Are Cons upset that Mitt Romney said that he thinks humans contribute to global warming?

He is cautiously believing that humans contribute. But, realizes that there have been other times of even greater warming and he doesn't know why. Then he goes into talking about oil dependence, our natural resources, trading energy with Canada, becoming more energy efiicient and developing all of our sources of energy. He said one statement about global warming and the next 6 min. talking about energy. I don't see that as a problem that he thinks people might have something to do with global warming. That's his opinion but his energy policy is very interesting and right on!! Go Romney!!