The Water Footprint of Modern Consumer Society

Arjen Hoekstra is the creator of the concept of the water footprint, and in this new book he analyses and details the water footprint of modern consumer society. As such, this is the most authoritative and up-to-date book on this important topic. Most readers will be familiar with the idea of the carbon footprint from which the water footprint was developed. This consists not only of direct water consumption, but includes the use of water at all stages of production processes of goods we consume. The central thesis of the book is that 'all problems of over-exploitation and pollution freshwater resources in this world relate to what we consume.' Water is a renewable but finite resource and freshwater availability is measured in terms of water volume per unit of time: in a certain period, one cannot consume more water than is available. This applies both to rivers and aquifers, some of which are in fact not rechargeable in the short-term. Freshwater is also a common resource vulnerable to free rider behaviour, as in the tragedy of the commons. Naturally, availability and demand vary a great deal in space and time. The footprint covers both production and the supply chain, and is divided into blue water used in the production process, green water referring to consumption of rainwater, and grey water to measure pollution. These three together constitute the water footprint.

Hoekstra provides detailed case studies of various products, starting with cola with its input of sugar, caffeine etc along with cans, packaging, labels and transport pallets. In addition, there is the water footprint of the factory itself. The sugar footprint will vary according to the country of origin - whether cane or beet. The total comes to 168 L with sugar beet from the Netherlands, as opposed to 309 L using sugarcane from Cuba and maize from India. Hot chocolate has the largest overall water footprint. A typical water footprint just for daily drinks would be 900 L or 10 bathtubs - a 125 g glass of wine is 200 L. Other chapters look at water for bread and pasta, cotton, the water footprint of biofuels and cut flowers and the supply chain footprint of paper. Towards the end of the book, there are discussions of the maximum sustainable water footprint per river basin, water use efficiency and the future allocation of freshwater resources. The overall footprint of meat is staggering given that feed crop production accounts for 33% of total arable land and the area occupied by grazing amounts to a further 26%. Reading a book like this the first step to raising awareness, and I hope the author will produce a popular version. Then, pressure for change will only come from informed consumers, as it has with other issues such as tuna.