The virtual water trade refers to the hidden movement of water that is used to produce food or other goods traded between places. This is also called embedded or embodied water. The virtual water trade means that water is moved along with goods and services. This idea helps people understand water problems in a new way. It helps compare different viewpoints, basic needs, and interests. It also helps show how water issues connect at global, regional, and local levels. However, using estimates of virtual water may not help leaders make decisions to protect the environment.
For example, cereal grains are a major part of virtual water in countries with little water. Importing cereal grains can help these countries make up for not having enough water locally. However, countries with low income may not be able to buy these imports in the future. This could cause problems with not having enough food and lead to starvation.
Concept
The idea of virtual water, also called embodied water, was introduced by John Anthony Allan (Tony Allan) in 1993. In 2008, he was honored with the Stockholm Water Prize for developing this concept.
Virtual water trade refers to the movement of water through the exchange of goods and services. For example, when a country imports one tonne of wheat instead of growing it locally, it saves about 1,300 cubic meters of water that would have been used domestically. If the importing country has limited water supplies, this saved water can be used for other needs. However, if the exporting country has limited water, the 1,300 cubic meters of water used to grow the wheat is no longer available for other uses in that country. This has important effects on countries with limited water, such as those in the Southern African Development Community (SADC) region.
Countries with limited water, like Israel, often avoid exporting water-intensive crops such as oranges. This helps them keep their water resources for local use instead of sending large amounts of water overseas.
In recent years, the idea of virtual water trade has become more important in both scientific and political discussions. The concept is not always clear, as it can be seen as a tool for analysis or as a strategy influenced by politics. As an analytical tool, it helps identify and evaluate policy choices in science and politics. As a political strategy, it raises questions about whether virtual water trade can be used in a way that is sustainable and fair for all people, economies, and the environment.
The data used in virtual water studies can help create water satellite accounts and be included in economic models that study international trade, such as the GTAP Computable General Equilibrium Model. These models can analyze how changes in water policies or water availability affect economies and how economic growth and trade policies influence water resources.
In summary, virtual water trade provides a new way to understand water challenges. It shifts the focus from managing water supply to managing water demand, which opens up new areas for governance and helps balance different needs and interests. It allows people to see water problems at global, regional, and local levels and how they are connected. If water issues cannot be solved locally or regionally, they must be addressed at higher levels. Virtual water trade helps move beyond a narrow focus on local water areas. A 2006 conference in Frankfurt, Germany, suggested that virtual water trade should be connected to integrated water resources management.
Related terms
The idea of virtual water trade was created to explain how countries can save water at home by buying food from other places. However, the food they buy comes from another location. In 2002, Arjen Y. Hoekstra, who worked for UNESCO-IHE, introduced the term "water footprint." A water footprint shows how the things people use or buy are connected to water use and pollution. Virtual water trade and water footprint are parts of a larger topic: how water use is linked globally.
For example, producing one tonne of wheat uses about 1,340 cubic meters of water on average worldwide. The exact amount may change based on weather and farming methods. Hoekstra described the virtual-water content of a product as "the amount of freshwater used to make the product, measured at the place where it was actually made." This includes all the water used during each step of making the product.
Some researchers have tried using methods from energy analysis, which estimate how much energy is used in production, to calculate how much water is used in making products.
Virtual water content of selected products
The table below shows the typical virtual water content for some products in several countries (m /ton):
Limitations
The ideas of virtual water and water footprint have been criticized. Australia's National Water Commission believes that measuring virtual water is not very helpful for making decisions about how to best use limited water resources.
In the MENA region (the Middle East and North Africa), another challenge is that importing food might increase political dependence. The idea of "self-sufficiency" has always been something the MENA region is proud of.