| 27 Jan 2026
ARTEMIS version 1.0: A Reactive Transport Enhanced Rock Weathering Model with Coupled Soil Carbon and Nutrient Dynamics
Abstract. Enhanced rock weathering (ERW) is increasingly considered to be a promising carbon dioxide reduction (CDR) strategy, but carbon removal can be is difficult to verify with field measurements. Reactive transport models (RTMs) have the potential to shed light on the soil dynamics affecting CDR, and to quantify the timescales involved. Here, we present a new 1-D RTM representing all major processes affecting the chemistry of soils. These processes include nitrogen cycling kinetics, sorption and the choice of open or closed systems with respect to gas diffusion. We demonstrate this model’s utility with a detailed investigation examining the impact of those key ERW and soil processes on CDR and topsoil pH at a site in the United States Corn Belt. Given continued annual applications of a metabasalt for 55 years, results indicate a 20-year lag time to achieve 10 tCO2 ha−1 for CDR based on solute export in drainage water, with long-term topsoil pH (7.5–8.0) maintained by sorption. Topsoil pH would stabilise below the maximum recommended limit of 7.4 with triennial metabasalt treatments, but the lag time would double. Five-year model runs with four annual metabasalt treatments suggest doubled bicarbonate export in the absence of nitrogen kinetics due to reduced strong acid weathering. Calcite deposition in the upper soil occurs if the metabasalt is replaced with a pure CaSiO3 feedstock, reducing CDR efficiency. For a pure Mg2SiO4 feedstock, calcite deposition limits Mg export because Mg replaces exchangeable Ca on soil clay surfaces. Without sorption, calcite saturation maintains topsoil pH near 8 for all feedstocks under open system conditions. However, topsoil pH was unrealistically high (∼ 10) for the CaSiO3 feedstock with a closed system. With these model runs, we illustrate the process representation useful for predicting solute export through soils at individual field sites. Critically, we also discuss the limitations of this model and possibilities for development of the next generation of ERW models.
Competing interests: DJB has minority equity stakes in two companies aiming to help mitigate climate change (Future Forest and Undo), and is an advisory board member of The Carbon Community, a UK carbon removal charity.
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