A recent study in Energy Research & Social Science by L. Campion, M.J. Spaniol, and T.P. Thomsen investigates the multifaceted uncertainties surrounding biochar carbon removal deployment using Denmark as a national case study. Biochar carbon removal, achieved by stabilizing biogenic carbon through biomass pyrolysis, serves as a prominent climate mitigation strategy designed to reduce greenhouse gas emissions while enhancing soil quality. However, despite ambitious national climate laws and substantial political commitments, large-scale implementation faces complex barriers. The authors combine semi-structured expert interviews, ranking methodologies, and participatory scenario modeling to map critical uncertainties and outline plausible long-term deployment pathways toward 2050.

The primary challenges identified center around regulatory fragmentation and economic instability rather than technical feasibility. Although pyrolysis technology is mature and capable of handling diverse domestic feedstocks like biogas residue fibers and sewage sludge, broader systemic variables complicate scaling. Specifically, the absence of harmonized national regulations governing biochar application in agricultural soils creates administrative bottlenecks and municipal-level inconsistencies. Furthermore, volatile carbon market pricing and delayed subsidy rollouts place financial strain on technology developers and stall long-term investment decisions.

To resolve these hurdles, the study maps out four distinct exploratory scenarios driven by varying carbon price levels and regulatory frameworks. Under favorable regulations and high carbon prices, biochar carbon removal evolves into a large-scale climate solution, albeit constrained over time by intense competition for sustainable biomass resources. Conversely, if high carbon prices coincide with restrictive agricultural regulations, biomass is largely diverted to bioenergy with carbon capture and storage, limiting biochar applications to non-agricultural sectors or international export markets. Under low carbon prices and restrictive rules, deployment narrows to specialized environmental solutions, such as sewage sludge remediation to eliminate contaminants like per- and polyfluoroalkyl substances. Finally, a low-price and favorable-regulation environment driven by energy and fertilizer shortages relies primarily on political subsidies and urgent agricultural demands to sustain growth.

The outcomes demonstrate that successful biochar deployment requires robust, no-regret actions, including compliance carbon markets, dedicated regulatory guidelines, and continuous field testing to validate agronomic performance. Ultimately, aligning economic incentives with transparent administrative frameworks will determine whether national biochar programs can successfully capture their intended climate and environmental benefits.

Source: Campion, L., Spaniol, M.J., & Thomsen, T.P. (2026). Pathways for biochar carbon removal: A national foresight study. Energy Research & Social Science, 141, 104988.