In May 2008, Cyclone Nargis killed more than 100,000 people in southern
….James Elsner, a climatologist at
The team statistically analysed satellite-derived data of cyclone wind speeds. Although there was hardly any increase in the average number or intensity of all storms, the team found a significant shift in distribution towards stronger storms that wreak the greatest havoc. This meant that, overall, there were more storms with a maximum wind speed exceeding 210 kilometres per hour (category 4 and 5 storms on the Saffir–Simpson scale).
Rising ocean temperatures are thought to be the main cause of the observed shift. The team calculates that a 1 ºC increase in sea-surface temperatures would result in a 31% increase in the global frequency of category 4 and 5 storms per year: from 13 of those storms to 17. Since 1970, the tropical oceans have warmed on average by around 0.5 ºC. Computer models suggest they may warm by a further 2 ºC by 2100.
…The results, says Peter Webster, a hurricane expert also at the Georgia Institute of Technology, add urgency to the need to find ways of improving forecasting and warning systems, particularly for poorer countries. "A warning lead time of two days may be long enough here, but it is clearly not long enough in
…"People should now stop saying 'who cares, storm activity is just a few per cent up'," says Curry. "It's the strongest storms that matter most."Tropical cyclone Nargis making landfall, NASA, Wikimedia Commons