Climate models calculate, on average, a slight decrease in the number of storms at temperate latitudes in the Northern Hemisphere. Besides, there are indications that the strength of the heaviest storms increases, although these indications are very uncertain.

For the wind climate in Western Europe it is important how global warming may induce changes in air circulation patterns. These determine the number, strength and the path followed by depressions. Therefore, they affect the future torm climate. Model calculations for air circulation patterns in our region vary considerably among themselves.

In the G and W scenarios the maximum daily wind speed per year hardly changes (≤ 1%). The climate models which have been used for the G+ and W+ scenarios show a slight increase in the maximum daily wind speed per year (Figure 12). The strength of the heaviest storms, that currently occur less than once per year, also shows a slight increase above northwest Europe.

The change of the maximum daily wind speed per year of approximately +2% per degree global temperature rise in the G+ and W+ scenarios, is relatively small compared to the natural year-to-year variation and the long term natural fluctuations (Figure 13). In none of the scenarios, the currently observed decreasing trend in the total number of storms in the Netherlands continues to the same degree.

Storm surges along the Dutch coast are associated with storms coming from western to northern directions. The model calculations used for the four scenarios show only small changes in the number of storms from these directions.