Climate change has made wildfires exponentially worse, and the deadly trend will only continue
On Monday afternoon, Craig Clements was one of the first outsiders allowed in to see what he calls “the vortex zone” at the Carr fire near Redding, California — a city of about 100,000 people, not far from the Oregon border. “It was pretty wild,” Clements, director of the Fire Weather Research Lab at San Jose State University, tells me by phone as he drives away from the site. His voice is a little shaky. Clements is a serious scientist who has been studying California wildfires for nearly 15 years. It takes a lot to spook him, but the Carr fire managed to do it. As of today, it has burned more than 100,000 acres, destroyed 1,000 structures and claimed six lives. It’s still burning.
The vortex zone is the mile-or-so square area of the fire where a terrifying fire tornado appeared last Thursday. Until the “firenado” emerged, firefighters considered the Carr fire a modest and predictable wildfire, one that demanded their full attention and posed real dangers to people living in the area, but one that they knew how to handle.
The firenado changed that in an instant. The wildfire became a spinning inferno that swept through the outskirts of Redding with ungodly speed and power. The fire was so hot and so intense that it manufactured its own weather, creating a giant cloud of hot smoke more than 10,000 feet high called a pyrocumulus, freaking out meteorologists and firefighters alike. “Full-on rotating convective column. Scary as hell,” tweeted Neil Lareau, assistant professor of atmospheric science at the University of Nevada at Reno, who was monitoring radar data and video images from the fire site. “I shudder to think about the destruction from flame and wind in there.”
On Monday, Clements had a look at that destruction. The force of the wind was so strong it had bent steel pipes around trees and blown all the topsoil off the land. Homes were burned into piles of rubble. Clements saw where four-year-old Emily Roberts, five-year-old James Roberts and their 70-year-old great-grandmother Melody Bledsoe died, wrapped in wet blankets. He visited the site where Redding firefighter Jeremy Stoke died the same night.
Although the fire has veered away from the most populated areas around Redding, the latest estimate is that it’s only 23 percent under control. And it’s only one of 13 wildfires burning in California right now, including the Ferguson fire in the central region of the state, which has burned 60,000 acres, killed two firefighters and forced the closure of Yosemite Valley.
These are on top of the devastating fires in Napa and Santa Rosa last year, which killed 42 people and caused more than $9 billion in damages, the costliest wildfires in California history. Four of the 10 most destructive fires in the state’s history have happened in the past 10 months.
On one level, these fires are entirely predictable. Scientists have been warning for decades that our warming climate will create more intense wildfire cycles, especially in mountainous regions like California. As heat rises, it sucks moisture out of plants, turning forests into stands of firewood and grassy valleys into combustion engines. (Even a child who plays with matches understands that dry things burn better than wet things.)
This year, Redding was dry as a tinderbox. It sits on a high, rugged plateau at the north end of California’s Central Valley. Mount Shasta, a spectacular extinct volcano, looms in the distance. Before the Carr fire erupted, Redding had two weeks of 100-degree-plus weather. “The moisture content in Northern California plants was really low, about 95 to 99 percent,” Clements says. “The fuels are primed, and it just takes the smallest thing to ignite them.”
I happened to visit the area in early July. The grass in the hills was so dry it felt like paper, and several times during the trip, I noticed plumes of smoke on the horizon. A big fire seemed inevitable. But nobody expected an inferno. Previous California wildfire catastrophes have all been driven by hot, dry, fierce winds. In Redding, the winds were essentially dead calm.
So what happened? Fire officials say the blaze was triggered by a spark from “mechanical vehicle failure” last Monday, July 23rd. It quickly spread through the hills and canyons around Whiskeytown Lake. These canyons, Clements says, have “gap winds,” which blow up through these passes and canyons and feed the fire. “When a big gust comes along, it creates a horizontal sheer,” Clements explains. “When that moves over the wildfire, it can create a kind of spinning column. Rotating columns are not rare in wildfires, especially in mountainous areas, but to be this strong is uncommon.”
Clements’ observations are reinforced by a new study from the National Center for Atmospheric Research, which tried to unravel the combustion dynamics of the King fire, which burned nearly 100,000 acres in California’s Sierra Nevada mountains in 2014. The study found that winds — both the localized kind related to topography and those created by the searing heat of the flames — were the reason the fire suddenly ran 15 miles up a steep canyon one afternoon.
What all this means is that big wildfires have the potential to be much more dynamic and destructive than scientists previously thought. And because local winds are difficult for meteorologists to measure at a distance, it also means big wildfires in mountainous areas may be much more difficult to predict than previously understood. In effect, a “firenado” like the one that erupted near Redding is a hot, deadly manifestation of chaos theory. It is Mother Nature saying to scientists, “You ain’t seen nothing yet.”
And for people living in a hot, crowded state like California, this is troubling news indeed. Risks can be reduced by stopping the suicidal practice of building in the fire-zone (60 percent of post-1990 homes have been built in areas designated as Wildland-Urban Interface), improving real-time fire mapping technology and electing a president and representatives in Congress who take climate change seriously. But right now, thanks in large part to our 200-year-long fossil-fuel binge, California is burning, and it’s not going to stop anytime soon.
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