World Spotlight: The Next Killer Cyclone

Cyclone Sidr, the category-4 storm that swept through Bangladesh on Nov. 15, killed more than 3,000 people. And while officials say the death toll could eventually reach 10,000, many are thankful that it wasn't higher. Sidr took far fewer lives than some previous Bangladeshi storms: 1991's Cyclone Gorky killed approximately 140,000 people. Cyclone Bhola, in 1970, left as many as 500,000 people dead and is the deadliest cyclone on record.

Bangladesh has gotten better at dealing with severe weather. Over the past decade, the country's early-warning and preparedness systems have improved considerably. Under Fakhruddin Ahmed, effectively the country's Prime Minister, officials evacuated some 3.2 million people who lived along the coastline, and the government stockpiled rescue and relief supplies in the days before Sidr hit. But keeping death tolls down is likely to get harder. Scientists believe that global warming will make cyclones in the region bigger and more frequent.

That's bad news for the low-lying nation, whose location and topography make it particularly susceptible to the effects of climate change and also hard to protect. Most of the country sits on a giant alluvial delta whose rivers are constantly shifting, making it difficult to build up protective banks or large dikes to hold back the sea. "The soil isn't steady as such--it's mud," says A. Atiq Rahman, a member of the Intergovernmental Panel on Climate Change. As sea levels rise in the coming decades and as rivers swell with water from melting Himalayan glaciers, vast swaths of the country might disappear, sparking an exodus of climate refugees. The question is, Where will they go?