Only sort of. A couple of years ago five SCOTUS justices decided CO2 was a "pollutant" the EPA could regulate under the Clean Air Act, thereby providing the Usurper with the legal basis for the action he's just taken. Congress, however, still could stop him, if it so chooses, by refusing to provide any money to implement the regulations, just as it's stopped him from closing Gitmo by refusing to provide funding.
Amazingly uneducated scientific beliefs promulgated as "truth" and "law".