El Niño has been dropping much-needed rain this winter on a parched American West. But it's making little difference to the greater water scarcity issues the US as well as the rest of the world is increasingly facing.

Here to talk about the state of the world situation for fresh water -- arguably the single most important resource to humans on the planet, next to oxygen -- is Sandra Postel, Director of the Global Water Policy Project, author, lecturer, and former National Geographic Fellow. The punch-line to her message: as more and more demands are placed on our finite freshwater supply by human consumption and climate change, intelligent conservation is now an absolute must.

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