Life Cycle Assessment in the Monitoring, Reporting, and Verification of Land-Based Carbon Dioxide Removal: Gaps and Opportunities.

Life cycle assessment (LCA) has been widely used to evaluate the carbon negativity and environmental impacts of carbon dioxide removal (CDR) pathways. Various monitoring, reporting, and verification (MRV) protocols have been developed to assess the carbon credits of CDR projects within voluntary and compliant carbon markets. Many MRV protocols incorporate life cycle thinking, LCA methods, and data. This perspective examined recent LCA studies and MRV protocols published by main carbon registries, focusing on four critical land-based CDR methods: bioenergy combined with carbon capture and storage, biochar, enhanced rock weathering, and afforestation and reforestation. We compared the carbon accounting and environmental impact assessment methods employed in these LCA studies and MRV protocols to identify their methodological similarities and differences. Our analysis reveals that the LCA community can support MRV protocols by providing critical insights into baselines, additionality, uncertainty, multifunctionality, environmental safeguards, holistic emission factors, and overlooked carbon pools. We recommend that future LCA research prioritize timing, permanence, scaling, and dynamic modeling for CDR. Addressing co-benefit and land use change impact assessment will further benefit both LCA and MRV development. Collaboration between the LCA and CDR communities is essential for developing robust frameworks to support carbon markets and policymaking.