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Opinion We won’t stop California’s wildfires if we don’t talk about climate change

Firefighters at the Mendocino Complex Fire on Tuesday. (Noah Berger/AP)

CALIFORNIA, THE nation’s most populous state and the world’s fifth-largest economy , is on fire. In a state already known for monster conflagrations, the past month has been unusually destructive. The Mendocino Complex fire north of San Francisco is now officially the largest in California’s history, having burned an area about the size of Los Angeles, and it is just one of the major blazes the state has had to face since last October.

President Trump tried to lay the blame on “bad environmental laws” and wasted water, claims that experts quickly debunked. The 14,000 firefighters on the ground do not lack for water; they are battling blazes next to big lakes and other major bodies of water. The state’s big rivers have not been “diverted into the Pacific,” as Mr. Trump claimed; they flow into the ocean as they always have, though with large amounts sent to cities and farmland for human use.

Should even more of that water be taken to keep wild plants and soil moist, and therefore more resistant to fire? That wouldn’t work. “Even if you built a massive statewide sprinkler system and drained all of our natural water bodies to operate it, it wouldn’t keep up with evaporation from warmer temperatures from climate change,” University of California at Merced professor LeRoy Westerling explained to NPR.

Yes, humans have made wildfires worse. Here?s how.

As much as the president might prefer to point fingers elsewhere, it is impossible to talk about California’s blazes without considering the role of climate change. Four of the five largest conflagrations the state has had to battle have come since 2012 , according to the Los Angeles Times, and that is probably no mere coincidence. Droughts, storms and heat waves have occurred throughout history, of course, and it is hard to attribute any single event to climate change. But scientists have concluded that climate change has increased the frequency of extreme weather and will continue to do so.

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In California, a half-decade-long drought was followed by swamping winter rains in 2016 and 2017, which encouraged rapid plant growth. Then, intense heat last summer dried out the land. That resulted in massive fires last October. Come July, triple-digit heat once again fueled huge blazes, as arid land served as an ideal tinderbox. The state may offer an alarming taste of the troubles to come.

Even after major periods of rain, uninterrupted high heat can produce arid conditions quickly, and arid conditions lead to big fires. A 2016 study published in the Proceedings of the National Academy of Sciences concluded that human-caused climate change is responsible for about half the additional drying that researchers have found since the 1970s, resulting in a doubling of the area forest fires have consumed since 1984. Climate change may also increase lightning strikes, which are a major source of wildfires, and generate the high winds that can drive big blazes. Meanwhile, earlier springtime melting means that the land has more time to dry out over the warmer months. Global warming will increasingly prime the environment for spectacular disasters.

Addressing global warming and hiring more firefighters are obvious responses; the federal government should also prepare to spend more money in disaster relief. Yet, pumping cash into ever-more firefighting is in part how forest fires got so bad in the West. So much of the U.S. Forest Service’s budget has gone to firefighting that too little has been left for care and restoration. Lawmakers should examine the many ways they can help prevent another summer like this one — or worse.

Read more:

Peter Gleick: Trump’s nonsense tweets on water and wildfires are dangerous

David Arkush and David Michaels: Climate change isn’t just cooking the planet. It’s cooking our workforce.

The Post’s View: There’s still hope on global warming — if the world gets to work

Robert J. Samuelson: Trump ignores the messy reality of global warming — and makes it all about him

The Post’s View: The practically cost-free way to slow global warming that Trump won’t adopt