Man-Made Climate Change Making Kindling of America's Forestlands

A rolling forest fire in Alberta, Canada, May 28, 2011. (Photo: Environment and Sustainable Resource Development/Government of Alberta)

Man-Made Climate Change Making Kindling of America's Forestlands

Researchers found that wildfires will worsen exponentially until there are no longer enough trees to sustain them

Apocalyptic images of fire and brimstone may well be the future of our planet, according to a new scientific study which found that the recent uptick in forest fires is due in large part to human-caused climate change.

The research team, from the University of Idaho and Columbia University, said that scientists have known for some time that global warming is making wildfires longer and more powerful as they eat up wide swathes of forestland across the western United States. But the study, published in the Proceedings of the National Academy of Sciences(PNAS) on Monday, sought to determine just how much of that increased fire activity can be attributed to anthropogenic warming--and how much worse will it get.

Warmer, drier air saps the moisture from trees and plants, turning them into prime kindling. And there is plentiful research to suggest that, thanks to fossil fuel emissions, the western United States in recent years has been sacked with increasing droughts and hotter temperatures.

The study found that since the 1970s, global warming is responsible for half the documented increase in drier, fire-prone "fuel," which in turn has doubled the areas susceptible for forest fires and lengthened the annual fire season.

Last year was a record year for wildfires in the U.S. with over 10 million acres burned. And in the first quarter of this year, wildfires already burned through 1.3 million acres of forest, which was reportedly double the average for that time.

According to the National Interagency Fire Center, "9 of the worst 10 years for acres burned have occurred since 2000."

"Although numerous factors aided the recent rise in fire activity, observed warming and drying have significantly increased fire-season fuel aridity, fostering a more favorable fire environment across forested systems," the study states. "We demonstrate that human-caused climate change caused over half of the documented increases in fuel aridity since the 1970s and doubled the cumulative forest fire area since 1984."

In just three decades, the forest fire area has grown 16,000 square miles. What's more, the analysis "suggests that anthropogenic climate change will continue to chronically enhance the potential for western U.S. forest fire activity."

Or, as the New York Timesput it, "Every degree that temperatures warm has a much bigger effect on the fire area than the previous degree did."

This pattern, according to co-author A. Park Williams, "is likely to continue as long as there is enough fuel to burn, but that there will come a point, probably in the middle of the century, when there are not enough trees left to sustain wildfires," the Times reported.

The wildfire study coincided with the publication of a second study, also in PNAS, which looked at the relationship between human-caused climate change and extreme flooding events. Focusing on New York City, the study found that "due to the compound effects of sea level rise and storm climatology change," the city is now three times more likely to experience another "Hurricane Sandy-like extreme flood" sometime in the next century.

"That climate change is becoming an increasingly important player in these types of events is not surprising at all," Arthur DeGaetano, director of the Northeast Regional Climate Center and a professor at Cornell University, toldThe Christian Science Monitor when asked about the pair of studies, with which he was not involved.

But, he added, "both studies highlight that climate change is increasing the magnitude of events like wildfires and floods by changing the baseline conditions," the Monitor reports.

Michael Mann, director of the Earth System Science Center at Pennsylvania State University, also told the newspaper that it is clear that "[c]limate change impacts are already threatening us here in the U.S. and around the world," and warned that they "will only worsen if we do not act on climate."

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