PREDICTING CHANGE IN NONLINEAR-SYSTEMS

Complex systems are characterized by surprising switches to new behavi ours. Evaluating and predicting these changes demands an understanding of the behaviour of the whole system. The combined ecosystem-climate system shows chaotic or pseudorandom behaviour, stochastic or truly ra ndom behaviour, as well as simple bifurcation and semi-stability. Semi stability involves the sudden change from a destabilized 'attractor' t o a new stable attractor which may occur after an apparently unpredict able time delay. We present some recent results for analyzing time ser ies data and for using simulations of non-linear models to predict the se changes.