Divakar Bhandari, who once tilled his own land on Lohachara island, now lives the life of a refugee with his family at Colony Para in Sagar island. “I had a small plot,” he told Newsline, “and the sea claimed some of it each day. And one day, it was all gone.

“It’s 22 years since I am living in this refugee colony.”

That sea, the scientists say, is now threatening more lives.

Among the most vulnerable are Ghoramara and the thickly populated Sagar islands. According to the School of Oceanographic Studies scientists, around 28,000 people may be forced to migrate soon from various parts of Sagar island unless the Centre and the state governments adopt preventive measures.

The study says Sagar island is likely to lose 15 per cent of its land over the next 14 years.

“What can be done at most is to delay the process of erosion by adopting proper measures, which unfortunately, have not been adequate,” said a scientist who is part of the research team.

Prof Hazra said: “Halting (sea-level rise) may be possible for another 20 years. A gradual shift (of people) needs to be planned. The authorities are only worried about tackling instantaneous disasters like floods and earthquakes. What about the slow-onset disasters? This is one of those.”

The study says: “Considering the probability of high intensity cyclones, surge-height, erosion of coastal area, crop yield, situation of properties (agricultural fields, aquaculture farms, jetties, markets), the total valuation of loss may be Rs 6,000 million by 2020.”

For the soon-to-be refugees, however, the cost is incalculable.