Bangla sea rise alert
New Delhi: Sea-level rise is likely to trigger population displacements in one-third of Bangladesh's districts, causing nearly 900,000 people to migrate to escape inundation within three decades, environmental researchers predicted on Tuesday.
The researchers listed Barisal, Chandpur, Munshiganj, Narayanganj and Shariatpur as the sources of nearly 60 per cent of the 900,000 expected migrants by 2050 in a study that sought to identify the source and destination districts of the displaced.
Using population and elevation maps and estimations of future sea-level rise, the study has predicted displacements in 33 to 53 per cent of Bangladesh's districts, depending on the sea-level rise.
"Sea-level rise is a very different type of migration driver from short-lived natural hazards, in that it will make certain areas permanently uninhabitable," said Kyle Frankel Davis, a scientist at Columbia University and the lead author of the study, published in the journal Environmental Research Letters.
Davis and his colleagues, who also used Bangladesh government data on inter-provincial migration, say that those displaced by rising seas would be unlikely to look far for attractive destinations because of the country's high population density.
Their analysis says that Dhaka, Madaripur, Comilla and Jhalokati would be among the key destinations for the migrants, and would face pressure to provide jobs and housing to them.
"Dhaka will need to prepare for the largest number of migrants, which may compound the area's already rapid urban growth," Davis said.
The study estimated that Dhaka could expect 207,000 people while Madaripur might receive about 83,000 and Comilla around 65,000.
The researchers did not consider cross-border migrations because, Davis said, these processes can be much more complex and because can move more freely within their own country. "There will likely be cross-border migration to a limited extent, but typically these types of migrations will take the path of least resistance," Davis told The Telegraph.
The study has also cautioned that sea level rise is also likely to impact livelihoods and food security through its impact on agriculture and aquaculture. Some studies have estimated that up to 1,000 sqkm of cultivated land on Bangladesh may be underwater by 2100.
"The country's coastal aquaculture is also vulnerable to climate change impacts," Davis said. "This will probably have nutritional and economic consequences given that 58 percent of animal protein in Bangladeshi diet comes from seafood."
The researchers say they plan to their study model to different countries and different types of climate impacts. Davis said: "In India, states with average low elevations such as Bengal and Gujarat as well as many communities along India's extensive coastline could be vulnerable to sea level rise and see human displacements as a result."