Future mean sea level - Based on data from IPCC AR6 WG 1 (2021)

Description

The future mean sea level in RH 2000 and the approximate future position of the shoreline along the Swedish coast are calculated for several different scenarios and for each decade from 2030 to 2150. The data are based on regional projections from the IPCC's compilation "AR6 Interim Report 1 - The Scientific Basis" published in August 2021. The calculations are adjusted for the local land uplift. The calculations are based on projections, which the IPCC considers likely, for five different emission scenarios: SSP1-1,9, SSP1-2,6, SSP2-4,5, SSP3-7,0 and SSP5-8,5. In addition to these, there are two calculations based on projections that the IPCC deems less likely, as they include processes associated with deep uncertainty related to the instability of the ice sheets: SSP1-2,6 less likely and SSP5-8,5 less likely. Three different levels are given for each scenario and decade. The three levels are the median and the 17th and 83rd percentiles. The extremes are not shown, i.e. neither the highest possible level nor the lowest possible. Data on future mean sea level in cm in RH 2000 are available for download in CSV format for each coastal municipality in Sweden (87). The levels can also be viewed in an interactive table at https://www.smhi.se/climate/rising-sea level/future-medium water level-1.165493 . Details of the future location of the shoreline are available for download in SHAPE format for the respective year and likely or less likely scenario. These can also be consumed via a WMS service. The mean sea level in cm in RH 2000 is available for download in TIFF format for the respective year and likely, or less likely scenario. LIMITATIONS The geographical extent of the map layers is limited to the area between about 10 km off the shoreline and 1.0 - 1.5 km inside the shoreline. Larger watercourses and lakes located within this area may have a sharp boundary in the map layers. Islands less than 1000 km2 are filtered out and are not included in the map layers. Comment on data in CSV format The future mean sea level for each SSP scenario and year may vary between grid cells within a coastal municipality. This is mainly due to variations in the rate of land uplift, especially in municipalities spreading north-south. The largest difference in long-term land uplift within its coastal area is Gotland, where it differs barely 1.8 mm / year between different areas. This gives a difference of 9 centimeters in 50 years. The average sea level during the reference period (1995-2014) can also vary within a municipality's coastal area, but these are minor variations of up to about 4 centimetres. The future mean sea level is therefore provided as an average for each coastal municipality. Comments on the map layers: 1. The mean water levels are combined with topographic information from Lantmäteriet. Areas with an altitude level lower than the calculated mean water level are classified as permanently flooded. Any variation in the accuracy of the topographic information may affect the outcome of the map layers. There may also be newer or more detailed topographic information than was used when the map layers were created. 2. The topographical map data used in the calculations may lack detailed information on where there are or are missing natural or constructed obstacles or passages between land and sea. This means that land that is lower than the future sea level, can appear as flooded even though in reality there may be obstacles for the sea to reach there. 3. There are instances where land rise in parts of Sweden is greater than sea level rise. This means that the sea level in the near future will be lower than it is today. In these places, where land rises faster than the sea rises, the future sea level is shown as if it were unchanged, i.e. at the same level as today. 4. Possible effects on the coastline of a change in mean sea level (e.g. erosion) cannot be deduced from the map layers. USE The average sea level determines where the sea surface and shoreline are normally located. The data can be used to study possible future mean water levels based on different emission scenarios and years. The data provides a comprehensive basis for information on future sea levels. The aim is not to provide a complete basis for decision-making, but to give an indication of the areas in which a more detailed basis should be developed. When there is a lot of wind, the sea can rise sharply above the mean sea level for a short time. This is called a high tide event. In the planning context, there may be a need to take into account also high tide events, wave effects and the like. High-water events and wave effects are not included in the data on future mean water levels. Read more about this on the following website: https://www.smhi.se/climate/ascending-sea-nivas/hog water tradeser-and-extremnivas-1.165445.

Resources

Name Format Description Link
0 https://opendata-download.smhi.se/framtida_medelvattenstand/baserat-pa-ipcc-ar6-wg-1-2021/raster
0 https://opendata-download.smhi.se/framtida_medelvattenstand/baserat-pa-ipcc-ar6-wg-1-2021/csv
0 https://www.smhi.se/klimat/stigande-havsnivaer/framtida-medelvattenstand-1.165493
0 https://opendata-download.smhi.se/framtida_medelvattenstand/baserat-pa-ipcc-ar6-wg-1-2021/shape
0 https://opendata-view.smhi.se/SMHI_medelvattenstand/wms?service=WMS&request=GetCapabilities

Tags

  • öppna-data
  • oceanografi
  • havsvattenstånd

Topics

  • ENVI

Categories