Temps de lecture :2 minutes
The science behind predicting disasters is uncertain. But with the best geological and meteorological knowledge in hand, along with models that assess the vulnerability of different populations, experts are starting to quantify just how grim the future will be. Steve Sparks, a volcanologist at the University of Bristol, UK, has looked at analyses of current trends by the German reinsurance firm Munich Re. “The world can now expect three to five major events per year, which each kill more than 50,000 people,” he says.
The mechanisms behind these disasters are not new; the basic factors that underlie volcanic eruptions, earthquakes, cyclones and floods are well understood, and so is the geographic distribution of risk. But there are still three mysteries: where and when a disaster will strike; what unforeseen consequences there might be; and how to get policy-makers and the public at large to take the problems, and the uncertainties, seriously.
Public preparedness rarely keeps pace with scientific knowledge. “The science,” says Sparks, who recently organized a meeting on natural disasters at the Royal Society in London, “is not getting through to policy-makers, planners and populations.” US meteorologists had often warned that their worst-case hurricane scenario would involve a storm breaking the protective levees around low-lying New Orleans. And that’s exactly what happened on 29 August with Katrina, which left 1,300 dead – the largest death toll from a natural disaster in the United States since the 1928 Okeechobee Hurricane. […]
The very enormity of the Indian Ocean tsunami is, in fact, a good example of unforeseen consequences. The seismic risk in the area was known, but the scope of the resulting tsunami, which affected a dozen countries, was totally unexpected. Unlike in Hawaii and Japan – where tsunamis are a relatively frequent phenomenon, and where education projects and early-warning systems exist – many people in southeast Asia, India and eastern Africa had never even heard of such waves. […]
Nature vol. 438,
December 15, 2005, p. 903-906