Does Sen. Marco Rubio believe in climate change? Based on what he told me an interview with ABC's "This Week" and his comments Tuesday at the National Press Club the answer is yes - but he doesn't think lawmakers can do anything about it because he does not believe human activity is a major contributor to the earth's changing climate.

Here's what the Florida Republican said at the National Press Club: "There is climate change. The issue is not whether the climate is changing, as it always is changing. The issue is whether there is legislative proposals before us that could do anything about it."

Does that contradict anything he told me on "This Week"? No.

He was explicit in his interview on "This Week" that he doubts scientists who say human activity is a primary driver of climate change, saying, "I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it."

But he did not dispute evidence that the earth's climate is changing - he was simply taking issue with the cause of that change. In fact, Rubio told me directly climate is changing - and always has been changing. Here's one exchange:

RUBIO: 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 - and say that this is now evidence of a longer-term trend that's directly and almost solely attributable to man-made activity…

KARL: You don't buy…

RUBIO: I do not agree with that.

Rubio spokesman Alex Conant tells me Rubio stands by that.