“Virtual Water”

How much water was in your coffee this morning? You might be surprised to learn that the answer is 140 litres. Even I didn’t drink that much. But as the environmental scientist Tony Allan explains: “That is the amount of water used in growing, producing, packaging and shipping the beans.” His book encourages us to look at such “virtual water” embedded in commodities, which lends a surprising new angle to global trade. (A country that imports wheat is in effect importing the water needed to grow it.)

distinguishes usefully, too, between “blue water” (rivers and lakes) versus “green water” (in plants and soil), the latter hard to cost.

He considers water policy in Spain, the United States, Egypt and China (in water terms, the one-child policy “saved the world”, he claims provocatively), and argues that the “hydrological mission” of irrigation and damming is always wrong, while explaining the connections between water, food and “energy security”.

The book is rather rambling, but it is friendly and clear. I was only saddened to see yet again the story of the poor frog which, according to the cliché, won’t jump out of a slowly heated pan of water. This amphibian libel must end now.

Virtual Water
Tony Allan
IB Tauris, 2011

— By Steven Poole


Copyright © Guardian News & Media, 2011