Sundarbans are the largest mangrove forests in the world, with an area of more than 10,000 square km of land and water (more than half of which is situated in India, the rest in Bangladesh) within the delta of the Ganges, Brahmaputra, and Meghna rivers – all pouring into the Bay of Bengal. This natural heritage site is a complex network of tidal waterways, mudflats, and small islands of mangrove forests – many inhabited by small farming and fishing communities.

Sunderban is known for its huge biodiversity – including 260 bird species, Indian otters, spotted deer, wild boar, fiddler crabs, and marine turtles.

Rising sea-level is the greatest threat and challenge within south Asia. Flooding of low-lying deltas, retreat of shorelines, and acidification of soils are affecting the local population. In addition to global sea-level rise, there is a continuous natural subsidence in the Sundarbans, which causes a rise of about 2.2mm in the sea-level every year. In some instances, as in the island of Sagar, the rise in sea-level is 3.1 mm per year. A 45 cm rise in global sea-level would destroy 75% of the Sundarbans.