Percentage change in annual precipiation from 1961-1990 to 2071-2100
Sources: Norwegian Meteorological Institute and Norwegian Water Resources and Energy Directorate, 2008
Increased precipitation
- Annual precipitation will continue to increase throughout the country, from 5 per cent in the south east to 20 per cent in the south west and on the coast of Finnmark.
- In autumn, precipitation will increase by over 20 per cent throughout most of the country. The increase will be most significant in the west and north of Norway.
- Extreme precipitation will be more common across the country, especially in Western Norway and in the north; in Troms and Finnmark.
- Sunny weather and drought will be more common during the summer in Eastern and Southern Norway.
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.
Increased risk of high seas and storm surge
The most significant increase in wave height will occur off the coast of Troms and Finnmark. Estimates show that in the most extreme cases wave heights will increase by one meter during the most powerful storms in the Barents Sea.
For the most powerful storms, an increase in storm surges has been estimated. For Bergen, on the west coast, this increase is calculated to be 7 centimetres, which is far less than the estimated increase of up to 40 centimetres on the west coast of Denmark.
More winter floods, fewer spring floods
There may be a considerable increase in floods during late autumn and winter for some areas, while in spring there may be reduced and earlier snow-melting floods. Altered precipitation patterns may also result in more frequent landslides and rockslides. Run-off of particles and nutrients from agricultural areas will increase, especially through rain on frozen and bare soils and frequent thawing and freezing. The increase in temperature and precipitation will also affect the energy sector. Hydroelectric power generation is expected to increase, while heating needs will decline in winter.
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.