Sea-level rise in Denmark: paleo context, recent projections and policy implications




projection, Denmark, coast, sea level, climate scenario


We present the most recent Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6) sea-level projections for four Danish cities (Aarhus, Copenhagen, Esbjerg and Hirtshals) under the Shared Socioeconomic Pathway (SSP) family of climate scenarios. These sea-level changes projected over the next century are up to an order of magnitude larger than those observed over the previous century. At these cities, year 2150 sea-level changes of between 29 and 55 cm are projected under the very low emissions scenario (SSP1-1.9), while changes of between 99 and 123 cm are projected under the very high emissions scenario (SSP5-8.5). These differences highlight the potentially significant impact of remaining opportunities for climate change mitigation. Due to this increase in mean sea level, the mean recurrence time between historically extreme events is expected to decrease. Under the very high emissions scenario, the historical 100-year storm flood event will become a 1- to 5-year event at most Danish harbours by 2100. There is considerable uncertainty associated with these sea-level projections, primarily driven by uncertainty in the future evolution of the Antarctic ice sheet and future sterodynamic changes in ocean volume. The AR6 characterises collapse of the West Antarctic ice sheet as a low-probability but high-impact event that could cause several metres of sea-level rise around Denmark by 2150. In climate adaptation policy, the scientific landscape is shifting fast. There has been a tremendous proliferation of diverse sea-level projections in recent years, with the most relevant planning target for Denmark increasing c. 50 cm in the past two decades. Translating sea-level rise projections into planning targets requires value judgments about acceptable sea-level risk that depend on local geography, planning timeline and climate pathway. This highlights the need for an overarching national sea-level adaptation plan to ensure municipal plans conform to risk and action standards.


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Author Biography

William Colgan, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark

Researcher, Marine Geology and Glaciology



AMAP. 2011: Cross-cutting scientific issues. Snow, water, ice and permafrost in the Arctic (SWIPA). Climate change and the cryosphere. xii + 538 pp. Oslo: rctic Monitoring and Assessment Programme (AMAP).

AMAP. 2017: Sea level contribution from Arctic land ice: 1850–2100. Snow, water, ice and permafrost in the Arctic (SWIPA). xiv + 269 pp. Oslo: Arctic Monitoring and Assessment Programme (AMAP).

Aschwanden, A., Bartholomaus, T., Brinkerhoff, D. & Truffer, M. 2021: Brief communication: a roadmap towards credible projections of ice sheet contribution to sea level. The Cryosphere 15, 5705–5715.

Aschwanden, A., Fahnestock, M., Truffer, M., Brinkerhoff, D., Hock, R., Khroulev, C., Mottram, R. & Khan, S. 2019: Contribution of the Greenland Ice Sheet to sea level over the next millennium. Science Advances 5(6), eaav9396.

Bamber, J., Oppenheimer, M., Kopp, R., Aspinall, W. & Cooke, R. 2019: Ice sheet contributions to future sea-level rise from structured expert judgment. Proceedings of the National Academy of Sciences 116, 11195–11200.

Bamber, J., Riva, R., Vermeersen, B. & LeBrocq, A. 2009: Reassessment of the potential sea-level rise from a collapse of the West Antarctic Ice Sheet. Science 324, 901–903.

Bennike, O., Andresen, K., Astrup, P., Olsen, J. & Seidenkrantz, M.-S. 2021: Late Glacial and Holocene shore-level changes in the Aarhus Bugt area, Denmark. GEUS Bulletin 47, 6530.

Bennike, O. & Jensen, J. 2011: Postglacial, relative shore-level changes in Lillebælt, Denmark. Geological Survey of Denmark and Greenland Bulletin 23, 37–40.

Bennike, O., Nørgaard-Pedersen, N., Jensen, J., Andresen, K. & Seidenkrantz, M.-S. 2019: Development of the western Limfjord, Denmark, after the last deglaciation: a review with new data. Bulletin of the Geological Society of Denmark 67, 53–73.

Bennike, O., Skov Andreasen, M., Jensen, J., Moros, M. & Noe-Nygaard, N. 2012: Early Holocene sea-level changes in Øresund, southern Scandinavia. Geological Survey of Denmark and Greenland Bulletin 26, 29–32.

Clemmensen, L., Bendixen, M., Hede, M., Kroon, A., Nielsen, L. & Murray, A. 2014: Morphological records of storm floods exemplified by the impact of the 1872 Baltic storm on a sandy spit system in south-eastern Denmark. Earth Surface Processes and Landforms 39, 499–508.

Clemmensen, L., Murray, A. & Nielsen, L. 2012: Quantitative constraints on the sea-level fall that terminated the Littorina Sea Stage, southern Scandinavia. Quaternary Science Reviews 40, 54–63.

Clemmensen, L., Richardt, N. & Andersen, C. 2001: Holocene sea-level variation and spit development: data from Skagen Odde, Denmark. The Holocene 11, 323–331.

Colgan, W., Box, J., Ribeiro, S. & Kjeldsen, K. 2019: Sea-level rise in Denmark: bridging local reconstructions and global projections. GEUS Bulletin 43, e2019430101.

Chambers, C., Greve, R., Obase, T., Saito, F. & Abe-Ouchi, A. 2021: Mass loss of the Antarctic ice sheet until the year 3000 under a sustained late-21st-century climate. Journal of Glaciology 68, 1–13.

Church, J., Godfrey, S., Jackett, D. & McDougall, T. 1991: A model of sea level rise caused by ocean thermal expansion. Journal of Climate 4, 438–456.<0438:AMOSLR>2.0.CO;2

Church J.A., et al., 2013. Sea level change. In: Stocker, T.F., et al. (eds): Climate change 2013: the physical science basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, pp. 1137–1216. Cambridge: Cambridge University Press.

Ditlevsen, C., Ramos, M., Sørensen, C., Ciocan, U. & Piontkowitz, T. 2019: Højvandsstatistikker 2017. Technical report. 86 pp. Lemvig: Kystdirektoratet.

Dutton, A., Carlson, A., Long, A., Milne, G., Clark, P., DeConto, R., Horton, B., Rahmstorf, S. & Raymo, M. 2015: Sea-level rise due to polar ice-sheet mass loss during past warm periods. Science 349, 6244.

Ehlert, D. & Zickfeld, K. 2018: Irreversible ocean thermal expansion under carbon dioxide removal. Earth System Dynamics 9, 197–210.

European Parliament. 2007: Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks. OJ L 288, 27–34.

Faragò, M., Rasmussen, E., Fryd, O., Rønde Nielsen, E. & Arnbjerg-Nielsen, K. 2018: Coastal protection technologies in a Danish context. Lyngby: Technical University of Denmark.

Fleming, K., Johnston, P., Zwartz, D., Yokoyama, Y., Lambeck, K. & Chappell, J. 1998: Refining the eustatic sea-level curve since the last glacial maximum using far- and intermediate-field sites. Earth and Planetary Science Letters 163, 327–342.

Fox-Kemper, B. et al. 2021: Ocean, cryosphere and sea level change. In: Masson-Delmotte, V. et al. (eds): Climate change 2021: the physical science basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, pp. 1211–1362. Cambridge: Cambridge University Press.

Fryd, O. & Jørgensen, G. 2019: Byerne og det stigende havvand: Innovative planlægningstilgange. IGN Rapport. 47 pp. Copenhagen: Københavns Universitet.

Fryd, O. & Jørgensen, G. (eds.). 2020: Byerne og det stigende havvand – Statusrapport 2019. IGN Rapport, 21 pp. Copenhagen: Københavns Universitet.

Garner, G.G. et al. 2021: IPCC AR6 sea-level rise projections. Version 20210809. PO.DAAC, CA. (accessed February 2022).

Gehrels, W. & Shennan, I. 2015: Sea level in time and space: revolutions and inconvenient truths. Journal of Quaternary Science 30, 131–143.

Gehrels, W., Szkomik, K., Bartholdy, J., Kirby, J., Bradley, S., Marshall, W., Heinemeier, J. & Pedersen, J. 2006: Late Holocene sea-level changes and isostasy in western Denmark. Quaternary Research 66, 288–302.

Hammond, W., Blewitt, G., Kreemer, C. & Nerem, R. 2021: GPS imaging of global vertical land motion for studies of sea level rise. Journal of Geophysical Research: Solid Earth 126, e2021JB022355.

Hansen, L. 2018: Sea level data 1889–2017 from 14 stations in Denmark. Mean, maximum and minimum values calculated on monthly and yearly basis including plots of mean values. DMI Report 18–16, 1–23.

Hauerbach, P. 1992: Skagen Odde – Skaw Spit. An area of land created between two seas. Folia Geographica Danica 20, 1–119.

Hede, M., Sander, L., Clemmensen, L., Kroon, A., Pejrup, M. & Nielsen, L. 2015: Changes in Holocene relative sea-level and coastal morphology: a study of a raised beach ridge system on Samsø, southwest Scandinavia. The Holocene 25, 1402–1414.

Holgate, S., Matthews, A., Woodworth, P., Rickards, L., Tamisiea, M., Bradshaw, E., Foden, P., Gordon, K., Jevrejeva, S. & Pugh, J. 2013: New data systems and products at the permanent service for mean sea level. Journal of Coastal Research 29, 493–504.

Houmark-Nielsen, M. & Kjær, K. 2003: Southwest Scandinavia, 40–15 kyr BP: palaeogeography and environmental change. Journal of Quaternary Science 18, 769–786.

Jevrejeva, S., Jackson, L., Riva, R., Grinsted, A. & Moore, J. 2016: Coastal sea level rise with warming above 2°C. Proceedings of the National Academy of Sciences 113, 13342–13347.

Joughin, I., Smith, B. & Medley, B. 2014: Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarctica. Science 344, 735–738.

Kabuth, A., Kroon, A. & Pedersen, J. 2014: Multidecadal shoreline changes in Denmark. Journal of Coastal Research 296, 714–728.

Kaufman, D., McKay, N., Routson, C., Erb, M., Dätwyler, C., Sommer, P., Heiri, O. & Davis, B. 2020: Holocene global mean surface temperature, a multi-method reconstruction approach. Scientific Data 7, 201.

Kystdirektoratet. 2018: Højvandsstatistikker 2017. 86 pp. Lemvig: Miljø- og Fødevareministeriet.

Kystdirektoratet. 2022: Kystatlas. (accessed July 2022).

Larour, E., Ivins, E. & Adhikari, S. 2017: Should coastal planners have concern over where land ice is melting? Science Advances 3, e1700537.

Larour, E., Rignot, E., Poinelli, M. & Scheuchl, B. 2021: Physical processes controlling the rifting of Larsen C Ice Shelf, Antarctica, prior to the calving of iceberg A68. Proceedings of the National Academy of Sciences 118, e2105080118.

Levermann, A., Clark, P., Marzeion, B., Milne, G., Pollard, D., Radic, V. & Robinson, A. 2013: The multimillennial sea-level commitment of global warming. Proceedings of the National Academy of Sciences 110, 13745–13750.

Levermann, A. et al. 2014: Projecting Antarctic ice discharge using response functions from SeaRISE ice-sheet models. Earth Systematic Dynamics 5, 271–293.

Liu, J., Milne, G., Kopp, R., Clark, P. & Shennan, I. 2016: Sea-level constraints on the amplitude and source distribution of Meltwater Pulse 1A. Nature Geoscience 9, 130–134.

Madsen, K., Murawski, J., Blokhina, M. & Su, J. 2019: Sea level change: mapping Danish municipality needs for climate information. Frontiers in Earth Science 7, 81.

Mangor, K., Dronen, N., Kærgaard, K. & Kristensen, S. 2017: Shoreline management guidelines (fourth edition). 13 pp. Hørsholm: DHI Group. ISBN 978-87-90634-04-9.

Marti, F. et al. 2022: Monitoring the ocean heat content change and the earth energy imbalance from space altimetry and space gravimetry. Earth Systems Science Data 14, 229–249.

Meehl, G.A. et al., 2007. Global climate projections. In: Solomon, S.D., et al. (eds): Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, pp. 748–845. Cambridge: Cambridge University Press.

Meinshausen, M. et al. 2020: The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500. Geoscientific Model Development 13, 3571–3605.

Mercer, J. 1978: West Antarctic ice sheet and CO2 greenhouse effect: a threat of disaster. Nature 271, 321–325.

Nerem, R., Beckley, B., Fasullo, J., Hamlington, B., Masters, D. & Mitchum, G. 2018: Climate-change–driven accelerated sea-level rise detected in the altimeter era. Proceedings of the National Academy of Sciences 27, 2022-2025.

Nauels, A., Rogelj, J., Schleussner, C.-F., Meinhausen, M. & Mengel, M. 2017: Linking sea level rise and socioeconomic indicators under the shared socioeconomic pathways. Environmental Research Letters 12, 114002.

O’Neill, B. et al. 2020. Achievements and needs for the climate change scenario framework. Nature Climate Change 10, 1074–1084.

Oppenheimer, M., et al. 2019: Sea level rise and implications for low-lying Islands, coasts and communities. In: Pörtner, H.-O. et al. (eds): IPCC special report on the ocean and cryosphere in a changing climate. pp. 321–445. Cambridge University Press, Cambridge.

Rignot, E., Mouginot, J., Morlighem, M., Seroussi, H. & Scheuchl, B. 2014: Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith, and Kohler glaciers, West Antarctica, from 1992 to 2011. Geophysical Research Letters 41, 3502–3509.

Steffelbauer, D., Riva, R., Timmermans, J., Kwakke, J. & Bakker, M. 2022: Evidence of regional sea-level rise acceleration for the North Sea. Environmental Research Letters 17, 074002.

Steffen, H. & Wu, P. 2011: Glacial isostatic adjustment in Fennoscandia – a review of data and modeling. Journal of Geodynamics 52, 169–204.

Su, J., Andrée, E., Nielsen, J., Olsen, S. & Madsen, K. 2021: Sea level projections from IPCC special report on the ocean and cryosphere call for a new climate adaptation strategy in the Skagerrak-Kattegat Seas. Frontiers in Marine Science 8, 12.

Szkornik, K., Gehrels, W. & Murray, A. 2008: Aeolian sand movement and relative sea-level rise in Ho Bugt, western Denmark, during the ‘little ice age’. The Holocene 18, 951–965.

The IMBIE Team. 2020: Mass balance of the Greenland Ice Sheet from 1992 to 2018. Nature 579, 233–239.

Thejll, P. et al. 2021: Methods used in the Danish climate atlas. DMI Report 21-41. Data version v2021a.

Thompson, P., Widlansky, M., Hamlington, B., Merrifield, M., Marra, J., Mitchum, G. & Sweet, W. 2021: Rapid increases and extreme months in projections of United States high-tide flooding. Nature Climate Change 11, 584–590.

Voosen, P. 2021: Ice shelf holding back keystone Antarctic glacier within years of failure. Science 374, 6574.

Wahl, T., Haigh, I., Nicholls, R., Arns, A., Dangendorf, S., Hinkel, J. & Slangen, A. 2017: Understanding extreme sea levels for broad-scale coastal impact and adaptation analysis. Nature Communications 8, 16075.

WCRP Global Sea Level Budget Group. 2018: Global sea-level budget 1993–present. Earth System Science Data 10, 1551–1590.

Weaver, A., Saenko, O., Clark, P. & Mitrovica, J. 2003: Meltwater Pulse 1A from Antarctica as a Trigger of the Bølling-Allerød Warm Interval. Science 299, 1709–1713.

Zanna, L., Khatiwala, S., Gregory, J., Ison, J. & Heimbach, P. 2019: Global reconstruction of historical ocean heat storage and transport. Proceedings of the National Academy of Sciences 116, 1126–1131.



How to Cite

Colgan, W., Henriksen, H. J., Bennike, O., Riberio, S., Keiding, M., Karlsson Seidenfaden, I. ., Graversgaard, M., Busck, A. G. ., Fruergaard, M., Knudsen, M. H., Hopper, J., Sonnenborg, T., Skjerbæk, M. R., Bjørk, A. A., Steffen, H., Tarasov, L., Nerem, R. S., & Kjeldsen, K. K. (2022). Sea-level rise in Denmark: paleo context, recent projections and policy implications. GEUS Bulletin, 49.




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