The World's Water Crisis

When it comes to water, says environmental explorer Fred Pearce, world maps no longer really tell the truth. As nice and natural as they may look in the crisp blue colors of an atlas, the fact is that today, dozens of the world's greatest rivers run dry long before they reach the sea.

Rivers such as the Yellow River, the Indus, the Rio Grande, and more are tapped out along their course by a voracious human appetite for water. And then there are the wells: millions of small farmers with their little pumps sucking aquifers dry.

Oil gets the attention, but a global water crunch could come quicker, says Pearce. For many, it's already here.

Hear about new reports from where the rivers run dry, and the world tapping out of water.

Guests:

Mark Stevenson, AP Correspondent in Mexico City

Fred Pearce, author of "When the Rivers Run Dry: Water - The Defining Crisis of the Twenty-First Century."