A new study highlights a critical misunderstanding in how biochar is used to fight climate change and improve soils, warning that oversimplified claims could undermine both scientific progress and carbon markets.
Biochar, a charcoal-like material produced from organic waste, has gained global attention as a promising tool for removing carbon dioxide from the atmosphere while also improving soil health. But researchers now say these two benefits are often mistakenly treated as one and the same.
In a new perspective published in Biochar , scientists from Bangor University argue that carbon storage and soil benefits are fundamentally different functions of biochar, and optimizing one often reduces the other.
“Not all biochar is equal,” said lead author Robert W. Brown. “We need to be clear about what a specific biochar is designed to do, whether that is locking carbon away for centuries or improving soil fertility in the short term.”
Biochar is produced by heating biomass such as crop residues or wood under low-oxygen conditions. The temperature and raw materials used during production strongly influence the final properties of the biochar. High-temperature biochars tend to be more chemically stable, meaning they can store carbon in soils for hundreds to thousands of years. This makes them attractive for carbon removal strategies aimed at slowing climate change.
However, this stability comes at a cost. As production temperatures increase, biochar loses many of the surface functional groups that help it interact with soil. These functional groups are essential for retaining nutrients, holding water, and binding contaminants.
In contrast, biochars produced at lower temperatures retain more of these reactive surfaces, making them better suited for improving soil fertility and reducing pollution. But these biochars break down more quickly, limiting their long-term carbon storage potential.
This creates an inherent trade-off. Biochar designed for maximum carbon storage may deliver fewer agricultural benefits, while biochar optimized for soil improvement may not store carbon as long.
The researchers warn that failing to distinguish between these functions can lead to misleading claims, especially in carbon credit markets. Biochar currently plays a major role in voluntary carbon markets, accounting for a large share of delivered carbon removal credits worldwide. Yet many studies and projects do not clearly report key properties such as production conditions or chemical composition.
Without this information, it becomes difficult to assess how long carbon will remain stored or what additional environmental benefits can realistically be expected.
The study also highlights that the effectiveness of biochar depends heavily on where it is used. Degraded or tropical soils often show stronger improvements in crop productivity, while fertile soils in temperate regions may see limited benefits. This variability further complicates efforts to generalize biochar performance.
Encouragingly, the researchers note that some strategies can help bridge the gap between stability and functionality. For example, combining biochar with compost, fertilizers, or beneficial microbes can enhance its interaction with soil while maintaining its structural stability.
Still, these approaches introduce additional costs and complexities, and their outcomes depend on local conditions.
The authors call for a shift toward what they describe as “designer biochar,” where materials are tailored to specific applications rather than expected to deliver all benefits at once.
“Clearer communication and better reporting are essential,” Brown said. “If we want biochar to play a credible role in climate mitigation and sustainable agriculture, we must match the right material to the right purpose.”
As interest in carbon removal technologies continues to grow, the study underscores the importance of transparency and precision. Recognizing that biochar is not a one-size-fits-all solution could help ensure that both climate and agricultural goals are achieved more effectively.
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Journal Reference: Brown, R.W., Chadwick, D.R. & Jones, D.L. Clarifying the conflation of biochar carbon stability and its soil co-benefits. Biochar 8 , 67 (2026).
https://doi.org/10.1007/s42773-026-00581-4
About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
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News article
Clarifying the conflation of biochar carbon stability and its soil co-benefits
2-Mar-2026