CO₂ sequestration and soil improvement in enhanced rock weathering: A review from an experimental perspective

Abstract

Enhanced rock weathering (ERW) is an emerging negative emission technology (NET) with significant potential for mitigating climate change and improving soil health through the accelerated chemical weathering of silicate minerals. This study adopts a critical research approach to review existing ERW experiments, focusing on the mechanisms of soil improvement and CO₂ sequestration, as well as the economic costs and environmental risks associated with its large-scale implementation. The results demonstrate that while ERW effectively enhances soil pH and provides essential nutrients for crops, its CO₂ sequestration capacity is highly dependent on variables such as soil type, rock type, application rate, and particle size. Furthermore, the economic feasibility of ERW is challenged by high costs related to mining, grinding, and transportation, and environmental risks posed by the release of heavy metals like Ni and Cr during the weathering process. Notably, significant discrepancies exist between laboratory experiments and field applications, highlighting the need for extensive in-situ monitoring and adjustment of ERW practices. This study underscores the importance of optimizing ERW strategies to maximize CO₂ sequestration while minimizing environmental impacts. Future research should focus on long-term field experiments, understanding secondary mineral formation, and refining the application techniques to enhance the overall efficiency and sustainability of ERW. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.