With the Whitewater-Baldy fire pushing 260,000 acres (New Mexico’s largest by a wide margin), I spent some time talking with the forest-climate community about climate change, forest health and the role of natural variability in creating the conditions for the southwest’s recent megafires:
Global warming is playing a role in the conditions in the Gila — “50-50 wouldn’t be a bad guess,” Betancourt told me last week — but the problem defies simplistic explanations. A big part of the warming is likely natural variability, driven by long-term natural ocean temperature patterns that influence continental weather, Betancourt said.
In addition to uncertainties in the climate attribution problem, Westerling pointed out that a century of human forest management has played a role in the recent fires, with grazing and fire suppression leading to woods choked with increasingly vulnerable fuel.
Wow John, I should have figured you’d be all over this. I actually wrote a similar piece for National Wildlife Federation’s blog the day after you published. I touched a bit on the forest management issue, but a commenter on Facebook brought up grazing and I’m glad you wrote about that.
Something I didn’t touch on at all was the recent record of large fires in the Southwest. From the Bear Complex in 2006 to Las Conchas to Whitewater Baldy, New Mexico has had multiple years of 100,000+ acre fires. But looking at the historical data, a “typical” fire season in the state during the past decade sees something like 100k-300k acres burned. 2011 had 1.1 million acres burned. Las Conchas was big, but it didn’t burn in a vacuum.
I also wonder what effect burned areas have on subsequent fire seasons: it looks like “big” fire seasons are followed by “small” ones–is that because the fuel is gone? A weather correlation?
Sigh–so many questions.