Every product, from bananas to beer, requires a certain quantity of water to create: its ‘water footprint’. When you eat a steak that was raised in Texas, you’re effectively drinking 15,000 litres of the ‘virtual water’ that went into growing the cow – water that the drought-stricken state may not be able to spare.
Now governments are starting to take notice of virtual water flows. “Countries that have traditionally exported goods are realising the need to keep their water at home”, says Arjen Hoekstra, co-founder of the Water Footprint Network. Saudi Arabia has announced plans to halt the export of vegetables grown in open spaces over the next five years to conserve water; Israel discourages the export of thirsty crops like oranges, and Spain is using water footprint analyses to manage industries in its river basins.
Wet countries are embracing virtual water for a different reason. “South America has the largest virtual water resources”, says Hoekstra. “Exporters there can’t compete from a carbon footprint perspective, but from the standpoint of water footprint, they’re sustainable.” Hoekstra advocates labeling products with their water footprint to help consumers make savvier choices.
While Hoekstra acknowledges that sometimes carbon and water footprints can clash – for example, growing biofuels may help reduce carbon emissions, but also uses a lot of water – he doesn’t think the conflict is irreconcilable. “Wasteful societies use too much of everything,” he says. “More efficient trade leads to smarter use of both water and carbon.”