Developing hedging strategies for the unexpected

One of the major challenges to policy makers concerned with sustainable development is how to cope with surprises and discontinuities, whether favourable or adverse, and how to develop contingency plans or "hedging" strategies that take into account not just the probable trends, but also the unexpected. Recent examples of surprises include the discovery of the Antarctic "ozone hole", the catastrophic accidents at Chernobyl and Bhopal, the dramatic spread of the AIDS epidemic worldwide, or the scientific discoveries leading to the rapid development of biotechnology. Such surprises often produce a huge societal response and rapid shifts in science and technology priorities. None of these events are foreseeable, especially as to their timing relative to many other political or technological developments.