Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small clique of nations found to dominate global trading web of food, water

23.03.2012
It's not easy, or economically feasible, to ship freshwater across the globe.

But when scientists use food as a proxy for that water - taking into account how much crops are irrigated and livestock are fed - they can get a glimpse of the flow of freshwater between countries. When one research group studied this "virtual water network," they found that the interconnectedness between countries has almost doubled over the last two decades - potentially lending some resiliency to the water trade. Still, a handful of nations control a majority of the freshwater flow, and some regions, including much of Africa, are left out of the trading loop.

"In general, we have more trade going on, and more and more countries are now connected," said Joel Carr, an ecohydrologist with the University of Virginia in Charlottesville and one of the authors of the new study. "But these increases in trade and connections are not equally spread among countries."

Food production is one of the primary uses of fresh water, and as countries grow in population, they need more food, and therefore more water, to support their residents. If they don't have the water to grow crops or raise livestock but have money to spend, countries can import food - essentially importing water. The virtual water network is a way to look at the global balance of this freshwater trade, Carr said.

Carr and his colleagues studied the changes in the network - variations in how much virtual water (i.e. food) was being traded, which countries were trading, etc. - between 1986 and 2008. In that first year, there were 205 countries trading with each other, with about 8,200 trade links between them. In 2008, the number of countries trading virtual water had increased to 232, and the number of links had almost doubled to about 15,800 links.

While part of that increase was due to geopolitical factors, such as the U.S.S.R. breaking up into more than a dozen new countries that joined in the network, it is mostly due to the boost fueled by globalization in the number of trading partners countries tend to have, Carr said. Still, countries in Africa have not experienced the same growth in interconnectedness other regions have. And links come and go between countries as they pick up or drop trading partners, he added.

"The network itself is extremely dynamic, there are very few permanent links," Carr said.

The research is published today in Geophysical Research Letters, a journal of the American Geophysical Union.

One of the findings is that as of 2008, the most recent year examined by the study, there are just five key players - Brazil, Argentina, United States, Canada and Australia - in the virtual-water world, which are responsible for most of the world's export of the resource.

"There are very few countries that supply the virtual water for the world," Carr said, noting that about 56 percent of the water trade is exported by countries that make up 8 or 9 percent of the world's population. "A very small percent of the global population is supporting the food resources of the rest, which has political implications."

But even the key, water-heavy connections between major importers and exporters are in flux. Brazil and Argentina, for example, are now major exporters, but didn't have a significant role in the 1980s. Conversely, China and Germany are now major importers. The trade links that the researchers consider part of the network's "backbone," connections between countries that carry more than half of the water trade, increased from 91 in 1986 to 170 in 2008. But only 24 of those connections remained constant throughout the two decades.

It's surprising that the network is so dynamic, with so few permanent links, said Samir Suweis, a physicist and environmental engineer at the University of Padua in Italy, who has studied the virtual water network (http://www.agu.org/pubs/crossref/2011/2011GL046837.shtml) but was not involved in the recent article.

"The links disappear and reappear, highlighting how countries change trading partners a lot," Suweis said. "The challenge will be understanding what drives this rewiring."

And the virtual water trade should be monitored, he said, as nations grow and need more food, and therefore more water, but the economics of trade come into play as well.

"One of the points the study highlights is we can see that a lot of trading is not driven by water need or food need, it's driven by economics" - that is, the probability of trading among two countries is proportional to their gross domestic product, regardless of their water need. While that is inevitable to some extent, he adds, policymakers worldwide should become aware of this virtual water trading pattern and consider policies to protect and encourage both local and global water balance.

Title:
"On the temporal variability of the virtual water network"
Authors:
Joel Adam Carr and Paolo D'Odorico: Department of Environmental Sciences, University of Virginia, Charlottesville, Virginia, USA;

Francesco Laio and Luca Ridolfi: Department of Environmental, Land and Infrastructure Engineering, Politecnico di Torino, Turin, Italy.

Contact information for the authors:
Joel Carr, Telephone: +1 (434) 924-1304 or Email: jac6t@virginia.edu

Kate Ramsayer | EurekAlert!
Further information:
http://www.agu.org

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>