Fire historian Richard Minnich blames California's fire suppression policies for the growing severity of the state's wildfires. Decades of putting out wildfires has actually increased the fire danger he says, and the state would be better off letting wilderness fires burn themselves out.

"We seem to think we can control fire," he says. "Let's play a word game. Smokey the Bear says, 'Help prevent earthquakes.' Smokey the Bear says, 'Help prevent tornadoes.' Smokey the Bear says, 'Help prevent hurricanes.' Nobody in Western culture assumes that we can prevent those things. Why do we assume we can prevent fires? "

Minnich has compared the fire ecology and historical records of fires in Southern California with conditions in Baja California, looking at an area stretching roughly 150 miles on each side of the border. The terrain, climate and vegetation are similar, and before heavy development, the California side looked much like the Mexican side with grasses, sage scrub and woody chaparral. In Baja, he says, there is no fire suppression.

"There are many small fires down there -- 10 times as many as the United States side but 10 times smaller," Minnich says.

He can find no natural reason for those differences and attributes the contrast to firefighting policies. U.S. agencies have a practice of putting out wildfires as quickly as possible. In Mexico they burn until they burn out.

California's fire suppression has created large swaths of dense, old-growth vegetation that hasn't burned in decades. When those areas do ignite, the devastation is wider spread. In an area that burns more often, the landscape forms patches of vegetation of varying ages. When an older, more combustible area burns, it eventually runs into a patch of less combustible younger growth that stops the fire's progress.

"In California, we're really good at putting out nine out of 10 fires," he says. "The survival of the fittest comes into play. That one 'fit' fire hammers the urban interfaces."

Minnich supports controlled burning as a way to clear out dense vegetation and in the urban interface, more stringent development policies.

"We need really vigorous zoning and land management to prevent people from building in those areas," he says. "We should treat chaparral as gasoline. No one in their right mind would build a house in a pool of gasoline."

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