Percentage change in annual precipiation from 1961-1990 to 2071-2100
Sources: Norwegian Water Resources and Energy Directorate and the Norwegian Meteorological Institute
- Precipitation is expected to continue to increase throughout the country. Annual precipitation levels for Norway will increase by 5 to 30 per cent towards the end of the century.
- Precipitation is expected to increase in all seasons and in all parts of the coutry, but we may still experience a few years with less precipitation in some parts of the country. Towards the end of the century, winter precipitation may increase by as much as 40 per cent in some parts of eastern, southern and western Norway.
- Summer precipitation in eastern and southern Norway is likely to decrease towards the end of the century. Apart from that, precipitation will increase for all seasons and all regions. However, the major natural variations may still entail a reduction in local precipitation levels for some decades.
- There will be more days with a lot of precipitation, and the average precipitation level during these days will be higher for all of Norway and for all seasons.
More floods, avalanches and landslides
Flood projections are highly uncertain. In general, however, floods are expected to increase in extent. However, there are great local variations. In some areas, flooding is projected to increase significantly, whereas other areas may see a reduction.
- Higher temperatures will result in spring floods earlier in the year and increase the risk of flooding in late autumn and in the winter.
- Melt water flooding will decrease in the long term, whereas rain flooding may increase, particularly in small, steep areas.
An increase in the number of days with heavy precipitation will increase the risk of landslides and avalanches in hilly areas.
- There is a clear connection between precipitation and various types of avalanches. Higher temperatures could reduce the risk of dry avalanches, but will increase the risk of wet avalanches and sludge avalanches in avalanche-prone areas. These could occur in other places than previously.
- The risk of landslides may increase from Trøndelag and northwards. The reason is the increased risk of heavy rainfall. Steep terrain will be particularly vulnerable.
Run-off of particles and nutrients from agricultural areas will increase, especially through rain on frozen and bare soils and frequent thawing and freezing.
Modest increase in wind speed
A modest increase in wind speed is expected. The increase will be most significant in autumn, when the average wind speed per day will increase by up to 0.5 m/s along the coast and in most of the mountain ranges. Wind speeds over 15 m/s will be more common in the North Sea, Skagerrak and off the coast of Finnmark.
Uncertain modelling factors
There is still considerable uncertainty regarding the regional impacts of climate change. Both nationally and internationally there is much focus on the issue, and researchers are working to gradually develop more reliable scenarios. For Norway, the uncertainty especially concerns the coastal areas north of the country. In addition, it is difficult to estimate short periodes of strong winds over land, due to Norway’s varied geography.