by Arjen Y. Hoekstra
19. August 2010 02:16
The desirability of reducing our carbon footprints is generally recognized – if not necessarily acted upon – by governments, corporations and individual consumers. Yet the related and equally urgent need to address our water footprint is often overlooked.
In fact, about 85 per cent of humanity’s water footprint is related to the consumption of agricultural products, particularly animal products that generally use much more water per calorific value than crops. This means that if people are considering reducing their water footprint, they need to look at their diet rather than at their water use in the kitchen, bathroom or garden.
A water footprint generally breaks down into three components. The blue water footprint is the volume of fresh water that is extracted from surface and groundwater. The green water footprint is the volume of water extracted from rainwater stored in the soil. The grey water footprint is the volume of water that is required to dilute polluted water to such an extent that the quality of the ambient water remains above agreed water quality standards.
The water footprint of beef from an industrial system may partly refer to the water used to grow feed in an area remote from where the animal is raised. In contrast, the water footprint of beef from a grazing system will mostly refer to green water used in nearby pastures. If the pastures used are dry- or wetlands that cannot be used for crop cultivation, that water could not have been used to produce food crops instead. If, however, the pastures can be substituted by cropland, the green water allocated to meat production ceases to be available for crop production. So the social and ecological impacts of water use at a certain location depend on the water availability and alternative uses of water at that location.
Animals are often fed with a variety of feed ingredients and feed supply chains are difficult to trace. So unless we have milk, cheese, eggs or meat from an animal that was raised and grazed locally, it is hard to say how any individual product has affected the world’s scarce freshwater resources. The increasing complexity of our food system in general and that of animal products in particular hides the existing links between the food we buy and their resource implications.
This situation has to change. Consumer and environmental organizations need to demand more product transparency of animal products from business and governments. Governments can put regulations in place that urge businesses along the supply chain of animal products to cooperate in creating product transparency. Businesses can cooperate in water labelling, certification and benchmarking schemes and produce annual water accounts that include a report of the supply-chain water footprints and associated impacts of their products. Wise water governance must become a shared responsibility of consumers, governments and businesses.
Arjen Y. Hoekstra is Professor in water resources management at the University of Twente, Enschede, The Netherlands. He is the creator of the water footprint concept and will be speaking on this subject at Compassion in World Farming’s Peter Roberts Memorial Lecture ‘Beef, Bread and Water: Ethical food in a warm and thirsty world’, which will take place in London on 20 September 2010 to coincide with the United Nations Millenium Development Goals Conference. He is a chapter author of an Earthscan book compiled by Joyce D’Silva (Compassion in World Farming’s Director of Public Affairs) and Professor John Webster entitled ‘The Meat Crisis’. This book will detail the growing evidence that we cannot progress along current supply and consumption paths and still expect to feed the world and provide sustainable livelihoods for farmers around the globe.
Related blog posts:
The Meat Crisis
Developing ethical, sustainable and compassionate food policies - the view from Mars
