When logging companies cut down trees to thin overcrowded forests, they are left with a costly headache: giant mounds of limbs and spindly trunks worth so little that it’s easier to burn them.
But they could turn this biomass trash into carbon-rich treasure, both making money and trapping much of the carbon dioxide that rises into the atmosphere from these blazing slash piles, according to new research.
In many parts of the arid western United States, companies could earn billions of dollars by simply burying the wood debris underground and selling carbon credits, according to research published today in Science Advances.
The new work shows that “pairing these two pathways together could enable more forest restoration as well as carbon storage,” said Sinéad Crotty, an ecologist and manager at the Carbon Containment Lab, a Connecticut-based nonprofit that studies ways to reduce greenhouse gas pollution.
The strategy is deceptively simple. Plants are the ultimate carbon capture device, sucking carbon dioxide from the atmosphere and storing it in wood and leaves. But the long-term fate of that carbon hinges on what happens when those plants are cut down or die.
Burn them, and much of it goes back into the atmosphere, where it contributes to global warming. Let them decay, and the same thing happens. But if you stick them underground and shield them from the air, much of that carbon should stay put. After all, that’s basically what happened with all that oil and coal we are now burning. It was once ancient vegetation buried under sediment.
While people are wrestling with the climate crisis, there is a simultaneous forest health emergency. Many western U.S. forests are overgrown and filled with flammable vegetation, thanks to a combination of dense forests that regrew after logging and decades of suppression of wildfire and Indigenous burning. Pair that with the current mega drought gripping much of the region and you have a recipe for the massive wildfires that blanket states in smoke this time of year.
Crotty and her collaborators wanted to see how viable it would be to tackle both the climate and forest problems by finding a revenue stream to help pay for forest thinning while simultaneously capturing some of the carbon inside the vegetation.
They compared the costs and carbon emissions from different scenarios: the conventional approach of burning the wood waste; burying it in a specially made landfill; burning it for energy and capturing the carbon rising from the smokestacks; letting it rot; or cooking it into a charcoal-like substance called biochar.
To make the calculations more realistic, the scientists considered factors that could affect the cost and effectiveness. They estimated the distance from forest thinning to sites where the wood could be buried or burned. They mapped variables such as rainfall that would influence how deep the wood needed to be buried to avoid rotting and emitting greenhouse gases.
The modeling revealed that in many cases, burying the vegetation made the most sense. Over a century, burning keeps just 4.5% of the carbon stored. Letting it rot is nearly as bad. Biochar stored 44% of the carbon. By contrast, burial in a special landfill captured 78% of the carbon, on par with the 81% from burning and carbon capture. With such carbon capture projects extremely rare, burial appears more realistic in the short term.
The financial math backed up these findings. Burning is the costliest, losing $49 for every ton of carbon dioxide due to expenses such as manpower and planning. If companies can sell carbon credits for $100 per metric ton—a common benchmark in the carbon credit world—burial would earn around $21 per ton, bioenergy would earn $12 and biochar would break even if the leftover char is sold.
With the federal government proposing to treat 3.5 million acres of forest this year, those cost differences add up. Rather than costing $3.1 billion to burn the leftovers, burial could store some 60 million tons of carbon dioxide and earn around $2 billion, the scientists found.
Some companies already see the possibility of spinning this wood waste into buried gold. One company, Graphyte, is turning wood into solid blocks, encasing them in plastic and burying them. It plans to open a plant in Arizona using wood from forest thinning. Colorado-based Woodcache is burying slash on a small scale, while Mast Reforestation is entombing dead trees left after wildfires.
Still, the researchers caution that burial won’t always be the right answer. Factors like soil conditions and rainfall can affect whether the carbon, once buried, will stay in the ground.
“In the wrong soil, digging a burial chamber can release more carbon than the wood could ever store,” cautioned Leah Clayton, the paper’s lead author and incoming Ph.D. student at Stanford University who previously worked at the carbon lab.
That puts a premium on detailed planning for individual sites.
“No single pathway is a silver bullet,” said Clayton. “But there are promising opportunities everywhere.”
Clayton, et. al. “Near-term, geospatial opportunity for biomass carbon storage to address the wildfire and climate crises.” Science Advances. Aug. 26, 2026.
Image: ©Anthropocene Magazine
