2026: Isotopic Constraints on In Situ Carbonate Precipitation and the Control on Potential Enhanced Weathering Fluxes in an Upper Mississippi Watershed (EDF)
Enhanced rock weathering (EW) is proposed as a scalable carbon dioxide removal strategy, yet uncertainty remains regarding the fate of weathering-derived alkalinity within river networks. In agricultural watersheds developed in sedimentary basins, secondary carbonate precipitation can remove alkalinity and return CO₂ to the atmosphere, reducing net CO₂ removal efficiency. This project will apply calcium and strontium stable isotopes to empirically quantify carbonate precipitation and alkalinity loss in the Sangamon River–Lake Decatur system. Integrating isotope data with solute chemistry, alkalinity measurements, and high-frequency monitoring, this proof-of-concept study will provide data-driven constraints on carbonate “leakage” and inform robust measurement, monitoring, reporting, and verification of EW CO₂ removal.
Cornell: Louis Derry (Cornell Duffield Engineering / Earth and Atmospheric Sciences)
EDF: Emily Oldfield (Agricultural Soil Carbon Scientist)