The wind plays a significant role in shipping and aviation, in which strong wind flows high up in the atmosphere are used to try to save fuel, particularly on longer journeys. Interest in wind power has also risen in recent years. The market for this energy source has grown explosively in Sweden, and in many other countries around the world, during the last decade.
Perhaps the most important aspect of mankind’s interest in the wind has been – and still is – when constructing various kinds of buildings. How should buildings, bridges and other structures be designed, and how strong do they need to be in order not to risk being destroyed by wind? The destructive power of the wind is also of great interest to Swedish forestry, in which strong storms have had devastating effects over the years on different parts of Sweden’s forest land.
The wind also has a significant impact on the height of water levels along our coasts. When the wind blows towards the coast, it pushes the water towards the land and thus raises the water level at the coast. Conversely, if the wind blows from the land and out over the sea, it can instead lower the coastal water level. This is of great significance for Sweden’s coastal communities in terms of the levels for which existing and future buildings should be planned.
SMHI has analysed how the wind climate across Sweden has varied historically. The main conclusion from this analysis was that no statistically significant trend could be seen in terms of the wind’s characteristics in the country as a whole.
Climate scenarios do not give any clear answers about how wind will change in a future climate at our latitudes. Many complex conditions and relationships control the path, strength and frequency of storms. A warmer sea surface with more water vapour in the atmosphere favours the development of storms.
At the same time, this warming may lead to smaller differences between warm and cool air masses, which plays an important role in the development of intense storms. This in turn can counter the strengthening effect of warming on the development of storms.
The low pressure systems that can develop into storms are generally expected to reduce in number in the northern hemisphere in a warmer climate. Regionally, it is hard to draw conclusions from the scenarios about changes in our region that exceed the natural variability in the system.
This therefore means that there will continue to be more or less stormy years or decades in future, and that this will probably not differ significantly from today’s climate conditions.
Increasing risk of damage
Milder, wetter winters are expected to be more common in a future climate, and ground frost conditions are also expected to change as a result. The risk of storm damage may therefore increase, regardless of wind climate changes.
The pattern of damage is also dependent on other factors that are related more to human behaviour and our vulnerability to infrastructure disruption, not least with regard to our dependency on electricity.