Current guidelines on how to account for future sea-level changes and use storm-surge return heights in planning are available from the Directorate for Civil Protection (DSB) (only Norwegian text available): "Havnivåstigning og stormflo - samfunnssikkerhet i kommunal planlegging".

The table shows the same numbers as presented in the guidelines from DSB.

Please note that the DSB recommends that the above numbers should be rounded to the nearest 10 cm before use in planning. Future sea-level changes and storm-surge return heights given here are in the NN2000 height system.

In the vertical datum tab these numbers can be given using alternative reference levels if required.

For future sea level, the projected top of the likely range (95%) for the scenario RCP8.5 and for the period 2081-2100 relative to 1986-2005 is used, as recommended in the guidelines from DSB.

See consequences of sea level changes in an interactive map.

The graph below shows projections of future sea-level change up until 2100 relative to the baseline period 1986-2005. Projections are given for three different greenhouse gas emission scenarios as described in the Fifth Assessment Report from the Intergovernmental Panel for Climate Change (IPCC).

Solid lines show the projected mean sea-level change with the colored area showing the likely range of the projections.

The error bars to the right show the mean and likely range for the period 2081–2100 relative to 1986–2005.

It is also possible to show the observed yearly mean values from the permanent tide gauges. In the table, that can also be downloaded as a PDF-document, you can find the mean and likely ranges for the periods 2041–2060 and 2081–2100 as well as for the year 2100.

Users should note that the projections presented here could be exceeded if the ice sheets respond to global warming faster than expected, for example, if a collapse of the marine-based parts of Antarctica is initiated. This potential additional contribution from Antarctica is not well understood and is an active area of research.

For the time beyond 2100, it is virtually certain that global sea-level rise will continue due to the long response times of the oceans and ice sheets.