Are Colorado's wildfires caused by global warming?

Climate models predict that in a warming world, the West and Southwest will become drier and hotter — conditions ripe for wildfires. Whether recent hot summers and active fires are a sign of the change already happening is still under debate, though.

"Some would say there is a pattern, because we have had several years with exceptionally large fires over western states, particularly the Southwestern states, Arizona, New Mexico, Texas and Colorado in particular," Doesken said. "Others would say, no, not enough data points yet to show that."

This year has been extreme in terms of heat and dryness, he said, as was 2002 (a record-breaking year for fires in Colorado). So far, 2012's weather looks very similar to the weather of 1910. That year, spring was warm and dry, which fed into a hellish fire season. Among the blazes was the Great Fire of 1910, also known as "the Big Burn," which destroyed 3 million acres of forest in Washington, Idaho and Montana.

Some studies do suggest that climate change is already affecting western wildfires. In 2006, researchers at the Scripps Institute of Oceanography in California analyzed 1,166 fires between 1970 and 2003 and found a dramatic increase in fire potency in the late 1980s. Though wildfire is a natural part of the western landscape, the researchers concluded that a warming climate was ramping up warm winters and springs, exacerbating natural fire cycles.

More recently, an analysis of 1,500 years of fire and tree-ring data revealed that a combination of climate change and human forest use could explain modern "megafires," the kind that destroy large swaths of forest. Fires were associated with a dry year following several wet years, because the moist periods allow undergrowth to spring up and provide fire fuel in dry years, researchers reported in May in the journal The Holocene. The study found that human activities such as livestock grazing and suppression of small fires compounded the problem, creating denser forests ripe for large blazes.

Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience. We're also on Facebook & Google+. 

• Natural Disasters: Top 10 U.S. Threats
• Dried Up: Photos Reveal Devastating Texas Drought
• Top 10 Surprising Results of Global Warming

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Previous

1 | 2