Interesting that they don't mention Uzbekistan, the failure of Soviet agriculture and the Aral Sea:

http://news.nationalgeographic.com/news/2009/08/images/090805-aral-sea-vanishing-picture_big.gif

That's all cotton for ya.

FUN FACT: 80% of the world's almonds and 50% of the world's pistachios are grown in California. One almond takes 1.1 gallons of water to produce. BUT:

Something raised by Scientific American a few years back was the "closed loop" nature of the world's water supply. The problem isn't that we're "using up" the water - after all, it runs to the sea, evaporates up, comes back down as rain, sunrise, sunset. The problem is we're moving the water. The places we have been growing are becoming more arid; the places we haven't been growing are suffering torrential downpours.

Those melting ice caps and rising sea levels are a reality, and they're a problem of more water. The issue is that the water isn't where we need it. And yeah - the Ogalala is being depleted in places. But it's being overfilled in others:

Which doesn't mean we aren't in for hard times. Those hard times just aren't related to a diminishing global supply of water.