Antonin Scalia

“ In short, the word "including" does not require the Court's (or the petitioners') result. It is perfectly reasonable to view the definition of "air pollutant" in its entirety: An air pollutant can be "any physical, chemical, . . . substance or matter which is emitted into or otherwise enters the ambient air," but only if it retains the general characteristic of being an "air pollution agent or combination of such agents." This is precisely the conclusion EPA reached: " [A] substance does not meet the CAA definition of 'air pollutant' simply because it is a 'physical, chemical, . ”

“ In this case, the petition for rulemaking asked EPA for "regulation of [greenhouse gas] emissions from motor vehicles to reduce the risk of global climate change." 68 Fed. Reg. 52925. Thus, in deciding whether it had authority to regulate, EPA had to determine whether the concentration of greenhouse gases assertedly responsible for "global climate change" qualifies as "air pollution." ”

“ The science of climate change is extraordinarily complex and still evolving. Although there have been substantial advances in climate change science, there continue to be important uncertainties in our understanding of the factors that may affect future climate change and how it should be addressed. As the NRC explained, predicting future climate change necessarily involves a complex web of economic and physical factors including: Our ability to predict future global anthropogenic emissions of GHGs and aerosols ”

“ But EPA has said precisely that--and at great length, based on information contained in a 2001 report by the National Research Council (NRC) entitled Climate Change Science: An Analysis of Some Key Questions:
"As the NRC noted in its report, concentrations of [greenhouse gases (GHGs) ] are increasing in the atmosphere as a result of human activities (pp. 9-12) . It also noted that ' [a] diverse array of evidence points to a warming of global surface air temperatures' (p. 16) . ”

“ Often, however, the examples standing alone are broader than the general category, and must be viewed as limited in light of that category. The Government provides a helpful (and unanswered) example: "The phrase 'any American automobile, including any truck or minivan,' would not naturally be construed to encompass a foreign-manufactured [truck or] minivan." ”