Fishermen on Sagar Island were hard at work as waves leapt across the embankment on the southern fringe of the island at high tide in August. Embankments in the area have failed repeatedly to hold back the sea.

The Indian delta region of Sundarbans is one of the areas worst affected by climate change. Sagar, one of the major inhabited islands in this archipelago, has been battling aggressively rising sea levels in recent decades. Itlost 7.37 sq km of land between 1979 and 2011.

Crumbling homes, abandoned shrines and tree stumps dot the landscape, and a school that stood not far from this site in 2013 has now been washed away. Farming and fishing, the region's economic mainstays, are becoming unproductive with saline water ingress, displacing thousands.

TOMORROW: Look out for the third of six weekly special reports in The Sunday Times examining how global warming is affecting the world.