In 2007, the Supreme Court ruled in Massachusetts vs. EPA that when the U.S. Congress passed the Clean Air Act in 1970, climate science was “in its infancy,” implying that government officials could never have intended for the legislation to cover the regulation of greenhouse gas emissions. In 2022, SCOTUS doubled down on that idea, ruling in West Virginia v EPA that since the Clean Air Act didn't explicitly talk about climate change, the EPA cannot regulate greenhouse gas emissions. Now, new historical evidence unearthed by a team of Harvard University researchers led by Naomi Oreskes calls the court's understanding of the history of climate science into question, which could have major implications for the government's ability to regulate climate-changing emissions.
It’s particularly important to understand this history at the moment. The Clean Air Act has always been a bugaboo for polluting industries, with tobacco, automotive, manufacturing, chemical and fossil fuel companies mobilizing early and working side by side from the 1970s through the 90s to weaken the legislation via groups like the Total Indoor Environmental Quality association (TIEQ, a tobacco industry front group paid for by RJ Reynolds to work against regulations on second-hand smoke, and run by the E. Bruce Harrison agency) and the National Environmental Development Association (formed in 1972, also by legendary PR guru E. Bruce Harrison, led by his wife, Patricia de Stacy Harrison, and championed by Senator Bob Dole). Members of those same groups eventually joined the Global Climate Coalition, another cross-industry group created by Harrison, to fight against the Kyoto Protocol. Steve Milloy, a longtime tobacco and coal industry operative, and a member of the Trump EPA transition team has worked for years to limit air pollution regulations, and described them as a “backdoor science scheme for regulating fossil fuel emissions.” Last year, as part of the Project 2025 blueprint spearheaded by the Heritage Foundation, former Trump EPA chief of staff Mandy Gunasekara wrote in her proposal for the EPA that a conservative administration should limit applications of the Clean Air Act in general, "limit EPA’s reliance on Clean Air Act section 30121 general rulemaking authority to ensure that it is not abused to issue regulations for which EPA lacks substantive authority elsewhere in the statute,” and that the agency should “update” its 2009 endangerment finding, which found that under Clean Air Act section 202(a) greenhouse gases in the atmosphere endanger both the public health and the environment for current and future generations.
Now the Supreme Court is getting in on industry-friendly interpretations of the Clean Air Act as well. Earlier this year, the court moved to get rid of Chevron deference—a legal precedent that held for decades that any ambiguity in regulations should be clarified by the agency experts tasked with regulating. Now the courts have seized that authority for themselves. Over the past five years the increasingly conservative court has also embraced the application of a previously rarely deployed legal theory called “the major questions doctrine,” which holds that the courts should weigh in on ambiguities in the law that pose “major questions” for how the economy or the government run. In the court’s 2022 ruling in West Virginia v EPA, for example, although the case was built on a moot point—an argument against the Obama administration’s Clean Power Plan, which was never actually implemented—the justices used major questions doctrine to weigh in on the question of whether or not the Clean Air Act explicitly grants the EPA the authority to regulate greenhouse gas emissions.
The question of what is explicit and what is implied in the Clean Air Act, as well as what Congress understood or intended the Act to do at the time of its passage, then, is fundamental to the EPA’s authority to do anything about climate change today.
