EPA Ignores Congress’ Intent in Unwinding Greenhouse Gas Rules

The Environmental Protection Agency repealed on Feb. 12 the finding that greenhouse gases “may reasonably be anticipated to endanger public health or welfare.”

This finding, which dated back to 2009, is a prerequisite for the regulation of greenhouse gases under the Clean Air Act and, as a result, the agency simultaneously repealed the greenhouse gas emission standards for vehicles. EPA’s principal justification for the repeal reflects a fundamental misunderstanding of the Clean Air Act.

EPA claims that when Congress enacted the Clean Air Act in 1970, it sought to “control air pollution that threatens health and welfare through local and regional exposure,” and wasn’t concerned with global pollutants like greenhouse gases. But EPA’s assertion ignores voluminous references to the contrary in the legislative debates, which show that Congress was in fact concerned about global pollution, including climate change.

As I explained in a 2020 academic article, the Clean Air Act’s legislative history is highly probative because it includes the bipartisan views of the relevant congressional leaders and the views of the Nixon administration agencies tasked with administering the statute.

For example, arguing for the Senate bill that would eventually become the Clean Air Act of 1970, Sen. Edmund Muskie (D-Maine), manager of the bill and chair of the relevant subcommittee, noted that pollution would “threaten irreversible atmospheric and climatic changes.”

In turn, Sen. Caleb Boggs (R-Del.), the subcommittee’s ranking member, entered into the record a portion of the First Annual Report of the Council on Environmental Quality (part of Executive Office of the President), stating that air pollution “alters climate and may produce global changes in temperature.” Similarly, Rep. Paul Rogers (D-Fla.), the bill’s sponsor, expressed concern about global climate change.

Boggs also submitted a statement by Senate minority leader Hugh D. Scott (R-Pa.) urging for the control of pollution and arguing that unless pollution is controlled, “scientists tell us we may very well experience irreversible atmospheric and climatic changes.” And Sen. Jennings Randolph (D-W.Va.), who chaired the full committee, entered into the record a study explaining that air pollution could “produce unacceptable worldwide climate changes.”

The legislative history even makes an explicit link between vehicle emissions and climate change. A submission to the Senate subcommittee by the Department of Health, Education, and Welfare, which at the time had the responsibility for administering the Clean Air Act, indicated that emissions from automobiles could be “a factor in climate modification.”

Likewise, the legislative history contains references acknowledging that carbon dioxide emissions, which are the most prevalent vehicle greenhouse gas emissions, could have “dramatic and long-term effects on world climate.” For example, Sen. Thomas Eagleton (D-Mo.), who chaired a field hearing on the bill, introduced into the record an article discussing scientific research on how the “atmospheric balance” would be altered if human beings interfere with this process by burning “ever-increasing quantities of oil and coal, filling the air with carbon dioxide.”

In its repeal of the endangerment finding, EPA acknowledges the relevance of legislative history in determining the scope of the Clean Air Act but then provides a grievously misleading account of the debate in Congress, stating that it indicates a concern for the effects of only local and regional pollutants and that Congress “did not reference climate change concerns.” Instead of grappling with the actual legislative record, EPA simply asserts that Congress was concerned only with “local or regional exposure, rather than gases that … may contribute to global phenomena.”

A major roadblock to EPA’s repeal of the endangerment is that the statutory definition of “welfare” includes “effects on … weather … and climate” (emphasis added). This problem is insurmountable for the agency position because it shows that Congress was sufficiently concerned about “climate” to include a reference in the statutory text. Clearly, Congress understood the difference between “climate,” which involves changes in long-term meteorological patterns, and “weather,” where the changes are short-term.

EPA tries to get around the problem of needing to assign different meanings to the two terms by saying the understanding of “climate” at the time was the “prevailing weather in a particular region.” And it stresses that terms “weather” and “climate” must be read by reference to “mechanisms of action that occur in a particular place or under regionally bounded conditions” and that “global climate change concerns … require a very different and much longer causal chain.”

For support, the agency relies on a dictionary and two cases not involving the Clean Air Act. EPA again ignores the explicit statements by congressional leaders who clearly understood the causal chains resulting from the combustion of fossil fuels and the difference between short-term changes in weather and long-term atmospheric changes, and who expressed concern about the latter. It also ignores the views of the Nixon administration on this matter. And, it similarly ignores the definition of “climate” in the contemporaneous dictionary most cited by the US Supreme Court, which defines climate as “the average course . . . of the weather at a particular place over a period of many years,” thus supporting the proposition that “effects on … climate” are long-term effects.

In July 2025, when EPA proposed repealing the endangerment finding, it relied in part on the claim that the finding no longer had the requisite scientific support. That claim has since been so thoroughly discredited that the agency is no longer using it to justify the repeal. So now the agency confines itself to arguments involving statutory interpretation. These, however, fare no better.

This article does not necessarily reflect the opinion of Bloomberg Industry Group, Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

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Richard L. Revesz is a law professor and dean emeritus at the New York University School of Law.

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