IMPACT OF POSSIBLE FUTURE CLIMATE ON COASTAL WINDS, STORM SURGES AND WAVE CONDITIONS IN THE NORTH SEA Hans VON STORCH, Arnt PFIZENMAYER, Ralf WEISSE, Katja WOTH, Institute for Coastal Research, GKSS Research Center, Geesthacht, Germany IUGG Sapporo, 7 July 2003, MC08, FUTURE CHANGES IN GLOBAL AND REGIONAL CLIMATE

Series of EU projects WASA ( ) STOWASUS ( ) PRUDENCE ( )

WASA: Mögliche Änderung der Windgeschwindigkeit der größten Stürme bei CO 2 Verdopplung STOWASUS: Ein ähnliches Szenario WASA, Institut für Küstenforschung I f K WASA results: 5 years of T106 2 x CO 2 time slice experiment North Sea wind: increase of up to 0.5 m/s (10%ile)

Kauker and Langenberg, 2001 WASA results: 5 years of T106 2 x CO 2 time slice experiment Mean water level: +10 cm Storm related sea level: + 5 cm

Institut für Küstenforschung I f K Langenberg et al., 1999 WASA results: 5 years of T106 2 x CO 2 time slice experiment

Langenberg et al., 1999 WASA results: 5 years of T106 2 x CO 2 time slice experiment

Zukünftige Szenarien WASA: Mögliche Änderung der Höhen der größten Wellen bei CO 2 Verdopplung CDV-2075: Mögliche Änderung des Überspülens von Deichen bei CO 2 Zunahme Günther et a., 1998 Institut für Küstenforschung I f K WASA results: 5 years of T106 2 x CO 2 time slice experiment North Sea waveheight: increase of up to 0.5 m (10%ile)

Andersen et al., 2001 STOWASUS results: 30 years of T106 2 x CO 2 time slice experiment North Sea wind: increase of up to 2 m/s (0.1%ile)

STOWASUS results: 30 years of T106 2 x CO 2 time slice experiment Flather and Wiliams, 2000 North Sea elevation: increase of up to 40 cm (estimated 50 yr return values) Kaas et al., 2001 North Sea elevation: increase of up to 20 cm (estimated 50 yr return values) RIKZ

STOWASUS results: 30 years of T106 2 x CO 2 time slice experiment Kaas et al., 2001 North Sea waveheight: increase of up to 0.5 m (0.1%ile)

Institut für Küstenforschung I f K Ralf Weisse, 2003 PRUDENCE results: RCM downscaling of HADCM3 A2 scenario, Rossby Center RCAO simulation

Institut für Küstenforschung I f K Katja Woth, 2003 Rossby Center RCAO simulation PRUDENCE results: RCM downscaling of HADCM3 A2 scenario,

Over the years, several projections for the changing storm and storm impact statistics in the North Sea area, related to anthropogenic arming, have been constructed. These projects WASA, STOWASUS and PRUDENCE have been or are funded by the European Commission. Conclusions

The scenarios indicate uniformly for the North Sea: A slight increase of higher wind percentiles of up to m/s. A slight increase of storm surge levels, of up to cm. A slight increase in significant wave height of up to 0.5 m. Conclusions

Climate change Temperature Winter Climate change Precipitation Winter Ole Bøssing Christensen, 2003 PRUDENCE regional scenarios Dynamically downscaled from HADAM3H