Biochar is a carbon-rich, stable solid created by heating organic material, such as wood waste or agricultural residues, to high temperatures in the absence of oxygen. This process, called pyrolysis, converts the organic material into a type of charcoal that enhances soil fertility, boosts agricultural outputs and provides an effective method of carbon sequestration by storing carbon in a stable form that resists decomposition. The dual benefits of enhancing soil health and combating climate change position biochar as a promising tool for the future of carbon sequestration.
Biochar is made from biomass derived from a variety of organic feedstocks, including agricultural and forestry waste, and sometimes urban waste. The biomass is often dried and ground into small pieces for more uniform heating, then heated to between 300 and 700 degrees Celsius in an environment with very low oxygen levels.
This absence of oxygen prevents the biomass from igniting, allowing it to break down into three components: solid biochar, liquid bio-oil and syngas. Both bio-oil and syngas can be captured for use as fuel. The biochar is collected and can be further processed for use as a soil amendment.
Normally, when organic matter decomposes naturally or is combusted, the carbon it contains is released back into the atmosphere as carbon dioxide and methane. Converting biomass into biochar disrupts the carbon cycle. Instead of being released, the carbon is locked into a stable, solid form that is slow to decompose. The carbon it contains stays sequestered in the soil for centuries, depending on the environmental conditions.
Scientists can determine the amount of carbon sequestered in biochar by analyzing its carbon and hydrogen content and conducting tests to simulate its long-term stability in soil. This helps estimate how quickly the biochar might release carbon dioxide. Soil samples taken before and after applying biochar are also useful for tracking changes in soil carbon levels.
Biochar is versatile and its potential to contribute significantly to sustainable agriculture, environmental protection and climate change mitigation is difficult to overstate.
To start, adding biochar to soil not only enhances water and nutrient retention but can also reduce the need for synthetic fertilizers by improving nutrient availability for crops, improving yields, and reducing environmental impacts.
Biochar also modifies the soil's microbial communities, which can help reduce the emission of other potent greenhouse gasses from the soil. Biochar can also play a role in remediating contaminated soils by immobilizing pollutants and preventing their uptake by plants.
Because biochar can be produced from various organic wastes, including agricultural residues, manure and wood waste, it also provides a sustainable way to reduce waste volume while converting it into a useful product. Adding biochar to compost can also help reduce emissions of greenhouse gasses such as methane and nitrous oxide during the composting process and improve the final compost's quality as a soil amendment.
But wait, there’s more.
Beyond its role in improving crop yields and carbon sequestration, biochar can also be used as a feed additive to promote animal gut health. Adding biochar to livestock feed has been shown to improve overall animal health and growth rates and can help reduce methane emissions from cattle and other ruminants, further contributing to greenhouse gas reduction efforts.
Biochar is porous, making it an excellent material for filtering water for improving overall water quality. Its porosity allows it to adsorb and remove contaminants — such as heavy metals, pesticides and other pollutants from water — making it useful in both drinking water treatment and wastewater management. Biochar can also absorb odors and be used in various applications, including livestock bedding, landfill cover material, air filters, and even kitty litter.
The process of producing biochar also generates bio-oil and syngas, which can be used as renewable energy sources. This not only provides a way to generate energy from waste biomass but also reduces dependence on fossil fuels.
Biochar carbon removal is a powerful tool in the fight against climate change, but verifying the integrity of biochar claims remains essential for building trust in biochar carbon credits.
Certification agencies are key to verifying carbon sequestration claims, ensuring biochar production and application processes adhere to specific standards for carbon capture and environmental sustainability. Organizations and frameworks — including International Biochar Initiative, Verra’s Verified Carbon Standard, Climate Action Reserve, Carbon Standards International and Puro.earth — have established standards for biochar carbon projects, including specifications for its physical and chemical properties, to ensure the biochar is of high quality and suitable for carbon sequestration. These standards enable biochar project developers to measure, report and verify emissions reductions and carbon sequestration accurately.
These entities and their certification systems set up frameworks for evaluating the carbon sequestration capabilities of biochar, ensuring projects contribute to climate change mitigation and comply with environmental and social best practices. By securing certification, biochar producers and developers can share the carbon sequestration advantages of their products and initiatives with the public, further allowing them to attract investment and carbon credit revenues associated with their project.
Carbon credits can provide a significant financial boost to the biochar industry by allowing producers to earn tradable credits — each credit representing 1 ton of CO2 equivalent greenhouse gas emissions removed or avoided.
Selling carbon credits creates an extra revenue stream for biochar projects, helping to offset production and application costs to make them more financially viable and help attract sector investment. Moreover, carbon credits can also help create a market for the environmental benefits of biochar beyond its use in agriculture and industry, potentially boosting demand and leading to the creation of new facilities or expansion of existing ones.
These financial incentives can also help spur technological innovation within the biochar sector, including advancements in pyrolysis methods, more efficient use of feedstocks, improved carbon sequestration, and the exploration of new uses for biochar to maximize its carbon storage potential.
The process of generating carbon credits requires rigorous accounting and verification to validate the authenticity of carbon sequestration claims — and in recent years, the establishment of specific methodologies for biochar projects in carbon markets has enhanced transparency and trust in the sector. The integration of biochar into the carbon market may also encourage regulatory and policy support for biochar production and application, potentially including subsidies, tax breaks or usage requirements, fostering further growth in the industry.
The global nature of carbon credit markets also offers biochar projects worldwide participation and benefit opportunities, facilitating the spread of biochar technology and practices globally and encouraging international cooperation and knowledge sharing.
Biochar is a powerful tool for combating climate change and we expect market demand to grow, fueled in part by growing projected investment and demand for high quality carbon credits working together to offer financial incentives to biochar producers, drive technological progress, and promote the widespread adoption of its many uses.
Interested in learning more about carbon removal? Check out our Essential Carbon Capture Guides, including Enhanced Rock Weathering, Direct Air Capture 101 and Renewable Gas 101.
