Enhanced weathering for carbon dioxide removal: mechanistic advances, field evidence, and governance challenges

Achieving net-zero emissions will require scalable and durable carbon dioxide removal (CDR) alongside deep mitigation.Enhanced weathering (EW) has long been proposed as a land-based CDR option, but its real-world performance and governance readiness have remained uncertain.This review assesses whether EW has progressed from theoretical promise to a credible CDR pathway by synthesizing recent advances in field evidence, monitoring-reporting-verification (MRV), life-cycle performance, risk management, and policy frameworks.Multi-year field trials since 2022 provide direct geochemical and isotopic evidence of additional atmospheric CO 2 removal (0.01-2 t CO 2 ha -1 yr -1 ), often accompanied by agronomic co-benefits.Advances in multiproxy MRV, integrating radiocarbon, stable carbon, and strontium isotopes with hydrological measurements, now enable robust attribution of removals to contemporary atmospheric CO 2 , although high analytical costs constrain scalability.Life-cycle assessments indicate that EW can achieve net-negative outcomes at projected costs of ~US$100-150 t CO 2 -1 under low-carbon energy and optimized supply chains.We conclude that EW has transitioned from concept to field-validated CDR; its future impact will depend primarily on scalable MRV, standardized accounting, and equitable governance rather than further geochemical refinement.