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 CO2 removal (≈0.01–2 t CO2 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 CO2, 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 CO2-1 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.