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Cited by 13Marine Plankton and BiogeochemistryClimate Change and GeoengineeringCO2 Sequestration and Geologic Interactions

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The Verification Challenge of Marine Carbon Dioxide Removal

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Fennel, Katja·2026·Annual Review of Marine Science
DOI 10.1146/annurev-marine-032123-025717
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Abstract

It is increasingly obvious that, even when reaching net-zero emissions, removal of anthropogenic CO 2 from the atmosphere will be required. Some ocean-based removal technologies, while not proven for routine operation at scale, show promise. All of these rely on inducing a flux of CO 2 from the atmosphere into the ocean that is directly attributable to the removal intervention. Crucial for the economic viability of these technologies is the quantification of the cumulative net air-sea flux of CO 2 that an intervention can verifiably deliver. Because this flux is the difference between a realistic case with and a hypothetical case without intervention, it cannot be determined by observation alone-one must rely on a combination of informative observations and skillful models. Major uncertainties in the quantification of net CO 2 uptake include the removal of seawater with a dissolved inorganic carbon deficit from direct contact with the atmosphere and the inevitable rebalancing of carbon among Earth's mobile carbon pools.

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Metadata

Authors
Fennel, K.
Affiliations
Dalhousie University (CA)
Corresponding author
Fennel, Katja
ORCID
Fennel, Katja
Venue
Annual Review of Marine Science
Publisher
Annual Reviews
Published
2026-01-16
Volume
18
Issue
1
Pages
141-164
ISSN
  • 1941-0611 (ISSN-L)
  • 1941-1405
DOI
10.1146/annurev-marine-032123-025717
OpenAlex
W4412977212
Cited by
13
References
3
Citations by year
2026: 12
FWCI
1.82
Type
journal article
Language
en
Open access
Licence
Locations
  • Annual Review of Marine Science (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Topics
  • Physical Sciences › Earth and Planetary Sciences › Oceanography › Marine Plankton and Biogeochemistry
  • Physical Sciences › Environmental Science › Global and Planetary Change › Climate Change and Geoengineering
  • Physical Sciences › Environmental Science › Environmental Engineering › CO2 Sequestration and Geologic Interactions
Keywords
marine carbon dioxide removal, air-sea CO2 flux, ocean alkalinity enhancement, ocean fertilization
MeSH terms
Atmosphere, Carbon Dioxide, Oceans and Seas, Seawater

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