In Massachusetts v. EPA, the Supreme Court held that the 1970 Clean Air Act granted the Environmental Protection Agency (EPA) the authority to regulate greenhouse gases as air pollution. But, while the Court found the Act to “confer the flexibility necessary” to respond to “changing circumstances,” the Justices expressed skepticism that legislators in 1970 would have been familiar with the climate-altering effects of CO2 and other heat-trapping gases. At the time of the Clean Air Act’s passage, the Court wrote, “the study of climate change was in its infancy.” That statement was misleading. By the late 1960s, scientists knew that greenhouse gases, derived from fossil fuel combustion, could alter the global climate with potentially serious and deleterious ensuing effects.
This Article reviews this history and its role in the passage of the Clean Air Act of 1970. This history has important implications for the scope of EPA’s authority under the Clean Air Act in light of the Court’s articulation of the major questions doctrine in West Virginia v. EPA. By requiring a threshold determination of clear congressional authorization for administrative actions of “vast economic and political significance,” the new major questions doctrine begets a novel type of legal-historical methodology that is distinct from both that of the era of strong purposivism and its textualist successor. We advance a template for the kind of historical analysis that may need to become standard in a post-West Virginia world.
