USA — Global warming will result in more than rising oceans and meltingicecaps. According to one of the world’s leading fire ecologists, the warmingtrend is also increasing the intensity and number of forest fires so much thatthe American West could lose half its forests by the end of the century.
60 Minutes correspondent Scott Pelley speaks to Tom Swetnam, a fire ecologist atthe University of Arizona, for a report on mega-fires to be broadcast thisSunday, Oct. 21, at 7 p.m. ET/PT.
“As fires continue to burn — these mega-fires continue to burn — we maysee, ultimately, maybe more than half the forest land converting to other typesof ecosystems,” says Tom Swetnam. “(It will happen) within somedecades, to a century, as warming continues and we continue to get large-scalefires,” he tells Pelley.
Last year was the worst fire season in recorded history and this season isalready second, with eight million acres burned. Average temperatures are up adegree, causing earlier springs and longer fire seasons and quadruple the numberof fires. “The fire season in the last 15 years has increased more than twomonths over the whole Western U.S.,” says Swetnam. “So actually 78days of average longer fire season in the last 15 years compared to the previous15 or 20.”
Tom Boatner, chief of fire operations for the federal government, says he hasseen the results up close on the fire line and in the statistics. “We gotrecords going back to 1960 of the acres burned in America. So, that’s 47 fireseasons. Seven of the 10 busiest fire seasons have been since 1999,” hetells Pelley. The fires are bigger and more frequent. “Ten years ago, ifyou had a 100,000-acre fire, you were talking about a huge fire … Now we talkabout 200,000-acre fires like it’s just another day at the office,” saysBoatner, who says he and his firefighters have battled two fires this year thatwere over 500,000 acres.
Part of the blame for the fires is a strategic mistake made by the forestservice. Throughout most of the 20th century, all forest fires sighted, big andsmall, were extinguished. This vigilance led to an increase in the amount offuel in forests. “So now, when the fires get going, there’s a lot more toburn than historically you would have seen,” Boatner tells Pelley.
With more to burn, the fires are more intense and all consuming, leaving verylittle to grow back and scant soil from which it can take nourishment. On afire-ravished landscape, Swetnam points to the ground. “We used to haveforest soil here that might have been this deep,” he says, indicating abouta foot of depth, “but now we’re just down to rock … sort of armored soiland that is not a good habitat for trees to re-establish,” he tells Pelley.