Direct evidence of CO2 drawdown through enhanced weathering in soils

The ability of engineered enhanced weathering to impact atmospheric CO2 has been challenging to demonstrate due to the many processes occurring in soils and the short time span of current projects. Here we report the carbon balance in an Icelandic Histic/Gleyic Andosol that has received large quanti...

Full description

Bibliographic Details
Published in:Geochemical Perspectives Letters
Main Authors: Linke, Tobias, Oelkers, Eric, Möckel, Susanne Claudia, Gíslason, Sigurður Reynir
Other Authors: Jarðvísindastofnun (HÍ), Institute of Earth Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
Format: Article in Journal/Newspaper
Language:English
Published: European Association of Geochemistry 2024
Subjects:
Koltvíoxíð
Basalt
Veðrun
Jarðvegsrannsóknir
Basalt weathering
Carbon dioxide
Alkalinity generation
Iceland
Online Access:https://hdl.handle.net/20.500.11815/5001
https://doi.org/10.7185/geochemlet.2415
Description
Summary:The ability of engineered enhanced weathering to impact atmospheric CO2 has been challenging to demonstrate due to the many processes occurring in soils and the short time span of current projects. Here we report the carbon balance in an Icelandic Histic/Gleyic Andosol that has received large quantities of basaltic dust over 3300 years, providing opportunity to quantify the rates and long term consequences of enhanced weathering. The added basaltic dust has dissolved continuously since its deposition. The alkalinity of the soil waters is more than 10 times higher than in equivalent basalt dust-free soils. After accounting for oxidation and degassing when the soil waters are exposed to the atmosphere, the annual CO2 drawdown due to alkalinity generation is 0.17 t C ha−1 yr−1. This study validates the ability of fine grained mafic mineral addition to soils to attenuate increasing atmospheric CO2 by alkalinity export. Induced changes in soil organic carbon storage, however, likely dominate the net CO2 drawdown of enhanced weathering efforts. This project was funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675219, from Landsvirkjun under the project number 2456, and the Icelandic Center for Research (Rannís) on behalf of the Doctoral Student Fund of the Ministry for the Environment and Natural Resources under the grant No 218929-051. Additional financial support was received from the Research Fund of the University of Iceland and the Travel grant for doctoral students at the University of Iceland. This research was partly supported by research grant CRG9 2020 KAUST-UI. Peer Reviewed

Similar Items