Direct Measurement of Carbon Dioxide Removal Due to Enhanced Weathering

[Geoengineering News]

https://pubs.acs.org/doi/10.1021/acs.estlett.5c00441

Authors

Ella Milliken, Alex Woodley, Noah J. Planavsky

28 July 2025

Abstract

Enhanced weathering (EW) is a durable carbon removal strategy with clear pathways to produce significant global supply on a decadal scale. Despite increasing interest and investment in this process, there have been limited direct, continuous observations of instantaneous carbon removal rates from feedstock dissolution. In this study, we monitor a soybean plot amended with basalt in Southeast Virginia using continuous in-soil CO2 monitors, a method not previously applied in agricultural EW trials. We provide clear evidence of CO2 flux reduction within the soil profile, equivalent to 1.04 tCO2 ha–1 yr–1. This removal is most substantial in the growing season, following significant rain pulses. This work supports that direct, continuous gas-phase measurements could play an important role in advancing our understanding of biotic and abiotic influences on enhanced weathering rates while demonstrating enhanced weathering to be a rigorous, scalable method of durable carbon removal.

Source: ACS Publications