The environmental ecologist Anthony Allan of King’s College London developed the concept of "virtual water" which relates the total quantity of water which is used during production of a product. The quantity of clean water which evaporates, is used or contaminated in the production process of a product is summarised here – from the watering of raw material plants to cooling water.
If the so-called "water footprint" of various products is calculated, a much higher water consumption is identified than one would think at first glance.