Biochar as a carbon dioxide removal strategy in integrated long-run climate scenarios

Limiting global warming to under 2°C would require stringent mitigation and likely additional carbon dioxide removals (CDR) to compensate for hard-to-avoid emissions. The relatively low cost and potential co-benefits of biochar as a soil amendment has gained attention in this context. We use a global multisector model to analyze biochar deployment in the context of energy system uses of biomass with CDR under different carbon price trajectories. We find that biochar can create an annual sink of up to 2.8 GtCO2, reducing global mean temperature increases by an additional 0.5-1.8% across scenarios by 2100 for a given carbon price path. In our scenarios, biochar’s deployment is dependent on potential crop yield gains and application rates, and the competition for resources with other CDR measures. We find that biochar can serve as a competitive CDR strategy, especially at lower carbon prices when bioenergy with carbon capture and storage is not economical.