Story highlights Ben Carson is a skeptic about man's role in climate change

So California Gov. Jerry Brown sent the candidate a U.S. report

Washington (CNN) Ben Carson says there's no convincing research to prove that man plays a role in climate change.

So California Gov. Jerry Brown has sent the retired neurosurgeon a U.N. report so he can brush up on the subject.

In a letter Brown sent to Carson on Thursday, he cited comments the Republican presidential contender made to the San Francisco Chronicle this week in which he said, "There is no overwhelming science that the things that are going on are man-caused and not naturally caused. Gimme a break."

But Brown, a Democrat, cited this summer's lengthy drought in California as one example of what he said was humanity's role in climate change, and even included a flash drive containing a report from the United Nations Intergovernmental Panel on Climate Change.

The letter ends with Brown writing, "Please use your considerable intelligence to review this material. Climate change is much bigger than partisan politics."

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