Water Footprint of European Cars: Potential Impacts of Water Consumption along Automobile Life Cycles Markus Berger,* ,† Jens Warsen, ‡ Stephan Krinke, ‡ Vanessa Bach, † and Matthias Finkbeiner † † Technische Universitä t Berlin, Department of Environmental Technology, Chair of Sustainable Engineering, Office Z1, Strasse des 17. Juni 135, 10623 Berlin, Germany ‡ Volkswagen AG, Group Research, Environmental Affairs Product, P.O. Box 011/1774, 38436 Wolfsburg, Germany * S Supporting Information ABSTRACT: Due to global increase of freshwater scarcity, knowledge about water consumption in product life cycles is important. This study analyzes water consumption and the resulting impacts of Volkswagen’s car models Polo, Golf, and Passat and represents the first application of impact- oriented water footprint methods on complex industrial products. Freshwater consumption throughout the cars’ life cycles is allocated to material groups and assigned to countries according to import mix shares or location of production sites. Based on these regionalized water inventories, consequences for human health, ecosystems, and resources are determined by using recently developed impact assessment methods. Water consumption along the life cycles of the three cars ranges from 52 to 83 m 3 /car, of which more than 95% is consumed in the production phase, mainly resulting from producing iron, steel, precious metals, and polymers. Results show that water consumption takes place in 43 countries worldwide and that only 10% is consumed directly at Volkswagen’s production sites. Although impacts on health tend to be dominated by water consumption in South Africa and Mozambique, resulting from the production of precious metals and aluminum, consequences for ecosystems and resources are mainly caused by water consumption of material production in Europe. ■ INTRODUCTION “Yet Another Footprint to Worry About: Water” was a headline in The Wall Street Journal 1 with regard to the foundation of the Water Footprint Network 2 in 2008, which published surprisingly high figures of 70 L virtual water consumption 3 per apple or 2700 L per cotton T-shirt. Starting from such volumetric tools, which simply aggregate consumptions of ground and surface water (blue water), soil moisture (green water 4 ), and volumes of polluted freshwater (gray water), substantial methodological developments were undertaken recently. Modern impact-oriented water footprinting methods, which were reviewed in a previous work, 5 characterize water consumption based on parameters such as local scarcity or sensitivity of population and ecosystems and model complex impact pathways. However, these methods were hardly tested or applied in complex industrial product systems. So far, most water footprint studies published focus on agricultural products such as food, 6,7 natural fibers, 8,9 or bioenergy 10 and biofuels. 11 Volkswagen has been analyzing the environmental effects of its cars and components by means of life cycle assessment (LCA) 12,13 for many years. 14 However, due to lack of data and appropriate impact assessment models, the consumption of freshwater has not yet been considered. Therefore, the aim of this study is to analyze freshwater consumption along the life cycles of three Volkswagen car models on both inventory and impact assessment levels. First, regionalized water inventories are determined, showing country-specific water consumption figures, for the Polo 1.2 turbocharged direct injection (TDI), Golf 1.6 TDI, and Passat 2.0 TDI (model year 2010). Based on these inventories, seven impact assessment methods, which represent different levels of sophistication and model different impact pathways, are applied. Further objectives comprise the discussion and comparison of impact assessment results, the identification of significant life cycle stages and processes, and the analysis of sensitivity of results to altered regionalization scenarios. Finally, the potential damages resulting from water consumption are compared to damages caused by other environmental interferences, such as resource use and emissions, in order to estimate the relevance of water for the automotive industry. Received: November 9, 2011 Revised: January 28, 2012 Accepted: March 5, 2012 Published: March 5, 2012 Article pubs.acs.org/est © 2012 American Chemical Society 4091 dx.doi.org/10.1021/es2040043 | Environ. Sci. Technol. 2012, 46, 4091-4099