4. EPA’s alternative basis for its decision—that even if it has statutory authority to regulate greenhouse gases, it would be unwise to do so at this time—rests on reasoning divorced from the statutory text.
Under the Act’s clear terms, EPA can avoid promulgating regulations only if it determines that greenhouse gases do not contribute to climatechange or if it provides some reasonable explanation as to why itcannot or will not exercise its discretion to determine whether they do. It has refused to do so, offering instead a laundry list of reasons not to regulate, including the existence of voluntary Executive Branch programs providing a response to global warming and impairment of the President’s ability to negotiate with developing nations to reduce emissions. These policy judgments have nothing to do with whether greenhouse gas emissions contribute to climate change and do not amount to a reasoned justification for declining to form ascientific judgment. Nor can EPA avoid its statutory obligation bynoting the uncertainty surrounding various features of climate change and concluding that it would therefore be better not to regulate at this time. If the scientific uncertainty is so profound that it precludes EPA from making a reasoned judgment, it must say so.
EPA now has to follow the Clean Air Act process to determine whether is should regulate greenhouse gases, something it didn't do.
Reading the syllabus (the first 6 pages) is useful for someone who doesn't plan to read the whole thing. I'll probably have more comments later.