In this campaign video, Sen. John McCainJohn McCainCoats: Trump seemed obsessed with Russia probe The Hill's Whip List: Senate ObamaCare repeal bill Meghan McCain slams 'felon' Dinesh D'Souza over tweets mocking father's captivity MORE (R-Ariz.) said he'd be a leader in global warming reform if he's elected president.

"Americans, I don't think, appreciate the fergility of our environment nor do they understand completely how vulnerable we are in our dependency of foreign oil," McCain said.