Temperature control on CO2 emissions from the weathering of sedimentary rocks

Soulet, Guillaume; Hilton, Robert G.; Garnett, Mark H.; Roylands, Tobias; Klotz, Sébastien; Croissant, Thomas; Dellinger, Mathieu; Le Bouteiller, Caroline

Abstract

Sedimentary rocks can release carbon dioxide (CO2) during the weathering of rock organic carbon and sulfide minerals. This sedimentary carbon could act as a feedback on Earth’s climate over millennial to geological timescales, yet the environmental controls on the CO2 release from rocks are poorly constrained. Here, we directly measure CO2 flux from weathering of sedimentary rocks over 2.5 years at the Draix-Bléone Critical Zone Observatory, France. Total CO2 fluxes approached values reported for soil respiration, with radiocarbon analysis confirming the CO2 source from rock organic carbon and carbonate. The measured CO2 fluxes varied seasonally, with summer fluxes five times larger than winter fluxes, and were positively correlated with temperature. The CO2 release from rock organic carbon oxidation increased by a factor of 2.2 when temperature increased by 10 °C. This temperature sensitivity is similar to that of degradation of recent-plant-derived organic matter in soils. Our flux measurements identify sedimentary-rock weathering as a positive feedback to warming, which may have operated throughout Earth’s history to force the surface carbon cycle.

Citation

Soulet, G., Hilton, R. G., Garnett, M. H., Roylands, T., Klotz, S., Croissant, T., Dellinger, M., & Le Bouteiller, C. (2021). Temperature control on CO2 emissions from the weathering of sedimentary rocks. Nature Geoscience, 14(9), 665-671. https://doi.org/10.1038/s41561-021-00805-1

• Journal Article Type: Article
• Acceptance Date: Jun 22, 2021
• Online Publication Date: Aug 30, 2021
• Publication Date: 2021-09
• Deposit Date: Jan 20, 2022
• Publicly Available Date: Mar 2, 2022
• Journal: Nature Geoscience
• Print ISSN: 1752-0894
• Electronic ISSN: 1752-0908
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 9
• Pages: 665-671
• DOI: https://doi.org/10.1038/s41561-021-00805-1
• Public URL: https://durham-repository.worktribe.com/output/1217423