At the frontline of climate change, Sagar Island at the confluence of the Ganga and the Bay of Bengal is losing the battle to sea level rise, coastal erosion, tidal surges and increasingly violent cyclones
“The water rushed in at night,” recalls Madan Mohan Pal of Hendalketki in Sagar Island. “By the morning, the entire village was under water. When the flood receded, the land was so saline that we could grow nothing for the next two years.” Although Pal has harvested a good paddy crop this January, memory of the sudden tidal surge remains fresh.
An unpredicted high tide broke the embankments of Muriganga River in the night of July 12, 2014, and swept through 14 villages spread over 30 sq. km. The damage was extensive in the eastern part of the island. It disrupted life for about 25,000 people. More than 4,000 houses were destroyed and some 500 hectares of cropland turned saline. The sea hasn’t really retreated from some of the villages since then.
Sagar Island is arguably an object lesson on how people are coping with a rising sea. Considered sacred by Hindus because it sits at the confluence of the Ganga and the Bay of Bengal, this large island of 160,000 people is buffeted by the worst effects of climate change — coastal erosion, rising sea levels, unpredictable tidal surges, land salinity and more violent cyclonic storms.
There has been an increase in the intensity of cyclones making landfall in the Sundarbans between 1951 and 2010, recent research suggests. Such an increase in intensity may be attributed to an increase in sea surface temperature. Cyclone Aila in May 2009 left more than a million people homeless and killed 339 people across India and Bangladesh.
Sagar is part of the Sundarbans, the world’s largest delta and contiguous mangrove forests that straddle Bangladesh and India. The Sundarbans have an archipelago of 102 islands, of which 54 are inhabited by more than four million people. Some of these islands, such as Bedford, Lohachara, Kabasgadi and Suparibhanga have already disappeared. Other like Ghoramara and Mousuni will soon be lost, swallowed up by rising sea. Tens of thousands of people who live in the Sundarbans have lost their homes.
The tides in the Sundarbans are so dramatic that about a third of the land disappears and reappears every day. It has been happening for centuries but the changes have become more extreme in the past few decades. In this delta of Ganga, Brahmaputra and Meghna (GBM) rivers, the sea is rising more dramatically than in other parts of the world, latest research shows. Known as the biggest carbon sink in South Asia, Sundarbans is recognised as a world heritage site.
“It is established by the world scientific community that the GBM delta has become increasingly vulnerable to the impact of climate change. The higher rates of rise of sea surface temperature, delayed and irregular monsoon, high rate (more than 8 mm every year) of sea level rise are important evidences,” says Sugata Hazra, Director of the School of Oceanographic Studies in Jadavpur University in Kolkata. “We are continuously losing land due to erosion from the estuarine islands like Sagar, Jambudwip, Ghoramara, Mousuni, Bhangaduani, Dalhousie, etc. at the sea-facing front. Even a light easterly breeze during high tide often inundates coastal areas of islands with saline water, breaking or overtopping embankments.”
In recent decades, Sagar Island has lost 30 sq. km of land, according to an estimate by the Sundarbans Development Board. The 225 sq. km island is also home to more than 25,000 refugees from other islands. Parts of the island are three metres below sea level. Clay embankments are built around low-lying areas, which breach every once in a while due to constant tidal action and indiscriminate clearing of mangroves. About 10,000 families live on the fringes of water.
“The sea and fishing have become more dangerous nowadays,” says Abdar Mullick of Gangasagar village on the southern, sea-facing edge of the island. “Unseasonal and sudden storms hurt fishermen and their catch, particularly those who fish in small boats.” Earning a livelihood is becoming increasingly difficult due to hostile weather and depleted fish stocks in the sea, says Mullick, who is a leader of the local fishermen’s association. “Most young boys are not interested in fishing,” he says. “They want out.”
In Sagar, a vast majority of the people earn a livelihood from agriculture and fishing, and extreme weather events are threatening both occupations, leading to an increase in migration by the youth. But not everybody is giving up. Faced with a hostile climate, they are coping as best they can.
For farmers, one way to tackle increased salinity in the soil is to plant native varieties of salt-resistant rice. “There are many native varieties of rice that can grow despite increased salinity in the soil,” says Amales Mishra, Secretary of Paribesh Unnayan Parishad (PUPA). The non-governmental organisation has been promoting the use of salt-resistant varieties of paddy in Sagar Island. “The response has been encouraging,” says Saheba Khatun, a resident of Phulbari village who works for PUPA. “Since the yields are good, the acreage under salt-resistant varieties is steadily rising.”
For fishermen, it is mostly a story of retreat. Higher tides have forced them to move their fish-drying fields inland, says Mullick. Most of the fish caught at sea around Sagar is sun-dried on the beaches before being shipped out in small packets. “This constant shift to higher ground is not sustainable. How long can we do that?” asks a despondent Mullick.
These efforts at mitigation and adaptation are expected to have only minimal effects in the long term, scientists and administrators say. The trend of an increasingly aggressive sea and faster coastal erosion is expected to continue in the whole of Sundarbans, which includes Sagar Island. “The delta with reduced sediment supply due to anthropogenic reasons is presently unable to cope with the accelerated rise of sea level,” says Hazra. “The same trend will follow and increase, particularly after 2050, as suggested by our recently published modelling data on Bangladesh.”
“There has been around 250 sq. km land loss from southern sea-facing islands over the last 45 years,” says Hazra. “Sagar will be considerably diminished and non-habitable partially, unless nurtured by the re-deposition of dredging dumps.” Some of the smaller islands will not be so fortunate. They will simply be “eroded off,” he says.
Pal may have saved his livelihood for a while by adapting farming practices to the shifts in natural conditions, but for how long? “The sea wants to come in all the time. Every year, the tidal waves become more unpredictable,” he says. “We have made nature very angry.”