The burning question

The California inferno has ignited the long-smoldering debate over whether we have brought Mother Nature's revenge upon ourselves.

By Katharine Mieszkowski

Read more: Politics, News, Global Warming, Katharine Mieszkowski

REUTERS/Joshua Lott

Flames approach a fire truck as the Poomacha wildfire rages on the La Jolla Indian Reservation in Southern California, Oct. 25. No firefighters were injured and the truck was not damaged.

Oct. 27, 2007 | The fires in Southern California this week raged through 500,000 acres, inspiring the largest-scale human evacuation in the state's history. Some half-million residents were displaced from their homes over six days, and more than 1,800 homes went up in flames. Eighty people were injured, and the death toll stands at seven. All told, more than a billion dollars of property damage has been reported, leading President Bush to declare seven counties a major disaster.

In the wake of the destruction, another fire is raging -- the debate over fire suppression, and what part it should play in national policy. Has 100 years of attempting to stop most wildfires backfired and caused more destructive infernos? Or is putting out as many fires as possible the only defense against massive devastation and loss of human life in combustible habitats home to millions of people? The Southern California inferno has given ammunition to impassioned scientists on both sides.

"We started fire suppression in 1900 and we started getting bigger fires by the 1920s -- and they've gotten ever bigger since," says Richard Minnich, a fire ecologist at the University of California, Riverside, speaking by phone from his office, where skies are gray from the wafting smoke of the still-burning fires. He argues that putting out small fires in wilderness areas, rather than letting them burn slowly, has created excess fuel for fires to ignite in dangerous weather conditions, such as the West's dry Santa Ana winds. "We're trying to conquer nature, and nature always wins out," he says. "Fire is the primary way that we decompose organic material in California. Growth and decomposition must be equal over time. We're trying to get rid of one-half of the equation."

The policy of protecting the wild from fires took shape in the Teddy Roosevelt years, when lands were being designated for national parks, forests and preserves. The wilderness must be saved for future generations, the thinking went, even if fires were started by natural causes like lightning. As decades passed, ecologists grew more aware of the natural role of fire in ecosystems, of how it thinned vegetation and germinated new flora. Of course, at the same time, more people moved into or near flammable habitats like the chaparral communities and Western pine forests in Southern California. Today, as the Los Angeles Times reported, nearly 5 million California homes are at high to extreme risk from wildfires, and 84 percent of them are in urban areas abutting wild lands.

In California, the National Park Service allows some wildfires to burn in the high Sierra in California and the Forest Service monitors some wildfires, like the recent Zaca Wildland Fire, which was contained in early September after burning more than 200,000 acres over two months. Yet, in general, there's an aggressive put-it-out policy that extinguishes most fires, because of potential danger to people and property. "There is zero tolerance for fire in Southern California, and that's never going to change," says Richard Halsey, a biologist who is also trained as a firefighter, who stayed home to successfully defend his house in Escondido last week. "It could kill somebody. The reason that they put fires out is that they kill people."

The suspected ignitions of the many fires this week were human -- downed power lines and arson -- not natural. But the fires took off because weather conditions were ripe for a major conflagration. "The Santa Anas themselves are one of the worst fire weather types in the whole world," says Max Moritz, a specialist in wild-land fire, and adjunct assistant professor at the University of California, Berkeley. The winds typically form when there's a high pressure system over the Great Basin, and a low pressure system over the Pacific. The winds gain heat as they cascade down mountain slopes to sea level. "By the time they hit Southern California, you have some really strong, warm, dry winds, which from a fire point of view is extremely dangerous," says Moritz.

In the midst of a longtime drought, Southern California had an unusually dry spring this year. By the fall, moisture in plants and trees has been greatly diminished, making them more flammable. Many of the areas that burned in Southern California this week were chaparral, a habitat that's especially combustible. "Much of what's happening is unfortunately inevitable, given these houses are built among chaparral plant communities," says Malcolm North, a research forest ecologist with the USDA Forest Service, Pacific Southwest Research Station.

Fire is nature's way in the chaparral, where plants, mostly shrubs, are adapted to warm, dry conditions. Some of them have seeds that do not germinate unless they've been heated through fire. Others are root sprouters, which means that when the entire aboveground part of the plant is burned off, it will simply sprout again from the roots below. "It's a system made to burn," says North. "When you build in chaparral communities, it's not a question of keeping the fires out, it's just a question of when it will burn, because fire is inevitable."

Next page: After all, it's not lightning that set San Diego on fire