In the hit movie Up in the Air, George Clooney plays a professional who travels around the U.S. to fire people on behalf of employers. Clooney's character logs thousands of air miles. In fact, he flies so often that one of his personal goals is to become a member of the exclusive ten-million-mile-club. I'm a fan of Clooney and appreciate a well-told story, but the question that kept nagging me during the movie was: "What do all those miles add up to in greenhouse gas (GHG) emissions?"