As wildfires continue to devastate the world, American logging companies and the U.S. Forest Service are dousing burned forests with Roundup to mitigate future burning. As investigative journalist Nate Halverson put it, these entities are taking pages out of Big Tobacco's "secret" playbook to control the narrative about the safety of potent and excessive glyphosate application.

The Dixie Fire of 2021 burned nearly 1 million acres of Northern California, including Lassen National Forest. It was the largest single-source wildfire in the state's recorded history. The Park Fire of 2024 burned another 430,000 acres nearby.

The Lassen National Forest, found along part of the infamous Pacific Crest Trail, is among California's most heavily sprayed forest areas.

Halverson fixed up an old hunting cabin about a 30-minute drive from the forest. He investigated this downpour of Roundup on Lassen and reported for Mother Jones.

What once was an idyllic landscape is now a "moonscape," as he described it, even nearly five years after the Dixie Fire.

"No bees, no flowers — it's a virtual dead zone," he wrote, "where the only life consists of row upon row of manually planted, tightly packed conifer saplings, all less than a foot tall."

Despite the drive's distance, the Dixie Fire burned "perilously close" to his home and his neighbors'. So when the Forest Service notified the community that Lassen was to be part of an ambitious new wildfire recovery project, it was a relief. 

Workers would remove selected trees, cull low-growing plants, and set prescribed fires, as Indigenous people have done for millennia, to keep forests healthy and reduce the risk of megafires. The agency also would plant new trees where few had survived.

But a single word in this notification from the Forest Service gave Halverson pause: "herbicides."

Starting this spring, the Forest Service would spray glyphosate, better known by its brand name, Roundup, on nearly 1,000 acres of public land in Lassen to wipe out plants and shrubs that might compete with the newly replanted trees. The needles of these conifers allow them to tolerate the potent chemical.

Glyphosate is a controversial herbicide globally. The World Health Organization's cancer agency classified it as "probably carcinogenic to humans" in 2015. 

While glyphosate is now off-patent and found in dozens of products, Roundup remains the dominant brand using it as an active ingredient. It was produced by Monsanto until 2018, when Bayer acquired it. Monsanto has reached settlement agreements in nearly 100,000 lawsuits from people who say Roundup gave them cancer or other ailments, paying approximately $11 billion.

The Forest Service and private loggers defend the use of glyphosate as a means to help commercially attractive conifers, like pine and Douglas fir, rebound faster after fires and timber harvests. Glyphosate does so by killing deciduous trees, native shrubs, flowering plants, and anything else that might compete for water, nutrients, and sunlight. 

"A key rationale for spraying a disputed chemical in natural settings boils down to executives and regulators treating forests, including our national forests, as tree farms," Halverson wrote.

Halverson is not the only individual concerned. Neighbors and local business owners are among the choir of people who oppose the Forest Service's glyphosate application in Lassen. 

Joe and Jillian Van Meter own the Mill Creek Resort near Lassen. They are raising their three young daughters on the property. "It seems like it's poison that they're putting into the woods," Van Meter told Halverson. "This is our backyard. This is where my children play.

"We need work to be done, and so I want to see that work done," he added, referring to the thinning and replanting of trees in the area. "But I want it done without the use of toxic chemicals."

Alongside his colleague, Melissa Lewis, Halverson analyzed over five million spraying reports from California dating back to the 1990s. This data revealed that approximately 266,000 pounds of herbicide were applied in 2023 alone by various government and commercial entities. This is nearly five times what it was two decades ago.

Halverson obtained thousands of pages of additional records that detailed a secret campaign the company hatched in the late 1990s, reminiscent of the tactics used by Big Tobacco decades earlier. The plan? To counter public health concerns and convince government agencies to keep approving its multibillion-­dollar product, Halverson wrote. 

These documents show how Monsanto "orchestrated, financed, and even ghostwrote studies that were published in peer-reviewed scientific journals under the names of supposedly independent researchers," Halverson said. Papers that state and federal agencies have used to justify spraying Roundup where Americans hike, swim, fish, camp, hunt, and live.

Because of these well-orchestrated lies, the only potential human risk acknow­ledged in the Forest Service's assessment has to do with people unknowingly ingesting glyphosate after foraging for mushrooms and plants in recently sprayed areas.

This was a ploy by Monsanto "to manipulate the scientific conversation and thereby the regulatory conversation, and to persuade people of the safety of a product [when], in fact, there is significant scientific evidence to raise concern," said Naomi Oreskes, a co-author of "Merchants of Doubt" that explored how corporations deliberately distort science to influence policy.

Halverson even warned there is evidence the practice won't help in the long run, saying "they may be setting us up for more trouble down the road," as deciduous hardwoods like oak and aspen can slow a fire's progression and are less flammable than other trees.

"A densely packed commercial conifer forest like the one I saw taking shape near Chester is, according to a growing scientific consensus, a megafire waiting to happen."

Despite the availability of nonchemical alternatives to wildfire management and scientific evidence that Roundup harms endangered species, and knowing that its own assessment of human safety revolves around an industry-driven review paper, since retracted, the Forest Service plans to continue to dump Roundup on California's forests. 

Halverson's piece argued that if the practice were to expand, the rest of the U.S.'s forests may be at risk.

Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.