5. “… one flap of a sea-gull’s wing may forever change the future course of the weather” (Lorenz, 1965)

6. 2-Day Ensemble Forecast from 24/12/99

7. Destruction of the church in Balliveirs (left) and the devastation of the ancient forest at Versailles (below). European Wind Storms: December 1999 100 lives lost 400 million trees destroyed

8. Ensemble techniques are being used to estimate uncertainty in global warming Murphy et al (2004) Stainforth et al (2005)

9. Ensemble members differ in the values of uncertain parameters in simplified representation of unresolvable eg cloud processes (< 300km)

10. IPCC (2001) range Previously unknown risk of catastrophic warming Stainforth et al (2005) Probability of Global Warming

11. The LACES Project Large Atmospheric Computation on the Earth Simulator 12-h development of Hurricane Earl: Sept.1, 1998: 1-km horizontal resolution