As governor of California, Democrat Jerry Brown is on the front lines of combatting the effects of climate change. A devastating drought and a string of wildfires across the state have made it a symbol of the consequences of a changing climate, straining the ability of the California government to respond.
So when Dr. Ben Carson, the retired neurosurgeon running for the Republican presidential nomination, visited California and cast doubt on the idea that human activity is fueling climate change, Brown understandably took issue.
"I know there are a lot of people who say 'overwhelming science,' but then when you ask them to show the overwhelming science, they never can show it," Carson told the San Francisco Chronicle last week. "There is no overwhelming science that the things that are going on are man-caused and not naturally caused. Give me a break."
Brown responded by sending Carson a letter citing his comments and detailing the overwhelming scientific consensus that climate change is a man-made phenomenon. The governor also enclosed a flash drive containing a report from the United Nations Intergovernmental Panel on Climate Change that shows just that:
As Brown writes, the U.N. report was one of the most comprehensive surveys of the scientific community about the effects of climate change: "This report assessed over 30,000 scientific papers and was written by more than 800 scientists, representing 80 countries around the world, who definitively concluded that 'human influence on the climate system is clear and growing, with impacts observed across all continents and oceans.'"
When asked by CNN on Saturday about the governor's letter, Carson's communications director Doug Watts said his candidate is not a "climate denier" but rather a "climate questioner." He also said Carson had not yet received the letter but "could be persuaded."
That was just what Brown was going for in writing his letter. "Please use your considerable intelligence to review this material," he writes. "Climate change is much bigger than partisan politics."