A Direct-Measurement Framework for Enhanced Rock Weathering

Enhanced mineralization (EM) offers a robust pathway for permanent carbon dioxide (CO₂) sequestration as dissolved inorganic carbon (DIC) through enhanced rock weathering (ERW), a process accelerated on farmland where CO₂ levels in soil pores exceed atmospheric concentrations. By mimicking natural weathering, ERW transforms rocks into secondary minerals, facilitating the stable storage of carbon in marine environments for up to 500,000 years. With mineral inventories estimated to sequester 35,000 Gt of CO₂ globally, ERW has significant scalability potential, with the U.S., China, and India each projected to capture about 0.5 Gt of CO₂ annually through farmland applications. ERW involves seven stages: quarrying, mineral transport, milling to enhance CO₂ reactivity, field application, and carbon capture, utilization, and sequestration (CCUS) through mineral weathering. While the initial stages emit CO₂—measurable by lifecycle analyses—the CCUS stage is complex to account for on individual fields, limiting ERW's inclusion in current carbon accounting frameworks. This methodology targets this critical step, drawing on U.S. farmland and federal data to quantify field-scale carbon removal and assess potential CO₂ losses, akin to monitoring hydrologic losses in subsurface carbon reservoirs. By providing a detailed approach for ERW deployment and monitoring, this methodology aims to overcome data and scale limitations, paving the way for large-scale, sustainable carbon sequestration on U.S. farmland.