California gov. confronts Trump on climate change

"We come from a perspective humbly where we submit the science is in and observed evidence is self-evident: that climate change is real, and that is exacerbating this," the Democratic governor said during a meeting with the president.

Trump, who has authorized federal disaster aid for both California and Oregon, questioned that science.

"It’ll start getting cooler, you just watch," he said. "I don’t think science knows."

Trump's administration has waged a series of legal battles with Democratic-run California, the most-populous U.S. state, on a variety of issues including immigration and environmental policy. The state for its part has sued his administration more than 100 times. Trump lost badly in California in the 2016 election and is expected to fare poorly there in November.