Potential CO2 removal from enhanced weathering by ecosystem responses to powdered rock

• Published in: Nature geoscience 2021-08, Vol.14 (8), p.545-549
• Main Authors: Goll, Daniel S., Ciais, Philippe, Amann, Thorben, Buermann, Wolfgang, Chang, Jinfeng, Eker, Sibel, Hartmann, Jens, Janssens, Ivan, Li, Wei, Obersteiner, Michael, Penuelas, Josep, Tanaka, Katsumasa, Vicca, Sara
• Format: Article
• Language: English
• Subjects: 639/4077/4057; 704/106/47/4113; 704/47/4113; Afforestation; Basalt; Carbon capture and storage; Carbon dioxide; Carbon dioxide removal; Carbon footprint; Carbon sequestration; Carbon sources; Climate change; Climate change mitigation; Deployment; Earth and Environmental Science; Earth Sciences; Earth System Sciences; Ecosystems; Emission analysis; Emissions; Feasibility studies; Fertility; Geochemistry; Geology; Geophysics/Geodesy; Land management; Land surface models; Ocean, Atmosphere; Paris Agreement; Perspective; Removal; Rocks; Sciences of the Universe; Soil; Soil amendment; Soil fertility; Soil improvement; Technology; Uptake; Weathering
• ISSN: 1752-0894; 1752-0908
• DOI: 10.1038/s41561-021-00798-x

Negative emission technologies underpin socioeconomic scenarios consistent with the Paris Agreement. Afforestation and bioenergy coupled with carbon dioxide (CO 2 ) capture and storage are the main land negative emission technologies proposed, but the range of nature-based solutions is wider. Here we explore soil amendment with powdered basalt in natural ecosystems. Basalt is an abundant rock resource, which reacts with CO 2 and removes it from the atmosphere. Besides, basalt improves soil fertility and thereby potentially enhances ecosystem carbon storage, rendering a global CO 2 removal of basalt substantially larger than previously suggested. As this is a fully developed technology that can be co-deployed in existing land systems, it is suited for rapid upscaling. Achieving sufficiently high net CO 2 removal will require upscaling of basalt mining, deploying systems in remote areas with a low carbon footprint and using energy from low-carbon sources. We argue that basalt soil amendment should be considered a prominent option when assessing land management options for mitigating climate change, but yet unknown side-effects, as well as limited data on field-scale deployment, need to be addressed first. The enhanced CO 2 uptake by vegetation in response to powdered rock should be considered in assessing the feasibility of enhanced weathering as a negative emission technology in mitigating climate change, suggest simulations of a land surface model.