How to fight desertification and reverse climate change

(NOTE: Statements in this talk have been challenged by scientists working in this field. Please read "Criticisms & Updates" below for more details.) "Desertification is a fancy word for land that is turning to desert," begins Allan Savory in this quietly powerful talk. And it's happening to about two-thirds of the world's grasslands, accelerating climate change and causing traditional grazing societies to descend into social chaos. Savory has devoted his life to stopping it. He now believes -- and his work may show -- that a surprising factor can protect grasslands and even reclaim degraded land that was once desert.