The amount of water needed varies with crops and depends from place to place, on local productivity and conditions of available water supply through rainfall or irrigation. Once the product is harvested and becomes available on the market, the water embedded in the product changes status from ‘real’ water to ‘virtual’ water.
The explosive growth of international trade has turned water into a traded commodity. Research into the water footprint of goods has revealed the true extent of the situation. It takes 650 litres of water to produce 1 pound (500g) of wheat, 2500 litres of water to produce enough meat for a burger and a staggering 4650 litres to produce a 300g beef steak.
So you want to save water? How much water is in that cup of coffee next to your desk? Well, about a cup, plus the bathtub full of water that it took t
PNAS Study: Population Growth Will be Constrained by the Limits of Trading Virtual Water (Food) -- The study by the Proceedings of the National Academy of Sciences calls into question the unsustainable global food export system based upon unsustainable export volumes of virtual water.