This year's IPCC report puts 40% of the world in the 'highly vulnerable' category when it comes to the impact of climatechange. We speak to one of its lead authors, Matthias Garschagen, about the adaptations we need to make before it's too late. We also head to Antarctica, where NYU mathematician David Holland is studying the so-called Doomsday Glacier. Plus: the competition for the world's most basic resource. We're in Madera County, California, where a never-ending drought is pitting citizens against corporations.