Dr. David Keller

Senior scientist in the Research Unit Biogeochemical Modelling. My position is financed by external funders including the BMBF and EU. I lead an unoffical group of postdocs / scientists, PhD students, the occasional M.Sc. student, and support staff who mostly work on the projects listed below.

Mailing Address:
GEOMAR Helmholtz Centre for Ocean Research Kiel

Wischhofstr. 1-3

24148 Kiel, Germany

Building 5, Tower 5, Room 5.508
E-Mail: dkeller(at)geomar.de

Research Interests

Ocean-based carbon dioxide removal (CDR) approaches.

Earth system model-based assessments of carbon dioxide removal.

Feedbacks between biogeochemical cycles and the climate.

Marine ecosystems and biogeochemistry.


GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
Senior scientist in the Marine Biogeochemical Modelling department (supported by external [grant] funding)

GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
Research Fellowship in the Marine Biogeochemical Modelling department

University of Maryland Center for Environmental Science, Horn Point Laboratory, Cambridge, MD
Graduate Research Assistant for Dr. Raleigh R. Hood

Current Projects

2023 - 2027
Ocean Alk-Align(Aligning ocean alkalinity for sustainable, safe and verifiable long-term CO2 removal)
Funder: Carbon to Sea Initiative
Role: Principal Investigator

2022 - 2026
RESCUE (Response of the Earth System to overshoot, Climate neUtrality and negative Emissions)
Funder: European Union Horizon Europe Programme
Role: Principal Investigator
Website: https://rescue-climate.eu/

2021 – 2024
RETAKE (CO2 removal by alkalinity enhancement: potential, benefits and risks)
Funder: German Federal Ministry of Research and Education (BMBF) via the German Alliance for Marine Research (Deutsche Allianz Meeresforschung; DAM) Research Mission “Marine carbon sinks in decarbonization pathways”
Role: Work Package 3.2 and 3.3 Leader
Website: https://retake.cdrmare.de/en/

2021 – 2024
sea4soCiety (Searching for solutions for Carbon-sequestration in coastal ecosystems)
Funder: German Federal Ministry of Research and Education (BMBF) via the German Alliance for Marine Research (Deutsche Allianz Meeresforschung; DAM) Research Mission “Marine carbon sinks in decarbonization pathways”
Role: Work Package 6 Leader
Website: https://sea4society.cdrmare.de/en/

2021 – 2024
ASMASYS (Unified ASsessment framework for proposed methods of MArine CDR and interim knowledge SYnthesiS)
Funder: German Federal Ministry of Research and Education (BMBF) via the German Alliance for Marine Research (Deutsche Allianz Meeresforschung; DAM) Research Mission “Marine carbon sinks in decarbonization pathways”
Role: Work Package 1.1, 2.1, and 2.2  Leader
Website: https://asmasys.cdrmare.de/en/

2020 – 2025
OceanNETs (Ocean-based Negative Emission Technologies - analyzing the feasibility, risks, and co- benefits of ocean-based negative emission technologies for stabilizing the climate)
Funder: European Union Horizon 2020 Programme
Role: Coordinator / Leader
Website: https://www.oceannets.eu/

2019 – 2023
COMFORT (Our common future ocean in the Earth system – quantifying coupled cycles of carbon, oxygen, and nutrients for determining and achieving safe operating spaces with respect to tipping points)
Funder: European Union Horizon 2020 Programme
Role: Work Package 5 Leader
Website: https://comfort.w.uib.no/

2015 – present
CDRMIP (The Carbon Dioxide Removal Model Intercomparison Project)
Funder: none
Role: Leader
Website: https://cdrmip.carbondioxide-removal.eu/


Fennel, K., Long, M. C., Algar, C., Carter, B., Keller, D. P., Laurent, A., Mattern, J. P., Musgrave, R., Oschlies, A., Ostiguy, J., Palter, J., and Whitt, D. B.: Modeling considerations for research on Ocean Alkalinity Enhancement (OAE), State Planet Discuss. [preprint], doi.org/10.5194/sp-2023-10, in press, 2023.

Boettcher, M., Chai, F., Conathan, M., Cooley, S., Keller, D. P., Klinsky, S., et al. (2023). A Code of Conduct for Marine Carbon Dioxide Removal Research. The Aspen Institute, Energy and Environment Program.

Uzoma, E. K., Adeniyi, M. O., Keller, D. P., Séférian, R., & Oladiran, E. O. (2023). The impact of carbon dioxide removal on temperature parameters over West Africa. Meteorology and Atmospheric Physics135(6), 55. https://doi.org/10.1007/s00703-023-00992-z

Bauer, N., Keller, D. P., Garbe, J., Karstens, K., Piontek, F., von Bloh, W., Thiery, W., Zeitz, M., Mengel, M., Strefler, J., Thonicke, K., and Winkelmann, R. (2023) Exploring risks and benefits of overshooting a 1.5° carbon budget over space and time. Environmental Research Letters.

Wu, J., Keller, D. P., and Oschlies, A. (2023) Carbon Dioxide Removal via Macroalgae Open-ocean Mariculture and Sinking: An Earth System Modeling Study. Earth System Dynamics. DOI 10.5194/esd-2021-104.

Babiker, M., Berndes, G., Blok, K., Cohen, B., Cowie, A., Geden, O., Ginzburg, V., Leip, A., Smith, P., Sugiyama, M., Yamba, F., Al Khourdajie, A., Arneth, A., Lima de Azevedo, I. M., Bataille, C., Beerling, D., Bezner Kerr, R., Bradley, J., Buck, H. J., Cabeza, L. F., Calvin, K., Campbell, D., Cols, J. C., Daioglou, V., Harmsen, M., Höglund-Isaksson, L., House, J. I., Keller, D. P. , Kleijne, K. d., Kugelberg, S., Makarov, I., Meza, F., Minx, J. C., Morecroft, M., Nabuurs, G. J., Neufeldt, H., Novikova, A., Nugroho, S. B., Oschlies, A. , Parmesan, C., Peters, G. P., Poore, J., Portugal-Pereira, J., Postigo, J. C., Pradhan, P., Renforth, P., Rivera-Ferre, M. G., Roe, S., Singh, P. K., Slade, R., Smith, S. M., Tirado von der Pahlen, M. C. and Toribio Ramirez, D. (2022) Cross-sectoral Perspectives. In: IPCC, 2022: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change., ed. by Shukla, P. R., Skea, J., Slade, R., Al Khourdajie, A., van Diemen, R., McCollum, D., Pathak, M., Some, S., Vyas, P., Fradera, R., Belkacemi, M., Hasija, A., Lisboa, G., Luz, S. and Malley, J.. Cambridge University Press, Cambridge, UK, pp. 1245-1354. DOI 10.1017/9781009157926.005.

Keller, D. P., Ketelhake, S., Meyer, J., Neumann, B., Oschlies, A. , Proelß, A. and Rickels, W. (2022) Achieving Climate Neutrality and Paris Agreement Goals: Opportunities for Ocean-Based Methods of Carbon Dioxide Removal, Science Policy Brief. CDRmare, Kiel, Germany, 8 pp. DOI 10.3289/cdrmare.oceannets_1.

Chien, C. T., Durgadoo, J. V., Ehlert, D., Frenger, I., Keller, D. P., Koeve, W., Kriest, I., Landolfi, A., Patara, L., Wahl, S. and Oschlies, A. (2022) FOCI-MOPS v1 – Integration of Marine Biogeochemistry within the Flexible Ocean and Climate Infrastructure version 1 (FOCI 1) Earth system model. Geoscientific Model Development, 15 . pp. 5987-6024. DOI 10.5194/gmd-15-5987-2022

Lee, J. Y., Marotzke, J., Bala, G., Cao, L., Corti, S., Dunne, J. P., Engelbrecht, F., Fischer, E., Fyfe, J. C., Jones, C., Maycock, A., Mutemi, J., Ndiaye, O., Panickal, S., Zhou, T., Milinski, S., Yun, K. S., Armour, K., Bellouin, N., Bethke, I., Byrne, M. P., Cassou, C., Chen, D., Cherchi, A., Christensen, H. M., Connors, S. L., Di Luca, A., Drijfhout, S. S., Fletcher, C. G., Forster, P., Garcia-Serrano, J., Gillett, N. P., Kaufmann, D. S., Keller, D. P. , Kravitz, B., Li, H., Liang, Y., MacDougall, A. H., Malinina, E., Menary, M., Merryfield, W. J., Min, S. K., Nicholls, Z. R. J., Notz, D., Pearson, B., Priestley, M. D. K., Quaas, J., Ribes, A., Ruane, A. C., Sallee, J. B., Sanchez-Gomez, E., Seneviratne, S. I., Slangen, A. B. A., Smith, C., Stuecker, M. F., Swaminathan, R., Thorne, P. W., Tokarska, K. B., Toohey, M. , Turner, A., Volpi, D., Xiao, C. and Zappa, G. (2021) Future global climate: scenario-based projections and near-term information. In: IPCC Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth: Assessment Report of the Intergovernmental Panel on Climate Change: Chapter 4., ed. by Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Pean, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R. and Zhou, B.. IPCC, Genf, Switzerland, pp. 1-195.

Costa, M. H., Cotrim da Cunha, L., Cox, P. M., Eliseev, A. V., Hensen, S., Ishii, M., Jaccard, S., Koven, C., Lohila, A., Patra, P. K., Piao, S., Rogelj, J., Syampungani, S., Zaehle, S., Zickfeld, K., Alexandrov, G., Bala, G., Bopp, L., Boysen, L., Cao, L., Chandra, N., Ciais, P., Denisov, S. N., Dentener, F. J., Douville, H., Fay, A., Forster, P., Fox-Kemper, B., Friedlingstein, P., Fu, W., Fuss, S., Garcon, V., Gier, B., Gillett, N. P., Gregor, L., Haustein, K., Haverd, V., He, J., Hewitt, H. T., Hoffman, F. M., Ilyina, T., Jackson, R., Jones, C., Keller, D. P. , Kwiatkowski, L., Lamboll, R. D., Lan, X., Laufkötter, C., Le Quere, C., Lenton, A., Lewis, J., Liddicoat, S., Lorenzoni, L., Lovenduski, N., MacDougall, A. H., Mathesius, S. , Matthews, D. H., Meinshausen, M., Mokhov, I. I., Naik, V., Nicholls, Z. R. J., Nurhati, I. S., O'Sullivan, M., Peters, G., Pongratz, J., Poulter, B., Sallee, J. B., Saunois, M., Schuur, E. A. G., Seneviratne, S. I., Stavert, A., Suntharalingam, P., Tachiiri, K., Terhaar, J., Thompson, R., Tian, H., Turnbull, J., Vicente-Serrano, S. M., Wang, X., Wanninkhof, R. and Williamson, P. (2021) Global Carbon and other Biogeochemical Cycles and Feedbacks. In: IPCC Climate Change 2021: The Physical Science Basis: Contribution of Working Group I to the Sixth : Assessment Report of the Intergovernmental Panel on Climate Change : Chapter 5. , ed. by Masson-Delmotte, V., Zhai, P., Pirani, A., Conners, S. L., Pean, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekci, O., Yu, R. and Zhou, B.. IPCC, Genf, Switzerland, pp. 1-221.

Kvale, K. F. , Keller, D. P. , Koeve, W. , Meissner, K. J., Somes, C. J. , Yao, W. and Oschlies, A. (2021) Explicit silicate cycling in the Kiel Marine Biogeochemistry Model version 3 (KMBM3) embedded in the UVic ESCM version 2.9. Geoscientific Model Development, 14 (12). pp. 7255-7285. DOI 10.5194/gmd-14-7255-2021

Tivig, M., Keller, D. P. and Oschlies, A. (2021) Riverine nitrogen supply to the global ocean and its limited impact on global marine primary production: a feedback study using an Earth System Model. Biogeosciences, 18 . pp. 5327-5350. DOI 10.5194/bg-18-5327-2021.

Keller, D. P., Brent, K., Bach, L. T. and Rickels, W. (2021) Editorial: The Role of Ocean-Based Negative Emission Technologies for Climate Mitigation. Frontiers in Climate, 3. Art.Nr. 743816. DOI 10.3389/fclim.2021.743816

Jebari, J., Táíwò, O. O., Andrews, T. M., Aquila, V., Beckage, B., Belaia, M., Clifford, M., Fuhrman, J., Keller, D. P. , Mach, K. J., Morrow, D. R., Raimi, K. T., Visioni, D., Nicholson, S. and Trisos, C. H. (2021) From moral hazard to risk-response feedback. Climate Risk Management, 33 . Art.Nr. 100324. DOI 10.1016/j.crm.2021.100324.

Pereira, L. M. , Morrow, D. R., Aquila, V., Beckage, B., Beckbesinger, S., Beukes, L., Buck, H. J., Carlson, C. J., Geden, O., Jones, A. P., Keller, D. P. , Mach, K. J., Mashigo, M., Moreno-Cruz, J. B., Visioni, D., Nicholson, S. and Trisos, C. H. (2021) From fAIrplay to climate wars: making climate change scenarios more dynamic, creative, and integrative. Ecology and Society, 26 (4). Art.Nr. 30. DOI 10.5751/ES-12856-260430.

Tran, G. T., Oschlies, A. and Keller, D. P. (2020) Comparative Assessment of Climate Engineering Scenarios in the Presence of Parametric Uncertainty. Journal of Advances in Modeling Earth Systems, 12 (4). Art.Nr. e2019MS001787. DOI 10.1029/2019MS001787.

Mengis, N., Keller, D. P., MacDougall, A., Eby, M., Wright, N., Meissner, K. J., Oschlies, A., Schmittner, A., Matthews, H. D., and Zickfeld, K. (2020) Evaluation of the University of Victoria Earth System Climate Model version 2.10 (UVic ESCM 2.10), Geosci. Model Dev., doi.org/10.5194/gmd-2019-373

Franke, A., Blenckner, T., Duarte, C. M., Ott, K., Fleming, L. E., Antia, A., Reusch, T. B. H. , Bertram, C., Hein, J., Kronfeld-Goharani, U., Dierking, J. , Kuhn, A., Sato, C., van Doorn, E., Wall, M., Schartau, M. , Karez, R., Crowder, L., Keller, D. P. , Engel, A. , Hentschel, U. and Prigge, E. (2020) Operationalizing Ocean Health: Toward Integrated Research on Ocean Health and Recovery to Achieve Ocean Sustainability. One Earth . DOI: 10.1016/j.oneear.2020.05.013

Kreuter, J., Matzner, N., Baatz, C., Keller, D. P., Markus, T., Wittstock, F., Bernitt, U. and Mengis, N. (2020) Unveiling assumptions through interdisciplinary scrutiny: Observations from the German Priority Program on Climate Engineering (SPP 1689), Climatic Change, 162, pp. 57-66. DOI: 10.1007/s10584-020-02777-4.

Reith, F., W. Koeve, D. P. Keller, J. Getzlaff, and A. Oschlies (2019) Meeting climate targets by direct CO2 injections: What price would the ocean have to pay? Earth System Dynamic,. 10, pp. 711-727. DOI: 10.5194/esd-10-711-2019.

Mengis, N., D. P. Keller, W. Rickels, M. Quaas, and A. Oschlies (2019), Climate Engineering-induced changes in correlations between Earth system variables - Implications for appropriate indicator selection. Climatic Change. doi: 10.1007/s10584-019-02389-7

Kvale, K. F., K. Turner, D. P. Keller, and K. Meissner (2018), Asymmetric dynamical ocean responses in warming icehouse and cooling greenhouse climates. Environmental Research Letters, 13 (12). Art.Nr. 125011. doi: 10.1088/1748-9326/aaedc3

Keller, D. P. (2018), Marine Climate Engineering. In: Handbook on Marine Environment Protection: Science, Impacts and Sustainable Management. , ed. by Salomon, M. and Markus, T.. Springer International Publishing, Berlin, Germany, pp. 261-276. ISBN 978-3-319-60154-0, doi: 10.1007/978-3-319-60156-4

Keller, D. P., A. Lenton, E. W. Littleton, A.  Oschlies, V. Scott, and N. E. Vaughan (2018), The Effects of Carbon Dioxide Removal on the Carbon Cycle. Current Climate Change Reports, 4 (3). pp. 250-265. doi: 10.1007/s40641-018-0104-3

Lenton, A., R. J. Matear, D. P. Keller, V. Scott, and N. E. Vaughan (2018), Assessing Carbon Dioxide Removal Through Global and Regional Ocean Alkalization under High and Low Emission Pathways. Earth System Dynamics, 9 . pp. 339-357. doi: 10.5194/esd-9-339-2018

Keller, D. P. , A. Lenton, V. Scott, N. E. Vaughan, N. Bauer, D. Ji, C. D. Jones, B. Kravitz, H. Muri, and K. Zickfeld (2018), The Carbon Dioxide Removal Model Intercomparison Project (CDRMIP): rationale and experimental protocol for CMIP6. Geoscientific Model Development, 11 . pp. 1133-1160. doi: 10.5194/gmd-11-1133-2018

Rickels, W., F. Reith, D. P. Keller, A. Oschlies, and M. Quaas (2018), Integrated Assessment of Carbon Dioxide Removal. Earth's Future, 6 (3). pp. 565-582. doi: 10.1002/2017EF000724

Mengis, N., D. P. Keller, and A. Oschlies (2018), Systematic Correlation Matrix Evaluation (SCoMaE) – a bottom–up, science-led approach to identifying indicators. Earth System Dynamics, 9 (1). pp. 15-31. doi: 10.5194/esd-9-15-2018

Feng, Y., W. Koeve, D. P. Keller, and A. Oschlies (2017), Model-based Assessment of the CO2 Sequestration Potential of Coastal Ocean Alkalinization. Earth's Future, 5 (12). pp. 1252-1266. doi: 10.1002/2017EF000659

Lenton, A., D. P. Keller, and P. Pfister (2017), How Will Earth Respond to Plans for Carbon Dioxide Removal? Eos: Earth & Space Science News, 98 . doi: 10.1029/2017EO068385

Oschlies, A., H. Held, D. P. Keller, K. Keller, N. Mengis, M. Quaas, W. Rickels, and H. Schmidt (2017), Indicators and metrics for the assessment of climate engineering. Earth's Future, 5 (1). pp. 49-58. doi: 10.1002/2016EF000449.

Reith, F., D. P. Keller, and A. Oschlies (2016), Revisiting ocean carbon sequestration by direct injection: A global carbon budget perspective. Earth System Dynamics, 7 . pp. 797-812. doi: 10.5194/esd-7-797-2016

Partanen, A. I., D. P. Keller, H. Korhonen, and D. H. Matthews (2016), Impacts of sea spray geoengineering on ocean biogeochemistry. Geophysical Research Letters, 43 (14). pp. 7600-7608. doi: 10.1002/2016GL070111

Feng, E. Y., D. P. Keller, W. Koeve, and A. Oschlies (2016), Could artificial ocean alkalinization protect tropical coral ecosystems from ocean acidification? Environmental Research Letters, 11 (7). doi: 10.1088/1748-9326/11/7/074008

Keller, D. P. , I. Kriest, W. Koeve, and A. Oschlies (2016), Southern Ocean biological impacts on global ocean oxygen. Geophysical Research Letters, 43 (12). pp. 6469-6477. doi: 10.1002/2016GL069630.

Mengis, N., T. Martin , D. P.Keller, and A. Oschlies (2016), Assessing climate impacts and risks of ocean albedo modification in the Arctic. Journal of Geophysical Research - Oceans, 121 (5). pp. 3044-3057. doi: 10.1002/2015JC011433.

Mengis, N., D. P. Keller, M. Eby, and A. Oschlies (2015), Uncertainty in the response of transpiration to CO2 and implications for climate change, Environmental Research Letters 10 (9). 094001. doi: 10.1088/1748-9326/10/9/094001

Kvale, K. F., K. J. Meissner, and D. P. Keller (2015), Potential increasing dominance of heterotrophy in the global ocean, Environmental Research Letters, 10(7). 074009, doi: 10.1088/1748-9326/10/7/074009

Kvale, K. F. , K. J. Meissner, D. P. Keller, M. Eby and A. Schmittner (2015), Explicit Planktic Calcifiers in the University of Victoria Earth System Climate Model, Version 2.9, Atmosphere-Ocean, doi: 10.1080/07055900.2015.1049112

Nickelsen, L., D. P. Keller, and A. Oschlies (2015), A dynamic marine iron cycle module coupled to the University of Victoria Earth System Model: the Kiel Marine Biogeochemical Model 2 for UVic 2.9, Geoscientific Model Development, 8(5), 1357–1381, doi: 10.5194/gmd-8-1357-2015

Keller, D. P., D. Y. Lee, and R. R. Hood (2014) Turbidity maximum entrapment of phytoplankton in the Chesapeake Bay.  Estuaries and Coasts. 37(2), 279-298. doi: 10.1007/s/122237-013-9692-2

Keller, D. P., E. Y. Feng, and A. Oschlies (2014), Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario, Nature Communications. 5, 1–11, doi: 10.1038/ncomms4304

Keller, D. P., Mengis, N. , Reith, F. and Oschlies, A. (2014) The UVic Earth System Climate Model. In: Modelling in Climate Engineering Research: Significance and Uncertainties. Kiel Earth Institute, Kiel, Germany, pp. 15-17.

Keller, D. P. and R. R. Hood (2013) Comparative simulations of dissolved organic matter cycling in idealized oceanic, coastal, and estuarine surface waters. Journal of Marine Systems. doi: 10.1016/j.jmarsys.2012.01.002

Keller, D. P., A. Oschlies, and M. Eby (2012) A new marine ecosystem model for the University of Victoria Earth system climate model. Geoscientific Model Development. 5, 1195-1220. doi: 10.5194/gmd-5-1195-2012

Lee, D. Y., D. P.Keller, and R. R. Hood (2012) Community metabolism and energy transfer in the Chesapeake Bay estuarine turbidity maximum. Marine Ecology Progress Series. 449, 65-82. doi: 10.3354/meps09543

Keller, D. P., and R. R. Hood (2011) Modeling the seasonal autochthonous sources of dissolved organic carbon and nitrogen in the upper Chesapeake Bay. Ecological Modelling. 222 (5), 1139-1162. doi: 10.1016/j.ecolmodel.2010.12.014