The link between the different levels is important to know when determining lot boundaries, developing the coastal zone, investigating insurance claims etc.
Projections of sea level for different scenarios
The curves present projections of future sea level up to year 2100 compared to the period 1986-2005. The change in sea level depends on the emission scenarios described in the Fifth Assessment Report from the Intergovernmental Panel for Climate Change (IPCC).
Three scenarios are examined here:
- RCP 2.6 is a low emission scenario, where emissions are reduced by 2020.
- RCP4.5 involves small changes in emissions until 2050, followed by reductions in emissions.
- RCP8.5 is a high emission scenario, also known as a «business as usual» scenario, with a continued increase in emissions until 2100.
The curves show the projected mean sea level change with the colored area showing the likely range of the projections. The error bar to the right shows the mean for the period 2081-2100 compared to 1986-2005 and its likely range. More information can be found in this article about the report.
The allowance is the value that has to be added to existing water levels to account for future sea level change for instance for planning purposes. The Directorate for Civil Protection (DSB) has recently published new guidelines on how to use the above sea level projections in practice: Havnivåstigning og stormflo – samfunnssikkerhet i kommunal planlegging (only in Norwegian)
The guidelines recommend that the top of the likely range for RCP8.5 and for the period 2081–2100 be used in planning.
We hope to make these numbers available here at Se havnivå shortly.
For the official storm-surge return levels please see the Water level tab.
The table below shows local GIA. During the last glacial period the land was pressed down owing to the huge weight of ice. The process of GIA describes the ongoing upward movement of the land after this ice load melted. The numbers in the table are computed from Kartverket's GIA model and values for 2030 and 2100 are given relative to 2000.