Model-based Assessment of the CO2 Sequestration Potential of Coastal Ocean Alkalinization.

Feng, Yuming, Koeve, Wolfgang , Keller, David P. and Oschlies, Andreas (2017) Model-based Assessment of the CO2 Sequestration Potential of Coastal Ocean Alkalinization. Open Access Earth's Future, 5 (12). pp. 1252-1266. DOI 10.1002/2017EF000659.

[thumbnail of Feng_et_al-2017-Earth's_Future.pdf]
Feng_et_al-2017-Earth's_Future.pdf - Published Version
Available under License Creative Commons: Attribution 4.0.

Download (880kB) | Preview

Supplementary data:


The potential of Coastal Ocean Alkalinization (COA), a carbon dioxide removal (CDR) climate engineering strategy that chemically increases ocean carbon uptake and storage, is investigated with an Earth system model of intermediate complexity. The CDR potential and possible environmental side effects are estimated for various COA deployment scenarios, assuming olivine as the alkalinity source in ice-free coastal waters (about 8.6% of the global ocean's surface area), with dissolution rates being a function of grain size, ambient seawater temperature and pH. Our results indicate that for a large-enough olivine deployment of small-enough grain sizes (10 μm), atmospheric CO2 could be reduced by more than 800 GtC by the year 2100. However, COA with coarse olivine grains (1000 μm) has little CO2 sequestration potential on this time scale. Ambitious CDR with fine olivine grains would increase coastal aragonite saturation Ω to levels well beyond those that are currently observed. When imposing upper limits for aragonite saturation levels (Ωlim) in the grid boxes subject to COA (Ωlim = 3.4 and 9 chosen as examples), COA still has the potential to reduce atmospheric CO2 by 265 GtC (Ωlim=3.4) to 790 GtC (Ωlim=9) and increase ocean carbon storage by 290 Gt (Ωlim=3.4) to 913 Gt (Ωlim=9) by year 2100.

Document Type: Article
Keywords: Carbon Dioxide Removal (CDR), ocean alkalinization, climate change mitigation, Earth system modelling
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-BM Biogeochemical Modeling
OceanRep > The Future Ocean - Cluster of Excellence
Refereed: Yes
Open Access Journal?: Yes
Publisher: AGU (American Geophysical Union), Wiley
Related URLs:
Projects: SPP 1689, Future Ocean, BIOACID, Opendap
Date Deposited: 20 Dec 2017 10:50
Last Modified: 23 Nov 2020 11:43

Actions (login required)

View Item View Item