Humans aren't causing climate change

Marco Rubio, a Republican out of Florida told ABC news that he does not believe that human activity is causing dramatic changes to the climate. Rubio also doesn't believe that any changes that our nation makes will have an impact on the environment. Does he honestly think that he is an expert on climate so that he can make those claims and if he thinks that we are not the cause of the climate change then who does he think caused it. As a member of the Tea Party lets hope he doesn't become president.