For decades, the author and scientist Giulio Boc­caletti has studied the substance that's come to define life as we know it: water. And in his book Water: A Biography, he traces the history of how humanity, regardless of continent or creed, has shaped entire civilizations around a resource that's both fickle and essential for life on earth. In this episode, All Things Considered host Ari Shapiro talks to Boccaletti about our long, complicated history with water, and why understanding the past is crucial to the fight with climate change.