It’s the Heat, Stupid!

We’ve just returned from a three week road-trip though parts of the Southwest.  Friends who met us at Canyon de Chelly in Arizona had had to detour because of the Yarnell fire NW of Phoenix which had already killed 19 firefighters. It was 106º in Winslow where we stopped for the night.  On the way home, in Brawley, CA it was 109º at 8:30 at night and 92º at 7:30 in the morning.  Along the way we saw smoke rising from the Dean Peak fire, SE of Kingman, AZ — still not out. And all over the west the bad news keeps burning:

Wildfires are chewing through twice as many acres per year on average in the United States compared with 40 years ago, U.S. Forest Service Chief Tom Tidwell told a Senate hearing last month. Since Jan. 1, 2000, about 145,000 square miles have burned, roughly the size of New York, New England, New Jersey, Delaware and Maryland combined, according to federal records.

and

Rising temperatures all over the West, for one, have created dangerous, dry conditions.

Over the past 35 years, Arizona has seen dramatic warming, with the state’s 10-year average temperature jumping from 59.1 degrees Fahrenheit in 1977 to 61.4 degrees last year – an increase of 2.3 degrees. By comparison, the entire continental U.S.’ 10-year average temperature jumped only 1.6 degrees during the same period. Experts say every little spike in temperature makes a big difference.

“Even a degree or so warmer, day in day out, evaporates water faster and that desiccates the system more,” said fire ecologist Steve Running of the University of Montana.

In Arizona, where a drought has persisted for nearly two decades, the manzanita, evergreen, mount mahogany and oak in the Yarnell area were so crispy Sunday that a nearby state fire-monitoring station recorded a near-maximum level of potential fuel in area vegetation.

And it’s not just Arizona, of course.  At the Remote Sensing Applications Center, 40 “Current Large Incidents” are being monitored.