The Weather of the Future: Heat Waves, Extreme Storms, and Other Scenes from a Climate-Changed Planet - Heidi Cullen (2010)

Part II. The Weather of the Future

Chapter 10. Dhaka, Bangladesh

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It’s hard to say why you fall in love with a person, or with a place. It’s the same with science: sometimes your research is a lifelong passion, but sometimes a problem suddenly assaults you out of the blue and forces you to work on it—for the rest of your life. In the case of Peter Webster, an atmospheric scientist at the Georgia Institute of Technology, you might say his research on floods in Bangladesh began with a dare that led to a blind date that ended in a committed relationship. But it’s probably better to just have him tell the story.

“It started off in a very strange way,” he explains. “I was at a meeting in Bangkok in late 1998. We had just published a paper on the Indian Ocean Dipole.” Webster’s specialty is ocean-atmosphere interactions. The ocean and the atmosphere can interact in important and predictable ways that play a role in climate and weather: El Niño is a prime example of ocean-atmosphere interactions. Webster has a PhD from the Massachusetts Institute of Technology (MIT) and was among a crop of very successful graduate students who came out of MIT in the 1970s. Many of them, including Webster, worked with Jule Charney, a legend in numerical weather prediction. Webster is beginning to develop into a legend as well. He’s received numerous scientific honors, including two of the most prestigious awards in the geosciences: the Carl Gustav Rossby Research Award from the American Meteorological Society (AMS) and the Adrian Gill Medal from the Royal Society. The wall of his office at the Georgia Institute of Technology in downtown Atlanta, where I met with him to talk about his research in Bangladesh, is a striking reminder of what the walls of accomplished people generally look like.

If you study climate science, you’ll soon learn that there are a lot of dipoles: places where some quantity, such as atmospheric pressure or temperature, flips and flops between high and low or hot and cold. A dipole is a classic example of an ocean-atmosphere interaction. In the case of the Indian Ocean Dipole (IOD), ocean temperatures in the eastern and the western Indian Ocean flip between warm and cool, with the rains following the warm ocean temperatures.1 The IOD also sets up what Webster calls “a seesaw of sea level” in the Bay of Bengal. Dipoles are important drivers of climate variability, and if you understand how they work, they can often help predict when a drought or a flood might be coming your way.

At the conference in Bangkok, Webster presented a paper suggesting a large-scale climate connection between the IOD, sea level in the Bay of Bengal, and the monsoon rains. This is exactly the kind of association climatologists search for, to better understand the physics of a system. Webster’s research showed that when sea level in the Bay of Bengal was high, so was the risk of flooding: that is, the two events were highly correlated. “And in 1998,” Webster explains, “the sea level in the Bay of Bengal was about a foot higher than normal.”

At the time of his talk, Bangladesh was at the tail end of what came to be known as “the flood of the century.” Sixty percent of the country had been flooded for more than three months, from July through September 1998. Dhaka, the capital of Bangladesh, was under 6 feet of water.2 When all was said and done, the flood of 1998 caused 1,100 deaths; inundated nearly 39,000 square miles; made 30 million people homeless; damaged 500,000 homes; caused heavy losses to infrastructure;3 and resulted in $2.8 billion in damages. Mother Nature has never cut Bangladesh a lot of slack.

Bangladesh has a problematic geography, and the floods are just the beginning. The geographic setting of Bangladesh makes the country highly vulnerable to many kinds of natural disasters. In addition to floods, it has experienced tropical cyclones, droughts, tornadoes, earthquakes, water contaminated by arsenic, and landslides. Bangladesh has seen more natural disasters than one might expect in such a small country—it is only about the size of the state of Iowa. But whereas Iowa has a population of 3 million, Bangladesh has a population of more than 162 million. That works out to some 2,900 people per square mile, making Bangladesh one of the most densely populated countries in the world.

Another problem is that two-thirds of Bangladesh is less than 17 feet above sea level; only in the extreme northwest will you find an elevation of more than 100 feet. And in this small, densely packed, low-lying country there are 230 rivers. Three of them—the Ganges, the Brahmaputra, and the Meghna rivers—come together to form a large floodplain. Eighty percent of Bangladesh sits within that floodplain, and everyone who lives there knows that in any given year, roughly one-quarter of the country will be flooded. And everyone also knows that every few years Bangladesh will experience a severe flood that inundates more than 70 percent of the country.4 That’s easy to predict. The hard part is predicting the details of where and when the floods will come. But one detail scientists are certain of is that climate change will make the floods worse.

And the floods already have the power to devastate. Farmers and fishermen can easily lose a year’s worth of income during a single flood. These were the people Webster was trying to reach with his weather forecasts. “My research had suggested that the floods could be related to sea level in the Bay of Bengal. It was as if the floods came whenever the drain in the Bay got clogged up,” Webster explains. So, at the end of his talk in Bangkok Webster made a rather provocative announcement: “We can now understand why Bangladesh has floods. And in understanding these large-scale controls, we can forecast them.” Those were mighty big words—and Webster knew it.

The rains in Bangladesh begin in May, when the southwest trade winds, known as the monsoons, are drawn to the Indian subcontinent by the intense heat and consequent low pressure over Pakistan. The trade winds blow across the North Indian Ocean, picking up moisture along the way, before they head into Bangladesh and go through to the Himalayas. When the winds hit the side of the Himalayas, it begins to rain as a result of a process called orographic uplift. As the air travels up the side of the mountain, it cools, forcing the moisture to condense and fall out as rain. Basically, the rain continues until early October. During these months, the total rainfall varies from 4 feet in the northwest of Bangladesh to 11 feet in coastal areas, and to more than 16 feet in the northeast. Needless to say, this is one of the rainiest places in the world.

“And so I kept getting these e-mails saying ‘Do you really believe you can predict the floods?’ I said, ‘Sure.’ And I was very cocky about that,” Webster says smiling. “Then they asked if I’d be interested in a grant to work on forecasting the floods. I said, ‘Yes, of course.’ So we wrote a proposal to develop a flood forecasting system for Bangladesh.”

Professors, as a rule, don’t turn down grant opportunities. And Webster saw this grant as a dare that had the potential to save hundreds or even thousands of lives each year. “I thought it would be a very easy problem, because all you really need for a flood forecast are four quantities: the forecasted rainfall, the sea level in the Bay of Bengal, and the levels of the two major rivers, the Ganges and the Brahmaputra, all the way to India,” Webster explains. “In fact, I could never understand why the Bangladeshis hadn’t already done it.” So Webster and his team went off to collect the ingredients for their flood forecast model. This was his blind date with Bangladesh.

“I remember the first time I went into the villages,” Webster says, thinking back. “I asked a farmer to tell me about the flooding. We were standing in his rice paddy, and he said, ‘These fields here always flood because we are in the lowlands.’ ” Farmers living in these lowland areas have adapted to the floods by building their houses on raised mounds and adjusting the way they farm.

“Naturally, I asked him if he would take me to the highlands. At which point we walked a little ways over and up a bank of no more than 2 or 3 feet. He said, ‘Here, these are the highlands.’ ” Webster says in amazement, “We were literally standing in a slightly raised paddy field. I would have never noticed the difference.” But the farmer knew the difference very well. During a flood, it was the highland crop that might have a chance of surviving, saving him and his family from starvation.

When Webster and his team got to Dhaka to assemble the forecast model, they soon discovered that India provided no stream gauge data to Bangladesh for the rivers that originated up north in India. “That explained why no one had ever issued a forecast. No one had any idea what the conditions were upstream,” Webster explains. Bangladesh may have a lot of rivers, but more than 90 percent of the water in those rivers comes from outside its borders. “The best we could do was a forecast out a day or two. And even that wasn’t any good, because the upstream conditions are so critical,” Webster says.

Data are the lifeblood of good research and the principal ingredient in a reliable forecast of weather or climate. That’s why scientists work so hard at setting up international observing networks. The climate system knows nothing of national borders; and just as Lewis Fry Richardson discovered when he started the science of weather prediction on a battlefield during World War I, a model run with lousy data will give you a lousy forecast. Garbage in, garbage out.

“So we decided to build a hydrological model for both the Brahmaputra and the Ganges River basin that could estimate the streamflow upstream,” Webster explains. They obtained data and weather forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) and fed them into the hydrological models. Their model also incorporates estimates of precipitation from two satellite-based systems, along with streamflow measurements of rivers inside Bangladesh. “We basically used the rainfall forecasts from ECMWF to feed the rivers with rain. And then we used satellite data to calibrate the rainfall. That’s how we worked around the problem. And we came up with a solid scheme for a ten-day forecast. Our first forecast was in 2003, and it was pretty darn good,” Webster says.

In the summer of 2004, Webster and his team generated ten-day forecasts showing that the Brahmaputra River would be likely to flood on two occasions in July.5 They were right. The 2004 floods inundated almost 40 percent of the country. But unfortunately their forecast had not been much help to the local people. At the time, the flood forecast still hadn’t been fully integrated into Bangladeshi warning systems, and more than 500 people in Bangladesh and India died in the rising waters. So Webster and his team went about setting up a communication network. They worked with the Flood Forecasting Warning Center (FFWC) in Bangladesh and the Asian Disaster Preparedness Center to develop a network to distribute the forecasts directly to people in five districts along the Brahmaputra and Ganges rivers, including impoverished families living on islands that were known as river chars.

“It’s all done using webs of cell phones, and it reaches over 100,000 people,” Webster says. Cell phones are everywhere, even in remote villages. “People are told that a flood of a certain level is coming at certain time. And that allows farmers to harvest early and protect their seeds,” he explains. Once the communication channels were improved, his forecasts began saving lives and livelihoods. “An economist we were working with calculated that people were saving, on average, 25 percent in infrastructure and household damage by knowing the flood was coming,” Webster says. “And saving 25 percent of everything is a lot.”

By 2008, after ten years of research and outreach, Webster and his team had proved they could make a skillful forecast. The next step was to operationalize the process. Webster wanted to assemble a team at the FFWC to produce and issue the forecasts. But the situation wasn’t that simple. “I had a rather disturbing interaction with the director of the FFWC,” Webster says. In May 2008, just as Bangladesh was entering the flood season, Webster set up a workshop in Dhaka where he taught meteorologists at the FFWC how to generate the ten-day flood forecasts.

“But the director told me the FFWC was hesitant to give out a ten-day forecast, even though we had demonstrated predictability,” Webster continues. “We argued and he said, ‘But what if the forecast is wrong?’ ” The director told Webster that the FFWC didn’t want to be held responsible for any losses. “So I said to him, ‘If you saw someone crossing a road just as a truck appeared over the horizon, would you wait to warn the poor soul until there was no chance for him to get away?’ It was an unpleasant conversation.”

Webster was shocked that someone would turn down an opportunity to give people enough lead time to prepare for and, it was hoped, prevent a disaster. “I think it’s morally wrong. You can’t do that.” Webster remains committed to getting the forecast out to people in rural areas, people who need as much time as the science of forecasting can allow. “Right now, the FFWC has agreed to monitor the ten-day forecasts but will not issue them,” he says.

It strikes me that maybe Webster’s story isn’t so different from the larger fight to communicate the risks of global warming. A forecast for 2050 is not so different from a ten-day forecast for flooding. Neither is perfect, but both are critical to making informed decisions. And many would argue that both carry the same moral obligation.

Omar Rahman is someone who has come to sense this moral obligation. Rahman is a demographer and physician who studies social networks and urbanization. “I’m not a climate change person,” Rahman explains over the phone from his home in Dhaka. “I got interested in climate change from a different perspective. I am interested in migration.” As it happens, Rahman is himself a living study in migration.

“I basically left Bangladesh to go to college in the 1970s and stayed in the United States for twenty-eight years,” Rahman says. After studying biochemistry at Harvard, he received a medical degree from Northwestern University. In 1996, he returned to Harvard as an assistant professor of demography and epidemiology at the School of Public Health. His work focused on the concept of resilience—specifically, the resilience of people living in rural Bangladesh.

“I found it odd that I was sitting in Cambridge writing about rural Bangladesh,” he says. Rahman had written extensively about issues of development and had begun to feel a pull back home. “I was an academic writing papers that very few people would read,” he explains. He began to question the impact of his research. The pull of a place can be quite powerful, and Rahman began to contemplate returning to Bangladesh.

“A friend of mine gave me a very good piece of advice,” Rahman says. “He told me, ‘If you go back home, you need to go back for good. Don’t just test the waters, because you’ll never stay.’ ” Rahman explains, “Developing countries are difficult places to work, and constant comparison is detrimental to staying.” And then came what might have been the last straw. “We were told we had to move out of our apartment in Cambridge,” Rahman says, laughing. “And so, in some ways, it came down to either moving to the suburbs or moving back to Bangladesh.” Rahman, his wife, and their two children moved back to Dhaka in 2003, the same year Webster issued his first flood forecast.

“Ultimately, I am interested in the people part of this whole thing,” Rahman says. And it is the human part of the problem of climate change in Bangladesh that makes everyone very nervous.

The most widely used estimate of how many people around the world could become climate refugees, a term heavy with political and moral overtones, is 200 million by 2050. To put that in perspective, about 1 million Irish immigrants came to the United States because of the potato famine during the late 1840s. These projections about climate refugees are based on a very crude formula for estimating migration, so it’s safe the say the numbers are still fuzzy. Modeling people’s behavior is a lot harder than modeling a flood. But whatever the number ends up being, it’s likely to be of a magnitude not seen before in human history. And in Bangladesh alone, the exodus is estimated to be in the millions. Projections range from 6 million to 15 million by 2050.

Most of the migration in Bangladesh right now is internal. People are moving from coastal and rural areas to cities such as Dhaka. The reasons for leaving the place where you were born are varied. However, “I will honestly tell you that right now, most of the migration is economic,” Rahman says. “None of the migration is driven by concern about climate change. That will come in twenty to thirty years.”

But some observers argue that climate migration is happening already, and that it’s being blamed on the weather instead of the climate. More severe floods and droughts are hitting the landless and poor farmers in the same villages that Webster visited. And the floods and droughts, which have always occurred in Bangladesh, will grow worse with time. Increased soil erosion and saltwater intrusion in coastal areas will make it more difficult to farm and work the nets for shrimp fry, leaving people with few options but to migrate. Many will end up in the slums of Dhaka. In the end, of course, it’s always the economy. In rural Bangladesh, the weather is the economy. And if you believe the climate models, the weather will get worse.

By 2050, the population of Bangladesh will have grown from about 162 million people today to more than 220 million.6 Today, more than 13 million people live in Dhaka. It’s the fastest-growing megacity in the world. And every year, slightly more than 400,000 people in Bangladesh move to the capital, hoping to find a better life. Nearly 15,000 new cars were sold in Dhaka in 2008, a record high. There may be plenty of people and cars, but there are acute shortages of just about everything else. There are no sidewalks. There is no mass transit system. And right now, there is enough power for only about 35 percent of the population. When I spoke with Omar Rahman on the telephone, he had been without power for eight hours that day. As he said, comparison with the developed world is detrimental. But nonetheless, when people along the coast who are unable to grow rice or work the nets to catch shrimp fry make the comparison between Dhaka and their own situation, they will still decide that Dhaka holds the keys to a better life. And by 2050, this megacity with very little energy, transportation, and water infrastructure is expected to be the home of more than 40 million people.7

Experts like Rahman worry about how Dhaka will cope with the rapid and unplanned urbanization in Bangladesh. Dhaka is not immune from the problems of geography that plague the rest of Bangladesh. The city is located in the coastal zone and is just as vulnerable as the rest of the zone to floods, storms, and tropical cyclones. Drainage is already a serious problem, and sewers routinely overflow during the monsoon season. And the slums, situated in the lowest-lying parts of the city, are even more vulnerable. The millions of poor who have settled there are crowded into metal shacks with no running water. They have merely traded one form of vulnerability for another.

“The impact of rapid urbanization is huge,” Rahman says. “We are trying to model it because we know there is no way to stop it. By 2050, Bangladesh will have transformed from a population where only 5 percent of people lived in urban areas in the 1970s to a population where 50 percent of people live in urban areas.” Rahman explains that the growth in Dhaka is a microcosm of the urbanization taking place across Africa and Asia. The UN Development Program estimates that by 2050, 70 percent of the world’s population will be living in urban areas.

The next step in the migration pattern is across national borders. “When most people think of these issues,” says Webster. “They mostly think about how terrible it’s going to be for the people there. But this is an enormous problem from a national security standpoint, too. Because all of a sudden you have 200 million people who are displaced, people who have become climate refugees. Where do they go? They go to India. They go to Myanmar. But they won’t be very happy people,” Webster concludes.

For national security experts, migration is one aspect of climate change that evokes a real sense of dread. In the global landscape the argument is simple: what happens in Bangladesh doesn’t stay in Bangladesh. The United Nations Department of Economic and Social Affairs estimates that 1.1 million migrants will enter the United States each year between now and 2050. Many are expected to come from Bangladesh.

It’s also estimated that more than 10 million Bangladeshis have already made the move to India during the past twenty years. This issue is a constant source of tension between the two nations, and climate change isn’t helping. India, for its part, sees climate change as bringing multiple threats, and apparently one threat is people. And so India is in the process of building a fence to keep them out. “I think they were going to build a fence anyway,” says Rahman. “The data on this isn’t clear, but I think the fence was ultimately built for political reasons. And the climate refugee argument is being used as an excuse,” Rahman adds.

India maintains that the purpose of the fence is to protect the country against smuggling and terrorism as well as illegal immigration, claiming that about 5 million Bangladeshis are in India illegally. This is a number the government of Bangladesh is quick to contest. The fence runs along India’s porous 2,500-mile border with Bangladesh. It is high, and it’s made of heavily reinforced barbed wire. Climate change may not have created the fence but provides a plausible reason to continue building it. Still, as the Indian government works to complete the fence in the hope of keeping people out, the problem is not so much the people as the climate. The fence won’t stop the floods, the cyclones, the droughts, or the rising sea level. The forecast for 2050 is going to require a lot more than a barbed wire fence.

Water, now and always, is at the heart of Bangladesh’s problems. The country suffers from both too much and too little water.

The scenarios for 2050 and beyond predict that this water problem will worsen, owing to a number of factors. Rising temperatures and decreasing winter precipitation will bring more drought. Rising sea level will bring salt water into the rice paddies and rob Bangladesh of its agricultural land. Floods that result from increased snowmelt and a stronger monsoon will happen more frequently and last longer. And more intense cyclones will batter the coast, an economic hub and cultural treasure, with higher storm surge. This small country has always been vulnerable, and climate change will make it more vulnerable. It doesn’t take a climate scientist to figure that out. Just ask Omar Rahman.

“I came into this field as somewhat of a climate skeptic,” Rahman admits. “As a scientist, I always want to see the data. But I have to say I was convinced. These were serious people, people who were not prone to exaggeration. And the data spoke for itself,” Rahman says. The Intergovernmental Panel on Climate Change (IPCC), the scientific group responsible for building the data and models that convinced Rahman, has issued a very strong statement about the changes that are taking place in Bangladesh. Temperatures in Bangladesh have already increased. The Fourth Assessment report indicates an increasing trend of about 1.8°F in May and 0.9°F in November during the fourteen-year period from 1985 to 1998. Annual average temperature in South Asia (5°N to 30°N, 65°E to 100°E) is projected to increase 3.2°F by 2050 and 5.6°F by 2100, according to the IPCC Fourth Assessment Report. The seasonal values for South Asia are shown in the accompanying table. Temperatures in Bangladesh are projected to increase 1.8°F and 2.5°F by 2030 and 2050, respectively, according to a recent assessment by the Bangladesh Centre for Advanced Studies (BCAS).

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Projected changes in surface air temperature for South Asia under the highest future emission trajectory (A1F1) for three time slices: 2020s, 2050s, and 2080s. (SOURCE: IPCC FOURTH ASSESSMENT REPORT)

These warmer temperatures spell trouble for the Himalayan glaciers, the largest body of ice outside the polar caps and a critical source of freshwater throughout Asia. About 15,000 Himalayan glaciers support perennial rivers including the Ganges and the Brahmaputra that, in turn, provide a lifeline to millions of people in Bangladesh and across Asia. Himalayan glaciers are receding faster than glaciers in any other part of the world; and if the planet keeps warming at the present rate, the likelihood that they will be disappearing by the year 2035, and perhaps sooner, is very high.

The roughly 20-mile-long Gangotri glacier has been receding alarmingly in recent years. Between 1842 and 1935, it was reced- ing at an average rate of 24 feet every year; the average rate of recession between 1985 and 2001 was about 75 feet per year. The current trends of glacial melt suggest that the Ganges and Brahmaputra, which crisscross the northern Indian plain, could run dry during the summer months in the near future as a consequence of climate change. And the IPCC report indicates that India will reach a condition of water stress before 2025. A fence won’t be of much help when that happens.

Whereas Rahman may have initially been a skeptic, the people who live in rural Bangladesh have watched the climate change with their own eyes. According to a study carried out by the International Union for Conservation of Nature (IUCN) in Bangladesh, people in rural communities are reporting excessive and erratic rainfall, an increase in the number of flash floods, temperature variation, changes in seasonal cycles, and an increased occurrence of droughts and dry spells. These effects are likely to worsen, and adaptation strategies are urgently required. The question is: how bad does a situation need to get before it makes people leave?

One complication is the fact that, like floods, droughts in Bangladesh are seasonal. Depending on their timing, they can devastate crops, especially in the northwestern region, which generally has lower rainfall than the rest of the country. Drought brings significant hardship to poor agricultural laborers and others who cannot find work. In these areas, unemployment leading to seasonal hunger is often a problem, especially in the months leading up to the November–December rice harvest. If the entire crop fails because of drought, the situation for poor people can become critical. The IPCC predicts lower and more erratic rainfall, resulting in increasing droughts, especially in the drier northern and western regions of the country.

Too much water is no better. The problem is, again, the timing. More than 80 percent of the roughly 7 feet of annual precipitation in Bangladesh comes during the monsoon period. Most of the climate models estimate that precipitation will increase dur- ing the summer monsoon. The reason is fairly straightforward. As the temperature increases, air over land will warm more than air over oceans in the summer. This will deepen the low-pressure system over land, which happens anyway in the summer, and will enhance the monsoon. Moreover, there is a link between Eurasian snow cover and the strength of the monsoon; when snow cover retreats—as it is expected to do with the higher temperatures—the monsoon strengthens.

Climate models indicate a general increase in the intensity of heavy rainfall events in the future, with large increases over the Arabian Sea, the tropical Indian Ocean, northern Pakistan, northwest India, northeast India, Bangladesh, and Myanmar.8 Scientists expect a roughly 10 percent increase in rainfall during monsoon the season by 2030, while dry seasons could see harsher droughts.

The problem for Bangladesh is that two things are happening at once. The warmer temperatures are intensifying the monsoon and they are melting the glaciers; and unfortunately the melting season happens to coincide with the monsoon season. Rapid glacier melt will mean more water flowing down the Ganges and Brahmaputra rivers during the monsoon months, causing even more devastating floods. Webster has been studying the changing frequency of flood events. “We’ve been looking at the flow of the Brahmaputra and the Ganges out to the year 2100. Two things happen. You see more flood events and the flood levels are much higher,” Webster explains. Scientists say once-in-twenty-year floods are already occurring about every four years. However, in the long term, as the water in the rivers disappears, the result will be more severe droughts.

Although floods and droughts are a serious concern, the most serious issue of all is a rising sea level. The 146 million people living within about 3 feet of mean sea level worldwide are at risk from the projected rise in sea level over the coming century. An even greater number—268 million living within about 16 feet—are at risk when the added impact of storm surge is considered. Moreover, these numbers are rising, owing to the combination of a growing population and its coastward migration. A 3.3-foot rise in sea level would inundate about 20 percent of Bangladesh’s total land, directly threatening 11 percent of the population with inundation (this figure is based on current population distribution). In addition, the backwater and increased river flow from sea level rise could affect 60 percent of the population.9

Oddly, the rise in sea level is the one estimate for which the cautious ways of the IPCC that Rahman so appreciated are wrong. In an effort to address the uncertainty, the IPCC chose to go with the most conservative estimate, which some would say is wildly conservative. The IPCC Fourth Assessment Report estimated global sea level rise over the coming century in a range from 11 inches to 31 inches. But it left room by stating, “The upper values of the ranges given are not to be considered upper bounds . . . for global sea level rise because existing models are unable to account for uncertainties such as changes in ice sheet flow.”

Even with these conservative estimates, the IPCC Fourth Assessment Report still projects that rising sea levels could wipe out more cultivated land in Bangladesh than anywhere else in the world. In Bangladesh, you can drive 60 miles inland from the coast, and you’ll go up only a few feet in elevation. When you get about 150 miles away from the shore, the land finally starts to rise up another 50 to 65 feet. I recently talked with experts who are preparing the next IPCC report; they said the projected value rise in sea level is actually closer to 5 feet, instead of the previously estimated 31 inches. It’s tough to wrap your mind around that. The factor driving migration is the land loss in coastal areas that will result from the rising sea level. “Somewhere between 20 to 25 percent of Bangladesh will be inundated in the next fifty years,” Rahman says. In Bangladesh, even the land is leaving.

The main impact of a rising sea level would be salinity ingress, causing the rivers in the coastal belt to become brackish or saline. This would have a serious impact on food production. In Bangladesh, production of rice and wheat might drop by 8 percent and 32 percent, respectively, by the year 2050.

Rising salinity levels as brackish water inundates cropland could hurt rice and wheat production. Overexploitation of groundwater in many countries of Asia has resulted in a drop in its level, leading to an ingress of seawater in coastal areas and making the subsurface water saline. India, China, and Bangladesh are especially susceptible to increasing salinity of their groundwater as well as surface water resources, especially along the coast, due to increases in sea level as a direct impact of global warming. The Meteorological Research Center at the South Asian Association for Regional Cooperation carried out a study on the recent rise in coastal sea level in Bangladesh. The study used twenty-two years of tidal data from three coastal stations. It revealed that the rate of rise in sea level during the last twenty-two years is many times higher than the mean rate of global rise over 100 years; this suggests that regional subsidence could be making the situation worse.

There are also the tropical cyclones. According to the UN Development Program, Bangladesh is the most vulnerable country in the world to cyclones. Scientists report that 2007 was the worst year on record for intense hurricanes in Bangladesh. “The worst-case scenario for Bangladesh is rising sea levels and increased floods,” says Webster. “But you add to that, of course, increased intensity of hurricanes in the spring and fall. So that would be the triple whammy.

“I’m not quite sure if Bangladesh is an adaptable country,” Webster continues. “Imagine a country the size of Iowa becoming half the size of Iowa with double the population.” That is the long-term forecast for Bangladesh. “Ultimately,” Webster explains, “they are running out of land.”

And some of the land is so beautiful. The Sundarbans—the wetlands region straddling the coasts of western Bangladesh and neighboring India—was formed by the deposition of materials from the Ganges, Brahmaputra, and Meghna rivers. If the Sundarbans is lost, the habitat for several valuable species will also be lost. An 18-inch rise in sea level would inundate 75 percent of the Sundarbans; a 26-inch rise could inundate all of the system. That would threaten what is now the single largest mangrove area in the world and is designated a World Heritage Site. The name Sundarbans means the beautiful forest in Bengali. The mangroves in this forest, within the delta of the Ganges, Brahmaputra, and Meghna rivers on the Bay of Bengal, act as natural buffers against tropical cyclones and as a filtration system for estuarine water and freshwater. They also serve as nurseries for many marine inverte- brate species and fish. The Sundarbans mangrove forests are well known for their biodiversity, including 260 bird species, Indian otters, spotted deer, wild boars, fiddler crabs, mud crabs, three marine lizard species, five marine turtle species, and several threatened species, such as the estuarine crocodile, the Indian python and the famous Bengal tiger. It was for these reasons that the Sundarbans National Park, India, and the Bangladesh part of the Sundarbans were added to the World Heritage List in 1987 and 1997, respectively.10

The rise in sea level and the decreased availability of freshwater—particularly during winter, when rainfall will be less—will cause an inland intrusion of saline water. As a result, many mangrove species, intolerant of increased salinity, may be threatened. In addition, the highly dense human settlements just outside the mangrove area will restrict the migration of the mangrove areas to less saline land. The mangroves are caught in the middle. The shrinking of the mangrove areas will have an effect on the country’s economy. Many industries that depend on raw materials from the Sundarbans will be threatened with closure, and large-scale unemployment could result. A project of the United Nations Development Program (UNDP) has evaluated the cost of building about 1,375 miles of protective storm and flood embankments that would supposedly provide the same level of protection as the Sundarbans mangroves. The capital investment was estimated at about $294 million and the yearly maintenance budget at $6 million—much more than the amount currently spent on the conservation of the mangrove forests in the area.

Webster may be a skeptic who thinks Bangladesh may not be adaptable, but Omar Rahman has no choice but to find adaptation strategies that will work for this country. It is his home. When I ask him what the year 2050 might look like if we stick with the status quo he is quick to respond. “I think if climate change is not taken seriously, if the predictions are right and sea level rises more than one meter, we would see an almost unimaginable catastrophe. It’s the worst-case scenario,” says Rahman.

He thinks the rapid urbanization exacerbates the problem. When 50 percent of a country is urban, it is no longer a rural country. And Rahman agrees that food production is problematic. “Right now the country is almost self-sufficient in rice production—which is pretty amazing, given that a country the size of Iowa can feed over 160 million people. But we will lose a lot of acreage, and that means we’ll have to import a lot of rice, like Japan. From an economist’s point of view, that’s going to be a big shock, but not something that is unapproachable, if we start thinking about it now. Better than if we sit and wait.

“It’s unfortunate that we seem to be beset by natural disasters. But when I think about the story of Bangladesh, I think it is a story of hope,” Rahman says.

Bangladesh arose in 1971 from a civil war. At the time, the U.S. secretary of state, Henry Kissinger, called Bangladesh an “international basket case.”

“Now I like to say Bangladesh has gone from being known as an international basket case to a Bengal tiger,” Rahman says. Until the worldwide economic slump that began in 2008, Bangladesh’s economy was growing at a pace not far behind India’s; Rahman attributed this to a developing culture of entrepreneurship and a thriving garment industry. Garments are the main export for Bangladesh, making up more than half of total exports.

“I don’t think anyone would have predicted that we would have become an entrepreneurial culture. The garment industry has bred a new class of entrepreneurs,” Rahman explains. In 2007, the World Bank predicted that Bangladesh could join the ranks of middle-income countries within two decades. “The best thing that’s happened to us is that we don’t have oil or mineral wealth,” Rahman says. “We’ve had to develop our people. And we’ve done spectacularly well, despite our natural disasters—famine, you name it, we’ve had it.”

The economic growth has happened because of the resilience and the tenacity of the Bangladeshi people. But Rahman would still like to see Bangladesh become more sustainable; that’s one of the reasons he came back.

“As a demographer I’m interested in structure. It has had the most successful family program. In the mid-1970s women had seven children; now it’s about 2.6.” Estimates project that the population should stabilize at around 250 million. That still is a lot people to feed on a plot of land that is only the size of Iowa, and which is expected to shrink by one-fourth, owing to a rising sea level, by the middle of the century.

Rahman has an idea that he thinks might help kick-start adaptation programs: an international center for climate change adaptation that’s actually located in the developing world. As he says, “You know you are underdeveloped when most of the literature about your country is written by people outside your country. We decided to set up the center inside the developing world.”

Rahman believes students will learn more in the living laboratory of Bangladesh than in a sterile classroom in Cambridge about what vulnerable countries need to tackle climate change. Rather than getting hung up on the fence, the country needs to build embankments. It needs cyclone shelters and research on rice. And it needs to address the already explosive internal migration to Dhaka.

“I said: Look. We as a university would like to sponsor a coordinated set of activities. Train the next generation of scientists. Not enough people have the right kind of skills. It will be international. Draw people from all over the world as well as from inside Bangladesh. We will train people to think on timescales climate change requires,” Rahman says. The program at the Independent University, in Dhaka, where Rahman is provost, will be a twelve- to eighteen-month master’s program. Students will spend time out in the field, as Webster did. And their research will cover all aspects of the problem. Climate change is a problem that will require engineers and computer scientists as well as chemists and anthropologists to solve. Climate change is not a problem that can be constrained in a straitjacket.

“As an educator, the best part is that you get a chance to mold young people. For decades now, people have gone to America because it offered so many opportunities. It’s changing now. There is an insularity. America has always struggled with being open versus retreating into itself. I benefited so much so I don’t want to see that change. The thing that I miss the most is the ability to reinvent yourself. That’s the best part of American culture. America is the most egalitarian place in the world. It’s the sense that you can be anyone. You don’t feel that you’re worse off. I want Bangladesh to move to that.”

Rahman seems to be suggesting that if he can help his students reinvent Bangladesh, they may in turn reinvent themselves. This is what happens when a trained psychiatrist works on global warming.

As Rahman looks to the future, he sees three adaptation options for Bangladesh: retreat, accommodation, and protection. “In view of the high population density and shortage of land, retreat is not possible. We should pursue the two other options. Some of the adaptation options are: raising of forest all along the coast, protection of mangrove forests, changing cropping pattern and variety in the coastal area, construction of embankments where feasible, construction of ‘safe shelters’ for emergency situations like extreme events, etc. In fact, many of these options are already in operation—on a limited scale, though.

“Adaptation has crosscuttings of different disciplines, and hence a multidisciplinary and integrated approach need to be taken up to reduce vulnerability. Adaptation will require thinking big and small—for instance, changing cropping patterns and developing new seeds able to survive in the changed climatic conditions. Part of our attempt is to train leaders to prepare before it happens. . . . You need to mobilize people and you need to empower them,” Rahman says.

In the end, it’s the people who have the potential to do this. They will improve the adaptive capacity of the country. Bangladesh may have a problematic geography, but it has great people—people who refuse to let the West define them as hopeless.

Leaders here estimate that it will cost $500 million just to raise embankments in some areas about 8 inches, a level that by the time construction is complete might not be high enough to keep growing storm surges at bay. Adaptation is not sexy or cheap. Scientists at the Bangladesh Rice Research Institute are working to develop a strain of rice that can withstand higher salinity levels.11 Adaptation will require infrastructure investments across the board. Bangladesh needs to build embankments and cyclone shelters. The government says the country’s power-generating capacity is at a maximum, 4,000 megawatts, which covers only 35 percent of the total population. The newly elected government has vowed to increase power generation in order to boost economic development. Rahman estimates that by 2015, the demand for electricity in Dhaka will rise to 10,000 megawatts. That, Rahman says, creates an enormous opportunity for clean energy projects to promote energy efficiency and renewables at a household level.

But he noted that resistance to spending precious dollars on more expensive low-carbon technologies in Bangladesh remains strong. Here, economic growth and fighting poverty remain the top priorities. “We are one of the most negligible emitters of greenhouse gas,” Rahman says. Bangladesh, currently one of the poorest countries on Earth, has virtually no hand in causing climate change. The average Bangladeshi emits about one-third ton of carbon dioxide each year—a lot less than the roughly 20 tons emitted annually by the average American. At the global level, Bangladesh emits less than 0.2 percent of world total. To put that in perspective, the city of New York alone emits about 0.25 percent of the world’s total greenhouse gases.

As Rahman says, “Cooking stoves account for almost 20 percent of emissions in Bangladesh. Cooking stoves. This is the level of industrialization we’re talking about.” Rahman still has hopes for megacities; he says that leaders need to start viewing land use and other aspects of city planning as critical components of preparing for climate change. “Properly managed, urbanization can be a good thing,” he said. “Improving urban management is itself an adaptation strategy.”

For people in Bangladesh, climate change is not a theoretical, academic, or distant concern. It is a question of survival. It is a question of infrastructure. It is a question of water and energy. It is a question of believing the forecast for 2050 and beyond.

At the end of our long phone conversation, Rahman couldn’t help making a comparison between his old life in the United States and his new life in Bangladesh, “I lived in the United States for twenty-eight years, and there are things I miss. There is no question about that. I would have had more things if I stayed in the United States: a bigger house, a bigger car. But even that . . . I don’t regret for an instant. I think I’ve come at a very exciting time. But there is no question in my mind that I made the right decision. This is not just about me; it’s about something larger than myself. I don’t think I could say that if I had stayed in the United States.”

I guess sometimes you do get to choose whom you fall in love with.

Bangladesh: The Forty-Year Forecast—Sea-Level Rise, Floods, and Climate Refugees

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Forecast January 2016

Nowhere was the issue of water more problematic than in South Asia. From the 29,029-foot Mount Everest in the Himalayas down to the lush, swampy mangrove forests of the Sundarbans, water was being held hostage by climate change. And that meant more than 1.3 billion people, dependent on the good graces of the climate system to deliver life-sustaining water in a timely and dependable manner, had a very big problem on their hands.

The problem came in several forms and started at the very top, in the Himalayas—mountains that stretch from Pakistan to India, China, Nepal, and Bhutan. The more than 15,000 glaciers that have covered the Himalayas for millennia bear a significant responsibility—they feed Asia’s nine largest rivers, including the Ganges, Indus, Brahmaputra, Mekong, Yangtze, and Yellow, and bring a steady supply of pure, cool water to the people of South Asia. The problem was that the glaciers draped over these majestic mountains were retreating at an alarming rate. Scientists estimated that most were pulling back between tens and hundreds of feet each year; this rate made the Himalayan glaciers the fastest-melting glaciers in the world. In this very remote and beautiful place, the sound of global warming had become deafening.

The sound itself came from what is known as a glacial lake outburst flood (GLOF). Glacial lakes, which form as a result of a melting glacier, had become overwhelmed by meltwater. Every few minutes the chemistry of global warming showed off its handiwork: somewhere along the 1,500-mile mountain chain, rising temperatures ripped heavy chunks of ice loose from glacier after glacier. As the ice came loose, it crashed down, adding more and more water to already overflowing glacial lakes. Eventually, the lakes had no choice but to burst—releasing huge quantities of water. By 2016, every country in the Himalayan region had suffered from glacial lake outburst flooding.12

The melt rate had begun to increase in the early 1990s. It was then that the now infamous Luggye glacier in Bhutan—retreating more than 520 feet a year—finally broke off, on October 7, 1994. The lake burst open, releasing more than 4 billion gallons of water down the Pho River, killing 21 people, and wiping out entire villages and farms.13 Floods like that were almost routine by 2016.

After countless floods, local villagers in Bhutan and across the Himalayas took matters into their own hands. They organized a small army of workers to combat the effects of climate change. Local officials estimated that by reducing glacial lake levels by 15 to 20 feet, they might be able prevent catastrophic flooding. The cost of widening just one lake ran upward of several million dollars. For the most part, the money was provided by the Least Developed Nations Fund—a special fund set up by the United Nations Framework Convention on Climate Change to help the world’s poorest nations adapt to climate change. In Bhutan the work was done without the help of heavy machinery—the workers used just picks and shovels. In their first year, people from across Bhutan working at the Thorthormi glacier managed to lower the lake’s level by 35 inches. But it would take years to get the lake to a safe level. And while there was a great sense of accomplishment with each inch the lake dropped, people realized that the risk of flooding would eventually be dwarfed by the problem standing in line behind it. The bigger catastrophe would come with the eventual disappearance of the glaciers. After the floods came the drought.

April 2022

Problems with water came from the mountains, but they also came from under the Earth. Groundwater—formed by the natural percolation of rain and snow into soil and stored in pockets of porous rock—was being depleted at an alarming rate. Satellites operated by NASA first revealed that groundwater levels in northern India had been declining by as much as 1 foot per year over the past two decades—a completely unsustainable rate. The Indians denied this, but the satellites did not understand politics. They clearly showed that 26 cubic miles of groundwater had disappeared from aquifers in areas of Haryana, Punjab, Rajasthan, and the nation’s capital territory, Delhi, over the past four years alone—enough water to fill Lake Mead, the largest man-made reservoir in the United States, three times over.14 The Indian government said that U.S. satellites should mind their own business.

The reductions of streamflow and groundwater did little to improve relations between India and Pakistan. A meeting was called between high-level Indian and Pakistani officials to renegotiate the Indus Waters Treaty, first signed by the two countries in 1960. Upon signing the treaty, the countries had agreed that the six primary rivers of the Indus basin would be split evenly between India and Pakistan. For more than sixty years the treaty withstood the strain of wars between India and Pakistan. But now that groundwater had also become scarcer and scarcer, Pakistan believed it was being taken advantage of and requested a larger share of Indus water. The fact that both countries had nuclear capabilities lent a chilling new dimension to the water negotiations.

August 2026

Woes involving water in the south came in a different form. In early August, millions of Bangladeshis had been marooned or displaced by floodwaters. The death toll currently stood at more than 5,000, but it was expected to rise. The floods had been coming more often, just as the models had predicted. Everyone was grateful for the seasonal and twenty-day flood forecasts routinely issued to Bangladeshis by the Asian Disaster Preparedness Center. At least these forecasts gave people a chance to prepare. With advance notice, they could postpone planting or hurry to harvest some or all of their crops, move livestock to safety, encircle fishponds with nets to prevent fish from escaping, and stock food and other supplies. It was something. And it allowed them to continue living in the place they loved.

In addition to relying on the flood forecasts, villagers also engaged in simple solutions they hoped would help decrease their vulnerability. Home foundations and frames were constructed using lightweight composite materials that could bend but would not break during a storm. Women wove these fibers from jute, one of Bangladesh’s common plants, with recycled plastics to form strong building material. The people of Bangladesh did everything in their power to stay. They even used materials that would float on the rising tide of a coastal surge—hoping these might serve as life rafts when the next flood came. But in the end, it was not their choice to make. With each successive flood more and more people began to pack what was left of their possessions and leave. First the numbers were in the thousands; then they gradually increased to the hundreds of thousands. A steady rain of refugees poured down on Dhaka—a city already overcrowded. Men and women sometimes arrived with dreams of finding better jobs and better lives. But many had left their villages with no dream other than to save the lives of their children—too many had been lost to the floodwaters already.

September 2039

In India, the groundwater situation worsened. Officials were forced to begin illegally withdrawing more water from the Indus River than they had been allotted. In response, Pakistan threatened to call in troops along the border.

As Himalayan glaciers retreated and groundwater was further drawn down, sea level continued its steady rise.15 As the sea level crept higher and higher, the saltwater front traveled hundreds of miles upstream, and the salinity in surface water increased almost sixtyfold. The increase in salinity altered soil quality and nutrient loads. Simply put, the salt water was killing the trees. Down in the Sundarbans, the mangroves were dying. And the ripple effect of climate change was not hard to predict. The mangrove forests of the Sundarbans contained one of the last remaining populations of wild Bengal tigers left in the world.

July 2050

Despite plenty of competition, South Asia remained the most food-insecure place on planet. Rice and wheat yields continued to spiral downward because of high temperatures and low water supply.16Governments around the region had tried to pool resources and engage in some of the less expensive adaptation measures. The hope was to moderate the predicted crop shortfalls and keep as many people fed as possible. As a result, planting dates were shifted and farmers switched to existing drought- and heat-tolerant crop varieties. Money was also spent on the development of new crop varieties and the expansion of irrigated areas. These measures showed some the biggest benefits. But in the end, there is only so much you can do without water. With an additional 130 million people pushed from food insecurity to famine, a mass exodus was under way. As part of an international agreement, the United States and the European Union agreed to take in millions of the hungry and displaced. And after years of fighting over what to call them, they were now officially known as climate refugees.

In Bangladesh, the water problem was surreal. With almost 25 percent of the country underwater—as a result of rising seas, recurrent flooding from increasingly malicious tropical cyclones, and the slow and deadly seepage of saline water into wells and fields—Bangladesh had become a wasteland. One by one, millions of men gathered their families and left their mud-caked villages, never to return. Many of them crossed illegally into India, hoping to find construction work in Assam and West Bengal.

Others, like Hassan and his family, fled to Dhaka. In his village Hassan had been a proud man, able to support his family with his handiwork. Now he was shining shoes on the streets of this megacity, whose population had swelled to more than 40 million. Hassan and his family were among the last to leave their village. It took him several months to persuade his wife to move away from the only place she had ever known. But finally, she gave in. He promised to take her to the Dhaka Zoo. She had always dreamed of seeing the Bengal tigers up close. The zoo was now the only place they could be found.