Biochar: A Climate Solution?

Anyone reading about climate change will have heard any number of technologies hyped as “silver bullets” that will “solve” this crisis. These include solutions to fossil fuel dependency like nuclear energy, directly capturing carbon from the air, and drastic measures such as geoengineering.

The reality, of course, is that there are no “silver bullets.” Instead, we need to really understand how different solutions, working together, can support a process of lowering emissions, starting locally but with wider climate and ecosystem benefits. 

My father, Marshall Webb, who inspired Shelburne Farms to commit to beyond net zero emissions by removing more carbon than we emit by 2028, believed in working locally to demonstrate how reducing emissions was possible, and to do it in ways that aligned with other local needs. And though he was incredibly passionate about biochar, he knew it wasn’t—and isn’t—a “silver bullet.” It is a climate solution that can complement and expand the impact of everything the farm is already doing: grass-based dairy management, woodlands management to support high sequestration of carbon, and finding new energy solutions for the building and operations’ reliance on fossil fuels. 

What about biochar is so exciting? 

One reason Marshall was so interested in biochar is that he loved trees and soil. Biochar is made from, and can potentially benefit both. 

Biochar is a kind of charcoal. It is made by heating biomass, like tree trimmings or plants, in an oxygen-limited environment so that the carbon naturally stored in these plants is trapped in the biochar left behind, not released into the air. Once added to soil, biochar keeps that carbon stored for years (potentially hundreds or thousands of years). Biochar is known as a “negative emissions technology” because of this sequestration. 

There are additional co-benefits: research has shown it can improve soil quality, reduce fertilizer use, increase crop yields, remediate depleted soil and even help to stop run-off into lakes. This is because biochar’s porous surface area holds a lot of spaces for nutrients like nitrogen and phosphorus that might otherwise be released into soils and water. It is being tried in places that have problems with long-lasting chemicals like PFAS.

But biochar has its own carbon footprint that we need to understand more fully through a life cycle analysis. Some questions include:

1. What feedstock is being used? Was the biochar made from waste wood from the lumber industry? (potentially good) Cutting trees? (definitely bad)
2. What energy is required to process, chip, and transport the feedstock?
3. What energy are we using to use and spread it on soils?

At Shelburne Farms, when we buy biochar we look for producers that adhere to national and international standards. We have also made demonstration batches of biochar using our own waste wood and plants. 

Applying biochar toward our net zero goal and more

We’ve recently updated our baseline emissions data to help us better understand the role that each building and product (like our cheese) has on our net zero goal, and where solutions lie. Buildings and the dairy make up the biggest share of emissions to date. In buildings we can reduce emissions by heating and cooling with geothermal and decarbonised electricity instead of fossil fuels or biomass. At the dairy, where cows produce methane as they digest and decomposing manure produces methane and nitrous oxide, climate solutions are less tried-and-tested, so we have more work to do in understanding and applying them effectively. 

Applying a shipment of biochar to one of our dairy manure pits in August 2023.

Biochar is one piece of the puzzle we are trying to understand. Dairy manager Sam Dixon has used different types of biochar to reduce ammonia (and potentially methane) in the manure. In late May, we applied the latest batch from Standard Biocarbon to our manure pits.  At the Market Garden, Josh Carter has applied biochar to the chicken coop and compost. Beyond informally observing its impact on soil fertility, chicken health, or dairy odors, however, we seek R&D partners to truly measure and understand biochar’s role in our farm system, and in mitigating climate change. 

We’re most interested in the potential for biochar in:

• liquid manure to reduce odors and methane
• bedded pack for the chickens and cows for reducing nitrous oxide emissions while keeping animals healthy
• feed additives for reducing enteric emissions 
• creating educational opportunities about our biochar applications
• partnering or sharing information with others who are working on similar applications

Through actively sharing our own biochar story, and seeking research partners, we are part of what is needed on climate action today: proactively seeking solutions, debunking the myth of silver bullets, and bringing our learning to all audiences.

How does what we do on Shelburne Farms link to bigger impact?

Despite the promising potential of biochar highlighted in scientific research, the large-scale commercialization of high-value biochar products has been relatively slow and limited so far. We cannot expect farmers or others to adopt a nascent product that hasn’t been fully designed for high performance at the right costs for their needs. Still, we’ve found inspiration from an Irish project "Farm Zero C" and research by University of Wisconsin and many conversations with biochar networks, producers and experts.

Experts say a coordinated public-private effort is needed to advance the industry. By sharing what we do, we hope to be part of that effort, which continues to be hampered by:

• Lack of Established High-Value Markets: While research points to potential uses in everything from construction materials to animal feed, there is a lack of proven large-scale demand and established markets for these higher-value biochar products currently. The low-risk agricultural applications remain the primary commercial outlet.
• Pricing Challenges: Like any early stage industry, prices fetched by biochar for soil amendment and other agricultural uses may not be high enough to support rapid scaling of production capacity. 
• Regulatory Uncertainty: Regulatory uncertainty around biochar production, certification standards and approved applications in certain regions could be hindering commercialization of new products. Standards in Europe for food grade biochar exist, for instance, but aren’t applied across the US. 
• Need for Further R&D: While the research is promising, some argue further R&D may still be needed to optimize biochar production processes, characterize product properties, and validate performance for specific high-value applications before companies invest heavily.

Shelburne Farms can’t solve these challenges that face the biochar industry, but we can be part of communities that are working to overcome them and contribute our own learning. Shelburne Farms offers a unique opportunity to showcase the use of biochar as a negative carbon technology, in its own practices at the dairy and market garden. If you’re interested in what we’re doing, please get in touch.

Additional resources:

• US Biochar Initiative 
• US Biochar Coalition
• The European Biochar Industry Consortium
• "This simple farming technique can capture carbon for thousands of years," Grist Magazine, August 22, 2024