Soil cation storage as a key control on the timescales of carbon dioxide removal through enhanced weathering

ABSTRACT Significant interest and capital are currently being channeled into techniques for durable carbon dioxide removal (CDR) from Earth’s atmosphere. A particular class of these approaches (referred to as enhanced weathering (EW)) seeks to modify the surface alkalinity budget to durably store CO2 as dissolved inorganic carbon species. Here, we use SCEPTER (a reaction- transport code designed to simulate EW in managed lands) to evaluate the throughput and storage timescales of anthropogenic alkalinity in agricultural soils. Through a series of alkalinity flux simulations, we explore the main controls on cation storage and export from ...