Welcome to Virtual Water and Global Food Security: Implications for Canada!

Canada is among seven countries that are responsible for more than 50% of global food exports. Canada is one of a few countries that have significant additional potential to increase food export.Countries that are water short are increasingly relying on the import of water intensive food. In this way they can save water that can then be used for essential domestic and industrial purposes. What should Canada’s food export strategy be, in light of increasing global food demands, potential financial benefits, increased climatic variability, and environmental considerations?

Hans Schreier and Garwood Pang 2012. Faculty of Land & Food Systems, University of British Columbia, Vancouver, B.C. V6T 1Z4, Email: star@mail.ubc.ca 


Global Water Challenges

Recent evaluations show that if we continue to use water in a "business as usual" manner several countries will have widespread water shortages. This is a particularly important issue for the two most populated countries China and India and the other water stressed Mediterranean and Middle Eastern areas which are experiencing the most rapid population growth. This chapter will provide data to show how precarious the water situation is in these places of the world.

Global Food Challenges

We need to increase global food production by 50-70% over the next 40 years in order to meet the food demands of 9 billion people by 2050. The reasons: Feeding an additional 2 billion new people, improving the diet of 900 million people who do not have enough to eat, supplying 1 billion people with meat as they increase their protein rich diet, and the loss of food production as a result of converting crops into biofuel. This chapter provides information on food production and changes in global food supplies.

Food Export & Virtual Water

Virtual water is the amount of water used to produce a food commodity that is then exported. The water used by the crop can then no longer be used for other purposes. This chapter shows how virtual water is calculated, how the water demand for food items differs from country to country, how much water is needed per kilogram of food, and how much water is required to maintain daily diets in different regions of the world. It also shows which countries are the largest virtual water exporters and importers.

Key Food Exporting Nations

In 2009 seven countries (USA, Canada, Brazil, Argentina, Australia, Russia and France) were responsible for more than 50% of the annual global exports of wheat, maize, soybeans, rapeseed, chicken and beef. In addition, two countries (Thailand and Vietnam) were responsible for 50% of the annually export of rice. Most of these exporting countries have access to significant amounts of annual renewable water resources, Australia being the exception. This chapter also shows how the amount of virtual water differs between the different countries.


Canada`s annual feed export value exceeds 14 billion $ per Year and the amount of virtual water exported is estimated at 67 billion m3. Meat is one of the most economically attractive export items but beef, pork and chicken are the most water intensive food to produce. Meat production also creates significant environmental problems. Beef requires the largest amount of water, is most inefficient in energy use, produces by far the highest nutrients in manure, and is responsible for 4% of the annual GHG emissions. These factors should be considered in Canada's food exporting strategy.

China and Middle East

China, which is the largest food producing nation, has one of the lowest arable land/person index (ha/person) and has significant water supply problems. It is already taking advantage of virtual water trade by continuing to increase the national production of water efficient food but also increasing the import of water intensive food. This saves water for domestic and industrial purposes. In the Middle East and North Africa (MENA) region, the import of virtual water is increasing rapidly because of high population growth rates, and water shortages.

Impacts of Increased Climatic Variability

Land use change and increased climatic variability are of significant concern to future global food supplies. Since we rely on very few countries for the bulk of exported food, any unusual climatic event will increase to risk of food insecurity. Examples of the effects of droughts and floods over the past 10 years in Europe, Australia, Russia, Texas and Thailand show how vulnerable the global food supply has become. It is important to find new ways to adapt to these emerging climatic conditions and virtual water trade can play a key role in improving food security.

A Virtual Water Strategy for Canada

Important factors to consider in future expansion of Canadian food exports include: Improved water accounting by paying attention to the differences in water demand for different foods; determining the value of virtual water for different foods; reducing the export of meat due to its high water demands and local environmental impacts; examining the sensitivity of different crops to higher temperatures and increased climatic variability; better accounting for the use of blue and green water; and determining the energy demand for producing different crops destined for export.

Summary & Conclusion

The production and determination of virtual water exports should be carried out on a watershed basis. This will enable the determination of water balances, account for the partitioning of water use, address the difference in local evapotranspiration rates, and determine the local environmental impacts. Food production and export data should also be collected on a watershed basis. A more sophisticated economic evaluation is needed that not only accounts for the production and transport costs, but also environmental costs.