​The rainy Asian monsoon season waters crops for nearly half the world’s population–but it may not be as reliable as we think. Scientists at Columbia University’s Lamont-Doherty Earth Observatory are reading the growth rings of ancient trees to understand the history and workings of the monsoon. What they are seeing sheds light on past civilizations–and possibly on the future.

Written and Narrated by Kevin Krajick

Produced by Arif Noori (twitter.com/anoori)

Earth Institute, Columbia University