Shushanto, 27, said her brother decided last year that he could no longer support his family by casting the river for shrimp fry. He left for India with his wife and child, and a few months later Shushanto's parents joined them. The men do construction work in the town of Gauramganagar, outside Kolkata.
"We are in trouble here. If the water comes up, we will have to move, as well," said Shushanto, who lost part of her home in a September flood. "I don't really want to go, but if the situation arises where I have to go, that's where we'll go."
Villagers readily acknowledge that in this region, which is so close to the border that Indian SIM cards work in Bangladesh cell phones, families have always traversed nations. After all, they share language and customs with their neighbors in India's West Bengal.
Bangladesh officials insist that they haven't detected any new dynamic in such back-and-forth border crossings.
"Even their tigers traverse the same territory," said Azad. "Given the fact that there's a porous border, there could be some possibility that people are moving to India, but moving for a job and coming back."
Some villagers agree. Shumitra, whose two sons moved to India last year for work, said she believes they will return to Harinagar "when there is work." Others say they're not so sure.
Gaurpodomando, 35, whose uncles, brothers and father are living in the same town of Gauramganagar in India, said his family has stopped talking about when they might return home. Instead, he said, his brothers are pushing him to join them in India. Shushanto said she doesn't expect her brother to come back to Harinagar. And even Shumitra, looking longingly at a photograph of her sons and insisting that her sons will come home soon, admits she's prepared to give up her life in Bangladesh.
"They'll be back," she said of her boys and sighed. "But if it doesn't work out for us here, then we'll have to go there."
India sees coastal flooding as 'a national security issue'
India, for its part, sees climate change bringing multiple threats. Rivers feeding both Bangladesh and Pakistan pass through India, but threaten to dry up because of melting glaciers. Meanwhile, the country can barely handle demands for resources from its own citizens and argues that it shouldn't have to accept the victims of a problem caused by the industrialized world.
"If one-third of Bangladesh is flooded, India can soak in some of the refugees, but not all," Retired Air Marshal A.K. Singh, the former commander of India's air force, told a London conference recently. "Low-lying coastal area flooding is a national security issue."
So far, about 1,600 miles of border fencing has been completed, with the work scheduled for completion by March 2010. India maintains that its purpose is to protect the country against smuggling and terrorism as well as illegal immigration. But its fence – much like the one the United States is building along the Mexican border – has provoked bitter debate.
"For the countries that build fences, it's not really a way to control immigration but a way to reassure the electorate," said Francois Gemenne, a research fellow at the Institute for Sustainable Development and International Relations in Paris.
"They're more symbolic than really an effective immigration tool."
But Cleo Paskal, an associate fellow at the Royal Institute of International Affairs in London, said the prospect of large-scale migration from Bangladesh represents a real threat to India, and it's one the West should take seriously.
"There are a lot of countries that would like to see India weakened," like China and Pakistan, Paskal said. She argued that if Bangladesh is destabilized by climate change, Islamic radical elements are more likely to prey on vulnerable communities. That, she said, could easily lead to more deadly attacks like the one in Mumbai, India, earlier this year.