Experts say warming not to blame

Are the massive fires burning across Southern California a product of global warming?

Scientists said it would be difficult to make that case, given the combustible mix of drought and wind that has plagued the region for centuries or more.

In other words, Southern California is already perfect for wildfire, and the small changes from global warming are unlikely to make it much worse at this time.

“That is a fire-prone environment regardless of whether we are in a climate-change scenario,” said Tom Wordell, a wildland fire analyst at the National Interagency Fire Center in Boise, Idaho. “I don’t want to be callous, because many people are homeless and suffering, but if you live in a snake pit, you’re going to get bit.”

Anthony Westerling, a climate scientist at the University of California, Merced, said the two factors driving this year’s wildfires – strong Santa Ana winds and a drought that turned much of the hillsides to bone-dry kindling – are staples of the region’s climatic history.

“Neither can be attributed to climate change,” he said.

Experts said what is new is the extensive development that has occurred over the chaparral-covered hills, increasing the risk of fire and providing more fuel for the flames.

The rest of the West, however, is likely to see more and bigger fires as temperatures rise – a transformation that already appears under way, according to recent research.

In a study published last year in the journal Science, Westerling and a team of researchers looking at Western federal forests found that nearly seven times more land burned between 1987 and 2003 than during the previous 17 years.

Their analysis attributed the increase primarily to a 1.5-degree rise in average spring and summer temperatures. With spring arriving earlier and snow melting faster, the forests dried out sooner, extending the average fire season by more than two months.

The trend is expected to continue as the climate warms.

The link between rising temperatures and more forest fires was most pronounced in the Rocky Mountain region, while in Southern California there was no significant increase in the frequency of fires.