14 Feb 2012:
‘Virtual Water’ Reliance
Puts Nations at Risk, Study Says
A new study calculates that about one-fifth of all water goes toward the production of crops and commodities for export
, part of a global phenomenon known as “virtual water” that researchers say
Click to enlarge
Arjen Hoekstra and Mesfin Mekonnen, PNAS
The virtual water balance, per country
could place pressure on finite water supplies in some nations. Using worldwide trade indicators, demographic data, and statistics on water use, researchers from the University of Twente in the Netherlands mapped the world’s water footprint, including patterns of trade they say are creating disparities in water use. According to the study, published in the journal Proceedings of the National Academy of Sciences
, many desert and island nations are becoming increasingly dependent on water from other countries, as they import not just food products but the water needed to produce it
. The nations most reliant on this virtual water include the island nation of Malta, which is 92 percent dependent, Kuwait (90 percent), Jordan (86 percent) and Israel (82 percent). Some of the most water-rich nations — including the U.S. and Japan — are also among the biggest importers because the products they import require so much water to produce.
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
Yale Environment 360
articles are now available in Spanish and Portuguese on Universia
, the online educational network. Visit the site.
Business & Innovation
Policy & Politics
Pollution & Health
Science & Technology
Antarctica and the Arctic
Central & South America
The 2015 Yale e360 Video Contest winner documents a Northeastern town's bitter battle over a wind farm. Watch the video.
is now available for mobile devices at e360.yale.edu/mobile
A 2015 Yale e360 Video Contest winner captures stunning images of wild salmon runs in Alaska. Watch the video.
video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs. Watch the video.
A three-part series Tainted Harvest
looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup. Read the series.
video goes onto the front lines with Colorado firefighters confronting deadly blazes fueled by a hotter, drier climate. Watch the video.