Sunday, March 11, 2012

Catestrophic Fire in the West

What if wildfire risk were catastrophically worse than we have imagined? Dr. Littell (University of Washington) walks us through just such a scenario in this USFS webinar. He starts by pointing out that the recent increase in wildfire area is not unprecedented. The traditional story has been that large "mega-fires" have increased in recent years, but Littell's reanalysis and recalculation of historical records found that the natural fire regime from 1910-1940 may have matched the last thirty years of large fires. (cf: The Big Burn) In both time periods perhaps 97% of the area burned was the result of less than 3% of the fires, the mega-fires.
Dr. Littell considers whether the dip in the middle is actually due to the triumph of fire suppression, or whether it is climatically driven:

What happens if it gets even warmer? Littell goes on to calculate fire probabilities based on temperature and precipitation and projects the results in a model of a 1 degree C climate change future:
Percentage Increase in Area Burned with +1C. White areas did not have a significant relationship between area burned and temperature.

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