Olagaray et al. (2026): Metal Accumulation Risks in Enhanced Rock Weathering: Risk Assessment Framework and Recommendations

Noemma Olagaray, Jonathan Edward Lambert and Tannis Thorlakson, IN: CDRXiv, https://doi.org/10.70212/cdrxiv.2026546.v1

Enhanced rock weathering (ERW) has emerged as a promising carbon dioxide removal (CDR) pathway that could mitigate climate change while improving agricultural soils. However, as the rocks used in ERW weather, metals posing an environmental safety risk can also be released. The nascency of ERW, complex dynamics of metal release and availability, and heterogeneity of global soil regulations make it difficult for practitioners to determine accumulation risks for many metals. To systematically evaluate these risks, the authors created the ERW Metal Accumulation Calculator (ERW-MAC), a conservative mass-balance model that combines global feedstock and soil datasets to estimate post-ERW deployment soil concentrations for 16 metals across a variety of baseline conditions, agricultural practices, and a range of basalt and peridotite application rates.

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