Studies suggest wildfires will worsen with global warming

Monday, May 19, 2014 | 7:51 a.m. CDT; updated 10:47 a.m. CDT, Monday, May 19, 2014
Fire engulfs a structure during a wildfire Thursday in Escondido, Calif. One of the nine fires burning in San Diego County suddenly flared Thursday afternoon and burned close to homes, triggering thousands of evacuation orders.

WASHINGTON — The devastating wildfires scorching Southern California offer a glimpse of a warmer and more fiery future, according to scientists and federal and international reports.

In the past three months, at least three different studies and reports have warned that wildfires are getting bigger, that man-made climate change is to blame, and that it's only going to get worse with more fires starting earlier in the year. While scientists are reluctant to blame global warming for any specific fire, they have been warning for years about how it will lead to more fires and earlier fire seasons.

"The fires in California and here in Arizona are a clear example of what happens as the Earth warms, particularly as the West warms, and the warming caused by humans is making fire season longer and longer with each decade," said Jonathan Overpeck, a University of Arizona geoscientist. "It's certainly an example of what we'll see more of in the future."

Since 1984, the area burned by the West's largest wildfires — those of more than 1,000 acres — have increased by about 87,700 acres a year, according to an April study in the journal Geophysical Research Letters. And the areas where fire has been increasing the most are areas where drought has been worsening, and "that certainly points to climate being a major contributor," the study's main author, Philip Dennison of the University of Utah, said Friday.

The top five years with the most acres burned have all happened in the past decade, according to federal records. From 2010 to 2013, about 6.4 million acres a year burned on average; in the 1980s, it was 2.9 million acres a year.

"We are going to see increased fire activity all across the West as the climate warms," Dennison said.

That was one of a dozen "key messages" in the 841-page National Climate Assessment released by the federal government earlier this month. It mentioned wildfires 200 times.

"Increased warming, drought and insect outbreaks, all caused by or linked to climate change, have increased wildfires and impacts to people and ecosystems in the Southwest," the federal report said. "Fire models project more wildfire and increased risks to communities across extensive areas."

Likewise, the Nobel Prize-winning Intergovernmental Panel on Climate Change noted in March that wildfires are on the rise in the western U.S., have killed 103 Americans in 30 years, and will likely get worse.

The immediate cause of the fires can be anything from lightning to arson. The first of the San Diego area fires, which destroyed at least eight houses, an 18-unit condominium complex and two businesses, seemed to start from sparks from faulty construction equipment working on a graded field, said Lynne Tolmachoff, a California Department of Forestry and Fire Protection spokeswoman.

But the California fires are fueled by three major ingredients: drought, heat and winds. California and Arizona have had their hottest first four months of the year on record, according to National Weather Service records. Parts of Southern California broke records Thursday, racing past 100 degrees. For the past two weeks, the entire state of California has been in a severe or worse drought, up from 46 percent a year ago, according to the U.S. drought monitor.

"With the drought this year, we're certainly going to see increased frequency of this type of event," Dennison said. "Because of the drought the fuels (dry plants and trees) are very susceptible to burning."

Another study last month in Geophysical Research Letters linked the ongoing drought to man-made climate change. Other scientists say that is not yet proven.

Scientists will have to do a lot of time-consuming computer simulations before they can officially link the drought to climate change. But Overpeck said what is clear is that it's not just a drought, but "a hot drought," which is more connected to man-made warming.

The other factor is the unusual early season Santa Ana winds, whose strength is a key factor in whipping the flames. So far, scientists haven't connected early Santa Ana to climate change, Dennison said.

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Michael Williams May 19, 2014 | 8:40 a.m.

The AP author is ignoring at least one other "cause."

The 100+ y/o deliberate suppression of fire. You know.....the "Only YOU can prevent forest fires" thingie.

As a result, we've allowed millions of acres of forests to accumulate vast amounts of dead fuel ready, willing, and able to keep a forest fire going for a long time over long distances. It's getting worse with the pine beetle destroying vase acreages of forests, leaving lots of carbon just waiting for a good lightning strike. By example, the whole of Rocky Mountain National Park should be set ablaze and started over.

Folks don't understand how important fire is to the ecology of forests, prairies, savannas, and many kinds of grass farmland (warm season grasses). Fire recycles nutrients in a real hurry, much faster than bacteria, beetles, grubs, and fungi. Fire gets rid of low-lying shrubs that can choke out young trees, grasses, and forbs.

Instead, we either fear fire (like Columbia's recent hissy-fit over smoke downtown) or blithely ignore it and build our homes in combustible woods.

As far as our western states go.....we should have been deliberately setting controlled forest fires a LONG time ago.

Increased fuel source = more frequent and violent fires. Is there anyone who does not agree with this equation?

But, the article has a "global warming" agenda, so any other explanation gets no mention whatsoever....not even in the interest of discussion. It assumes one cause, then builds the article around it. Bah!

(Report Comment)
Ellis Smith May 19, 2014 | 1:13 p.m.

Maybe this commentator needs to be tied to a tree (in a tinderbox dry Western forest) and forced to read Timothy Egan's best selling non-fiction work, "The Big Burn: Teddy Roosevelt and the Fire that Saved America," Houghton Mifflin Harcourt Publishing Company (New York, 2009).

Firestorms on the order of the present ones in California and other Western states are not new. Are we supposed to believe they were rare before today? It's been awhile since Teddy Roosevelt was President: that was even before MY time!

This certainly doesn't rule out global warming as a further aggravation of an existing bad situation; also, humans electing to build structures in areas never meant to have such structures in them (like building on what's obviously a flood plane, and then being shocked when one is flooded out), coming unglued when bothered by indiginous wildlife, which existed there before people showed up.

What's amazing is that with as many EXPERTS as we seem to have in the Fourth Estate, and expert on so many topics, that we continue to have any problems at all.

I wonder where in the United States Mr. Borenstein grew up. One of the largest and most destructive wild fires in our national history took place in Wisconsin, which doesn't appear to be a very "Western," location, nor is it a state habitually plagued with drought.

(Report Comment)

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