"Just as wars over oil played a major role in 20th-century history, a new book makes a convincing case that many 21st-century conflicts will be fought over water.

In Water: The Epic Struggle for Wealth, Power and Civilization, journalist Steven Solomon argues that water is surpassing oil as the world's scarcest critical resource.

Only 2.5 percent of the planet's water supply is fresh, Solomon writes, much of which is locked away in glaciers. World water use in the past century grew twice as fast as world population."

NPR's All Things Considered interviewed the author January 3, 2009. [2]