Some terms from the world of science and sustainability are not so easy to understand. But don’t worry – in our new series “Simply explained”, we break down complex topics and technical terms into understandable words. This makes science accessible, entertaining and exciting for you!
What is virtual water?
This refers to the amount of water consumed during the production of a product. It is also often referred to as “hidden”, everyday water consumption. Water is used throughout the entire production chain – in the cultivation of raw materials, in further processing and in waste disposal. We therefore not only consume hundreds of liters of water every day when cooking, showering and washing, but also indirectly when shopping for food or clothing.
How much water do we use?
Some products, such as T-shirts, coffee or beef, require a particularly large amount of water during production. Around 16,000 liters of water are used to produce one kilogram of beef and around 15,000 liters for a cotton T-shirt. If you like to drink a cup of coffee in the morning, you use about 140 liters of water. But cocoa, strawberries and many other foods also consume an enormous amount of water. Overall, it is estimated that each person in Austria consumes an average of around 4,700 liters of virtual water every day – an enormous amount in addition to the 127 liters of water that are “visible” in everyday life.
Green, blue and gray water
The so-called “blue water” comes from rivers, lakes and groundwater. Much of this water is usually imported into European countries from Asian countries such as India or China via crops and agricultural goods. Green water is rainwater, i.e. our natural irrigation system. Gray water is contaminated wastewater that has to be treated. Strawberries from dry regions in Spain require a lot of “blue” water – in the form of artificial irrigation. In contrast, cocoa plants in African growing regions can be supplied with “green” water, as there is sufficient rainfall in these areas. In many countries of the Global South, a lot of water is used for the production of export products, which in turn is not available for local people and local agriculture.
How can you save virtual water?
If you enjoy drinking coffee, it is advisable to choose Arabica coffee instead of Robusta. Arabica thrives mainly in rainy mountain regions, while Robusta grows in lowland areas with little rainfall. In general, you should make sure that products are grown organically, as this reduces the proportion of “grey” water because they are grown without synthetic chemical fertilizers and pesticides. Another way to save water virtually is to buy second-hand clothing, clothing made from hemp, linen or organic cotton. This is because conventional cotton requires a lot of water and is still cultivated in many dry regions of the world. Instead of water-intensive roses, which are usually imported from Kenya, you can prefer locally produced cut flowers from organic cultivation.