The journal Biochar recently published a study by Jennifer M. Rhymes and her colleagues that explores a new strategy for improving the effectiveness of carbon dioxide removal. The research investigates the synergy between two different climate mitigation methods: the application of biochar and the restoration of peatlands through rewetting. While biochar is well-known for its ability to store carbon for centuries, its long-term stability often depends on the specific conditions of the soil where it is placed. Most current carbon removal schemes focus on highly stable biochars that require intense heat during production. However, this high-heat process significantly reduces the amount of carbon captured from the original plant material. By placing biochar into the oxygen-poor environment of a rewetted peatland, the researchers found that even biochars typically considered less stable can remain preserved for very long periods.

Current carbon removal strategies face a significant trade-off between the stability of biochar and the amount of carbon that can be produced from a single batch of biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More. To ensure that carbon stays in the ground for hundreds of years, industrial standards typically require biochar to be produced at high temperatures, often exceeding 500 degrees Celsius. While this creates a very hardy material, it also causes a large portion of the carbon in the original wood or plant waste to be lost as gases and oils during the heating process. This inefficiency is a major problem because there is a limited global supply of biomass, and the biochar industry must compete for these resources with the energy and construction sectors. Furthermore, when biochar is applied to typical dry agricultural soils, the presence of oxygen and active microbes can cause up to 67 percent of the carbon in lower-stability biochar to be lost to the atmosphere within a century.

The proposed solution involves a strategic shift in both the production and the placement of biochar to maximize the total carbon stored. Instead of focusing only on making the most stable biochar possible, the researchers suggest producing biochar at lower temperatures, which allows more of the original carbon to be retained in the solid material. To prevent this less stable material from breaking down, it is applied to peatlands that have been restored to their natural, waterlogged state. In these saturated conditions, the lack of oxygen naturally suppresses the microbial activity that would otherwise decompose the biochar. This method essentially uses the environment to provide the stability that was previously sought through high-energy manufacturing. The study used data from established soil models to estimate that this combination could effectively break the traditional trade-off between production yield and long-term permanence.

The outcomes of this analysis show that rewetted peatlands can dramatically increase the viability of biochar as a large-scale climate tool. For lower-stability biochars, the increase in carbon retention over a 100-year period was approximately 40 percent when compared to dry reference soils. When looking at the entire system from the initial plant material to the final stored carbon, the use of lower-stability biochar in wet environments resulted in a 33 percent improvement in total carbon removal efficiency. This is a significant gain because it allows for more carbon to be sequestered using the same amount of limited biomass. Additionally, the study suggests that this approach could support the restoration of 50 million hectares of drained peatlands globally as outlined in international climate agreements. By integrating biochar into peatland infill or restoration projects, the industry can achieve higher sequestration rates while providing co-benefits like reduced methane emissions and improved water retention.

Source: Rhymes, J. M., McNamara, N. P., Jones, D. L., Albanito, F., & Evans, C. D. (2026). Harnessing peatland rewetting for effective biochar-based carbon dioxide removal. Biochar, 8(16).https://doi.org/10.1007/s42773-025-00524-5