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WIldfires Caused by - What Else? - Climate Change
Are wildfires in the Western United States getting bigger and more severe? There's a fair bit of evidence that yes, they have been. And, ecologists and fire experts say, that's not a fluke. Thanks to both climate change and shifting forestry practices, humans may bear some responsibility here.A research ecologist 1) Global warming. Huge wildfires are, of course, more likely during droughts, when the forests are dried out and filled with kindling. And many parts of the West are facing "severe" or "extreme" droughts right now. But, Allen notes, data from tree-ring studies suggest that there have often been large droughts in the West. "What's different today," he says, "is that it's also getting warmer, which can amplify the fire severity in the West." Historically, Allen says, the snowy mountains have acted as giant "fire towers" that release water slowly throughout the spring and summer. But when there's less snow to go around, soils and forests get parched more quickly, which exacerbates droughts and can make large wildfires more likely. This year, snowpack in the Colorado Rockies peaked on March 6, a full month earlier than the historical average date. (Note, however, that there are still plenty of other, non-climate-change reasons why the current Colorado fires are so vicious, such as a high-pressure system that has prevented clouds from forming.) Plenty or other reasons, he says. Still, climate change is listed first among three "drivers", the other two of which are not at all theoretical. 2) Sprawl has pushed more people into forest areas, increasing the odds of fires. Many forest fires are caused by lightning. But others are caused by human activities. And as more and more people push deep into forested regions, that increases the risk of accidents. "More smokers, more ignition from motorized vehicles... even more arson," says Allen. He offers up one salient example: The record-setting Las Conchas fire in New Mexico last year, which consumed 40,000 acres, began when an aspen tree toppled onto a power line that was serving just six homes in a remote area. 3) Changing forestry practices have made wildfires more destructive. A look at tree-ring data shows that the Southwest has seen massive fires going back for centuries. But, in the past, many of these fires were low-intensity "surface" fires that mostly cleared out underbrush and prevented forests from building up too thickly. That all changed around the 1900s, when the area's population grew and forest managers began suppressing these natural fires. Southwestern forests became much more dense with trees and brush. And that means when fires do break out, there's more fuel to burn and the fires are often far more destructive. The scale of these "megafires," which can spread all the way up to the tree canopy, appears to be unprecedented in the historical record. So two unquestionable causes rooted in man, and one highly questionable theory are put on the same level. The Sunday version of this article noted forest-thinning is limited by the Spotted Owl and offered the choice of the Spotted Owl or wildfires. No wonder that got culled out! Posted by: Bobby 2012-07-03 |
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