출처 : http : / / travel . yahoo . com / p - interests - 3941237710 Natural Wonders to See Before They DisappearBy Sean O ' Neill 10 Smallest Bars in the World 9 Record - Breaking Theme - Park Thrills 10 Most Beautiful Churches More from Yahoo ! TravelCheck flight deals now ! Tips for Wellness on the RoadYou ' ve heard the grim timelines : if warming continues , the Great Barrier Reef will be bleached by 2030 ; glaciers in the Swiss Alps , on Mt . Kilimanjaro , and in Glacier National Park will disappear in under 40 years ; and Arctic ice melt will leave the North Pole bare and polar bears extinct . The immediacy of these timelines prompts flocks of curious eco - tourists to travel to environmentally fragile areas . Tourism is both bane and boon : it can add strain to already distressed areas , but it can also provide income , which in turn can help preserve these wonders . In time for Earth Day , we spotlight 10 areas under threat — some lesser known than others — that can still be visited responsibly . 1 . Belize Barrier ReefOne of the most diverse reef ecosystems in the world is home to whale sharks , rays , and manatees , as well as sturgeon , conch and spiny lobsters . The Threat : Like the Great Barrier Reef in Australia , the Belize Barrier Reef leads a tenuous existence . A section of the nearly 700 - mile - long Mesoamerican Reef that reaches from Mexico to Honduras , the Belize reef suffered a severe bleaching in 1998 , with a loss of 50 percent of its coral in many areas , including much of its distinctive staghorn coral . Since the bleaching , its decline has continued , due to global warming of the world ' s seas , agricultural pollution , development , and increasing tourism , which has given rise to more coastal development and an invasion of cruise ships . The Belize Barrier Reef is one of the most diverse reef ecosystems in the world , home to whale sharks , rays , and manatees as well as sturgeon , conch and spiny lobsters . Perhaps the most famous site from the reef is this one , of the Great Blue Hole . Photo : Courtesy Samuel Chow / Wikimedia CommonsMore from BudgetTravel . com 2 . The Congo BasinTropical rainforests like the Congo Basin produce 40 percent of the world ' s oxygen and serve as a vital source of food , medicine and minerals . The Threat : At more than 1 . 3 million square miles , the Congo Basin has the world ' s second - largest rainforest , after the Amazon ' s . According to the UN up to two - thirds of the forest and its unique plants and wildlife could be lost by 2040 unless more effective measures are taken to protect it . Extending across six nations , ten million acres of forest is degraded each year due to mining , illegal logging , farming , ranching , and guerilla warfare . Roads cut by loggers and miners have also enabled poachers and bushmeat hunters to prey on endangered animals like mountain gorillas , forest elephants , bonobos , and okapis . As the forest shrinks , less carbon dioxide is absorbed , and rain decreases , adding to climate change . Roads cut by loggers and miners have also enabled poachers and bushmeat hunters to prey on endangered animals like bonobos ( pictured ) , forest elephants , and okapis . Photo : Courtesy © Frans Lanting / Corbis 3 . The Dead SeaIt ' s the lowest spot on earth ( 1 , 312 feet below sea level ) , has 10 times more saline than seawater ( so humans float like corks ) , and is believed to contain therapeutic minerals . The Threat : In the last four decades , the Dead Sea has shrunk by a third and sunk 80 feet — 13 inches per year ! — stranding formerly seaside resorts and restaurants nearly a mile from shore . The Jordan River is the lake ' s sole source , and as surrounding countries increasingly tap its waters , little reaches the Dead Sea , which could disappear within 50 years . Further pressure is put on the sea by the cosmetic companies and potash producers who drain it for minerals . one proposed solution is the controversial Red - Dead Canal , channeling water 112 miles from the Red Sea , but its environmental impact could be negative ( some worry that it would increase seismic activity in the region ) . The Dead Sea is the lowest spot on earth ( 1 , 312 feet below sea level ) , has 10 times more saline than seawater ( so humans float like corks ) , and is believed to contain therapeutic minerals . Photo : Courtesy LiorDrZ ? / Getty 4 . The EvergladesThis 2 . 5 million – acre wetland encompasses cypress swamps , mangroves , sawgrass and pine savannahs . It ' s the only place in the world where crocodiles and alligators share territory . The Threat : A host of dangers are putting this fragile wetland at risk : pollution from farms , invasive species , and encroaching development , not to mention the fact that 60 percent of the region ' s water is being diverted to nearby cities and farms . As a result , The Everglades is now half the size it was in 1900 . Worse , this is the sole habitat of the Florida panther , and there are less than 100 of the creatures left in the wild . These big cats may be completely lost within the next 40 years as their habitat disappears ( they ' re not alone , either — at least 20 species in the Everglades are endangered , including turtles , manatees , and wading birds ) . At least 20 species in the Everglades are endangered including panthers , turtles , manatees , and great white egrets ( shown here ) . Photo : Courtesy Rasmus Bøgeskov Larsenøg / Flickr 5 . MadagascarMore than 80 percent of Madagascar ' s flora and fauna are found nowhere else on Earth , thanks to millions of years of isolation in the Indian Ocean off of Africa . The Threat : If nothing is done to save the world ' s fourth - largest island , its forests will be gone in 35 years ( once 120 , 000 square miles , they ' re now down to 20 , 000 ) , and their unique inhabitants along with them . Forest ecosystems are being destroyed by logging , burning for subsistence farms , and poaching . The 20 species of lemurs for which Madagascar is renowned are in danger of disappearing . Though there are game reserves , they ' re not large ( occupying only five percent of the island ) , nor are they contiguous , thus failing to provide corridors for the animals to travel through . Some of Madagascar ' s endemic species have never even been recorded , and will likely be lost before they can be studied . Erosion is also a concern in Madagascar . The Betsiboka River , above , is red thanks to the large quantity of sediment it carries to the sea . Photo : Courtesy oledoe / Flickr 6 . The MaldivesThe nation is rich in coral reefs and endangered fish — like the giant Napolean wrasse , leopard shark , and some 250 manta rays ( most with wingspans of 10 feet ) . The Threat : Few scientists hold out much hope for the Maldives — the world ' s lowest nation — if global warming continues to melt the ice caps and raise sea levels . Its 1 , 190 small islands and atolls ( 200 of which are inhabited ) scattered across the Indian Ocean rise a mere eight feet above sea level . In 2008 , the President of the Maldives announced the government would start buying land in other countries , including India , for future homes for citizens displaced by rising waters . In 2009 , he held a cabinet meeting underwater to stress the islands ' vulnerability . Only 200 of the islands of the Maldives are inhabited , and none rise higher than eight feet above sea level . Few scientists hold out much hope for the country if global warming continues to melt the ice caps and raise sea levels . Shown here : Baa Atoll . Photo : Courtesy Sakis Papadopoulos / Getty 7 . The PolesThe natural phenomena here are unique and inspiring : towering icebergs , Aurora Borealis , and majestic animals ( penguins , polar bears , whales ) . The Threat : The Woods Hole Oceanographic Institute , the world ' s largest non - profit ocean research group , has predicted that 80 percent of the emperor penguin population of Antarctica will be lost , and the rest in danger of extinction , if global warming continues . In the Arctic , the polar bear is also endangered by the steady loss of sea ice ( which has decreased 3 percent per decade since the 1970 s ) . As sea ice disappears at the poles , so do entire ecosystems : the phytoplankton that grows under ice sheets feeds zooplankton and small crustaceans like krill , which are on the food chain for fish , seals , whales , polar bears and penguins . Studies predict that with continued warming , within 20 - 40 years , no ice will form in Antarctica . In the Arctic , the polar bear is also endangered by the steady loss of sea ice , which has decreased 3 percent per decade since the 1970 s . Photo : Courtesy Ansgar Walk / Wikimedia Commons 8 . Rajasthan , RanthamboreOne of the best places in the world to see tigers . The Threat : The world ' s population of wild tigers has fallen to as few as 3 , 200 , more than half of which live in India . If extreme efforts are not undertaken , the big cat may be extinct within our lifetime — possibly in as soon as a dozen years . ( Compare this number to the 100 , 000 tigers that lived in India in 1900 and you can see just how drastically things have changed in the past two centuries . ) Their habitats have been reduced 93 percent , and though there are reserves across Asia , most are small and have no corridors between them for the normally far - roaming felines . It ' s estimated that a tiger a day is killed for use in Chinese traditional medicine . The tiger ' s habitats have been reduced 95 percent , and though there are reserves across Asia , most are small and have no corridors between them for the normally far - roaming felines . It ' s estimated that a tiger a day is killed for use in Chinese traditional medicine . Photo : Courtesy Bjoern Ognibeni / Flickr 9 . The Tahuamanú RainforestParrots and macaws feed off of the world ' s largest salt lick . They share this pristine wonderland with endangered creatures like giant armadillos , ocelots , jaguars , and giant otters . The Threat : This magnificent rain forest in Peru ' s Madre de Dios region holds some of the last old - growth stands of mahogany in South America . But illegal logging is depleting the rainforest — and the U . S . is responsible for buying 80 percent of the mahogany . A single tree can create as much as $ 1 million worth of furniture . Loggers build roads , allowing farmers and hunters to enter , further crowding the indigenous people and destroying the delicate ecosystem . In nearby areas , gold mining has released mercury into the air and water . Parrots and macaws feed off of the world ' s largest salt lick in the Tahuamanu rainforest . Photo : Courtesy Frans Lemmens / Getty 10 . The Yangtze River BasinExotic creatures like giant pandas , dwarf blue sheep , Yangtze finless porpoises , and Siberian cranes call this region home — along with some 400 million people . The Threat : It ' s too early to know the exact impact of the creation of China ' s massive , $ 24 billion Three Gorges Dam , but many , including the Chinese government , have acknowledged that the Yangtze Basin region is in danger of losing its most distinctive marine and animal life . Deforestation has occurred from clearing land for displaced farmers , and the reservoir has flooded villages , farms , factories , and mines , adding to the Yangtze River ' s existing pollution from shipping , industry , agriculture and raw sewage . Landslides have also happened , and seismologists wonder if the water pressure above two fault lines might result in a disastrous earthquake . It ' s too early to know the exact impact of the creation of China ' s massive , $ 24 billion Three Gorges Dam , but many , including the Chinese government , have acknowledged that the Yangtze Basin region is in danger of losing its most distinctive marine and animal life . Photo : Courtesy chenyingphoto / FlickrSee More Pictures of 10 Natural Wonders to See Before They ' re Lost