a) The Congress will have power to set and collect taxes, duties, and tariffs, to pay debts and provide for the common defense and general welfare of the United States. All of these things will be the same throughout the United States.
b) Congress can borrow money on the credit of the United States, regulate commerce with foreign nations, establish laws on bankruptcy, provide for the punishment of counterfeiting the currency of the United States, establish Post Offices, give out copyrights and patents, make tribunals inferior to the Supreme Court, define and punish piracies and felonies committed at sea, and offenses against the Law of Nations, declare war and capture land and sea, raise and support armies, provide and maintain a Navy, make rules for the governing and regulation of the land and naval forces, have exclusive legislature over any and all lands owned by the government (including a district for the seat of the government not to exceed ten miles square), make laws that will be necessary for carrying out all of these powers.
I don’t see anything about emissions standards there. It seems to me that the Ninth and Tenth Amendments would apply.