Sunday, January 25, 2009

Peak Water?

Times Online | A swelling global population, changing diets and mankind's expanding “water footprint” could be bringing an end to the era of cheap water.

The warnings, in an annual report by the Pacific Institute in California, come as ecologists have begun adopting the term “peak ecological water” — the point where, like the concept of “peak oil”, the world has to confront a natural limit on something once considered virtually infinite.

The world is in danger of running out of “sustainably managed water”, according to Peter Gleick, the president of the Pacific Institute and a leading authority on global freshwater resources. Humans — via agriculture, industry and other demands - use about half of the world's renewable and accessible fresh water. But even at those levels, billions of people live without the most basic water services, Dr Gleick said.

A key element to tackling the crisis, say experts, is to increase the public understanding of the individual water content of everyday items.

A glass of orange juice, for example, needs 850 litres of fresh water to produce, according to the Pacific Institute and the Water Footprint Network, while the manufacture of a kilogram of microchips — requiring constant cleaning to remove chemicals — needs about 16,000 litres. A hamburger comes in at 2,400 litres of fresh water, depending on the origin and type of meat used.

The water will be returned in various forms to the system, although not necessarily in a location or at a quality that can be effectively reused.

There are concerns that water will increasingly be the cause of violence and even war.