Climate scenarios used by the climate panel IPPC reveal a possible future climate, which is notmeant to be used as a climate prediction. However, such scenarios are misused frequentlyto determine policy and strategy, for instance infrastructure, water management and energyfacilities. On 15 March 2010, Jason Frank, researcher at the Centrum Wiskunde & Informatica,was appointed full professor Dynamical Systems and Numerical Analysis at the University ofAmsterdam. In his inaugural lecture, delivered on 21 April 2011, he gives a mathematicalview on the predictability of natural systems, such as the climate system, and looks at thechallenges, techniques and the role of computational methods.