PNNL

Abstract

Land-based mitigation policies face uncertainty and challenges in their implementation and effectiveness due to institutional and sustainability factors. The consideration of such options differs in mitigation pathways produced by Integrated assessment models (IAMs), leading to compounded uncertainty and fundamental disparities in their findings. Here we produce pathways with varying strength and scope of land-based carbon mitigation policies using a widely-used IAM to investigate the integrated roles of land carbon storage and bioenergy with carbon capture and storage (BECCS). The results reveal a wide range of global cumulative end-of-century land-based carbon dioxide removal (CDR) estimates (100 to 700 GtCO2), with notable trade-offs between the two measures due to land competition. The range of land removal efficiency (7 to 18 tCO2ha-1yr-1) and agricultural price impacts (+5% to +60%) are consistent with the literature, emphasizing the need for improved modeling and greater attention to broader trade-offs when designing land-based mitigation policies.