The Giant Forest in Sequoia National Park is a wash of green and brown hues and undulating textures. But amidst that familiar landscape, something new has appeared.
Sequoia trees and historic park signage have been cloaked in a shiny layer of foil to deflect the flames from the expansive KNP Complex Fire. Foil has become an increasingly common wildfire defense for homes and natural wonders alike in California, as freakishly intense blazes maraud near (and sadly, through) towns and recreational sites.
The trees are being protected for good reason. General Sherman is the single largest living organism in the world. Standing in the shadow of the immense tree, even with a horde of summer tourists, is still an experience that can change your view of the world and relationship to nature.
But the unnatural intrusion of climate change has now put the tree and others in the Giant Forest in danger. Rising temperatures coupled with decades of forest mismanagement have made large, destructive wildfires more common and intense. Sequoias are no strangers to fire, but they’ve adapted to lower intensity burns that crawl along the ground, rather than the scorching ones of our new era.
The foil wrapped around General Sherman helps deflect some of the heat from the flames, essentially providing a more fail-safe version of sequoias’ thick, fire-adapted bark. The shiny stuff also blocks embers landing on the tree in another line of defense. It’s not your grocery store tinfoil, which, among other issues, would take ages to unspool and wrap around a tree that’s more than 36 feet (11 meters) wide. Rather, it’s a specialized type of foil, and we’ve reached out to the KNP Complex public affairs team to get more details on this material.
This isn’t the first time the shiny stuff has appeared in the woods this summer; It showed up notably around Lake Tahoe, where the Caldor Fire has raged in the communities on the outskirts of South Lake Tahoe. There were no monster trees to protect in the area that fire was burning, but there were plenty of homes. Firefighters wrapped some in foil, and the technique worked to save at least one house. The San Francisco Chronicle got some of the details:
It’s aluminum on the outside, woven threads of polyester and fiberglass inside, and laminated with a high-temperature adhesive, according to Dan Hirning, founder of Firezat, a San Diego company that sells the foil.
“It’s not tin foil,” he said. “It’s so perfectly engineered after all these years.”
Hirning told the outlet the inspiration for it came in 1988, when firefighters in Yellowstone National Park cut up their protective fire shelters—basically last-ditch protections firefighters carry in case they’re overrun by flames—and tacked them to a historic building in a remote section of the park before they fled the flames.
“They think that’s part of what saved them,” he said.
That fire ended up destroying 750,000 acres of the park, largely burning over lodgepole pine forests. The KNP Complex in Sequoia National Park is thankfully not that big, clocking in at more than 11,000 acres as of Friday.
But it is threatening trees that have been hit hard by climate change and are much rarer than the dime-a-dozen lodgepoles (no shade to lodgepole lovers, whoever you are). Last year’s Castle Fire burned in the park and destroyed 10% to 14% of the world’s entire sequoia population. The flames were so intense, and the winter that followed so dry, that a sequoia was found still smoldering in April.
In an effort to protect the trees currently under siege, fire crews have cleared debris from the forest floor and were planning controlled burns to essentially create more defensible space around the giants, some of which were saplings when Julius Ceasar was killed.
“We’re really prepared to attack that thing once it does get up into the Giant Forest,” Mark Garrett, a spokesperson for the firefighting operation, told the Los Angeles Times.
Indeed, the trees will need all the added protection they can get as fire conditions could prove challenging in the coming days.
“Good ventilation will favor fire growth. Westerly afternoon and evening winds of 15 to 25 mph with gusts to 40 mph will continue to surface over the wind prone mountain and desert areas through the middle of this week,” Inciweb, the clearinghouse for U.S. wildfire information, wrote in an update on Friday about the KNP Complex.
The foil is one way to preserve some of the most iconic sequoias from this fire. But it’s clear that a lot of work needs to be done, from more controlled burns to reducing carbon pollution, to ensure wrapping the trees like macabre Christmas presents isn’t an annual occurrence.
Update, 9/17/21, 4:58 p.m. ET: This post has been updated with more info about the foil as well as other preparations beyond the foil wrappings to protect the sequoias in the Giant Forest.