PNNL

Abstract

Limiting global warming to under 2°C would require stringent mitigation and likely additional carbon dioxide removal (CDR) efforts to compensate for hard-to-avoid emissions. Given its relatively low cost and potential co-benefits as a soil amendment, biochar has gained renewed attention in this context. Here, 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 . Based on our modeled scenarios, 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. We find that biochar’s deployment is dependent on potential crop yield gains and application rates, as well as the competition for resources with other CDR measures. In our scenarios, we find that biochar can serve as a competitive CDR strategy, especially at lower carbon prices at which bioenergy with carbon capture and storage is not economical.