Black Is The New Green: Exploring Biochar's Potential to Moderate Wildfire, Store Carbon

From almost any scenic viewpoint in Utah, the problem becomes readily apparent; among evergreen and aspen is a peppering of gray: standing dead trees.

Utah forests have had an especially tough couple of decades, and foresters are grappling to manage the remnants. An emerging tool — biochar — shows potential to benefit both forest and the greater ecosystem, according to USU forestry resources specialist Darren McAvoy.

Two-decades of megadrought have left forests vulnerable, allowing bark beetles to wheedle their way across the West. These harsh conditions have left behind an overwhelming mass of what foresters call “hazardous fuels” on public lands.

There is serious risk that the dry material could intensify wildfires, and much of it isn’t left to lie where it falls. It is instead piled and burned by hand — a practice that helps to mitigate the intensity of wildfire but adds to the problem of global warming through the release of copious amounts of smoke into the atmosphere.

Biochar has potential to both reduce the risk of wildfire on public lands and limit the amount of greenhouse gasses released when burning hazardous fuels, said McAvoy, from the Quinney College of Natural Resources.

Biochar is a type of charcoal produced by heating organic materials, such as wood or plant waste, in a low-oxygen environment, a process called pyrolysis. This process preserves from one-third to half of the carbon in the wood, compared to pile burning where all of the material is converted to smoke. The stable carbon left behind can be held in soil for hundreds of years under the right circumstances, and the product offers a host of benefits for soil health, water quality and soil productivity, McAvoy said.

When added as an amendment to soil, carbon stored as biochar can improve fertility and provide a stable source of carbon for soil microorganisms. It can also absorb pollutants, preventing them from leaching into groundwater or surface water and can improve soil structure and water retention, which can help plants grow faster.

The production of biochar is not without challenges. The most obvious on public land is the portability of the equipment, McAvoy said. At a recent public event, he and a team of biochar enthusiasts demonstrated the utility of small kilns, biochar production equipment that is more portable and easier to use in backcountry settings.

McAvoy himself designed a “big box” kiln, small enough to be hauled behind a truck. The dumpster-sized metal box is double-walled to hold in the heat and increase safety for people participating on site, said McAvoy, who heads the Utah Biomass Resource Group.

“As overwhelming as it may seem right now, with these advances we can get a handle on the problem of hazardous fuels,” McAvoy said. “And the biochar process shows incredible promise in that toolbox of solutions.”