CSG Law Alert: Rescission of the CO₂ Endangerment Finding
Background: The 2009 CO₂ Endangerment Finding
In 2009, the U.S. Environmental Protection Agency (EPA) issued the Endangerment Finding for greenhouse gases (GHGs), concluding that carbon dioxide (CO₂) and other GHGs threaten public health and welfare. This determination was both scientific and legal in nature and was significant because the finding became the foundational justification for federal regulation of CO₂ emissions under the Clean Air Act, 42 U.S.C. 7401 et. seq., particularly from motor vehicles.
Against this regulatory and legal backdrop, the EPA’s February 2026 action marked a fundamental departure from prior federal climate policy.
Rescission of the Endangerment Finding and Immediate Impacts
On February 12, 2026, EPA withdrew the Endangerment Finding. By rescinding it, the agency removed the foundational justification for federal limits on CO₂ and other GHGs from cars, trucks, and engines, and repealed the related emissions standards that had been built on that determination. The EPA framed this action as a legal reinterpretation rather than a new scientific conclusion, arguing that the Clean Air Act does not clearly authorize regulation of globally dispersed pollutants such as CO₂ for climate purposes.
From an environmental perspective, the immediate impact of the rescission is a rollback of nationwide GHG controls in the transportation sector, which is one of the largest sources of U.S. emissions.
Legal Uncertainty and Longer‑Term Environmental Consequences
The longer‑term environmental consequences of the rescission depend on legal outcomes and state‑level responses. The decision is already being challenged in court by a coalition of public health and environmental organizations (See, e.g., American Public Health Association, et al., v. United States Environmental Protection Agency and Lee Zeldin, Administrator).
A more significant question is the impact of the recission on other state, non-transportation-related GHG regulatory programs. Many states have defined CO₂ and other GHGs as pollutants under their respective state air statutes and regulations and also go so far as to regulate those emissions, or the reporting of those emissions, in state-issued permits. Although EPA discusses the issue of preemption and was clear regarding the preemptory impact of the decision on GHG in the transportation sector, and out of state emissions, EPA was not entirely clear on its impact on other state regulations governing GHGs. This could result in a patchwork of state‑level standards rather than a single national framework. If the rescission ultimately stands, federal climate regulation would be significantly constrained unless Congress enacts new legislation, shifting the center of climate protection efforts away from federal agencies and toward states, courts, and market‑driven or voluntary initiatives.