First of all, the Supreme Court doesn't make such an argument, and the fact that CO2 fits the definition of pollutant was upheld in federal jurisprudence. The

First of all, the Supreme Court doesn't make such an argument, and the fact that CO2 fits the definition of pollutant was upheld in federal jurisprudence. The CAA does not contain a specific list of pollutants. It has a definition, and the EPA may regulate any emissions of substances that fit those definitions. So, the EPA can consider a given substance that fits the definition to be under the purview of a program under the CAA on a case by case basis.