Mitigate Climate Change - Sea Level - Ocean Central
Global sea levels are rising by roughly 3.3 millimeters a year, driven by melting glaciers and the thermal expansion of warming water.
This rise is reshaping coastlines, flooding wetlands, submerging habitats such as mangroves and seagrasses, and threatens the livelihoods of millions of people. By 2050, hundreds of coastal cities will likely face chronic flooding and infrastructure loss. Tracking sea level trends is critical for adaptation. Data on sea level changes is available through platforms such as the NASA Sea Level Change Portal and Copernicus Marine Service.
Key Stats
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~3.3 mm/year
Global average annual sea level rise.
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570
Coastal megacities exposed to sea level rise by 2050.
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800 Million
People at risk of displacement from coastal flooding.
NASA (no date) NASA Sea Level Change Portal. Available at: https://sealevel.nasa.gov/ (Accessed: December 12 2025).
Copernicus Climate Change Service, Climate Data Store, (2018): Sea level gridded data from satellite observations for the global ocean from 1993 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/cds.4c328c78
Globally, average sea level has risen 9.9 cm since 1993.
Building Coastal and Ecosystem Resilience
SDG 13.1 calls for strengthening resilience to climate hazards, and SDG 14.2 for protecting and restoring marine ecosystems. Both are critical as sea level rise increases coastal risks and threatens marine habitats, requiring adaptation and ecosystem-based solutions.
Safeguarding Biodiversity Under Climate Pressure
The Kunming-Montreal Global Biodiversity Framework target 8 aims to minimize climate change impacts on biodiversity and boost ecosystem resilience. Rising seas drive habitat loss, making stronger adaptation and protection measures essential.
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Data Frequency
The number of years of available data.
32Years
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Data Quality
Sufficient - At least 2 data points available for trend analysis AND at least one data point in the last 7 yearsInsufficient – Does not have any data at all for analysis Expired – Does not have any data in the last 10 years Not Recent – At least one data point in the last 8 to 10 years Recent – At least one data point in the last 7 years Sufficient – At least 2 data points available for trend analysis AND at least one data point in the last 7 years
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Global Goal(s)
2050 Goal - Low QualityNone – No Global Goal Established Low – The goal is broad Medium – The goal is specific High – The goal is measurable
There is still so much we do not know about our oceans.
Join us in filling critical gaps in ocean data.
Sea level rise is accelerating as ice sheets in Greenland and Antarctica melt at record rates.
Roughly 60% of global sea level rise comes from ice melt, with the remaining caused by thermal expansion. Low-lying nations and deltas are especially vulnerable, where high tides already overlap with storm surges, transforming ordinary weather events into floods.
To manage these escalating risks, countries are adopting nature-based solutions such as living shorelines, early warning systems, and managed retreat strategies. These approaches offer viable pathways to protect lives, infrastructure, and ecosystems. However, progress remains uneven due to gaps in high-resolution elevation data, complex legal and social challenges linked to relocation, and insufficient climate finance—particularly in vulnerable developing regions.
Effective adaptation will require coordinated global investment, stronger governance, and local empowerment to ensure that no coastal community is left behind.
Rising seas are driven mainly by thermal expansion of warming seawater and melting land-based ice sheets and glaciers. These processes, intensified by greenhouse gas emissions, vary regionally due to ocean currents, land subsidence, and climate patterns.
Horwath, M., Gutknecht, B. D., Cazenave, A., Palanisamy, H. K., Marti, F., Marzeion, B., Paul, F., Le Bris, R., Hogg, A. E., Otosaka, I., Shepherd, A., Döll, P., Cáceres, D., Müller Schmied, H., Johannessen, J. A., Nilsen, J. E. Ø., Raj, R. P., Forsberg, R., Sandberg Sørensen, L., Barletta, V. R., Simonsen, S. B., Knudsen, P., Andersen, O. B., Ranndal, H., Rose, S. K., Merchant, C. J., Macintosh, C. R., von Schuckmann, K., Novotny, K., Groh, A., Restano, M., and Benveniste, J.: Global sea-level budget and ocean-mass budget, with a focus on advanced data products and uncertainty characterisation, Earth Syst. Sci. Data, 14, 411–447, https://doi.org/10.5194/essd-14-411-2022, 2022.
Globally, 60% of sea level rise is due to melting ice sheets and glaciers.
Sea level rise is increasing flood risks worldwide, with regional coastal trends showing uneven impacts depending on geography and climate. Low-lying coastal cities face the greatest threat, where large populations and critical infrastructure are at risk of inundation.
Explore flood risk by scenario at Coastal Risk Index.
National Oceanic and Atmospheric Administration (NOAA) Center for Operational Oceanographic Products and Services (n.d.) Sea Level Trends. Available at: https://tidesandcurrents.noaa.gov/sltrends/ (Accessed: 24 July 2025).
U.S. Global Change Research Program (no date) Sea Level Explorer – Global Sea Level Change. Available at: https://earth.gov/sealevel/sea-level-explorer/?type=global&scope=section_1 (Accessed: December 12 2025).
Kulp, S.A., Strauss, B.H. New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding. Nat Commun 10, 4844 (2019). https://doi.org/10.1038/s41467-019-12808-z
Sea level rise threatens vital coastal ecosystems such as saltmarshes and mangroves, which provide critical habitat, store carbon, and buffer shorelines. As seas encroach, these ecosystems face loss, fragmentation, and reduced capacity to support biodiversity.
Bunting P., Rosenqvist A., Lucas R., Rebelo L-M., Hilarides L., Thomas N., Hardy A., Itoh T., Shimada M. and Finlayson C.M. (2018). The Global Mangrove Watch – a New 2010 Global Baseline of Mangrove Extent. Remote Sensing, 2018, 10, 1669; https://doi.org/10.3390/rs10101669
Ward, P.J., Winsemius, H.C., Kuzma, S., Bierkens, M.F.P., Bouwman, A., De Moel, H., Díaz Loaiza, A., Eilander, D., Englhardt, J., Erkens, G., Gebremedhin, E.T., Iceland, C., Kooi, H., Ligtvoet, W., Muis, S., Scussolini, P., Sutanudjaja, E.H., Van Beek, R., Van Bemmel, B., Van Huijstee, J., Van Rijn, F., Van Wesenbeeck, B., Vatvani, D., Verlaan, M., Tiggeloven, T. and Luo, T. (2020) Aqueduct Floods Methodology: Technical Note. Washington, D.C.: World Resources Institute. Available at: https://www.wri.org/research/aqueduct-floods-methodology. (Accessed: 25 July 2025).
Globally, 99.9% of mangroves are exposed to sea level rise in 2080 under a high emissions scenario (SSP5-RCP8.5).
Mcowen C, Weatherdon LV, Bochove J, Sullivan E, Blyth S, Zockler C, Stanwell-Smith D, Kingston N, Martin CS, Spalding M, Fletcher S (2017). A global map of saltmarshes (v6.1). Biodiversity Data Journal 5: e11764. Paper DOI: https://doi.org/10.3897/BDJ.5.e11764 ; Data DOI: https://doi.org/10.34892/07vk-ws51
Ward, P.J., Winsemius, H.C., Kuzma, S., Bierkens, M.F.P., Bouwman, A., De Moel, H., Díaz Loaiza, A., Eilander, D., Englhardt, J., Erkens, G., Gebremedhin, E.T., Iceland, C., Kooi, H., Ligtvoet, W., Muis, S., Scussolini, P., Sutanudjaja, E.H., Van Beek, R., Van Bemmel, B., Van Huijstee, J., Van Rijn, F., Van Wesenbeeck, B., Vatvani, D., Verlaan, M., Tiggeloven, T. and Luo, T. (2020) Aqueduct Floods Methodology: Technical Note. Washington, D.C.: World Resources Institute. Available at: https://www.wri.org/research/aqueduct-floods-methodology. (Accessed: 25 July 2025).
Globally, 97.6% of saltmarshes are exposed to sea level rise in 2080 under a high emissions scenario (SSP5-RCP8.5).
Acting now to address sea level rise is critical to safeguard marine ecosystems and the communities that depend on them.
Taking Action
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Strengthen Coastal Defenses
Build nature-based solutions like mangroves, wetlands, and oyster reefs to buffer rising seas.
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Adapt Urban Infrastructure
Elevate, relocate, or redesign critical assets in low-lying cities.
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Enhance Monitoring and Early Warning Systems
Expand satellite and tide gauge networks for better projections and early warnings.
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Mitigate Emissions
Reduce greenhouse gas emissions to slow ice melt and thermal expansion.
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Protect Displaced Communities
Develop legal and financial frameworks for climate migration.
View relevant data layers on the globe using the available map toggle in the top right of each card in the left panel.
View relevant data layers on the globe using the available map toggle in the top right of each card in the left panel.
View relevant data layers on the globe using the available map toggle in the top right of each card in the left panel.