Must the federal government regulate carbon dioxide? The EPA final rule titled \u201cRescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas Emission Standards Under the Clean Air Act\u201d reverses the legal obligation to regulate greenhouse gas emissions\u2013 a major blow to climate regulation.[1]<\/a> The rescission overturns the Obama era \u201cEndangerment Finding\u201d, which enables carbon dioxide to be regulated under the Clean Air Act.[2]<\/a> The EPA boasts this as \u201cone of the largest deregulatory acts in U.S history.\u201d[3]<\/a> Indeed, the Clean Air Act\u2019s reach is crucial to federal climate protections. Its adoption in 1970 was a watershed moment of \u201cstatutory and institutional transformation\u201d for environmentalism in the U.S.[4]<\/a> Today, environmental rules and regulation are built upon the foundation established by the Clean Air Act. For example, national ambient air quality standards provide a fundamental regulatory mechanism.[5]<\/a> As a cornerstone of environmental protection, interpretation of the Clean Air Act\u2019s meaning and scope has significant implications for the future of climate policy.<\/p>\n\n\n\n In this article, I argue that EPA Administrator Lee Zeldin\u2019s legal rationale for the rescission is self-defeating. Zeldin does not provide sound reasoning showing how U.S. law supports a departure from Massachusetts v. EPA<\/em>, the case permitting greenhouse regulation. Zeldin\u2019s usage of Loper-Bright v. Raimondo<\/em> is self-defeating because Loper<\/em>\u2019s core principle of nondelegation cuts against the very legal interpretation Zeldin asserts.<\/p>\n\n\n\n This paper will proceed as follows: In Section II, I outline the legal history culminating in the rescission of the Endangerment Finding, in Section III, I describe the Massachusetts<\/em> precedent that Zeldin sets out to overturn. In Section IV, I delve into the legal rationale of the Rescission Rule, emphasizing two fundamental issues, and in Section V, I suggest that the issues identified indicate a significant contradiction in Trump-era legal reasoning.<\/p>\n\n\n\n The legal dispute centers on section \u00a7202(a)(1) of the CAA which states that the EPA Administrator will create and revise, \u201c…standards applicable to the emission of any air pollutant from \u2026 new motor vehicles \u2026 which in his judgment cause, or contribute to, air pollution which may reasonably be anticipated to endanger public health or welfare.\u201d[6]<\/a> EPA Administrators have vacillated, in step with political affiliation, on whether carbon dioxide emissions and resulting climate change are under the jurisdiction of the CAA according to the text of \u00a7202(a)(1).[7]<\/a> The consequences of this debate are profound; interpretation of \u00a7202(a)(1) determines if carbon dioxide is legally a pollutant, and in turn, if the Clean Air Act obligates the U.S. government to address climate change.[8]<\/a><\/p>\n\n\n\n Interpretive disagreement stretches back to 1999, when a group of lawyers calling themselves the \u201cCarbon Dioxide Warriors\u201d petitioned the Environmental Protection Agency to begin regulating motor vehicle emissions of CO2 under \u00a7202(a)(1).[9]<\/a> President George W. Bush\u2019s EPA denied the petition in 2003, arguing that the CAA does not apply to the issue of global climate change, and thus, that the CAA does not authorize regulation to address global climate change.[10]<\/a> The dispute culminated in the 2007 Supreme Court Case, Massachusetts et al. v. Environmental Protection Agency<\/em> in which the Court struck down the Bush denial, ordering the EPA to \u201cproperly engage\u201d with the statutory text to make an endangerment finding.[11]<\/a> Bush\u2019s reasons for refusal were roundly rejected as the Court set the bounds of future greenhouse decisions to be grounded in the text of the CAA rather than policy concerns.[12]<\/a><\/p>\n\n\n\n In response to Massachusetts<\/em>, the Obama Administration\u2019s EPA published the 2009 endangerment finding titled \u201cEndangerment and Cause or Contribute Findings for Greenhouse Gases Under Section \u00a7202(a)(1) of the Clean Air Act\u201d.[13]<\/a> This rule found \u201c…elevated concentrations of greenhouse gases in the atmosphere may reasonably be anticipated to endanger the public health and to endanger the public welfare\u201d and that \u201c…greenhouse gases from new motor vehicles contribute to the air pollution that may reasonably be anticipated to endanger public health and welfare.\u201d[14]<\/a> As such, the Endangerment Finding established the EPA\u2019s ability to regulate greenhouse gasses from motor vehicles in accordance with Massachusetts<\/em>.[15]<\/a> Then, in February 2026, the EPA under Trump published Rescission wherein Zeldin argued that the EPA does not have the statutory authority to regulate Greenhouse gas emissions from vehicles under the CAA afterall, undoing the U.S government\u2019s legal obligation to address climate change.[16]<\/a><\/p>\n\n\n\n Federal carbon dioxide regulation largely rests upon the CAA, a law with no express purpose of dealing with Climate.[17]<\/a> The back and forth conflict in the Executive and Judiciary over interpretation of \u00a7202(a)(1) reveals how \u2013in the absence of fresh legislation\u2013 interpreting aging laws like the CAA privileges the jurisprudence of a handful of Supreme Court Justices and EPA lawyers with enormous influence in casting the fate of climate protection.<\/p>\n\n\n\n Legal Timeline (Figure One)<\/strong><\/p>\n\n\n\nI. Background<\/h1>\n\n\n\n