Disappearing world wonders

Maldive Islands

Country: Republic of Maldives
At stake:
$490 million

On the Ground: This chain of islands in the Indian Ocean is about three feet above sea level, and scientists fear it could be submerged by 2050. A $63 million buffer built in the 1990s hasn’t solved the problem, so the government is in talks to relocate all 386,000 of its residents to either Sri Lanka, Australia, or India. That would end the Maldives’ tourism industry—more than 600,000 people visit annually—which accounts for 30 percent of the country’s gross domestic product.

By the numbers: The Maldives could be completely submerged as early as 2050.

Dalmation Coast

Country: Croatia
At stake:
$9 billion

On the ground: The Dalmatian coast, with its picturesque white beaches, became a travel-media darling about a decade ago. Since 1999, the annual tourist count has shot up from 5 million to 11 million. To help boost revenue in its tiny seaside villages, Croatia initially encouraged foreign investment in the villas that dot its coast. But last year, the government reversed its position, imposing a new set of laws on villa owners that requires them to register for business as well as ­residential permits, a process that can take as long as a year. The new layer of red tape has scared away ­foreign ­investment and is threatening Croatian tourism revenue, which makes up 12 percent of the country’s GDP.

By the numbers: Since 1999, the annual tourist count has shot up from 5 million to 11 million.

Great Barrier Reef

Country: Australia
At stake:
$46 million

On the ground: Because of heavy tourist traffic, ocean acidification, and rising water temperatures, the 135,000 square miles of live coral off Australia’s northeast coast are shrinking rapidly. To slow the erosion, the Great Barrier Reef Marine Park Authority has imposed limits on ship passage and has blocked off some areas surrounding the reef to oversize yachts and cruise lines like Royal Caribbean. So far, these measures have had little impact: In January, the Australian Institute of Marine Science released a study stating that the coral’s natural growth has decreased by 14 percent since 1990. Experts say that by 2050, water temperatures will rise by 1.5°C and the reef will have lost about 95 percent of its living coral.

By the numbers: By 2050, the reef will have lost an estimated 95 percentof its living coral.

Mount Kilimanjaro

Country: Tanzania
At stake:
$1 billion

On the ground: About 15,000 climbers tackle Kilimanjaro each year, making the mountain one of the world’s most popular climbs. But the glaciers that cover the landmark are receding rapidly. They’ve lost 84 percent of their ice since 1912 and today cover less than one square mile. Scientists believe the glaciers could be gone completely by 2020, taking with them Tanzania’s main tourist draw. As a result, travelers are flocking to the mountain in greater numbers than ever before. Some of them are combining troubleshooting with sightseeing to help alleviate the problem: Abercrombie & Kent offers expeditions in which travelers (paying $8,195 apiece) deliver weather-monitoring devices to various spots on the cliffs.

By the numbers: Mount Kilimanjaro’s glaciers have lost 84 percent of their ice since 1912.

The Alps

Country: Switzerland
At stake:
$17 billion

On the ground: More than 8 million people travel to Switzerland every year, many of them to ski the country’s world-famous Alps. Because of global warming, it is estimated that about 40 percent of the mountain range’s pristine skiing areas will disappear by 2100. Low-altitude destinations are especially susceptible because of their warmer temperatures, and owners have already had to turn to artificial snow to get through the season. The owner of one ski complex in Ernen sold his property to a British businessman for one Swiss franc last year. Other spots—like the $125 million InterContinental Davos, slated to open in 2011—are scrambling to add attractions that don’t require snow, such as indoor sports facilities and spas.

By the numbers: About 40 percent of the Alps’ skiing areas will disappear by 2100.

Galápagos Islands

Country: Ecuado
At stake: $418 million

On the ground: The number of visitors to the archipelago, where Charles Darwin developed his theory of evolution, has increased from 40,000 to 180,000 since 1990; air traffic, meanwhile, has risen by 193 percent since 2001. Those trends are likely to accelerate this year, the 200th anniversary of Darwin’s birth. Even today, scientists consider the Galápagos to be the world’s purest biodiversity environment, so they’re especially concerned about the way the traffic surge will affect the islands’ life forms. They consider 39 percent of animal species, 50 percent of marine species, and 59 percent of plant species to be threatened. To curb the problem, Ecuador is considering setting a yearly tourist cap and imposing an entry fee of up to $300.

By the numbers: Since 1990, visitors to the Galápagos have more than quadrupled, to 180,000.