"It's the only the option we have to effect big change," said Jon Keeley, a fire ecologist with the U.S. Geological Survey.
Keeley, who has studied fire in California ecosystems since the early 1970s, spoke at a public discussion of the subject at the agency's regional headquarters in Menlo Park.
Creating a 100-foot area of "defensible space" by clearing vegetation around homes helps, but it won't stop burning embers, which can travel up to a mile, from raining down on roofs, which spread many catastrophic fires, he said.
"Fire management around the neighborhood, that's good," he said, as it will stop smaller fires from spreading. "But it's going to be business as usual unless we make decisions on where we build and how we manage growth," Keeley said.
"The biggest problem in all of this is we're increasing our population substantially, and no one wants to talk about that," he added.
As an indication of the toll of increasing development into the wilderness, a recent U.S. General Accounting Office report stated that the U.S. Forest Service and the Bureau of Land Management spend between 50 and 95 percent of their firefighting budgets protecting homes next to federal lands. That's upward of $1.2 billion a year, the report stated.
Only 15 percent of the interface between urban and wild areas is developed, the report added. If homes are built along 50 percent of this "wildland urban interface," the costs will rise to upward of
$4.3 billion annually for the two federal agencies alone, the report concluded.
Humans also cause almost all the fires between the mountains and coast in California, he added. Historically, lightning caused most fires, and then only infrequently.
"Now, probably 99.9 percent of all fires are by caused by people," he said. "Humans have saturated the environment with their ignitions."
Keeley described one wilderness area in the mountains near Santa Monica in which records show that lightning triggered a fire only once or twice a century.
"The Santa Monica mountains now have fire on average every 13 years way in excess of what the natural regime could have ever been," he said.
During his talk in a large auditorium, Keeley worked to debunk the notion that a century of so-called fire-suppression practices triggered large wildfires in Southern California in recent times, due to a buildup of vegetation, or "fuel loads."
"We have fuel loads well within historic ranges," Keeley said, particularly in Southern California. He added that some of the areas scorched there this month were also burned in the 2003 conflagration.
The lack of a significant buildup of vegetation is largely true of Northern California, he added, although there are exceptions, such as in crowded subdivisions built on the flank of Mount Tamalpais in Marin County.
In California forests, however, which have surface fires that are relatively easy to extinguish, vegetation buildup from fire suppression is a problem, he added. But in the tinder-dry California foothills, with highly flammable chaparral plant communities, fires quickly rage out of control.
With these frequent fires, there's no chance for fuels to build up. Thus the catastrophic blazes cannot be caused by the high fuel loads, he said.
Keeley emphasized that strong winds and dry weather are the key factors that turn smaller fires into raging conflagrations. He cited the well-known role of the Santa Ana winds, which reached up to 100 miles per hour and lasted longer than usual during this week's Southern California fires, in dispersing the flames.
In the Bay Area, the Santa Ana winds' counterpart is the so-called "Diablo wind" (or "Mono wind" if it shifts and arrives from the northeast).
"Bad fires in the Bay Area have been under the Diablo winds," Keeley said, including the 1991 Oakland hills fire and an infamous 1921 fire in Berkeley.
In addition to the enormous costs and human suffering caused by fierce wildfires, the increased frequency of fires in Southern California is threatening native plants and wildlife, Keeley said.
Even though the ecosystems in the region are adapted to fire the seeds of many plants require the heat of flame or smoke to germinate they collapse under fires that occur too frequently.
"What they're adapted to is a particular fire regime, which means fires at certain intervals," explained Keeley. "If you increase that interval, you greatly stress the system to the point where you lose the native species."
For example, he said, some plants need one or two decades to produce seeds. If fires occur before that interval has elapsed, the plants won't reproduce, and invasive grasses take their place.
"You'll lose species because they can't make seeds," Keeley said. "We have lots of examples in Southern California of fires converting native shrub lands to non-native grasslands."
Wild animals are especially stressed by fires, he added, since they have to find a new place to burrow, nest or hide, as well as secure a new food supply, which is hard to come by in a charred landscape.
"There's a lot of challenge for wildlife," Keeley said.
Keeley believes that fire protection officials need to change their thinking from working to stop fires from occurring to recognizing that they will occur, and pushing for policies that keep people out of harm's way.
That would entail land-use planning that limits development in vulnerable areas, as well as designing communities with wider distances between homes and the wilderness, among other measures.
One developer, he noted, has proposed building a new community with a golf course circling the homes, instead of at the center of the development.
"They essentially have a greenbelt around the community," Keeley said.
Fire management practices are also evolving in the state, noted CalFire spokeswoman June Iljana.
After Jan. 1, she said, new homes built in the state will require features to reduce the incidence of fire, such as flame-resistant walls and roofs, double-pane glass tempered to resist heat, and vents and rain gutters designed so that embers can't fall into them. Rebuilt roofs after that date will also have to adhere to the new rules.
But Keeley insists that until local and state leaders address the core issue behind the high losses in property and sometimes in human life from fires that of building homes in Southern California next to wild areas that become tinder dry in the fall then the vivid images of fiery flames and devastated homeowners will play out regularly in newspapers and on television.
"We ought to treat fires more like earthquakes," Keeley said. "With earthquakes, we recognize that they're going to happen, and we plan around it."
Contact Suzanne Bohan at email@example.com or 650-348-4324.