Virtual water and the water footprint

A shopping bag filled with food weighs a few kilograms, the largest share of which is water contained in foodstuffs. Each product also comprises so-called virtual water, sometimes thousands of litres.

Virtual or hidden water refers to all water consumed during a product’s life cycle from raw material production until the product is disposed of as waste. A virtual water volume can be calculated for any product. Around one thousand litres of water are needed to produce one litre of milk, whereas it takes approx. 400,000 litres to manufacture a car.

When you add the virtual water to people’s direct water consumption, we get the water footprint, a figure that illustrates the volume of water that is required to maintain our lifestyle. The daily water footprint of an average Finnish person is almost four thousand litres, nearly one half of which is virtual water contained in imported products.

While the water footprint is an explicit indicator, it does not alone give the full picture of the harms caused by water consumption. We have enough raw water for everything we produce in Finland, whereas in dry regions, large-scale production of water-intensive export products exacerbates water shortages. Consequently, an apple grown in Finland is a much better choice than a packet of dates.

The source of the water should also be factored in: if the date farm uses rainwater, the harms are smaller than if it consumes limited groundwater resources.

Image: Pixabay