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Virtual water no substitute for the real thing

by Brian Warmoth
June 08, 2011

Water faucet

Brian Warmoth/MEDILL

Virtual water can offset water shortages, but researches caution against depending on it as a fix-all solution.

In the summer heat, virtual water may not rehydrate you, but some researchers believe that it could help remote communities where fresh water is scarce.

Ecologists at the University of Virginia in Charlottesville, Va., Tuesday published a report in the Environmental Research Letters, casting doubt on the impact of giving goods to regions suffering from water shortages.

Virtual water refers to the use of goods—often in international trade deals in agricultural, industrial and even consumer products—to balance out inequalities of existing fresh water. Whether virtual water can actually counteract shortages and contribute to economic and social stability remains a topic for industries and governments.

By looking at virtual water in the context of data from the United Nations, however, ecologist and lead author David Seekell concluded that international trade relationships as they currently exist are not optimized for virtual water to be a one-stop solution.

"Water isn't the deciding factor in trade decisions," Seekell said. Freshwater distribution will become a bigger issue as populations grow in areas with poor access and water security. Although virtual water can play a role in remedying those issues, Seekell explained that other solutions are needed, since trade priorities, tariffs and political motivations do not always align with populations’ needs.

Seekell’s study focused on United Nations calculations assessing the world’s total renewable water resources, agricultural water footprint, industrial water footprint, household use water footprint, population, amount of arable land and other factors. The data, available on, looks at how much water various agricultural and industrial processes use.

For instance, 15,000 liters of water are required to produce 1 kilogram of beef, according to a December 2010 report published by the Institute for Water Education. A May 2011 report from the same organization estimated that the water footprint of a U.S. citizen is 2,840 cubic meters of water per year per capita.

“There's this idea that virtual water can contribute to substituting for water,” Michael Pace, a co-author and ecologist at the University of Virginia, explained.

The researchers compared water resources to populations’ usage by country, based on the U.N.’s human development index.

Virtual water transfers from high water use to low water use countries can still improve disparities, according to Seekell. He cautioned, however, that such transfers can artificially bloat populations and threaten their ability to respond to natural disasters and other emergency situations where real water availability can be crucial.

Comparative water use among populations will have to even out in the future, he maintained. But sustainable regional practices based on resources of fresh water will have to remain part of the equation.