U.S. Geological Survey research scientist Jon Keeley has studied the origin of western fires since 1910. He says that 95% of all fires originate with humans. "This is a people problem," Keeley told The Mercury News. "What's changing is not the fires themselves but the fact that we have more and more people at risk.
Keeley notes, for instance, that the number of homes threatened by wildfire in the Western U.S. surged from about 607,000 in 1940 to 6.7 million in 2010. That's a more than 1,000% rise. It's a basic matter of population impinging on wilderness areas.
Moreover, a 2017 study found that, since 1970 the number of fires burning 300 acres or more has actually declined. How can that be? Fires once raged across pristine forests and grasslands. But they had far fewer people or small towns in the way, as Keeley notes.
"The story can't be a simply that warming is increasing the numbers of wildfires in California because the number of fires is declining. And area burned has not been increasing either," University of Washington climatologist University of Washington Cliff Mass wrote last August, in response to that month's fires.
So, if not climate, what is the cause? The mismanagement of both state and federal forest lands. It's the triumph of "green" ideology over common sense.
Beginning in 1994, with the best of intentions, President Clinton put in place a plan to limit logging of old-growth trees to protect the endangered Spotted Owl in Western forests. Those moves pretty much ended what had been a policy of active management of fire threats in our national forests. Logging halted, the burnable fuel on the forest floor built up, and fires, while not more frequent, became more intense and threatening to nearby towns and homes.
"(Before 1994) mostly fuels were removed through logging, active management ? which they stopped ? and grazing," Bob Zybach, a reforestation consultant who has a Ph.D. in environmental science told the Daily Caller Foundation in an interview. "You take away logging, grazing and maintenance, and you get firebombs."
The Western Governors Association even warned about the mismanagement of our forest resources as far back as 2005 in a report:
"Over time the fire-prone forests that were not thinned, burn in uncharacteristically destructive wildfires, and the resulting loss of forest carbon is much greater than would occur if the forest had been thinned before fire moved through," the report warned. "In the long term, leaving forests overgrown and prone to unnaturally destructive wildfires means there will be significantly less biomass on the ground, and more greenhouse gases in the atmosphere."