Although Earth is known as the "Blue Planet," very little of that which makes it blue is of much use to us. Fully 97 percent of the world's water is too salty for us to use to slake our thirst, grow our food or wash our clothes.
The wise management of the small amount of available freshwater will pose one of the biggest challenges to mankind during the coming decades. Many great civilizations have vanished as their sources of potable H2O disappeared. As the planet’s population swells to nine billion people by the year 2050, concerned scientists and citizens say it is important that measures are taken now to ensure our global society's sustainability.
In this slide show, Scientific American.com explores the peril of diminishing water supplies as well as the promise of new technologies and practices that can save water and increase its availability. So although iconic images of the receding water levels in the Colorado River's Lake Mead reservoir are cause for alarm, the advent of cheaper desalinization methods and even more efficient sanitation systems show how we can avert a global catastrophe.