Wednesday, May 6, 2009

Water Myths

The Water to Grow Beef 5/5/09

In the water world there is growing interest in measuring and reporting how much water is needed to produce "things" -- goods and services that humans desire. See the table "The Water Content of Things" from the new volume of The World's Water 2008-2009 (Peter Gleick, editor, Island Press, Washington D.C.). Several different tools and approaches have been developed and described, including "virtual water" (most people, including me, credit this concept to Professor Tony Allen of the School of Oriental and African Studies, University of London); the "water footprint"; and "embedded water." All of these are based on the same idea: it takes water to do things. One of the most remarkable, and most remarked on, numbers to come out of these efforts is the water to produce beef, and so that is my "water number" for today's post:

Water Number: It takes around 16,000 liters (or kilograms) of water (and sometimes up to 70,000 kilograms) to make a single kilogram of beef.

For those of you who have no basis for comparison, this is a VERY BIG NUMBER. It takes only around 1000 kilograms of water to make a kilogram of grain, which partly explains why it is so big for beef -- it take a lot of grain, forage, and roughage to feed a cow, as well as water to drink and service the cow. When all of this is added up, it comes to around 16,000 kg water/kg meat produced. In comparison, other meats like chicken, lamb, and goat also require substantial amounts of water, but typically far less than beef. Read More

According to the Journal of Animal Science, livestock production only accounts for 11% of the total US water use. The other thing that the author didn’t do was to do a nutritional comparison between foods. It may take more water to raise some food, but you also need to look at the energy return as well. The fact of the matter is that it takes water to do everything. Everything with life requires it, but humans are still the biggest culprit of wasting water.

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