Professor John Anthony Allan, We Salute You!

The Sotckholm Water Prize, often considered the 'Nobel Prize" of the environmental sciences was awarded to
Professor John Anthony Allan this year for his innovative "Virtual
Water" concept.  According to the Stockholm International Water
Institute:

Professor Allan pioneered the development of key concepts in the understanding and communication of water issues and how they are linked to agriculture, climate change, economics and politics.

Source: siwi.org

Virtual
water is only unlike real water insomuch that it accounts for all the
uses of water hidden from the everyday consumer.  For example, a cup of
coffee isn't just a cup's worth of water; instead, about 140 liters of
water are required to grow, harvest, package, and ship that cup of
coffee to you.

The motivation behind developing something like virtual water lies in its socioeconomic utility:

Virtual water has major impacts on global trade policy and research, especially in water-scarce regions, and has redefined discourse in water policy and management. By explaining how and why nations such as the US, Argentina and Brazil ‘export’ billions of litres of water each year, while others like Japan, Egypt and Italy ‘import’ billions, the virtual water concept has opened the door to more productive water use. National, regional and global water and food security, for example, can be enhanced when water intensive commodities are traded from places where they are economically viable to produce to places where they are not.

Source: siwi.org