Global Modelling: Managing Uncertainty Complexity and Incomplete Information

Human activities change the environment on a global level. Global modelling is used to derive insights in the interactions between humans and the ir environment. However, the possibility to validate those global models is limited. In fact, t oo little information is available, many subjective assumptions are made and a single model cannot cover all relevant scale levels and processes. These limitations already appeared in th e early seventies. Current global modelling activities still deal with the same dilemma’s, ofte n in the same way as the strongly criticised world models of the early seventies. We sketch some rec nt developments which can help to manage the persistent dilemma’s. We focus on the us e of different modelling paradigms and on the use of different world views to analyse the con sequences of subjective assumptions to be made in global models. keywords global modelling, validation, complexity, uncertain ty