I don't agree with the notion that some are putting out there — including scientists — that somehow, there are actions we can take today that would actually have an impact on what's happening in our climate. Our climate is always changing. And what they have chosen to do is take a handful of decades of research, and say that this is now evidence of a longer-term trend that's directly and almost solely attributable to manmade activity.
This Week, ABC News, 2014-05-11, quoted in David (11 May 2014), "Marco Rubio Says Scientists Are Wrong: 'Human Activity' Does Not Cause Climate Change", Crooks and Liars, retrieved on 2014-05-17