Global environmental change is happening. Human activities, including those related to food, are now recognised to be partly responsible for changing the world's climate and giving rise to other, globally and locally important environmental changes. These include alterations in supplies of freshwater, in the cycling of nitrogen, in biodiversity and in soils. There is growing concern that the ability to provide food - particularly to more vulnerable sections of society - will be further complicated by global environmental change (GEC). There is also concern that meeting the rising societal demand for food will lead to further environmental degradation, which will, in many cases, result in further uncertainties for food provision systems. Policies need to be formulated that enable societies to adapt to the added complication GEC will bring to food provision, while promoting socio-economic development and limiting further environmental degradation. Such policy formulation needs to be built upon an improved understanding of the links between GEC and food provision. "Global Environmental Change and Food Systems" (GECAFS) is designed to meet this need.