Ringsby and Maher , in their letter published in Environmental Research Letters, challenge the current oversimplified metrics used to assess biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More durability for carbon dioxide removal (CDR). They argue that these metrics, which primarily rely on the molar H/C ratio, may undervalue the true potential of biochar for long-term carbon storage.  

The authors re-analyzed existing biochar incubation data and conducted case studies, revealing that current durability standards are biased towards certain feedstocks and fail to account for key environmental factors. They propose a series of recommendations to improve the accuracy of biochar CDR assessments, including the creation of representative distributions for feedstocks and environmental gradients, and the integration of in-field measurement protocols.   The findings suggest that the perceived “durability problem” of biochar may be an artifact of oversimplification. By adopting more nuanced and comprehensive assessment methods, we can better understand and harness the true potential of biochar for climate change mitigation.  

SOURCE : Ringsby, A. J., & Maher, K. (2025). Do oversimplified durability metrics undervalue biochar carbon dioxide removal? Environmental Research Letters, 20(3), 034001. http://DOI 10.1088/1748-9326/adac7b