Presentation delivered as part of Darwin College Lecture Series 2010 - Risk on 2010 February 26th at Darwin College, University of Cambridge.
Abstract: Natural catastrophes – rare, high-consequence events – present us with a unique conjunction of problems so far as risk is concerned. First, they can have an extremely long recurrence interval, so long that the greatest may not have occurred within living human memory. Secondly, the effects of events with which we are all too familiar, for example earthquakes, floods, volcanoes and storms, are easily trumped by the impacts of objects – comets and asteroids – that reach Earth from outer space; and thirdly, the largest of these events have a global reach, in principle threatening not just our civilisation but perhaps life on Earth itself. However, recognising that such events occur very rarely, should we 'make hay while the sun shines' and ignore, ostrich-like, the significant actuarial risk; or should we seek to understand the phenomena and develop strategies to mitigate the threat and perhaps technologies to avert it? Our response often depends less on a purely rational assessment than on personal circumstances and how we have been brought up, but in any case, the nature of the risks, which are poorly understood, means that we must be prepared to handle the law of unintended consequences (i.e. could our actions make things worse?). We must also be prepared to explore what happens if, perhaps inevitably, our current scientific understanding turns out to be less certain than many experts believe.
Last Revised: 2010 March 2nd