Commentary on the Supreme Court’s grant of certiorari in the greenhouse gas case has addressed the question taken for review: whether EPA permissibly decided that regulating motor vehicle greenhouse gas emissions triggered permitting regulations for stationary sources like power plants. (See Garrett and Buente blogs). This is an interesting question of statutory interpretation, but it may be more important that the Court declined to review EPA’s fundamental finding that greenhouse gases “may reasonably be anticipated to endanger public health or welfare.” The D.C. Circuit panel in the case agreed with EPA that the scientific evidence amply supported action under the precautionary standard of endangerment which allowed the agency to act in the face of scientific uncertainty and without a complete quantification of risks, costs, and benefits of regulation. Relying on its 1976 decision upholding EPA’s regulation of lead additives in gasoline under the same part of the Clean Air Act, the D.C. Circuit panel had no difficulty concluding that EPA had made the case for control of greenhouse gases from motor vehicles as a precautionary rule. This holding and its reasoning will be important support to EPA as the agency moves forward with the more complex and costly initiative to set emission standards for power plants. Electric generating plants contributed over 38% of U.S. CO2 emissions in 2012, with coal-fired plants accounting for nearly three quarters of those emissions.
Some observers may have dismissed the possibility of Supreme Court review of the endangerment finding considering the strength and complexity of the scientific evidence. However, a Court that has eviscerated federal campaign finance and voting rights law, disregarding congressional intent and its own precedents, can’t be counted on to defer to a science-based EPA decision just because the overwhelming majority of scientists endorses the agency’s conclusions. Some of the justices may well agree with Judge Janice Rogers Brown’s vigorous dissent from the D.C. Circuit’s vote to deny rehearing en banc of the panel decision. Invoking memories of living near Los Angeles in the seventies when smog hid the mountain views, Judge Brown argued that the Clean Air Act is aimed at “inhaled” pollution of the type that kills people and not pollution that harms public health or welfare less directly through impairment of natural resources like water resources or crops by climate change—harm, as she put it, coming “at the end of a long speculative chain.” Though mistaken in her interpretation of the Clean Air Act, Judge Brown’s opinion illustrates the challenge of educating both the courts and the public on the more complex chains of causation involved in defining harm from ecological damage and less traditional pollutants. Her opinion is a good reminder that advocates of regulation to safeguard ecological resources, including our climate, have work to do to build greater understanding of profoundly serious risks.