Assessing the permanence and performance of enhanced weathering for carbon sequestration using geospatial modelling.

Lindsay Hornstein, Dobbs Ferry High SchoolF. Garrett Boudinot and Benjamin Houlton, Dept of Ecology and EvolutionaryBiology, Cornell UniversityAssessing the permanence and performance of enhanced weathering for carbonsequestration using geospatial modelling Enhanced silicate rock weathering (ERW) has the potential to drive carbon dioxideremoval (CDR) across a wide range of landscapes, including croplands, through theconversion of atmospheric CO2 to the water-soluble bicarbonate (HCO3) or solidmineral carbonate (e.g., CaCO3) in soils and soil waters. While models and trials havedemonstrated the capacity for ERW to sequester carbon, potentially at a gigatonne-scale globally, questions remain regarding the downstream fate and permanence ofcarbon following conversion to bicarbonate and carbonate. Integratinggeospatial mapping, field data from ERW trials in New York, and existing nationalsoil and hydrologic databases, we develop a computational method to quantitativelyassess the impact of soil chemistry and soil water transport on the fate of bicarbonateto reveal the land-to-water transfer of ERW products on a regional scale. We showhow these methods can help trace the impacts of ERW, and can facilitate strategicERW deployment for optimal CDR outcomes. We will discuss the environmental,political, and economic implications of such modelling approaches, related to theirability to assess the long-term impact of ERW in croplands to facilitate long-termCDR.