A forest-fed perennial river Cauvery in Southern India, which has been a life-line of South India for many millennia, is now dying. 87% of the basin’s original tree cover is lost in last 50 years. On the back of 23-years grassroots work, Cauvery Calling is enabling 5.2 million farmers to grow 2.42 billion trees in the Cauvery river basin (lifeline of Southern India) in the next 12 years by shifting farmers to tree-based agriculture.