All laws have been voted on and passed by the House and the Senate and signed by the President. All of them. In many instances, Congress has passed laws giving broad direction to Executive branch agencies and DIRECTION to write regulations conforming to and enforcing the directive legislation. It is commonplace. It's informative to see you all treat the EPA as your new boogeyman. It makes it clear that your motivation denying AGW isn't based even on some warped and misguided idea of sound science.