John Radke is a UC Berkeley associate professor who specializes in fire modeling. As part of his coursework, he likes to lead students into the winding thickets of Claremont Canyon in the Oakland hills, where the underbrush can reach chest-high, to show them the likely site of one of the next major East Bay fires.
“I was up there one day in the fall and you could hear the leaves cracking they were so dry,” Radke said. “Going in, my students said they were doing great – this is wonderful, we’re out in nature. Then after describing how the fire would burn, I asked them, ‘How do you guys feel?’ They said, ‘We can’t wait to get out of here. Because it’s a fire trap.’”
The funneled geography of the canyon and the vegetation that grows in it – vegetation that’s becoming drier each year in our warming climate – creates a natural chimney that’d be devastating in a fire. Winds blowing from the west would drive heat and radiation upslope in a ferocious purge. In Diablo conditions, with gusts surging over the ridge from the east, flames would pour downslope wiping out vegetation and homes – similar to what happened with the destructive 2018 Woolsey Fire in the L.A. region.
“I would not go and visit anybody during fire season there, because that is just waiting to go,” said Radke. “And when Claremont Canyon goes, I don’t know how you stop it.”
One way to try to stop it is to remove fuels. And that’s what UC Berkeley has done over the past month on its property as part of its Claremont Canyon Evacuation Support Project, largely funded by a $3.6 million Cal Fire grant. Travel into the upper reaches of Claremont Avenue and you’ll notice the land on either side of the road denuded as if swiped by a good-sized razor. Remaining are stumps, piles of wood chips, and in a pull-out off Grizzly Peak Boulevard, a graveyard of hundreds of stacked logs.
The idea is to keep the road clear during an evacuation caused by fire or landslide, said university spokeswoman Janet Gilmore.
“Numerous trees and abundant shrubby fuels were removed near Claremont Avenue (in a band of 100-foot width from pavement edge) that can fall across the road and block traffic,” she emailed, “or burn with such intensity that passage is prohibited during a wildfire…. Logs produced by the operations are being stored near Signpost 24, to be removed within the next few months, and will be gone prior to fire season.”
The university removed all the trees in the 100-foot buffer zones “regardless of species,” and shrubs and trees that burn intensely, “primarily, young eucalyptus, sapling Monterey pine and French broom seedlings,” according to a September memo prepared for Cal’s capital strategies department.
The project, which wrapped up last week, has created a “much-improved line of sight along the road, making even non-emergency travel safer,” said Gilmore. It also placed a couple of logs near Signpost 29 to “prevent ill-advised parking and unauthorized vehicular access to university property.”
The clearing of trees in the new 100-foot buffer zones is “spectacular,” said Jon Kaufman, president of the local nonprofit Claremont Canyon Conservancy. “I know trees are pretty and you want to keep them, and it’s a question of aesthetics and that’s important. But saving lives has to come first.”
Not everybody’s a fan. Dan Grassetti, managing director of the environmental group Hills Conservation Network (which successfully blocked UC Berkeley from using FEMA funds to cut down trees in 2016), is supportive of the university clearing underbrush along the road because of people doing “stupid stuff” like making campfires and torching cars. “Around here, the fires are all human-caused and they all start at ground level.”
Grassetti’s less enamored of what he called the “plainly excessive” chopping of large trees. “Removing the eucalyptus canopy is the worst thing you can do because in the absence of an overstory you create an environment that’s great for species with extreme fire risk,” he said. “This year or next, if it starts raining, we expect to see fields of poison hemlock, thistle, and broom. These are species that emerge when soil is disturbed and the shade canopy is removed…. Everyone agrees those species are a real big problem; they’re very ignitable and burn hot with a long flame length.”
There are also climate concerns. “When you cut down a 100-foot-tall eucalyptus or Monterey pine, what you’re doing is taking a large amount of biomass and causing it to gradually release whatever sequestered carbon it has,” Grassetti said. “So, you’ve lost a large amount of carbon sink, you’ve lost raptor habitat, you’ve destabilized the soil, and what you got from that is very little reduction in fire risk because most of that stuff [in large trees] isn’t going to burn.”
Falling eucalyptuses are a problem in the Bay Area – one killed a man on the UC Berkeley campus in 2019 – but Radke’s not convinced they’ll hinder evacuees on Claremont Boulevard. “You’d have to wait around for quite a while so it’s burning before it actually topples over and blocks egress,” he said. “And if you’re egressing at that point, you’ve made a huge, horrible mistake in your life. You’ve waited for the fire to get really raging.”
What’s more important is the cleared space on each side of the road, he said, which creates a fire break and could stop a wildfire from expanding into a true monster. “If Claremont Canyon catches fire, there’s probably not enough water to put it out,” he said.
“When a fire gets above a thousand BTUs, even live trees are susceptible to ignition. Firefighters are not the most effective thing to throw at a fire at that point because it will kill them. So, what you try to do is make it so the fire reaches an edge, and it can’t burn anything else.”
Update, 3 pm. The story has been updated to remove a quote from Gilmore about the erosion controls in the creekbed taken by UC Berkeley. The contractor is still removing debris from the creekbed.
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