A combination of climatic changes and a lack of sediment flow is playing havoc with the ecology of the Sunderbans, experts said during a meeting at Jadavpur University recently.
They said the region needs innovative funding support to sustain its unparalleled biodiversity and human population of around 5 million.
The meeting on “Climate-induced Loss and Damage in the Indian Sunderbans” was jointly held by the International Water Management Institute (IWMI) and the School of Media, Communication & Culture at Jadavpur University.
“The temperature of the surface of the Bay of Bengal is increasing by 0.5 degree Celsius every decade because of climate change. The sea level around the Sunderbans is rising more than twice as fast as the global average,” said Kalyan Rudra, the chairperson of the state PCB, referring to the state climate action plan report, which is presently with the Centre for approval.
According to the report, the sea level surrounding the Sunderbans has risen nearly 275 millimeters since Independence. The water level during high tides is also consistently increasing triggering large-scale erosion.
Rudra also pointed out that the delta was shrinking because of a lack of enough sediment flow.
The delta is not getting enough sediment from upstream because of two reasons. First: An eastward shift of the delta leading to the beheading of all Ganga distributaries such as Bhagirathi, Bhairav, Jalangi and Ichamati, hence arresting the sea-ward sediment flow. Second: The construction of sluice gates in the upper catchment for which the sediment supply to the delta has substantially reduced.
Rudra explained that the factors work in tandem. “Lack of enough sediment weakens the power of river water to push back the encroaching sea,” he said.
Sugata Hazra, a professor in the oceanography department of Jadavpur University, listed several forms of climate-inflicted losses in the Sunderbans.
“The Sunderbans have lost about 50sqkm of land and 110sqkm of mangrove area over the past two decades, Apart from the obvious economic losses involved, we have also been losing the ecological services and carbon-catching potential of mangroves. Then there are damages inflicted by cyclones, parts of which can be recovered,” Hazra said.
A presentation, based on state government data, showed that the Sunderbans had suffered losses worth ₹1.5 lakh crore because of only three cyclones — Bulbul, Amphan and Yaas between November 2019 and May 2021.
Nilanjan Ghosh, an ecological economist and head of the Calcutta chapter of thinktank Observer Research Foundation (ORF), pointed out that the detailed valuation of the climatic impacts in the Sunderbans, including the wide-range ecological services that it provides, has not yet been carried out and was urgently needed.
“We need a loss and damage assessment to arrange for funds to support the people of the delta and its unique biodiversity. We need to scout funds beyond government, definitely international support but from the private sector as well,” Ghosh said.
“I see no reason why we cannot request the major Bengal-based companies to provide part of their corporate social funds to combat climate change in West Bengal, particularly the Sunderbans,” added Ghosh.
