"A possible 45 centimeters (18 inches) rise in the sea level by the year 2050 may inundate 75 percent of the Sundarbans," warned the inter-governmental panel on climate change.

In a draft report called "Considering Adaptation to Climate Change in the Sustainable Development in Bangladesh" the experts warned a climate change, could lead to a drop in the number of fresh-water plants.

"Eventually, the species offering dense canopy cover would be gradually replaced by non-woody shrubs and bushes," the report said. This, it said, could lead to the extinction or degradation of the rich flora and fauna, including Bangladesh's Royal Bengal tigers which are on an endangered species list.

The Sundarbans, which stretch to neighbouring India's West Bengal state, is one of the United Nations' World Heritage sites.