Society's greatest use of water is in food production; a fact that puts farmers centre stage in global environmental management. Current management of food value chains, however, is not well set up to enable farmers to undertake their dual role of feeding a growing population and stewarding natural resources. The book considers the interconnected issues of real water in the environment and "virtual water" in food value chains and investigates how society influences both fields. This perspective draws out considerable challenges for food security and for environmental stewardship in the context of ongoing global change. The book discusses these issues by region and with global overviews of selected commodities. Innovation relevant to the kind of change needed for the current food system to meet future challenges is reviewed in light of the findings of the regional and thematic analysis.