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From Field Trial to Carbon Register: Evidence Gaps and an Auditable Earth-Information Architecture for Verifiable Enhanced Weathering

Year: 2026
Type: preprint
Abstract: Enhanced rock weathering on managed land could become a meaningful carbon dioxide removal pathway before 2040, but only if removals can be verified. The difficulty is structural: durable removal is inferred, rather than observed directly at registry scale, from measurements that sample different parts of an open weathering system. We assembled a structured field-evidence catalog of 27 publicly reported terrestrial deployment programs in 13 countries and analyzed current registry protocols and public repository practices. Thirteen programs have multiple linked outputs, nine contain at least one unresolved-removal result, and only seven provide open processed data. These findings motivate an auditable Earth-information architecture linking raw evidence, mechanistic constraints, observation operators, calibrated uncertainty, spatial propagation, and registry decisions through explicit provenance. The framework separates gross geochemical uptake from net credited removal and distinguishes hard physical bounds from conditional bounds, reference states, and process predictions. We test it with a synthetic case and the published Illinois Energy Farm trial. Reproducing the Illinois dissolution operator from public data reveals strong block-to-block heterogeneity. When published dissolution and below-30-cm export estimates are placed on one stoichiometric basis, the probability that the export estimate exceeds dissolution is 0.89 under the Kantola uncertainty treatment but 0.39 under the Derry reanalysis. Without incorporating a downstream export observation, 30th-percentile creditable removal spans 1.1–5.5 t CO2 ha−1 over four years across the tested operator choices. The analysis shows that measurement compatibility, uncertainty structure, and unassimilated downstream observations can control credit issuance as strongly as the headline removal estimate. Plain Language Summary Spreading crushed volcanic rock on farmland speeds a natural reaction that has helped regulate Earth’s atmospheric carbon dioxide over geological time. As the rock dissolves, carbon moves through soil water, exchange sites, drainage, rivers, and eventually the ocean. No single field measurement follows that whole journey, so durable removal has to be inferred from partial measurements and models. We assembled a catalog of 27 publicly reported field programs in 13 countries and found that their results are difficult to combine because they measure different stages of the weathering pathway with uneven information about uncertainty and data access. We therefore developed a verification architecture that connects field evidence to physical constraints, models, uncertainty, and carbon-credit decisions through a traceable record. Applied to a well-studied Illinois trial, it shows that published estimates can conflict when placed on the same accounting basis, and that the amount eligible for credit depends strongly on downstream export data that have not yet been integrated with the soil-based estimates. A carbon claim should therefore show not only how much removal is estimated, but how the estimate was produced and how confidently it can be checked.
DOI: 10.22541/essoar.15009286/v1
Language: English
Open Access status: green
OpenAlex ID: W7214061978
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