. [30] Even so, because this dispute centers on statutory interpretation rather than constitutional doctrine, the Court may exercise greater restraint in revisiting established precedent. Ultimately, each of the EPA’s three principal justifications, the narrowed interpretation of “air pollutants” in the CAA, the invocation of the  major questions doctrine, and the de minimis rationale, proves analytically weak when measured against the statutory text, controlling precedent, and the scientific record. Taken together, these deficiencies suggest that the rescission rests on an unstable legal foundation and is unlikely to withstand sustained judicial scrutiny.

Edited by Evalina Sain

Sources

[1] Meredith Hankins, “5 Facts About the Endangerment Finding,” Natural Resources Defense Council, January 21, 2026, https://www.nrdc.org/media/5-facts-about-endangerment.

[2] “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act,” United States Environmental Protection Agency, February 10, 2026, https://www.epa.gov/climate-change/endangerment-and-cause-or-contribute-findings-greenhouse-gases-under-section-202a.

[3] Massachusetts v. EPA, 549 U.S. 497, 500 (2007).

[4] Clean Air Act, 42 U.S.C. §7521 (2013).

[5] Jessica Wentz, “Responding to EPA’s Claim that U.S. Motor Vehicle Emissions Have a ‘De Minimis’ Impact on Climate-Related Harms,” Climate Law Blog: Sabin Center for Climate Change at Columbia Law School, February 20, 2026, https://blogs.law.columbia.edu/climatechange/2026/02/20/responding-to-epas-claim-that-u-s-motor-vehicle-emissions-have-a-de-minimis-impact-on-climate-related-harms/.

[6] Exec. Order No. 14154, 90 C.F.R. 8353 (2025).

[7] Karen Feldscher, “EPA will no longer consider health-related monetary benefits of reducing air pollution,” Harvard T.H. Chan School of Public Health: News, January 15, 2026, https://hsph.harvard.edu/news/epa-will-no-longer-consider-health-related-monetary-benefits-of-reducing-air-pollution/.

[8] “President Trump and Administrator Zeldin Deliver Single Largest Deregulatory Action in U.S. History,” United States Environmental Protection Agency, February 12, 2026, https://www.epa.gov/newsreleases/president-trump-and-administrator-zeldin-deliver-single-largest-deregulatory-action-us.

[9] Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards, 90 C.F.R. 36310 (2025).

[10] Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act, 90 C.F.R. 7711 (2025).

[11] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7723.

[12] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7728.

[13] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7711.

[14] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7711.

[15] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7718.

[16] Massachusetts v. EPA, 549 U.S. 497, 500 (2007).

[17] Clean Air Act, 42 U.S.C. §7521 (2013); Clean Air Act, 42 U.S.C. §7602 (2013).

[18] “The Major Questions Doctrine,” Congress.gov, November 2, 2022, https://www.congress.gov/crs-product/IF12077.

[19] West Virginia v. Environmental Protection Agency, 597 U.S. 697 (2022).

[20] Utility Air Regulatory Group v. EPA, 573 U.S. 302 (2014).

[21] Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act, 90 C.F.R. 7724 (2025).

[22] Jessica Wentz, “Responding to EPA’s Claim that U.S. Motor Vehicle Emissions Have a ‘De Minimis’ Impact on Climate-Related Harms,” Climate Law Blog: Sabin Center for Climate Change at Columbia Law School, February 20, 2026, https://blogs.law.columbia.edu/climatechange/2026/02/20/responding-to-epas-claim-that-u-s-motor-vehicle-emissions-have-a-de-minimis-impact-on-climate-related-harms/.

[23] West Virginia v. Environmental Protection Agency, 597 U.S. 697 (2022).

[24] Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act, 90 C.F.R. 7728 (2025).

[25] Rescission of the Greenhouse Gas Endangerment Finding, 90 C.F.R 7689.

[26] Jessica Wentz, “Responding to EPA’s Claim that U.S. Motor Vehicle Emissions Have a ‘De Minimis’ Impact on Climate-Related Harms,” Climate Law Blog: Sabin Center for Climate Change at Columbia Law School, February 20, 2026, https://blogs.law.columbia.edu/climatechange/2026/02/20/responding-to-epas-claim-that-u-s-motor-vehicle-emissions-have-a-de-minimis-impact-on-climate-related-harms/.

[27] Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act, 90 C.F.R. 7691 (2025).

[28] Jessica Wentz, “Responding to EPA’s Claim that U.S. Motor Vehicle Emissions Have a ‘De Minimis’ Impact on Climate-Related Harms,” Climate Law Blog: Sabin Center for Climate Change at Columbia Law School, February 20, 2026, https://blogs.law.columbia.edu/climatechange/2026/02/20/responding-to-epas-claim-that-u-s-motor-vehicle-emissions-have-a-de-minimis-impact-on-climate-related-harms/; “Report on the Social Cost of Greenhouse Gases: Estimates Incorporating Recent Scientific Advances,” United States Environmental Protection Agency, November 2023, https://www.epa.gov/system/files/documents/2023-12/epa_scghg_2023_report_final.pdf; “GHG emissions of all world countries,” European Comission, 2025, https://edgar.jrc.ec.europa.eu/report_2025.  

[29] Massachusetts v. EPA, 549 U.S. 525-526 (2007). 

[30] Karen Zraick, “Trump Erased a Bedrock Climate Rule. Here Come the Lawsuits.,” New York Times, February 13, 2026, https://www.nytimes.com/2026/02/13/climate/endangerment-finding-legal-court-lawsuits.html.