Where the Waters Are Rising

A close-up look at the low-lying Maldives, where global warming hits the seawall

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CITY ON A LILY PAD: On the capital island of Male, where 80,000 people live less than 4 ft. above sea level, the margin of safety is increasingly slim

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The islands of the Maldives--little circles and half-moons of platinum sand--seem as fragile as they are exquisite. To see them is to marvel--as Charles Darwin did--that they did not long ago succumb to "the all-powerful and never-tiring waves." But as Darwin went on to explain, these islands are more substantial than they seem. They are in fact the visible crests of massive limestone reefs that extend from the sea floor to the surface. The limestone is made of the consolidated skeletons of tiny marine organisms, including untold generations of coral polyps that millions of years ago began growing on the slopes of a long-vanished volcanic mountain chain--and have kept pace with sea level ever since.

This is not to say the Maldives have remained the same over time. Twenty thousand years ago, at the height of the last Ice Age, says Abdulla Naseer, director of the Marine Research Center in Malé, the Maldives were not the low-lying coral islands we see today. Due to frigid ocean temperatures and vast amounts of water locked up as ice, sea levels were some 400 ft. lower then, and the reef crests loomed above the sea's surface as sheer-sided limestone pinnacles. Then, as the earth warmed and the ice melted, the rising ocean overtopped these pinnacles, providing new surfaces for the corals to colonize. Around 5,000 years ago, after the corals brought the reefs close enough to the sea's surface, coral sand and gravel began to accumulate in shallow depressions, and the present-day islands formed.

These islands are extremely dynamic, continuously changing shape in response to shifts in the monsoon winds. Each year, in fact, sand swirls around with the waves; beaches grow in one season and shrink in the next; and this process has been going on for a very long time. Geographer Paul Kench of New Zealand's University of Auckland has collected evidence suggesting that the islands of the Maldives emerged from the sea when their reefs were quite a bit lower than today, meaning that larger, more energetic waves would have slammed into them during a critical formative period. In their natural state, Kench thinks, the islands might prove remarkably resilient in the face of sea-level rise.

Of course, the people who live on such islands want protection from marauding waves, and for millenniums the islands' reefs have provided it. The value of that protection became clear in 1987 after Malé expanded out to the edge of its reef, burying it beneath a thick layer of coral sand and gravel. In April of that year, an armada of giant waves--stirred up, some think, by a distant cyclone in the Indian Ocean--attacked the city, gouging out big chunks of landfill and nearly washing away the car in which Gayoom was riding. A short time later, he gave the first of a series of famous speeches that invoked the image of the Maldives being swallowed by the sea.

With help from the Japanese, the Maldivian government has shored up Malé's perimeters with sea walls and breakwaters (at a cost of $60 million, about 10% of the nation's gross domestic product in 2002). It has also taken steps to protect the living coral breakwaters that shield the rest of the island chain. Among other things, it has banned the mining of coral stone that for centuries has been used by villagers to construct mosques and houses. But what the government can't control is the temperature of the surrounding ocean--and that does not bode well for the future.

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