This paper argues that, both in the natural and life sciences and in the social sciences, we urgently need to develop a trans-disciplinary approach to environmental problems which does away with the presumed differences between "cultural" and "natural" processes. This may usefully be achieved by drawing upon the conceptual apparatus provided by the "Complex Systems" approach. In such a "socio-natural" perspective, the key concept is resilience (rather than sustainability). The resilience of socio-natural systems is in many situations dependent on the capacity of the human societies involved to process in the time available all the information necessary to deal effectively with the complex dynamics of the system as a whole. The paper then sketches how human institutions may be conceived of as self-organising, information processing, flow-structures. It then asks how the dynamics of these affect the resilience of a socio-natural system, and defines a number of parameters that may be used to gauge that resilience. The first group of these concerns all the external parameters of a disturbance, and the second those that relate to the reactivity of the system to such a disturbance. The paper ends with a brief outline of an example Ð the study of two successive crises in the Comtat area in France, one century apart. In the first crisis, the area was very resilient, and in the second it was not. The paper points to a number of the interacting factors that may be held accountable for the difference in response.