Bangkok is one of 13 of the world’s largest 20 cities at risk of being swamped as sea levels rise in coming decades, according to warnings at the recent Intergovernmental Panel on Climate Change held here.
The still expanding megapolis rests about 3 1/2 to 5 feet above the nearby gulf, although some areas already lie below sea level. The gulf’s waters have been rising by about a tenth of an inch a year, about the same as the world average, says Anond Snidvongs, a leading scientist in the field.
But the city, built on clay rather than bedrock, has also been sinking at a far faster pace of up to 4 inches annually as its teeming population and factories pump some 2.5 million cubic tons of cheaply priced water, legally and illegally, out of its aquifers. This compacts the layers of clay and causes the land to sink.