One...key area that I’m concerned about is China...As you know, they get a lot of their water from melting glaciers and snow in the Himalayas. And as it gets warmer, these glaciers...are melting at an accelerated rate. That’s been shown. Right now it looks good for the people there because they have more water than they’re used to. But what happens when the glaciers go away? That’s fossil water--they were formed thousands of years ago--and when they’re gone, just like somebody turning the tap off. It’s all over. So, in northwest China roughly 300 million people there are facing a water crisis within the next couple of decades. Where are they going to go? I don’t know, but the answers are not very attractive.--Tim Barnett of Scripps Institution of Oceanography and co-author of Human-Induced Changes in the Hydrology of the Western United States in the 1 Feb Science podcast (transcript pdf).
See also Prioritizing Climate Change Adaptation Needs for Food Security in 2030.