References UNEP, 2007. Global environment outlook geo 4: environment for development. United Nations Environment Programme, Valletta, Malta. Hoekstra, A. Y., Chapagain, A.K., Aldaya, M.M., Mekonnen, M.M., 2009. Water footprint manual: state of the art 2009. Water Footprint Network, Enschede, The Netherlands. Acknowledgments The authors would like to thank Aveleda S.A. for their collaboration in providing first hand information. The authors also gratefully acknowledge FCT (Science and Technology Foundation – Portugal) for the scholarship granted to Ana Cláudia Dias (SFRH/BPD/20363/2004). To quantify the water footprint (WF) of a specific Portuguese white wine: the ‘vinho verde’ and to identify the main sources of water consumption.