Calculating Water Footprints: How Much Water in Your Food?

The environmental impact of food production in terms of contribution to climate change is well documented. Fertilizer use, soil degradation, and transportation from far flung farms to the table are all sources of greenhouse gas emissions. However, food production also has a steep water footprint. The water footprint is an environmental yardstick that measures how much water goes into the production of goods.

In 2009, the Food Ethics Council (FEC) declared in a report that food products should come with water footprint information in addition to carbon information. Because water scarcity is such a growing problem, they argued that such information will make consumers more aware of the impact of their buying habits.

As a general rule of thumb, crops like sugar and vegetables are more water-intensive than cereals. Meat and dairy are even more water intensive. One cup of fresh coffee needs 140 litres of water to produce while the production of one kilogram of beef requires 16,000 litres of water. According to the FEC report, in order to understand how to reduce our use of water, we need to measure this "embedded" or "virtual" water.

Another recently released report by WRAP and WWF examined how much water is wasted in the UK when food is thrown away. It found that nearly two-thirds of this wasted embedded water originated outside the UK. For example, most 'summer' vegetables like tomatoes, melons etc are imported from Spain. It takes 24,000 litres of water to produce one kilogram of chocolate, most of which comes from Ghana. According to the Water Footprint Network, a kilogram of tomatoes requires 160 litres of water in comparison.

The  report focuses on the water and carbon footprint of wasted household food and drink in the UK for the first time. They hope that this information will highlight the major environmental consequences of food and drink waste in the UK and globally. The Best Foot Forward network recently released an infographic that gives the water footprint of various foods at a glance. They are sustainability consultants who are leading the way in carbon and ecological footprinting.

According to the Water Footprint Network the water footprint of US citizens is 2840 cubic meter per year per capita. About 20% of this water footprint is external. The largest external water footprint of US consumption lies in the Yangtze river basin, China. The organization has worked to develop the Water Footprint Standard that companies are now using to reduce the water footprint of their products.

Several companies like Pepsico and Coca-Cola have been focusing on reducing their water footprint through innovative initiatives. Including water labels on products may be an effective way to educate consumers about their individual water footprints. For many consumers who are unaware or are on the fence about environmental issues, it may prove to be information overload much like the introduction of carbon information. However, it is a matter of time before consumers start thinking about water and carbon labels as a norm just like we do nutritional information.