Energy Secretary Rick Perry does not believe CO2 emissions from human activity are a main driver of climate change, he told CNBC on Monday, echoing a belief expressed by Environmental Protection Agency head Scott Pruitt in March. Perry's comments are at odds with top government scientists' conclusions on the causes of climate change. "The fact is this shouldn't be a debate about, 'Is the climate changing, is man having an effect on it?'" Perry said. "Yeah, we are. The question should be just how much, and what are the policy changes that we need to make to effect that?"