About 10 years ago, people in the small village of Gajoldoba on India’s stretch of the trans-boundary Teesta river started noticing significant changes in their environment.

Their fields weren’t yielding the same number of crops. The water level in the wells was dropping. And the fish – once so abundant that many families lived off their catch of fishes – were starting to disappear from the river.

More strangely, rainfall patterns had begun to change. It fell in erratic bursts, incredibly heavy storms – and then nothing for weeks. The river also seemed to have grown more destructive – instead of eroding the land during the monsoon season (as it usually did), the land was crumbling away all the year round. Homes had to be moved, and agricultural plots were disappearing into the hungry river.