Articles | Volume 19, issue 15
https://doi.org/10.5194/bg-19-3537-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-19-3537-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Aug 2022
Research article |
| 01 Aug 2022
| 01 Aug 2022
Ocean alkalinity enhancement – avoiding runaway CaCO3 precipitation during quick and hydrated lime dissolution
Charly A. Moras
CORRESPONDING AUTHOR
Faculty of Science and Engineering, Southern Cross University,
Lismore, NSW, Australia
Lennart T. Bach
Ecology & Biodiversity, Institute for Marine and Antarctic Studies,
University of Tasmania, Hobart, TAS, Australia
Tyler Cyronak
Department of Marine and Environmental Sciences, Nova Southeastern
University, Fort Lauderdale, FL, USA
Renaud Joannes-Boyau
Faculty of Science and Engineering, Southern Cross University,
Lismore, NSW, Australia
Kai G. Schulz
Faculty of Science and Engineering, Southern Cross University,
Lismore, NSW, Australia
Related authors
Niels Suitner, Jens Hartmann, Selene Varliero, Giulia Faucher, Philipp Suessle, and Charly A. Moras
EGUsphere, https://doi.org/10.5194/egusphere-2025-381, https://doi.org/10.5194/egusphere-2025-381, 2025
Short summary
Short summary
Alkalinity leakage limits the efficiency of ocean alkalinity enhancement. Drivers of this process remain unquantified, restricting accurate assessments. The induced runaway process can be modeled using surface area and aragonite oversaturation as key factors. This study proposes a framework for improving predictability of alkalinity loss due to runaway precipitation, emphasizing the need for field experiments to validate theoretical models concerning dilution and particle sinking processes.
Julieta Schneider, Ulf Riebesell, Charly André Moras, Laura Marín-Samper, Leila Kittu, Joaquín Ortíz-Cortes, and Kai George Schulz
EGUsphere, https://doi.org/10.5194/egusphere-2025-524, https://doi.org/10.5194/egusphere-2025-524, 2025
Short summary
Short summary
Ocean Alkalinity Enhancement (OAE) is an approach to sequester additional atmospheric CO2 in the ocean and may alleviate ocean acidification. A large-scale mesocosm experiment in Norway tested Ca- and Si-based OAE, increasing total alkalinity (TA) by 0–600 µmol kg-1 and measuring CO2 gas exchange. While TA remained stable, we found mineral-type and/or pCO2/pH effects on coccolithophorid calcification, net community production and zooplankton respiration, providing insights for future OAE trials.
Niels Suitner, Giulia Faucher, Carl Lim, Julieta Schneider, Charly A. Moras, Ulf Riebesell, and Jens Hartmann
Biogeosciences, 21, 4587–4604, https://doi.org/10.5194/bg-21-4587-2024, https://doi.org/10.5194/bg-21-4587-2024, 2024
Short summary
Short summary
Recent studies described the precipitation of carbonates as a result of alkalinity enhancement in seawater, which could adversely affect the carbon sequestration potential of ocean alkalinity enhancement (OAE) approaches. By conducting experiments in natural seawater, this study observed uniform patterns during the triggered runaway carbonate precipitation, which allow the prediction of safe and efficient local application levels of OAE scenarios.
Charly A. Moras, Tyler Cyronak, Lennart T. Bach, Renaud Joannes-Boyau, and Kai G. Schulz
Biogeosciences, 21, 3463–3475, https://doi.org/10.5194/bg-21-3463-2024, https://doi.org/10.5194/bg-21-3463-2024, 2024
Short summary
Short summary
We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain sizes dissolved faster but calcium carbonate precipitated earlier, suggesting that medium grain sizes are optimal for kinetics.
Falilu Adekunbi, Michaël Grelaud, Gerald Langer, Lucian Chukwu, Marta Álvarez, Shakirudeen Odunuga, Kai George Schulz, and Patrizia Ziveri
EGUsphere, https://doi.org/10.5194/egusphere-2025-3201, https://doi.org/10.5194/egusphere-2025-3201, 2025
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
This study is the first to explore seasonal changes in coccolithophores, microscopic algae important for ocean life and the carbon cycle, off the coast of Nigeria. Their abundance and diversity increased during the rainy season, driven by shifts in the Intertropical Convergence Zone. Despite regional differences, these coastal communities show patterns similar to other parts of the world, revealing possible shared environmental pressures.
Niels Suitner, Jens Hartmann, Selene Varliero, Giulia Faucher, Philipp Suessle, and Charly A. Moras
EGUsphere, https://doi.org/10.5194/egusphere-2025-381, https://doi.org/10.5194/egusphere-2025-381, 2025
Short summary
Short summary
Alkalinity leakage limits the efficiency of ocean alkalinity enhancement. Drivers of this process remain unquantified, restricting accurate assessments. The induced runaway process can be modeled using surface area and aragonite oversaturation as key factors. This study proposes a framework for improving predictability of alkalinity loss due to runaway precipitation, emphasizing the need for field experiments to validate theoretical models concerning dilution and particle sinking processes.
Julieta Schneider, Ulf Riebesell, Charly André Moras, Laura Marín-Samper, Leila Kittu, Joaquín Ortíz-Cortes, and Kai George Schulz
EGUsphere, https://doi.org/10.5194/egusphere-2025-524, https://doi.org/10.5194/egusphere-2025-524, 2025
Short summary
Short summary
Ocean Alkalinity Enhancement (OAE) is an approach to sequester additional atmospheric CO2 in the ocean and may alleviate ocean acidification. A large-scale mesocosm experiment in Norway tested Ca- and Si-based OAE, increasing total alkalinity (TA) by 0–600 µmol kg-1 and measuring CO2 gas exchange. While TA remained stable, we found mineral-type and/or pCO2/pH effects on coccolithophorid calcification, net community production and zooplankton respiration, providing insights for future OAE trials.
Niels Suitner, Giulia Faucher, Carl Lim, Julieta Schneider, Charly A. Moras, Ulf Riebesell, and Jens Hartmann
Biogeosciences, 21, 4587–4604, https://doi.org/10.5194/bg-21-4587-2024, https://doi.org/10.5194/bg-21-4587-2024, 2024
Short summary
Short summary
Recent studies described the precipitation of carbonates as a result of alkalinity enhancement in seawater, which could adversely affect the carbon sequestration potential of ocean alkalinity enhancement (OAE) approaches. By conducting experiments in natural seawater, this study observed uniform patterns during the triggered runaway carbonate precipitation, which allow the prediction of safe and efficient local application levels of OAE scenarios.
Sebastian I. Cantarero, Edgart Flores, Harry Allbrook, Paulina Aguayo, Cristian A. Vargas, John E. Tamanaha, J. Bentley C. Scholz, Lennart T. Bach, Carolin R. Löscher, Ulf Riebesell, Balaji Rajagopalan, Nadia Dildar, and Julio Sepúlveda
Biogeosciences, 21, 3927–3958, https://doi.org/10.5194/bg-21-3927-2024, https://doi.org/10.5194/bg-21-3927-2024, 2024
Short summary
Short summary
Our study explores lipid remodeling in response to environmental stress, specifically how cell membrane chemistry changes. We focus on intact polar lipids in a phytoplankton community exposed to diverse stressors in a mesocosm experiment. The observed remodeling indicates acyl chain recycling for energy storage in intact polar lipids during stress, reallocating resources based on varying growth conditions. This understanding is essential to grasp the system's impact on cellular pools.
Lennart Thomas Bach, Aaron James Ferderer, Julie LaRoche, and Kai Georg Schulz
Biogeosciences, 21, 3665–3676, https://doi.org/10.5194/bg-21-3665-2024, https://doi.org/10.5194/bg-21-3665-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is an emerging marine CO2 removal method, but its environmental effects are insufficiently understood. The OAE Pelagic Impact Intercomparison Project (OAEPIIP) provides funding for a standardized and globally replicated microcosm experiment to study the effects of OAE on plankton communities. Here, we provide a detailed manual for the OAEPIIP experiment. We expect OAEPIIP to help build scientific consensus on the effects of OAE on plankton.
Charly A. Moras, Tyler Cyronak, Lennart T. Bach, Renaud Joannes-Boyau, and Kai G. Schulz
Biogeosciences, 21, 3463–3475, https://doi.org/10.5194/bg-21-3463-2024, https://doi.org/10.5194/bg-21-3463-2024, 2024
Short summary
Short summary
We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain sizes dissolved faster but calcium carbonate precipitated earlier, suggesting that medium grain sizes are optimal for kinetics.
Aaron Ferderer, Kai G. Schulz, Ulf Riebesell, Kirralee G. Baker, Zanna Chase, and Lennart T. Bach
Biogeosciences, 21, 2777–2794, https://doi.org/10.5194/bg-21-2777-2024, https://doi.org/10.5194/bg-21-2777-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a promising method of atmospheric carbon removal; however, its ecological impacts remain largely unknown. We assessed the effects of simulated silicate- and calcium-based mineral OAE on diatom silicification. We found that increased silicate concentrations from silicate-based OAE increased diatom silicification. In contrast, the enhancement of alkalinity had no effect on community silicification and minimal effects on the silicification of different genera.
Jiaying A. Guo, Robert F. Strzepek, Kerrie M. Swadling, Ashley T. Townsend, and Lennart T. Bach
Biogeosciences, 21, 2335–2354, https://doi.org/10.5194/bg-21-2335-2024, https://doi.org/10.5194/bg-21-2335-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement aims to increase atmospheric CO2 sequestration by adding alkaline materials to the ocean. We assessed the environmental effects of olivine and steel slag powder on coastal plankton. Overall, slag is more efficient than olivine in releasing total alkalinity and, thus, in its ability to sequester CO2. Slag also had less environmental effect on the enclosed plankton communities when considering its higher CO2 removal potential based on this 3-week experiment.
Lennart Thomas Bach
Biogeosciences, 21, 261–277, https://doi.org/10.5194/bg-21-261-2024, https://doi.org/10.5194/bg-21-261-2024, 2024
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a widely considered marine carbon dioxide removal method. OAE aims to accelerate chemical rock weathering, which is a natural process that slowly sequesters atmospheric carbon dioxide. This study shows that the addition of anthropogenic alkalinity via OAE can reduce the natural release of alkalinity and, therefore, reduce the efficiency of OAE for climate mitigation. However, the additionality problem could be mitigated via a variety of activities.
David T. Ho, Laurent Bopp, Jaime B. Palter, Matthew C. Long, Philip W. Boyd, Griet Neukermans, and Lennart T. Bach
State Planet, 2-oae2023, 12, https://doi.org/10.5194/sp-2-oae2023-12-2023, https://doi.org/10.5194/sp-2-oae2023-12-2023, 2023
Short summary
Short summary
Monitoring, reporting, and verification (MRV) refers to the multistep process to quantify the amount of carbon dioxide removed by a carbon dioxide removal (CDR) activity. Here, we make recommendations for MRV for Ocean Alkalinity Enhancement (OAE) research, arguing that it has an obligation for comprehensiveness, reproducibility, and transparency, as it may become the foundation for assessing large-scale deployment. Both observations and numerical simulations will be needed for MRV.
Tyler Cyronak, Rebecca Albright, and Lennart T. Bach
State Planet, 2-oae2023, 7, https://doi.org/10.5194/sp-2-oae2023-7-2023, https://doi.org/10.5194/sp-2-oae2023-7-2023, 2023
Short summary
Short summary
Ocean alkalinity enhancement (OAE) is a marine carbon dioxide removal (CDR) approach. Publicly funded research projects have begun, and philanthropic funding and start-ups are collectively pushing the field forward. This rapid progress in research activities has created an urgent need to learn if and how OAE can work at scale. This chapter of the Guide to Best Practices in Ocean Alkalinity Enhancement Research focuses on field experiments.
Kai G. Schulz, Lennart T. Bach, and Andrew G. Dickson
State Planet, 2-oae2023, 2, https://doi.org/10.5194/sp-2-oae2023-2-2023, https://doi.org/10.5194/sp-2-oae2023-2-2023, 2023
Short summary
Short summary
Ocean alkalinity enhancement is a promising approach for long-term anthropogenic carbon dioxide sequestration, required to avoid catastrophic climate change. In this chapter we describe its impacts on seawater carbonate chemistry speciation and highlight pitfalls that need to be avoided during sampling, storage, measurements, and calculations.
Andreas Oschlies, Lennart T. Bach, Rosalind E. M. Rickaby, Terre Satterfield, Romany Webb, and Jean-Pierre Gattuso
State Planet, 2-oae2023, 1, https://doi.org/10.5194/sp-2-oae2023-1-2023, https://doi.org/10.5194/sp-2-oae2023-1-2023, 2023
Short summary
Short summary
Reaching promised climate targets will require the deployment of carbon dioxide removal (CDR). Marine CDR options receive more and more interest. Based on idealized theoretical studies, ocean alkalinity enhancement (OAE) appears as a promising marine CDR method. We provide an overview on the current situation of developing OAE as a marine CDR method and describe the history that has led to the creation of the OAE research best practice guide.
Moritz Baumann, Allanah Joy Paul, Jan Taucher, Lennart Thomas Bach, Silvan Goldenberg, Paul Stange, Fabrizio Minutolo, and Ulf Riebesell
Biogeosciences, 20, 2595–2612, https://doi.org/10.5194/bg-20-2595-2023, https://doi.org/10.5194/bg-20-2595-2023, 2023
Short summary
Short summary
The sinking velocity of marine particles affects how much atmospheric CO2 is stored inside our oceans. We measured particle sinking velocities in the Peruvian upwelling system and assessed their physical and biochemical drivers. We found that sinking velocity was mainly influenced by particle size and porosity, while ballasting minerals played only a minor role. Our findings help us to better understand the particle sinking dynamics in this highly productive marine system.
Kristian Spilling, Jonna Piiparinen, Eric P. Achterberg, Javier Arístegui, Lennart T. Bach, Maria T. Camarena-Gómez, Elisabeth von der Esch, Martin A. Fischer, Markel Gómez-Letona, Nauzet Hernández-Hernández, Judith Meyer, Ruth A. Schmitz, and Ulf Riebesell
Biogeosciences, 20, 1605–1619, https://doi.org/10.5194/bg-20-1605-2023, https://doi.org/10.5194/bg-20-1605-2023, 2023
Short summary
Short summary
We carried out an enclosure experiment using surface water off Peru with different additions of oxygen minimum zone water. In this paper, we report on enzyme activity and provide data on the decomposition of organic matter. We found very high activity with respect to an enzyme breaking down protein, suggesting that this is important for nutrient recycling both at present and in the future ocean.
Allanah Joy Paul, Lennart Thomas Bach, Javier Arístegui, Elisabeth von der Esch, Nauzet Hernández-Hernández, Jonna Piiparinen, Laura Ramajo, Kristian Spilling, and Ulf Riebesell
Biogeosciences, 19, 5911–5926, https://doi.org/10.5194/bg-19-5911-2022, https://doi.org/10.5194/bg-19-5911-2022, 2022
Short summary
Short summary
We investigated how different deep water chemistry and biology modulate the response of surface phytoplankton communities to upwelling in the Peruvian coastal zone. Our results show that the most influential drivers were the ratio of inorganic nutrients (N : P) and the microbial community present in upwelling source water. These led to unexpected and variable development in the phytoplankton assemblage that could not be predicted by the amount of inorganic nutrients alone.
Aaron Ferderer, Zanna Chase, Fraser Kennedy, Kai G. Schulz, and Lennart T. Bach
Biogeosciences, 19, 5375–5399, https://doi.org/10.5194/bg-19-5375-2022, https://doi.org/10.5194/bg-19-5375-2022, 2022
Short summary
Short summary
Ocean alkalinity enhancement has the capacity to remove vast quantities of carbon from the atmosphere, but its effect on marine ecosystems is largely unknown. We assessed the effect of increased alkalinity on a coastal phytoplankton community when seawater was equilibrated and not equilibrated with atmospheric CO2. We found that the phytoplankton community was moderately affected by increased alkalinity and equilibration with atmospheric CO2 had little influence on this effect.
Jiaying Abby Guo, Robert Strzepek, Anusuya Willis, Aaron Ferderer, and Lennart Thomas Bach
Biogeosciences, 19, 3683–3697, https://doi.org/10.5194/bg-19-3683-2022, https://doi.org/10.5194/bg-19-3683-2022, 2022
Short summary
Short summary
Ocean alkalinity enhancement is a CO2 removal method with significant potential, but it can lead to a perturbation of the ocean with trace metals such as nickel. This study tested the effect of increasing nickel concentrations on phytoplankton growth and photosynthesis. We found that the response to nickel varied across the 11 phytoplankton species tested here, but the majority were rather insensitive. We note, however, that responses may be different under other experimental conditions.
Shao-Min Chen, Ulf Riebesell, Kai G. Schulz, Elisabeth von der Esch, Eric P. Achterberg, and Lennart T. Bach
Biogeosciences, 19, 295–312, https://doi.org/10.5194/bg-19-295-2022, https://doi.org/10.5194/bg-19-295-2022, 2022
Short summary
Short summary
Oxygen minimum zones in the ocean are characterized by enhanced carbon dioxide (CO2) levels and are being further acidified by increasing anthropogenic atmospheric CO2. Here we report CO2 system measurements in a mesocosm study offshore Peru during a rare coastal El Niño event to investigate how CO2 dynamics may respond to ongoing ocean deoxygenation. Our observations show that nitrogen limitation, productivity, and plankton community shift play an important role in driving the CO2 dynamics.
Kai G. Schulz, Eric P. Achterberg, Javier Arístegui, Lennart T. Bach, Isabel Baños, Tim Boxhammer, Dirk Erler, Maricarmen Igarza, Verena Kalter, Andrea Ludwig, Carolin Löscher, Jana Meyer, Judith Meyer, Fabrizio Minutolo, Elisabeth von der Esch, Bess B. Ward, and Ulf Riebesell
Biogeosciences, 18, 4305–4320, https://doi.org/10.5194/bg-18-4305-2021, https://doi.org/10.5194/bg-18-4305-2021, 2021
Short summary
Short summary
Upwelling of nutrient-rich deep waters to the surface make eastern boundary upwelling systems hot spots of marine productivity. This leads to subsurface oxygen depletion and the transformation of bioavailable nitrogen into inert N2. Here we quantify nitrogen loss processes following a simulated deep water upwelling. Denitrification was the dominant process, and budget calculations suggest that a significant portion of nitrogen that could be exported to depth is already lost in the surface ocean.
Michelle N. Simone, Kai G. Schulz, Joanne M. Oakes, and Bradley D. Eyre
Biogeosciences, 18, 1823–1838, https://doi.org/10.5194/bg-18-1823-2021, https://doi.org/10.5194/bg-18-1823-2021, 2021
Short summary
Short summary
Estuaries are responsible for a large contribution of dissolved organic carbon (DOC) to the global C cycle, but it is unknown how this will change in the future. DOC fluxes from unvegetated sediments were investigated ex situ subject to conditions of warming and ocean acidification. The future climate shifted sediment fluxes from a slight DOC source to a significant sink, with global coastal DOC export decreasing by 80 %. This has global implications for C cycling and long-term C storage.
Lennart Thomas Bach, Allanah Joy Paul, Tim Boxhammer, Elisabeth von der Esch, Michelle Graco, Kai Georg Schulz, Eric Achterberg, Paulina Aguayo, Javier Arístegui, Patrizia Ayón, Isabel Baños, Avy Bernales, Anne Sophie Boegeholz, Francisco Chavez, Gabriela Chavez, Shao-Min Chen, Kristin Doering, Alba Filella, Martin Fischer, Patricia Grasse, Mathias Haunost, Jan Hennke, Nauzet Hernández-Hernández, Mark Hopwood, Maricarmen Igarza, Verena Kalter, Leila Kittu, Peter Kohnert, Jesus Ledesma, Christian Lieberum, Silke Lischka, Carolin Löscher, Andrea Ludwig, Ursula Mendoza, Jana Meyer, Judith Meyer, Fabrizio Minutolo, Joaquin Ortiz Cortes, Jonna Piiparinen, Claudia Sforna, Kristian Spilling, Sonia Sanchez, Carsten Spisla, Michael Sswat, Mabel Zavala Moreira, and Ulf Riebesell
Biogeosciences, 17, 4831–4852, https://doi.org/10.5194/bg-17-4831-2020, https://doi.org/10.5194/bg-17-4831-2020, 2020
Short summary
Short summary
The eastern boundary upwelling system off Peru is among Earth's most productive ocean ecosystems, but the factors that control its functioning are poorly constrained. Here we used mesocosms, moored ~ 6 km offshore Peru, to investigate how processes in plankton communities drive key biogeochemical processes. We show that nutrient and light co-limitation keep productivity and export at a remarkably constant level while stoichiometry changes strongly with shifts in plankton community structure.
Cited articles
Bach, L. T., Gill, S., Rickaby, R., Gore, S., and Renforth, P.: CO2
removal with enhanced weathering and ocean alkalinity enhancement: Potential
risks and co-benefits for marine pelagic ecosystems, Front. Clim.,
1, 7, https://doi.org/10.3389/fclim.2019.00007, 2019.
Bates, N. R., Best, M. H. P., Neely, K., Garley, R., Dickson, A. G., and Johnson, R. J.: Detecting anthropogenic carbon dioxide uptake and ocean acidification in the North Atlantic Ocean, Biogeosciences, 9, 2509–2522, https://doi.org/10.5194/bg-9-2509-2012, 2012.
Burt, D. J., Fröb, F., and Ilyina, T.: The sensitivity of the marine
carbonate system to regional ocean alkalinity enhancement, Front.
Clim., 3, 624075, https://doi.org/10.3389/fclim.2021.624075, 2021.
Bustos-Serrano, H., Morse, J. W., and Millero, F. J.: The formation of
whitings on the Little Bahama Bank, Mar. Chem., 113, 1–8, 2009.
Canadell, J. G., Le Quéré, C., Raupach, M. R., Field, C. B.,
Buitenhuis, E. T., Ciais, P., Conway, T. J., Gillett, N. P., Houghton, R.,
and Marland, G.: Contributions to accelerating atmospheric CO2 growth
from economic activity, carbon intensity, and efficiency of natural sinks,
P. Natl. Acad. Sci. USA, 104, 18866–18870, 2007.
Carter, B. R., Feely, R. A., Wanninkhof, R., Kouketsu, S., Sonnerup, R. E.,
Pardo, P. C., Sabine, C. L., Johnson, G. C., Sloyan, B. M., and Murata, A.:
Pacific anthropogenic carbon between 1991 and 2017, Global Biogeochem.
Cy., 33, 597–617, 2019.
Caserini, S., Pagano, D., Campo, F., Abbà, A., De Marco, S., Righi, D.,
Renforth, P., and Grosso, M.: Potential of Maritime Transport for Ocean
Liming and Atmospheric CO2 Removal, Frontiers in Climate, 3, 575900, https://doi.org/10.3389/fclim.2021.575900, 2021.
Chang, R., Kim, S., Lee, S., Choi, S., Kim, M., and Park, Y.: Calcium
carbonate precipitation for CO2 storage and utilization: a review of
the carbonate crystallization and polymorphism, Frontiers in Energy
Research, 5, 17, https://doi.org/10.3389/fenrg.2017.00017, 2017.
Chave, K. E. and Suess, E.: Calcium Carbonate Saturation in Seawater:
Effects of Dissolved Organic Matter 1, Limnol. Oceanogr., 15,
633–637, 1970.
Chen, T., Neville, A., and Yuan, M.: Calcium carbonate scale
formation – assessing the initial stages of precipitation and deposition,
J. Petrol. Sci. Eng., 46, 185–194, 2005.
Cyronak, T., Schulz, K. G., Santos, I. R., and Eyre, B. D.: Enhanced
acidification of global coral reefs driven by regional biogeochemical
feedbacks, Geophys. Res. Lett., 41, 5538–5546, 2014.
De Choudens-Sanchez, V. and Gonzalez, L. A.: Calcite and aragonite
precipitation under controlled instantaneous supersaturation: elucidating
the role of CaCO3 saturation state and
Dickson, A. G.: Standards for ocean measurements, Oceanography, 23, 34–47,
2010.
Dickson, A. G. and Millero, F. J.: A comparison of the equilibrium constants
for the dissociation of carbonic acid in seawater media, Deep-Sea Res., 34, 1733–1743, 1987.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to best practices
for ocean CO2 measurements, PICES Special Publication 3, IOCCP Report
8, Sidney, British Columbia, North Pacific Marine Science Organization, 191 pp., https://doi.org/10.25607/OBP-1342, 2007.
Doney, S. C., Fabry, V. J., Feely, R. A., and Kleypas, J. A.: Ocean
acidification: the other CO2 problem, Annual Rev. Mar. Sci.,
1, 169–192, 2009.
Feng, E. Y., Keller, D. P., Koeve, W., and Oschlies, A.: Could artificial
ocean alkalinization protect tropical coral ecosystems from ocean
acidification?, Environ. Res. Lett., 11, 074008, https://doi.org/10.1088/1748-9326/11/7/074008, 2016.
Feng, E. Y., Koeve, W., Keller, D. P., and Oschlies, A.: Model-Based
Assessment of the CO2 Sequestration Potential of Coastal Ocean
Alkalinization, Earth's Future, 5, 1252–1266, 2017.
Gafar, N. A. and Schulz, K. G.: A three-dimensional niche comparison of Emiliania huxleyi and Gephyrocapsa oceanica: reconciling observations with projections, Biogeosciences, 15, 3541–3560, https://doi.org/10.5194/bg-15-3541-2018, 2018.
Gattuso, J.-P., Magnan, A., Billé, R., Cheung, W. W., Howes, E. L.,
Joos, F., Allemand, D., Bopp, L., Cooley, S. R., and Eakin, C. M.:
Contrasting futures for ocean and society from different anthropogenic
CO2 emissions scenarios, Science, 349, aac4722, https://doi.org/10.1126/science.aac4722, 2015.
GESAMP: High level review of a wide range of proposed marine geoengineering
techniques, edited by: Boyd, P. W. and Vivian, C. M. G., IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UN Environment/UNDP/ISA Joint Group of
Experts on the Scientific Aspects of Marine Environmental Protection, GESAMP, Rep.
Stud. GESAMP No. 98, 144, 1020–4873, 2019.
González, M. F. and Ilyina, T.: Impacts of artificial ocean
alkalinization on the carbon cycle and climate in Earth system simulations,
Geophys. Res. Lett., 43, 6493–6502, 2016.
Goodwin, P., Brown, S., Haigh, I. D., Nicholls, R. J., and Matter, J. M.:
Adjusting mitigation pathways to stabilize climate at 1.5 ∘C and
2.0 ∘C rise in global temperatures to year 2300, Earth's Future,
6, 601–615, 2018.
Harvey, L.: Mitigating the atmospheric CO2 increase and ocean
acidification by adding limestone powder to upwelling regions, J.
Geophys. Res.-Oceans, 113, C04028, https://doi.org/10.1029/2007JC004373, 2008.
Hoegh-Guldberg, O., Mumby, P. J., Hooten, A. J., Steneck, R. S., Greenfield,
P., Gomez, E., Harvell, C. D., Sale, P. F., Edwards, A. J., and Caldeira,
K.: Coral reefs under rapid climate change and ocean acidification, Science,
318, 1737–1742, 2007.
Hoegh-Guldberg, O., Jacob, D., Taylor, M., Bolaños, T. G., Bindi, M.,
Brown, S., Camilloni, I., Diedhiou, A., Djalante, R., and Ebi, K.: The human
imperative of stabilizing global climate change at 1.5 ∘C,
Science, 365, eaaw6974, https://doi.org/10.1126/science.aaw6974, 2019.
Huppmann, D., Kriegler, E., Krey, V., Riahi, K., Rogelj, J., Rose, S. K.,
Weyant, J., Bauer, N., Bertram, C., and Bosetti, V.: IAMC 1.5 ∘C Scenario Explorer and Data hosted by IIASA, International Institute for Applied Systems Analysis & Integrated Assessment Modeling Consortium, https://doi.org/10.22022/SR15/08-2018.15429, 2018.
Ilyina, T., Wolf-Gladrow, D., Munhoven, G., and Heinze, C.: Assessing the
potential of calcium-based artificial ocean alkalinization to mitigate
rising atmospheric CO2 and ocean acidification, Geophys. Res. Lett., 40, 5909–5914, 2013.
IPCC: Summary for Policymakers, in: Climate Change 2021: The Physical
Science Basis. Contribution of Working Group I to the Sixth Assessment
Report of the Intergovernmental Panel on Climate Change, edited by: Masson-Delmotte,
V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N.,
Chen, L., Goldfarb, M. I., Gomis, M., Huang, K., Leitzell, E., Lonnoy, J. B. R., Matthews, Y., Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R., and Zhou, B., Cambridge University Press, Cambridge University Press, Cambridge, United Kingdom and New
York, NY, USA, 3−-32, https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf, https://doi.org/10.1017/9781009157896.001, 2021.
Keller, D. P., Feng, E. Y., and Oschlies, A.: Potential climate engineering
effectiveness and side effects during a high carbon dioxide-emission
scenario, Nat. Commun., 5, 1–11, 2014.
Kheshgi, H. S.: Sequestering atmospheric carbon dioxide by increasing ocean
alkalinity, Energy, 20, 915–922, 1995.
Köhler, P., Hartmann, J., and Wolf-Gladrow, D. A.: Geoengineering
potential of artificially enhanced silicate weathering of olivine,
P. Natl. Acad. Sci. USA, 107, 20228–20233, 2010.
Köhler, P., Abrams, J. F., Völker, C., Hauck, J., and Wolf-Gladrow,
D. A.: Geoengineering impact of open ocean dissolution of olivine on
atmospheric CO2, surface ocean pH and marine biology, Environ. Res. Lett., 8, 014009, https://doi.org/10.1088/1748-9326/8/1/014009, 2013.
Lenton, T. M. and Vaughan, N. E.: The radiative forcing potential of different climate geoengineering options, Atmos. Chem. Phys., 9, 5539–5561, https://doi.org/10.5194/acp-9-5539-2009, 2009.
Lenton, A., Matear, R. J., Keller, D. P., Scott, V., and Vaughan, N. E.: Assessing carbon dioxide removal through global and regional ocean alkalinization under high and low emission pathways, Earth Syst. Dynam., 9, 339–357, https://doi.org/10.5194/esd-9-339-2018, 2018.
Lewis, E. and Perkin, R.: The practical salinity scale 1978: conversion of
existing data, Deep-Sea Res., 28,
307–328, 1981.
Lioliou, M. G., Paraskeva, C. A., Koutsoukos, P. G., and Payatakes, A. C.:
Heterogeneous nucleation and growth of calcium carbonate on calcite and
quartz, J. Colloid Interf. Sci., 308, 421–428, 2007.
Lueker, T. J., Dickson, A. G., and Keeling, C. D.: Ocean pCO2
calculated from dissolved inorganic carbon, alkalinity, and equations for K1
and K2: validation based on laboratory measurements of CO2 in gas and
seawater at equilibrium, Mar. Chem., 70, 105–119, 2000.
Marion, G. M., Millero, F. J., and Feistel, R.: Precipitation of solid phase calcium carbonates and their effect on application of seawater
Mehrbach, C., Culberson, C., Hawley, J., and Pytkowicx, R.: Measurement of
the apparent dissociation constants of carbonic acid in seawater at
atmospheric pressure 1, Limnol. Oceanogr., 18, 897–907, 1973.
Millero, F., Huang, F., Zhu, X., Liu, X., and Zhang, J.-Z.: Adsorption and
desorption of phosphate on calcite and aragonite in seawater, Aquat.
Geochem., 7, 33–56, 2001.
Mongin, M., Baird, M. E., Lenton, A., Neill, C., and Akl, J.: Reversing
ocean acidification along the Great Barrier Reef using alkalinity injection,
Environ. Res. Lett., 16, 064068, https://doi.org/10.1088/1748-9326/ac002d, 2021.
Montserrat, F., Renforth, P., Hartmann, J., Leermakers, M., Knops, P., and
Meysman, F. J.: Olivine dissolution in seawater: implications for CO2
sequestration through enhanced weathering in coastal environments,
Environ. Sci. Technol., 51, 3960–3972, 2017.
Moras, C. A.: Quick and hydrated lime dissolution for Ocean Alkalinity Enhancement, Australian Ocean Data Network [data set], https://doi.org/10.26198/8znv-e436, 2022.
Morse, J. W. and He, S.: Influences of T, S and pCO2 on the
pseudo-homogeneous precipitation of CaCO3 from seawater: implications
for whiting formation, Mar. Chem., 41, 291–297, 1993.
Morse, J. W., Wang, Q., and Tsio, M. Y.: Influences of temperature and Mg:
Ca ratio on CaCO3 precipitates from seawater, Geology, 25, 85–87, 1997.
Morse, J. W., Gledhill, D. K., and Millero, F. J.: CaCO3 precipitation
kinetics in waters from the great Bahama bank: Implications for the
relationship between bank hydrochemistry and whitings, Geochim.
Cosmochim. Ac., 67, 2819–2826, 2003.
Morse, J. W., Arvidson, R. S., and Lüttge, A.: Calcium carbonate
formation and dissolution, Chem. Rev., 107, 342–381, 2007.
Mucci, A.: The solubility of calcite and aragonite in seawater at various
salinities, temperatures, and one atmosphere total pressure, Am.
J. Sci., 283, 780–799, 1983.
National Academies of Sciences, Engineering, and Medicine: A Research Strategy for
Ocean-based Carbon Dioxide Removal and Sequestration, The National Academies
Press, Washington, DC, 322 pp., https://doi.org/10.17226/26278, 2022.
Ni, M. and Ratner, B. D.: Differentiating calcium carbonate polymorphs by
surface analysis techniques – an XPS and TOF-SIMS study, Surf. Interface Anal., 40, 1356–1361, 2008.
Pan, Y., Li, Y., Ma, Q., He, H., Wang, S., Sun, Z., Cai, W.-J., Dong, B.,
Di, Y., and Fu, W.: The role of Mg2+ in inhibiting CaCO3
precipitation from seawater, Mar. Chem., 237, 104036, https://doi.org/10.1016/j.marchem.2021.104036, 2021.
Pytkowicz, R. M.: Rates of inorganic calcium carbonate nucleation, The
Journal of Geology, 73, 196–199, 1965.
Renforth, P. and Henderson, G.: Assessing ocean alkalinity for carbon
sequestration, Rev. Geophys., 55, 636–674, 2017.
Renforth, P. and Kruger, T.: Coupling mineral carbonation and ocean liming,
Energ. Fuel., 27, 4199–4207, 2013.
Renforth, P., Jenkins, B., and Kruger, T.: Engineering challenges of ocean
liming, Energy, 60, 442–452, 2013.
Riebesell, U., Fabry, V. J., Hansson, L., and Gattuso, J.-P.: Guide to best
practices for ocean acidification research and data reporting, Office for
Official Publications of the European Communities, Luxembourg, 258 pp.,
https://doi.org/10.2777/66906, 2011.
Riley, J. and Tongudai, M.: The major cation/chlorinity ratios in sea water,
Chem. Geol., 2, 263–269, 1967.
Rushdi, A., Pytkowicz, R., Suess, E., and Chen, C.: The effects of
magnesium-to-calcium ratios in artificial seawater, at different ionic
products, upon the induction time, and the mineralogy of calcium carbonate:
a laboratory study, Geol. Rundsch., 81, 571–578, 1992.
Schulz, K. G., Bach, L. T., Bellerby, R. G., Bermúdez, R.,
Büdenbender, J., Boxhammer, T., Czerny, J., Engel, A., Ludwig, A., and
Meyerhöfer, M.: Phytoplankton blooms at increasing levels of atmospheric
carbon dioxide: experimental evidence for negative effects on
prymnesiophytes and positive on small picoeukaryotes, Frontiers in Marine
Science, 4, https://doi.org/10.3389/fmars.2017.00064, 2017.
Sharp, J. D., Pierrot, D., Humphreys, M. P., Epitalon, J.-M., Orr, J. C., Lewis, E. R., and Wallace, D. W. R.: CO2SYSv3 for MATLAB (Version v3.2.0), Zenodo, https://doi.org/10.5281/zenodo.3950562, 2021.
Simkiss, K.: The inhibitory effects of some metabolites on the precipitation
of calcium carbonate from artificial and natural sea water, ICES J.
Mar. Sci., 29, 6–18, 1964.
Statista: Global cement industry – Statistics & Facts, https://www.statista.com/topics/8700/cement-industry-worldwide/ (last access: 28 March 2022), 2021.
Tang, H., Wu, X., Xian, H., Zhu, J., Wei, J., Liu, H., and He, H.:
Heterogeneous Nucleation and Growth of CaCO3 on Calcite (104) and
Aragonite (110) Surfaces: Implications for the Formation of Abiogenic
Carbonate Cements in the Ocean, Minerals, 10, 294, https://doi.org/10.3390/min10040294, 2020.
The Royal Society and Royal Academy of Engineering: Greenhouse Gas Removal, https://royalsociety.org/-/media/policy/projects/greenhouse-gas-removal/royal-society-greenhouse-gas-removal-report-2018.pdf (last access: 7 May 2022), 2018.
Uppstrom, L.: The boron/chlorinity ratio of deep-sea water from the Pacific
Ocean, Deep-Sea Res., 21, 161–162, 1974.
Wolf-Gladrow, D. A., Zeebe, R. E., Klaas, C., Körtzinger, A., and
Dickson, A. G.: Total alkalinity: The explicit conservative expression and
its application to biogeochemical processes, Mar. Chem., 106, 287–300,
2007.
Wolf, S. E., Leiterer, J., Kappl, M., Emmerling, F., and Tremel, W.: Early
homogenous amorphous precursor stages of calcium carbonate and subsequent
crystal growth in levitated droplets, J. Am. Chem.
Soc., 130, 12342–12347, 2008.
Wurgaft, E., Steiner, Z., Luz, B., and Lazar, B.: Evidence for inorganic
precipitation of CaCO3 on suspended solids in the open water of the Red
Sea, Mar. Chem., 186, 145–155, 2016.
Wurgaft, E., Wang, Z., Churchill, J., Dellapenna, T., Song, S., Du, J.,
Ringham, M., Rivlin, T., and Lazar, B.: Particle triggered reactions as an
important mechanism of alkalinity and inorganic carbon removal in river
plumes, Geophys. Res. Lett., 48, e2021GL093178, https://doi.org/10.1029/2021GL093178, 2021.
Zeebe, R. E. and Wolf-Gladrow, D.: CO2 in seawater: equilibrium,
kinetics, isotopes, 65, Gulf Professional Publishing, 360 pp, ISBN 9780444509468, 2001.
Zhong, S. and Mucci, A.: Calcite and aragonite precipitation from seawater
solutions of various salinities: Precipitation rates and overgrowth
compositions, Chem. Geol., 78, 283–299, 1989.
Short summary
This research presents the first laboratory results of quick and hydrated lime dissolution in natural seawater. These two minerals are of great interest for ocean alkalinity enhancement, a strategy aiming to decrease atmospheric CO2 concentrations. Following the dissolution of these minerals, we identified several hurdles and presented ways to avoid them or completely negate them. Finally, we proceeded to various simulations in today’s oceans to implement the strategy at its highest potential.
This research presents the first laboratory results of quick and hydrated lime dissolution in...
Altmetrics
Final-revised paper
Preprint