25 April 2008

Water Footprint

If you want to move beyond your carbon footprint and worry about a whole new thing, check out your water footprint.

A glass of beer and an apple both have about the same impact: 75 and 70 liters of water, respectively (that's a little more than a quart, in case I have a reader in the US). Double that, at 140 liters, for a cup of coffee. Does that mean I should switch my morning coffee to a glass of beer? No, better off switching to a cup of tea at 30 liters per cup.

A kilogram (2.2 pounds) of chicken requires 3900 liters in comparison to 200 liters for an egg, but that kilo of chicken will fill more bellies; a kilogram of soybeans requires 1800 liters of water, so in terms of water footprint alone it seems we're better off getting our protein from the eggs.

Compare that to a pound of beef at 15,500 liters per kilogram, and it looks like switching one hamburger a week to an omelet, a basket of chicken wings, or a General Tso's bean curd has pretty decent impact.