Friday, June 06, 2008

HOW MUCH WATER ARE YOU REALLY USING?

THOMAS M. KOSTIGEN, DISCOVER MAGAZINE I've been mindful of the amount of water I use when making a pot of coffee ever since learning that one-third of the tap water used for drinking in North America is actually used to brew our daily cups of joe-and that if each of us avoided wasting just one cupful of coffee a day, we could save enough water over the course of a year to provide two gallons to every one of the more than 1.1 billion people who don't have access to fresh water at all.

That is a stark statistic, when as many as 5 million people die unnecessarily each year because of lack of water and water-related illnesses; one-third are under age 5.

So for me that excess cold coffee at the bottom of the pot became a bothersome reminder. But I had never thought beyond that-about how much water it takes to actually grow the coffee. That amount is called virtual water). . .

Here's how it is figured: It takes about 155 gallons of water on average to grow a pound of wheat. So the virtual water of this pound of wheat is 155 gallons. For a pound of meat, the virtual water is 5 to 10 times higher. There's a virtual water count for everything. The virtual water footprint of a cup of coffee is 37 gallons; an apple, 19 gallons; a banana, 27; a slice of bread, 10; a sheet of paper, 3; and a pair of leather shoes, 4,400, according to Waterfootprint.org, a UNESCO-run Web site providing a calculator for individual and national water use. In fact, virtual water in internationally traded food and products such as these accounts for 15 percent of global water consumption. . .

Right now we lose 30 to 50 percent of the food we grow-and all the virtual water in it-by the time it is ready for consumption, says Daniel Zimmer, executive director of the World Water Council in Marseille, France. These losses come in harvesting, production, processing, transportation, and storage. Tossing out leftovers wastes every drop of water it took to grow the food (and think of all the times you don't ask for a doggie bag). Indeed, the third most common refuse found in landfills is food, according to the Environmental Protection Agency. ". . .

The average person on earth has a virtual water footprint of about 328,410 gallons each year; that includes everything used to make the food, clothing, and other water-driven products we consume. In China the average footprint is only 185,412 gallons, while in the United States it is 656,012-the largest on the planet.