"Biochar soil amendment offers a viable method for carbon dioxide removal (#CDR), but assessing its effectiveness depend
s on the durability of biochar in soil. Current methodologies rely on the H/C ratio to estimate durability but often overlook environmental factors, leading to potential biases and undervaluation. Re-analysis suggests the "durability problem" stems from oversimplified definitions. Improved databases, field measurements, and deployment-aligned models are needed to enhance accuracy and project integrity."