How do you fit 130 litres of water in a single cup? The answer: fill it with coffee. Growing coffee beans is a thirsty business, as is growing cotton – 10,000 litres of water in a pair of jeans – and 2,500 litres in the average T-shirt. Avocados, almonds – even bottles of water themselves, are all highly water-intensive enterprises. Agriculture uses about 70% of freshwater across the globe.
Regions that export water-intensive crops are effectively exporting their water, in a trade known as “virtual water” or “invisible water”. Agricultural products are the most obvious trades in virtual water, but vast numbers of manufactured goods also require large quantities of water. When countries and regions with water shortages pour their water into exports, on the surface it can look as if they are making a profit, but in the long term their reliance on diminishing water resources will be damaging.
“The concept of virtual water can help countries that lack abundant water resources to meet food needs without using precious water for thirsty agricultural practices,” says Vincent Casey, senior manager at WaterAid. “It doesn’t make sense for Saudi Arabia to use vast quantities of limited water resources for agriculture when food grown elsewhere can be imported.”