Limits and CO₂ equilibration of near-coast alkalinity enhancement

Abstract Ω Arag CO 2 CO 2 Δ Δ ∘) global circulation model. We find that the sustainable OAE rate varies over 1–2 orders of magnitude between different coasts and exhibits complex patterns and non-local dependencies which vary from region to region. In general, OAE in areas of strong coastal currents enables the largest fluxes and depending on the direction of these currents, neighboring OAE sites can exhibit dependencies as far as 400 km or more. At these steady state fluxes most regional stretches of coastline are able to accommodate on the order of 10s to 100s of megatonnes of negative emissions within 300 km of the coast. We conclude that near-coastal OAE has the potential to scale globally to several Gt CO 2 - 1 CO 2 CO 2 uptake. Regions of significant downwelling (e.g., around Iceland) should be avoided by OAE deployments, as in such locations up to half of the CDR potential of OAE can be lost to bottom waters. The most ideal locations, reaching a molar uptake ratio of around 0.8, include North Madagascar, California, Brazil, Peru and locations close to the Southern Ocean such as Tasmania, Kerguelen and Patagonia, where the gas exchange appears to occur faster than the surface residence time. However, some locations (e.g., Hawaii) take significantly longer to equilibrate (up to 8–10 years) but can still eventually achieve high uptake ratios.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Limits and CO₂ equilibration of near-coast alkalinity enhancement ; volume:20 ; number:1 ; year:2023 ; pages:27-43 ; extent:17 ; Biogeosciences ; 20, Heft 1 (2023), 27-43 (gesamt 17)

Contributors, Places and Time

• Creator: He, Jing ; Tyka, Michael D.

Further information

• DOI: 10.5194/bg-20-27-2023
• URN: urn:nbn:de:101:1-2023010504145713637039
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 15.08.2025, 7:20 AM CEST