The devastating wildfire in Southern California that destroyed 26 homes and threatened hundreds of others in the San Jacinto Mountains before it was mostly contained on Sunday has prompted some scientists to examine whether climate change has impacted on the onset and severity of wildfire season.
The so-called Silver Fire is expected to be fully contained by Monday, according to California officials. But on Friday, as the fire moved toward Palm Springs and threatened some 500 homes, NASA hosted a Google Hangout with a panel of scientists and researchers to discuss the factors behind this and other recent blazes. NASA said that ground surveys and its own satellites have shown that fire season in the western part of the country is beginning earlier in the spring than usual.
"We've seen more fires, larger fires and more deadly fires," said Bill Patzert, a climatologist with NASA's Jet Propulsion Laboratory, during the hangout. "We're living in a warmer world. In the West, it's a drier world."
So far in 2013, fire officials have battled 4,300 wildfires -- a stark increase from the yearly average of about 3,000 they faced from 2008 to 2012, Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection, told The Associated Press.
As of last week, those fires had burned 111 square miles, or more than 71,000 acres, up from 40,000 acres during the same period last year.
Doug Morton, a research scientist with NASA's Goddard Space Flight Center, said that scientists are interested in using the latest climate models to understand how hot and dry conditions that favor fire activity will play out.
"We're seeing years – like, for example, 2012, which was very dry across the front range of the Rockies and the Midwest of the country – [and] that kind of a fire season [could become] the new normal by the end of this century," Morton said.
Photos: Silver Fire spreads through San Jacinto
The panel of experts also talked about how the long-distance travel of smoke resulting from fires can have a significant impact on the environment. Morton pointed to fires in Quebec in 2003 in which smoke plumes reached Maryland and Washington D.C., more than 700 miles away. He added that smoke, or aerosols, from fires in the United States that are transported to Canada and Greenland can also affect climate change.
"Those aerosols and the black carbon that rains out on the ice sheets in Greenland has a significant impact on how quickly that ice is melting and how rapidly this link between fires and melting ice helps play a role in the global earth system picture," Morton said.
The question of how climate change affects wildfires has also been on the minds of firefighters.
Carroll Wills, communications director for the California Professional Firefighters, a union which represents about 30,000 firefighters in the state, said wildfires around the country "certainly started earlier in the season this year."
"Definitely something is happening in terms of the size and scope of wildland fires, and it would be myopic not to look at the possibility that one factor is climate change," Wills told Al Jazeera.
The wildfire in the San Jacinto Mountains has destroyed more than 19,000 acres, but there have been a number of other dangerous, sometimes deadly, fires this year as well.
A wildfire in Yarnell, Ariz., in late June killed 19 firefighters and destroyed about 200 homes. Another deadly fire in June in Colorado charred more than 14,000 acres, destroyed more than 500 homes and killed two people.
Wildfires have burned some 90 million acres in the United States since 2000, said Jennifer Jones, an official with the U.S. Forest Service. That is roughly three times the size of the state of New York, according to government statistics.
Patzert also pointed to migration and to locations where people have moved in the United States as significant factors in the impact of wildfires.
"In Southern California in 1950, there were 9 million people, now there are more than 20 million people between San Diego and Santa Barbara, and more and more of them are living in harm's way. And so climate change is the real deal, but human behavior is the dominant factor," he said.
Jones told Al Jazeera that the current 10-year average for the number of acres burned annually is 7.2 million – which is more than twice what it was 40 years ago.
Using data from the federal government's National Interagency Fire Center, Jones calculated that the 10-year average for the number of acres burned annually from 1973 to 1982 was 3.4 million.
But whatever the dominant factor is behind the increase, Elizabeth Reinhardt, the national program leader for fire research and development at the U.S. Forest Service, said it's important to look at the long-term trends.
"Any given fire, just like any storm, we can't really say, 'Oh, this is a climate change-caused event,'" Reinhardt said.
She added, "We know that fire in general is episodic and highly variable, the fires we see might have been seen 100 years ago or 200 years ago – any individual fire – but what I think we need to keep our eye on is trends. And when we look at fire occurrence in the West, we do see a very, very strong trend in the last 25 years that I think we can't ignore."
Al Jazeera and wire services