Thursday, October 25, 2007

Not your father's wildfire

Yeah, Southern California is a natural desert area and yes, it gets especially dry every year in early fall. And yes, the Santa Ana winds blow every year creating a heightened risk of fast-moving fire. But this year the conditions were different. It had been hotter and drier through this past summer. The winds blew harder. And housing development further into the brush was just tempting disaster.

My friend, Paul, who lives in San Diego, tells me that San Diego County used to have a 40 acre minimum lot size in the backcountry and there was intense debate on changing the zoning. In what is called GP 2020, the general plan is to make room for a million more residents by 2020. Here's a Sierra Club call for action sent to its members in 2003. It calls for lower density development, lower population and (as a result) less commute traffic in what was were the rural boundaries of eastern San Diego. It could be argued that development alone did not cause the current firestorm, but obviously the exposure of more housing to the potential of wildfires stretches the ability of fire departments to respond and protect. In other words, you move into one of those developments and YOU'RE ASKING FOR IT. Impacts on insurance, taxes, lives and our collective emotions are unavoidable.

The Chief of the U.S. Forestry Service, Gail Kimbell, says, "Fires are burning hotter and bigger, becoming more damaging and dangerous to people and to property. Each year the fire season comes earlier and lasts longer." And as the same S.F. Chronicle article points out:

The 16 wind-blown fires that forced the largest mass evacuation in California history may or may not be the result of climate change, but studies have shown that the hot drought conditions that fed the flames are becoming more common.

The flames stretching from Malibu to the Mexican border struck during the driest year in Southern California history. Measurements taken by the California Department of Forestry and Fire Protection detected less than 10 percent moisture in the region's vegetation. The moisture level in kiln-dried lumber is generally 12 percent.

"They got less rain than they've ever gotten," said Hugh Safford, a Forest Service ecologist. "Any time you have a dry year like this one, you are going to get fires."

It is so dry that state forestry officials said a newly shod horse started a fire earlier in the year from the sparks it created running on the pavement.

Chronically drier than normal conditions promotes the growth of invasive plant and insect species that may add to flammable material. We all know about the bark beatles that are killing off conifers and leaving forests of firewood. And sources of ignition - specifically lightning - are predicted to increase with the increase of CO2 concentration in the atmosphere.

Other experts quoted in the Chronicle article pointed out that the Santa Ana winds had sustained longer than usual in fanning the San Diego flames. And though none could say for sure that the fire was a result of climate change, it was undeniable that the smoke from the fires is contributing to global warming.

One link that can be made, according to Tom Bonnicksen, a California forest and wildfire expert, is how the fires are contributing to global warming. Almost 20 million tons of greenhouse gases - the equivalent of what is emitted in one year by 3.6 million cars - have been spewed into the atmosphere, he said.

"The problem isn't global warming causing fires," he said. "The real problem is these fires contributing to the greenhouse gas emissions that cause global warming."

All of which could be a foreshadowing of worse problems in the future. Kimbell said the fire threat in California and other states is more severe because cities are now pushing up against the wilderness.

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