Although Azzam Alwash and his family lived in California, he had very fond memories of growing up in Iraq’s marshes with his father. So when he heard that Saddam Hussein was punishing a group of so-called “Marsh Arabs”—rebels who made their living along the wetland’s islands—by cutting off their water supply and draining the marshes, he went back to Iraq to do something about it. The marshlands in question are not only sentimental, but about as historic as places get—it’s the Cradle of Civilization, the origin of the Sumerian empire and, some believe, the location of the Garden of Eden. His work, which began in 2001, became an obsession that took a sad toll on his personal life, but he has seen the land spring back to life. A scientific study in 2010 found that numerous species which had left the region were starting to return, and the population around the marshes had increased tenfold …