Anthropogenically Stimulated Carbonate Dissolution in the Global Shelf Seafloor Is Potentially an Important and Fast Climate Feedback
van de Velde, S.J.; Vervoort, P.; Smith, R.O.; Law, C.S.; Currie, K. (2026). Anthropogenically Stimulated Carbonate Dissolution in the Global Shelf Seafloor Is Potentially an Important and Fast Climate Feedback. AGU Advances 7(1): e2025AV001865. https://dx.doi.org/10.1029/2025AV001865
In: AGU Advances. Wiley: United States. e-ISSN 2576-604X, more
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| Author keywords |
seafloor;alkalinity;carbon cycle;calcium carbonate;greenhouse-gas concentrations;dissolved inorganic carbon;ocean acidification;calcium-carbonate;permeable sediments;total alkalinity;atmospheric co2;coral-reefs;new-zealand;model |
| Authors | | Top |
- van de Velde, S.J., more
- Vervoort, P.
- Smith, R.O.
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| Abstract |
Carbonate mineral production and dissolution regulate atmospheric carbon dioxide (CO2) concentrations via modulation of the ocean alkalinity content. The anthropogenic rise in atmospheric CO2 reduces calcification rates and enhances calcium carbonate dissolution, which increases ocean alkalinity, counteracts acidification, and stimulates ocean CO2 uptake. However, carbonate dissolution takes place primarily in the deep ocean, so this feedback is slow, maintaining ocean CO2 uptake over millennial timescales. Here, we present evidence that seawater alkalinity on the continental shelf is increasing on annual-decadal timescales, at a rate that is orders of magnitude faster than the deep ocean feedback. Biogeochemical model analyses suggest this fast feedback results from calcium carbonate dissolution in the shelf seafloor driven by increasing atmospheric CO2 concentrations. Extrapolating these results to the global continental shelf suggests that shelf carbonate dissolution has been accelerating since the 1800s and may account for up to 10% of the missing similar to 0.3 Pg C yr-1 in ocean model carbon budgets. |
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