Pacific Swell

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Draft National Climate Assessment predicts more global warming woes for California

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Climate change will bring significantly higher temperatures and sea levels to California by the end of the century, and it’s already worsening droughts and fires. Those are among the conclusions of scientists who gathered at USC yesterday to preview a federal climate report they helped write.

The draft report is the National Climate Assessment. It’s prepared by the U.S. Global Change Research Program, a 23-year-old initiative overseen by the White House that coordinates research among 13 federal departments and agencies.

RELATED: Download the Draft National Climate Assessment

The USC Schwarzenegger Institute for State and Global Policy hosted an event on Monday with several of the scientists who contributed to the climate assessment. Former Gov. Arnold Schwarzenegger compared what’s in the report to what the doctor tells you at an annual physical.

“If we’re smart we listen to our doctors and we make the adjustments,” said Schwarzenegger, who also published an editorial on the subject. “But if we’re stupid we ignore their advice then it takes a heart attack to start making those changes that the doctor recommended in the first place.”

As a diagnosis, what the scientists handed out was grim. They used words like massive, apocalypse, and unprecedented.

The University of Arizona’s Thomas Swetnam studies fire ecology at the University of Arizona. He says hotter temperatures have already lengthened fire season in California and other southwestern states by two months in the last twenty years. Fire season, he says, is also more intense.

“Fire ecologists, fire scientists, we’ve never seen anything like this before,” said Swetnam. He conjured up “holocaust conditions, basically killing all of the trees,” with slides of fires in New Mexico and Arizona. Swetnam said that prior to about 1980, “the largest wildfire was about 50,000 acres and that was over three weeks of burning. Now we’re seeing 40,000, 50,000, 60,000 acres burned in a day.”

Swetnam and others said California’s crowded cities also worsen climate risks. More people have moved into fire-prone areas even as they grow hotter and drier. And the experts say the Colorado River and California’s water system won’t quench southern California’s thirst.

“Now what’s particularly diabolical, we’ve been in a wet period in the 20th century,” said David Pierce, a researcher at the Scripps Institution of Oceanography in San Diego. “That’s when we built all the infrastructure. That’s when all these people moved out here. That’s when we set our expectations for what the water supply would be like.”

At the same time, the Pacific Institute’s Matthew Heberger says sea levels will rise along the southern California coast six inches within 20 years, and three feet or more by the end of the century.

“It’s not a gradual, creeping menace, but rather something that is going to evidence itself during floods,” said Heberger. “Floods in the future are going to be more intense and more frequent, tremendous risks to lives and property and infrastructure.”

The draft national climate assessment doesn’t offer solutions to the politicians who -- in theory -- will read it. But its authors, including Heberger, say the goal is to offer enough evidence to convince Washington that climate change requires action.

“We need to avoid the unmanageable and we need to manage the unavoidable,” said Heberger. “And so we need to start talking more and more about climate adaptation, how to deal with some of these changes we know are going to take place.”

Climate researchers say the science of predicting global warming is growing more accurate. At USC Monday, they admitted some uncertainty remains, but they expressed concern that policymakers and the public don’t appreciate the risks posed by climate change. Hilda Blanco, who directs USC’s Center for Sustainable Cities and is a lead author of the climate assessment’s chapter on the southwest, used the metaphor of “the frog in the  pot of water. So you put the frog in lukewarm water, and he’s very happy there. And then you turn up the flame very slowly and he’s very happy there until he burns.”

The scientists preparing the national climate assessment are accepting public comments until Friday. Their goal is to finish the report in time to present it to President Obama and Congress next January. 

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