The world is getting thirstier, and drier. More than 2,500 experts from around the world will discuss the issues facing one of the world's most precious natural resources at World Water Week this week in Stockholm, from the millions of gallons of water hidden inside biofuels to the ongoing scandal of poor sanitation.

As our in-depth report on the subject notes, 20 percent of the world's population already can't get enough water. Americans aren't helping things by guzzling 400 liters (106 gallons) on average every day, compared to 200 liters (53 gallons) for the average European and just 10 liters (3 gallons) per day for the rest of the world.

In addition to just wasting water, humanity is also polluting it with waste and then, because water is so precious, using said wastewater to grow crops. Throughout the developing world, from rice paddies in China to vegetable patches in Ghana, water fouled with human waste is used directly in agriculture, spreading human disease, particularly diarrhea. Diarrheal diseases kill more than 1.4 million children every year, or 5,000 every day.

And climate change will only make water scarcity more acute, as wetter regions get wetter (and therefore more prone to flooding) while drier regions get even more parched. This means humanity will have to get a lot less profligate with the water we have; for example, the U.S. throws out 40 trillion liters of water a year in the form of food.