Coastal infrastructureBay of Bengal: Rising seas to force 13 million to evacuate to higher grounds

Within the next thirty years, a substantial area — called the Sundarbans — in the Bay of Bengal will be underwater as a result of climate change-induced rising sea levels. The roughly thirteen million people living in the region, which consists of approximately 200 delta islands in India and Bangladesh, will be forced to abandon their homes, making their displacement the largest exodus in modern history.

CBS News reported last week that the Sundarbans, spread over an area of 9,630 square kilometers in India and 16,370 square kilometers in Bangladesh, are slowly being overtaken by the sea. Many people have already moved from the Bay of Bengal coastline to higher grounds inland. One local resident told CBS that he had been forced to move five times in the last five years due to rising seas.

A 2013 study by the Zoological Society of London found that the Sundarbans coastline was retreating at a rate of about 650 feet a year. The Geological Survey of India also reports that at least eighty-one square miles of the Indian-controlled coastline has eroded in the last few decades. At least four islands are now underwater, with dozens of others abandoned due to fear of rising seas and constant erosion.

Scientists estimate that global waters are rising at roughly three millimeters per year. This figure may not sound threatening, but for the Sundarbans, the smallest increase in sea level is a dire threat. Global warming causes sea levels to rise around the world, but the specific rate of increase in different places varies, as it is affected by the Earth’s gravitational pull and tectonic shifts. The Examiner notes that the Sundarbans are experiencing sea level rise at twice the global rate, and sometimes higher. Add to that the fact that the mean elevation in the Sundarbans is less than a meter above sea level, and that sea levels are rising faster today than they were just a few decades ago.

In three decades, the migration of eight million Bangladeshis and five million Indians inland will create the largest group of “climate refugees,” which will challenge social, agricultural, logistical, and governmental structures in nearby countries and cities.

RTCC reports that earlier this month, a team of fifty scientists, led by Robert Nicholls, Professor of Coastal Engineering at the University of Southampton, visited the Indian Sundarbans to find ways to secure water supplies, health, and food for the millions currently living in the region. “Adaptation can be practiced locally like changing the agriculture from high-yielding paddy to conventional and sustainable paddy farming using indigenous seeds. You can go for fishing, aqua-culture farm, crab fattening and so on,” said professor Sugata Hazra, director of School of Oceanographic Studies, Jadavpur University, India.

Adaptation poses its challenges, but the team will review migration to a safer place as an option. “Migration should be seen in the framework of adaptation rather than seeing it as the failure,” Hazra said.

At the completion of the five year program, scientists will be able to predict the future of the region under various scenarios. Results from the study could also be used to help similar deltas in Egypt and Ghana, home to some 500 million people in total, cope with rising sea levels, said Tuhin Ghosh, Joint Director, School of Oceanographic Studies, Jadavpur University.