Are you familiar with the term "virtual water"? A large amount of water is used in food production. For example, it takes about 1,300 liters of water to produce 1 kg of wheat, and about 15,500 liters of water to produce 1 kg of beef (Chapagain and Hoekstra 2004). This means that importing wheat or meat is equivalent to importing water. Virtual water is the calculation of how much water would have been needed if the imported food had been produced, and is a concept proposed by John Anthony Allan in 1993.

The amount of freshwater which can be used for agriculture and other purposes varies greatly from region to region. Virtual water trading can play a role in adjusting this unequal distribution of water, and it can be said that water has moved across borders through food trade. Japan imports a lot of food from overseas, so it does not need to use domestic water that would have been needed for its production. It is said that the amount of virtual water imported to Japan from overseas per year is about the same as the annual water consumption in Japan (Ministry of the Environment website).

The majority of water used by humans is for food production, and future population growth and climate change are expected to affect virtual water.

On Friday, December 6, the JICA Ogata Sadako Institute for Peace and Development will hold the JICA Ogata Research Institute Knowledge Forum "Water Resource Strategies for Achieving Food Security in a World of Climate Change," and Professor Taikan Oki of the University of Tokyo Graduate School, a world-renowned researcher in the field of water, will give a lecture. Sakiko Shiratori, project leader of the Japan International Research Center for Agricultural Science, will also participate as a panelist. If you are interested, please join us. For more information, please see here .
 

References

Allan, John Anthony. “Fortunately There are Substitutes for Water, Otherwise our Hydro-Political Futures Would be Impossible.” In Priorities for Water Resources Allocation and Management, 13–26. London: Overseas Development Administration, 1993.

Chapagain, Ashok K., and Arjen Y. Hoekstra. "Water footprints of nations." 2004.

Ministry of Environment, virtual waterr　https://www.env.go.jp/water/virtual_water/#main  accessed on Dec 3, 2024.

JICA Ogata Research Institute Knowledge Forum "Water Resource Strategies for Achieving Food Security in a World of Climate Change,"　https://www.jica.go.jp/jica_ri/news/event/1553927_23518.html accessed on Dec 3, 2024.

Contributor, SHIRATORI Sakiko, Information and Public Relations Office