The Water- energy-food security nexus in the Mediterranean: challenges and opportunities Atef Hamdy 1 , Noureddin Driouech 2 and Amine Hmid 2 1 Emeritus Professor, Water Resources Management, CIHEAM/Mediterranean Agronomic Institute, Bari-Italy 2 Environmental Sciences, MAIB Alumni Network (FTN) -CIHEAM/Mediterranean Agronomic Institute, Bari-Italy Extended abstract Some of the biggest challenges the world is facing hinge on the growing scarcity and allocation of resources vital to sustaining life-water energy and food. Food, water and energy security are finally being recognized as the most important national and international security issues. To make enough food to support a growing population we need more water and energy. Producing energy requires water to cool power plants and produce biofuel, while making water accessible and clean for human consumption demands energy. According to UN estimation, by 2030 we will need 30% more water, 455 more energy and 60 % more food. Understanding the complex relationship between water, energy and food systems has become critically important to the development of a sustainable and secure future for all nations and regions. This was clearly highlighted at the Bonn 2011 nexus conference held in the preparation for the United Nations (UN) Rio +20 Conference which brought to light the need to address sustainability issues in the closely related sectors of water, energy and food security. This was also a central lesson that emerged from last year’s observance of the International Year for Water Cooperation. The relationship between water, energy and food security demonstrate how deep are the inter-linkages between these systems. At heart of the relationship is the interdependence of resources- how demand for one resource can derive demand from another one? Similarly, how the cost of one resource can determine the efficiency of production of others. Today we are more than convinced that amplified interconnectedness of global food, energy, water security and environmental sustainability exists. In addition it is well recognized that efforts to address only one part of systematic problem by neglecting other inherently inter-linked aspects may not lead to desirable and sustainable outcomes. In this perspective for an increasing number of nations policy decision-making requires a nexus approach that reduces tradeoffs and builds synergies across sectors, and helps to reduce costs and increase benefits for humans and nature compared with independent approaches to the management of water energy food and the environment. There are many synergies and tradeoffs between water, energy use and food production using water to irrigate crops might promote food production but it can also reduce rivers flows and hydropower potential. Growing bio-energy crops under irrigated agriculture can increase overall water with drawls and jeopardize food security. Converting surface irrigation into high