Elon Musk criticized climate change skeptics on Twitter Saturday, as wildfires spreading across California led to outcry from scientists. The fires have led to 31 deaths and over 200 more unaccounted for as of Monday.

Musk, who has pressed for a fast transition to sustainable energy, shared a link to an interview with scientist Michael E. Mann where he said that “what we can conclude, with a great deal of confidence now, is that climate change is making these events more extreme.” Musk responded by writing that “we know we’ll run out of dead dinosaurs to mine for fuel & have to use sustainable energy eventually, so why not go renewable now & avoid increasing risk of climate catastrophe? Betting that science is wrong & oil companies are right is the dumbest experiment in history by far. Makes me so mad when smart, ethical scientists I know are accused of publishing climate papers for ‘grant money’. They earn [peanuts] vs their other opportunities, but give that up to help world. But their accusers make billions by slowing down clean energy. Which is more credible?”

See more: Videos Show Three Wildfires Tearing Through California, Thousands Evacuate

As CEO of Tesla, Musk has spurred the construction of the Gigafactory in the Nevada desert, which when complete will produce enough battery storage to transition one percent of global energy usage onto renewables. In July 2017, he laid out a possible roadmap for transitioning the United States entirely onto solar. In December 2017, Tesla switched on the world’s largest lithium-ion battery in South Australia, storing 100 megawatts of renewable energy to cover variations in power generation. For Musk, these projects are aimed at stopping what he described to Joe Rogan as “the dumbest experiment in human history.”

Musk also called on oil companies to help aid this transition: “Right move is for oil companies truly to think of themselves as energy companies, but move rapidly towards clean, sustainable energy. Means lower profits short-term, but will make them stronger long-term.” Musk has previously criticized these firms for funding advertising that presses journalists to write negative news about Tesla.

The California wildfires have spread across 621,743 acres as of November 4, nearly double that of the 316,654 acres from the same period last year and almost triple that of the five-year average of 231,453 acres for the same period.