Virtual water

During the World Water Week conference held in Stockholm in August 2008, the environmental group WWF released a report that demonstrated the extent to which the UK consumes the water of other countries.

The concept of virtual water was created by Professor John Allan of King’s College, London, who was awarded the 2008 Stockholm Water Prize for it. It measures the amount of water that’s used in food production and in industrial processes such as the manufacture of textiles. The WWF report says 62% of the water consumed in Britain is virtual water from other countries.

Another term for it is embedded water. Other terms environmentalists use when discussing problems of water supply are water footprint, the amount of water, both virtual and visible, used by a country, a business or an individual (a term closely related to carbon footprint), and blue water, water that’s withdrawn from ground and surface reserves, as opposed to green water, which is taken directly from rainfall.

The concept of “virtual water” holds immense relevance for the water-scarce countries. Much water can be saved by cultivating only those food crops which need less water and importing the food items and other agricultural produce that need high amounts of water.

Khaleej Times, Dubai, 22 Mar. 2008

Academics behind the “virtual water” calculations have also created a worldwide league table for the water footprint of different countries. The US is the biggest offender, with a water footprint of close to 2,500 cubic metres per year per capita, while Italy is a close second. Britain’s water footprint is relatively modest at 1,245 cubic metres per year per capita.

Belfast Telegraph, 21 Apr. 2008