A biogeochemical model of mineral-based ocean alkalinity enhancement

Impacts on the biological pump and ocean carbon uptake

Bibliographic Data

ID15547426
AuthorsMojtaba Fakhraee (0000-0002-2461-6374, Georgia Institute of Technology), Zijian Li (0000-0003-0924-4880, Georgia Institute of Technology), Noah J Planavsky (0000-0001-5849-8508, Whitney Museum of American Art), Christopher T Reinhard (0000-0002-2632-1027, Georgia Institute of Technology, corresponding author)
Year2023
Volume18
Issue4
Pages044047-044047
Publication date2023-04-01
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/acc9d4
OpenAlexW4362575059
LanguageEN
Citations received6
References cited64

Minimizing anthropogenic climate disruption in the coming century will likely require carbon dioxide removal (CDR) from Earth’s atmosphere in addition to deep and rapid cuts to greenhouse gas emissions. Ocean alkalinity enhancement—the modification of surface ocean chemistry to drive marine uptake of atmospheric CO 2 —is seen as a potentially significant component of ocean-based CDR portfolios. However, there has been limited mechanistic exploration of the large-scale CDR potential of mineral-based ocean alkalinity enhancement, potential bottlenecks in alkalinity release, and the biophysical impacts of alkaline mineral feedstocks on marine ecology and the marine biological carbon pump. Here we a series of biogeochemical models to evaluate the gross CDR potential and environmental impacts of ocean alkalinity enhancement using solid mineral feedstocks. We find that natural alkalinity sources—basalt and olivine—lead to very low CDR efficiency while strongly perturbing marine food quality and fecal pellet production by marine zooplankton. Artificial alkalinity sources—the synthetic metal oxides MgO and CaO—are potentially capable of significant CDR with reduced environmental impact, but their deployment at scale faces major challenges associated with substrate limitation and process CO 2 emissions during feedstock production. Taken together, our results highlight distinct challenges for ocean alkalinity enhancement as a CDR strategy and indicate that mineral-based ocean alkalinity enhancement should be pursued with caution

Alkalinity · Biogeochemical cycle · Biogeochemistry · Biological pump · Biology · Carbon cycle · Carbon dioxide · Carbon sequestration · Climate change · Ecosystem · Greenhouse gas · Ocean Acidification · Total inorganic carbon · Chemistry · CO2 Sequestration and Geologic Interactions · Environmental Science · Methane Hydrates and Related Phenomena · Ocean Acidification Effects and Responses · Ecology · Environmental Chemistry · Geology · Oceanography

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