Iceland

Coastal flood risk Iceland

The thinning of large glaciers, such as the Vatnajökull ice cap, one of Europe's largest ice masses, reduces the load on the Earth's crust which rebounds. Consequently large parts of Iceland are now experiencing uplift. The uplift does not, however, reach to the urban south west part of Iceland, where subsidence is occurring (1,14).

The uplift along the south coast may reduce the impacts of rising global sea levels during the 21st century. If subsidence continues in the south west part of Iceland, it will exacerbate the impact of rising sea levels. Measurements in Reykjavik show that relative sea level rise was 5.5 mm/year from 1997 - 2007. Once these results have been adjusted to account for local subsidence, absolute sea level in Reykjavik during this period was about 3.4 mm/year, which is close to the global sea level rise (1).

Sea level rise is a concern, as the population is primarily located in settlements along the coast. Available measures to minimise consequent damages to roads, harbours and property are being assessed. Potential sea level rise will be taken into account when harbour infrastructure needs to be rebuilt (2).

Future absolute sea level rise in Iceland will probably be much less than the global average: the melting of the Greenland ice sheet will affect the gravitational field around Greenland in a way that, with other things being equal, would lower sea level in the vicinity of Greenland, including Iceland (14). 

Global sea level rise

Observations

For the latest results: see Europe Coastal floods

Projections

For the latest results: see Europe Coastal floods

Extreme water levels - Global trends

More recent studies provide additional evidence that trends in extreme coastal high water across the globe reflect the increases in mean sea level (6), suggesting that mean sea level rise rather than changes in storminess are largely contributing to this increase (although data are sparse in many regions and this lowers the confidence in this assessment). It is therefore considered likely that sea level rise has led to a change in extreme coastal high water levels. It is likely that there has been an anthropogenic influence on increasing extreme coastal high water levels via mean sea level contributions. While changes in storminess may contribute to changes in sea level extremes, the limited geographical coverage of studies to date and the uncertainties associated with storminess changes overall mean that a general assessment of the effects of storminess changes on storm surge is not possible at this time.

On the basis of studies of observed trends in extreme coastal high water levels it is very likely that mean sea level rise will contribute to upward trends in the future.

References

The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Iceland.

1. Ministry for the Environment of Iceland (2007)
2. http://www.scotland.gov.uk
3. Bindoff et al. (2007), in: IPCC (2012)
4. Church and White (2011), in: IPCC (2012)
5. Velicogna (2009); Rignot et al. (2011); Sørensen et al. (2011), all in: IPCC (2012)
6. Marcos et al. (2009); Haigh et al. (2010); Menendez and Woodworth (2010), all in: IPCC (2012)
7. Cazenave et al. (2014)
8. IPCC (2014)
9. Watson et al. (2015)
10. Yi et al. (2015)
11. Church et al. (2013), in: Watson et al. (2015)
12. Shepherd et al. (2012), in: Watson et al. (2015)
13. Church et al. (2013), in: Watson et al. (2015)
14. Icelandic Ministry for the Environment and Natural Resources (2018)