Coalition for Responsible Regulation v. EPA

After Massachusetts v. EPA held greenhouse gases could qualify as air pollutants under the Clean Air Act, the EPA (defendant) issued an Endangerment Finding (concluding greenhouse gases may reasonably endanger public health and welfare), a Tailpipe Rule setting vehicle emissions standards, and Timing and Tailoring Rules. The Coalition for Responsible Regulation, states, and industry groups (plaintiffs) petitioned for review, arguing the EPA misconstrued the Clean Air Act by not weighing regulatory consequences, that the underlying science was too uncertain, and that the EPA should have considered stationary-source permitting costs before regulating vehicle emissions.