Virtual water

      Virtual water is the actual amount of water required for the manufacture of any goods or agricultural or industrial product. It is a concept created in 1993 by the British researcher John Anthony Allan, which is key to understanding the current water crisis.

      Now if a country exports products that use too much water, this country would be exporting water, while the importing country would no longer need to use its water to get this product and so that way the water can be used for other ends.

      Whenever a country imports something, it also imports the virtual water involved in its production. About 90% of the trade of "virtual water" is in food and cotton.

      We not only consume the water that we drink or the water that escapes from the shower when we wash. We also consume water, and a much larger amount, when we eat, write on a sheet of paper, dress, or when we get any product. Because water is used for everything, and it is important to understand our need to anticipate shortages, and to adapt our industrial policies.

      How is this calculated? Take an extreme example, no more and no less than 22,000 litres of water are needed to produce just one kilo of beef compared to just 1,000 litres for each kilo of grain. To get these numbers, we calculated the amount of water required to grow the grass that feeds the cow, the amount of water that was needed to cool and store the meat, the amount of water needed for its transportation, and many other details and moments of the process that are usually invisible to us.

      Another example could be orange juice: 22 litres of water are used -for example, to irrigate orange groves and wash the fruit- to produce each litre of juice.

      Food grown on irrigated land will naturally leave a larger water footprint than food that is grown in fields that only rely on rainfall. The countries with warm climates tend to use more water, as do the countries with a high consumption of meat.

      There is little trade of real water, because it is heavy and expensive to transport over long distances. But the trade of virtual water takes place continuously, and it is estimated to reach about 15% of the water people use. There are great differences between countries. The United States, Canada, Argentina and Thailand are all major exporters of virtual water, while Japan, Sri Lanka, Italy, the Republic of Korea, the Netherlands, Holland, Korea and China (this is the country with a population of 1,336,718,015 people and agricultural products to meet the needs of its population) are large importers. Exporters make great demands on their own water resources, importers effectively transfer much of their demand elsewhere.



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CEP Santa Rosa Marist Brothers - Sullana (Peru) and IES Manacor - Mallorca (Spain)
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