Climate change impact on extreme wave conditions in the North Sea

The North Sea is characterized by densely populated and highly industrialized coasts, by offshore activities, and by busy shipping routes. The areas along the coasts and the human activities are vulnerable to storms, storm surges and wind waves generated by these storms. Anthropogenic climate change may cause long-term changes in the wind and wave conditions of the North Sea which could have significant impacts on human safety (e.g. coastal protection) and activities. At the Institute for Coastal Research four climate projections for the wave conditions in the North Sea for 2071-2100 were compared to reference simulations for 1961-1990 to estimate possible future changes in case of anthropogenic climate change. The results of this study were now published in "Ocean Dynamics".

DThe analysis of the four climate realizations shows that there are large uncertainties in the magnitude and the spatial patterns of the climate signals. For large parts of the southern and eastern North Sea extreme wave heights may increase by about 0.25 to 0.35 m (5-8 % of reference values) towards the end of the 21st century (Fig. 1). This increase is associated with an increase in future frequency of extreme wave heights and in their duration. In detail the four climate projections show significant differences. These differences result from the two different scenarios of future emissions (different future development in socio-economy) and from the driving climate models. Generally, the model caused differences are larger than the scenario caused differences and are in the same order of magnitude as the estimated changes in future extreme wave heights.

The results of the study were published in

Grabemann and R. Weisse, 2008. Climate change impact on extreme wave conditions in the North Sea: an ensemble study. Ocean Dynamics 58, 199-212, 10.1007/s10236-008-0141-x




Figure 1. Long-term 99 percentile significant wave height in meters for 1961-1990 as obtained from one of the reference simulations (left) and mean climate change signal for long-term 99 percentile significant wave height in meters for 2071-2100 (right). Shading indicates areas where the climate change signal has at least the same sign in all four climate projections (orange: positive, blue: negative).


Iris Grabemann
GKSS Research Centre
Institute for Coastal Research
Coastal Climate

Max-Planck-Straße 1
21502 Geesthacht

Email: iris.grabemann[at]