As global warming melts the world's ice, and heats the oceans, sea levels are on the rise. Although it may take decades for some coastal areas to begin to feel the effects, few places on Earth are as threatened right now as the low-lying coastlines off the vast Bay of Bengal, where the Ganges, Meghna and Brahmaputra Rivers meet the Indian Ocean.
Just south of Calcutta, India, the Royal Bengal Tiger prowls the Sunderbans Islands. The Sunderbans Tiger Reserve is part of the world's largest unbroken mangrove forest. The park is also home to many rare and unusual plants and animals such as the barking deer, estuarine crocodile, hundreds of bird species and the Sundari tree after which the region is thought to be named. Pranabes Sanyal, a former director of the park, says the Bengal Tiger is a sensitive barometer of changes in these coastal forests. He says rising sea level is making the brackish waters around the southernmost islands too salty, destroying the tigers' habitat, and pushing the animals into nearby villages. There, the number of conflicts with tigers is increasing, risking human life and threatening the future of this rare and majestic animal. "The percentage of man-eating has increased in recent years," he says referring to the tiger's famous ability and willingness to attack humans.
The truth of Sanyal's concern is seen plainly in a crowded ward at PG Hospital in central Calcutta. There twenty-nine year-old Anup Mallick lies rigidly on the floor, a white bandage wrapped under his chin and over the top of his head, framing his gaunt face. Worried friends and family are gathered nearby. Mallick was attacked by a tiger while harvesting crabs in the Sunderbans. The incident occurred as he and fellow crabbers were having a smoke, just before returning home after a day's work. "The tiger came and jumped on me," he says. "My friends had clubs in their hands, so the tiger took me ten or fifteen feet away from them, and left me. Then it ran away." His companions found Mallick missing part of his left ear and with deep wounds on his neck. He says from now on he will find less dangerous work. "I'll look around to find some work at home," he say, "but I'll never go to the jungle."
The rising water is also a direct menace to the people of the Sunderbans, many of whom live and work below sea level. Before the Sunderbans were cleared for farming, the tides washed them every day. Then dwellers erected thousands of miles of mud dikes, encircling each island in a protective hug. The rivers and the sea remain at the center of everyday life; at birth, babies are sprinkled with drops of the holy river Ganges. And the same waters sometimes wield a terrifying power.
As Tushar Kanjilal, the secretary of the Tagore Society for Rural Development, explains life on such low-lying land, "every day the people living in Sunderbans islands, they go to sleep under water." The white-haired Kanjilal was a schoolmaster in the Sunderbans for three decades. He says the earthen embankments require constant vigilance and frequent maintenance, and even the newest, strongest dikes break up in storms. Once they do "all the crops are damaged, all the mud houses collapse, all the waters in the ponds, creeks, canals, become saline," he says. "And you won't even find a drop of drinking water."
On Sagar, the most exposed of all inhabited Sunderbans islands, a Hindu priest chants and struts at the Kapil Muni temple. When tropical cyclones slam the Indian coast, Sagar receives the first, and often the heaviest, blows. This temple is the destination of an annual pilgrimage, a Hindu celebration of the Ganges River. The origins of this shrine are long forgotten, though it is believed to be about 1500 years old. What is certain is that the temple has been destroyed and rebuilt at least three times before, as the island's edge has crumbled under the relentless pounding of the sea. The pace of erosion is expected to pick up now, as sea levels climb.
A few steps from the temple, Mohammed Sheikh Gafur serves visitors sweet tea in tiny cups. Gafur once farmed twenty-five or thirty acres of rice and chili peppers, and raised fish in shallow freshwater ponds. With his wife and six sons he built a house of baked mud. But about twelve years ago, the thin dike protecting his land breached in a cyclone. His house melted into the sea like a sand castle at high tide, along with most of his rice paddies and fish ponds. Gafur and his wife now live in their teashop, a beach hut made of plastic tarps hung from a frame of bamboo poles. His sons, scattered elsewhere, work the land of others. "We're fed up with telling people our story," says Gufar angrily, when asked about his lost land. "It's no use, they just listen, and when they leave, nothing happens."
As a younger man in the world's largest democracy, Gufar took an active interest in politics. But over many years, a succession of natural disasters and failed attempts by the Indian government to mitigate them has left him embittered. "The only thing that the government can do now is pull out all the people from the islands," he says.
Gafur is not alone in his troubles. About half of nearby Ghoramara Island has disappeared beneath the waves. Some of its inhabitants are now his neighbors on Sagar. Many farmers have abandoned island life altogether, further swelling the slums of Calcutta. Sugata Hazra, an oceanographer at Calcutta's Jadavapur University predicts India's Sunderbans islands will lose 15% of their area by 2020, about 40 square kilometers, displacing up to 100,000 people. "People are losing their homeland, people are losing their original habitat," he says, "and they are becoming a kind of environmental migrant." Hazra says as the impact of climate change intensifies, such environmental migrants will increasingly strain social services in India and the highly populated coastal delta of Bangladesh, just north of Calcutta on the Bay of Bengal.
Bangladesh, home to 150 million, is the seventh most populous country in the world, although it's only about the size of Louisiana. Most of Bangladesh is less than 40 feet above sea level. For many months each year more than ten percent of the country's surface area is water. In 1988, and again in 1998, more than half of the country was flooded. With sea level expected to rise up to three feet in this century, an additional ten to twenty percent of Bangladesh could be permanently lost, displacing millions of people and destroying farmlands and fresh water supplies.
Ainun Nishat, Bangladesh's representative to the International Union for Conservation of Nature, calls his country, where droughts, heat waves and floods are common, "nature's laboratory on natural disaster." Nonetheless, he complains that foreign non-governmental organizations over-emphasize the hazards of the slow and steady climb of sea level as a possible catalyst to future refugees and chaos. "I believe that's Western agenda," he says, "not Bangladesh's agenda." Nishat says the world has underestimated how resilient his country will be in the face of adversity, such as the natural disasters, its people have faced for millennia. He says his country will develop the necessary infrastructure to protect its people from the slow but inexorable rise of the sea.
What Nishat is worried about is the likelihood that cyclones will increase in intensity and frequency. Cyclone Sidr, which struck the region on November 15 of 2007, is the kind of storm he fears. Sidr hit Bangladesh with 140-mile-per-hour winds and 20-foot waves. After the storm passed, three- to five-thousand people were dead and ten times that were injured. Half a million houses were destroyed. Such storms will push farther inland as the sea rise.
Atiq Rahman, director of the Bangladesh Center for Advanced Studies, an environmental think-tank, says food security is his country's largest concern. Bangladesh already has difficulty feeding its people. At its current rate of growth, the population will double by mid century. But global warming could reduce agricultural production. For example, in 2007 Sidr and other storms and flooding wiped out 6% of Bangladesh's rice harvest. Such storms could grow worse.
Shafiqul Islam, a heavy-set man dressed in wrinkle-free pants and a spotless polo shirt drives through the outskirts of Khulna, the third-largest city in Bangladesh. The director of a small college, Islam is a former locally-elected official, and founder of the Pani (which means water) Committee, a grassroots farmers' rights group. From his car, Islam gesticulates toward a man-made pond, rice seedlings poking up from its surface, a dirt dike holding the brown water captive. Like the Sunderbans, this area was once a mangrove forest. And though more than 50 miles from the sea, it is so low and flat that the tide used to overflow the low banks of natural channels and flood nearly the entire region with mucky water. Farmers built dikes around the highest land, to create freshwater paddies for rice and fish farming; but their flimsy embankments often gave way in storms and seasonal river floods. In the 1960's at the behest of the government, international aid organizations began helping to construct a system of sturdier dikes, creating permanent river channels.
The college director says the massive dike project, which in time led to disaster, was guided by the mistaken notion that foreigners know better than locals. The modern dikes confined sediment to river channels. Over time, therefore, river bottoms rose. Paddies, in contrast, sank without new infusions of silt, as old soil compacted. Rivers and dikes began to tower over the farmlands like elevated highways, reversing the natural order. In a matter of decades, once-productive plots stagnated and became infertile. People had no food.
Shafiqul Islam and others proposed cutting dikes to let silty water flow in and out for a few years to replenish the depleted paddies, as it once had. But water officials and engineers rebuffed their suggestion. So, in 1997 a band of frustrated farmers decided to defy the government and test the idea, right where he's parked his car, at the crest of a dike. An estimated 20,000 farmers watched as a team of strong men hacked a hole in the dike with shovels. The police were there too, but Islam says they were helpless to stop the revolt. "Thousands and thousands of people were there to help us," he says, "and we did it."
The plan to save the paddies outside the city of Khulna worked. In a brief three years they collected a 4-foot-deposit of fresh silt. The rent in the dike was patched. Rice and fish flourish there once again. Islam and environmentalists involved in climate change policy, including Ainun Nishat, say if more widely adopted, the same method could be crucial for shoring up Bangladesh's delta lands against the slow advance of the sea.
So far the idea of replenishing land behind dikes by selectively letting water flow in, either to renew productivity or to climate proof the land, has only gained grudging support. Sheikh Nural Ala, chief engineer for this region of the Water Development Board, the agency that operates dikes now says that the technique, called Tidal River Management can be beneficial. But he says sea level is expected to rise too far this century for TRM to be effective. "So it is not the permanent solution," he says. "We have to search for permanent solution again."
Permanent or not the solution could be helpful inside as well as outside of Bangladesh. A recent study of 33 of the world's largest river deltas found that subsiding land and rising sea level could cause flooding to increase by 50% this century, exposing hundreds of millions of additional people to new risks.