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Calculating Water Footprints: How Much Water in Your Food?

| Friday June 10th, 2011 | 3 Comments

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.

 


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Categorized: Agriculture & Food|

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  • http://www.foodethicscouncil.org Tom MacMillan

    Thanks – interesting article. Water scarcity is indeed a huge problem and agriculture a big part of it. To clarify, the Food Ethics Council recommended that if products were to be labelled with water information, that should relate to stewardship practices rather than simply to the water footprint (how many litres it took to make a kilo of the product). That is because whether a high water footprint is a big deal depends on lots of issues, including whether a product is being grown in a wet or a dry place. Hope that helps!

  • http://www.TigerGreen.co.uk Alison Tottenham

    I am glad that this topic is now being ‘aired’. However, there is one thing that I would like to ask, and one thing that I would like to add for consideration.
    For comparison with the information given. Does anyone know how much water it takes to grow a kilogram of lentils, chickpeas, or soya beans or any of the other pulses?

    To the water used for using crops such as pulses and cereals for a protein-rich food, one must remember to add the amount of water used in order to cook them. This does need to be added to the figures if one is to be able to compare them with the water cost of meat production, since meat comes with its own water/blood/juice!
    Certainly, our huge world population is putting a strain on the water resources. However, I suspect that the waste in the so-called 3rd world countries is a lot less than in Europe and USA. I suggest that this difference comes about from the way in which so many of us rely on value added foods, and on being able to go into a supermarket and buy whatever frest food we want, when we take a fancy to it! This means that shelves are always over stocked, leading in part at least to the huge amount of wasted food. Perhaps we have to learn how to reduce our population to a sustainable level and with it our production potential.

    We also have to be aware that as we all actually reduce the water we use, so the water companies put up the price of water supplied to our homes. This does not encourage people to use less!

  • http://www.TigerGreen.co.uk Alison Tottenham

    Reading some of the other articles on this topic, that do not provide space for comment, the following occurs to me.

    Much of the water used by plants is used during the process of Transpiration and is thus simply moved from soil to the atmosphere. Hence it is put straight back into circulation and will fall again as rain, dew etc. in the near future; or remain as clouds either reflecting the sunlight back towards space or acting as a GHG by absorbing the IR radiations. So, although this water is essential for the growth of the crop, it is, like the washing of yards and equipment, not actually removed from the local water cycle – though it may have come in from a river or been piped from a reservoir. Whereas the water in the vegetable produce, and indeed in the meat and milk, is often far removed from its source before being returned to the natural water cycle.