The energy–water–food (EWF) nexus approach recognizes the dynamic and complex interlinkages between energy, water and food security, all of which are key goals in the context of sustainable development. The approach is a structured planning method that aims to capture the interdependency of resource use and availability across all three major sectors. In so doing, it can lead to a more optimal allocation of resources, improved economic efficiency, lower negative environmental and health impacts, and better economic development conditions.

Agriculture is the largest consumer of the Earth’s available freshwater, accounting for 70 percent of withdrawals. The challenges of the food–water nexus are characterized by overexploitation of groundwater together with the increased use of fertilizers and agro-chemicals, leading to water contamination and soil degradation. The water–energy nexus is characterized by the extensive use of water in the production of primary energy and power generation, and the role of energy in the extraction and distribution of water, wastewater treatment and the heating of water for domestic and industrial uses. These interlinkages expose both sectors to risks. Energy is needed along the entire value chain of food production, with end-use energy demand in the global food sector representing around one-third of total global final energy demand. Among the risks facing the food–energy nexus are: the diversion of food crops for the production of biofuels, and increased biofuels production leading to greater competition with the agri-culture sector for water resources.

The implications and risks related to the nexus sectors vary from one region to another. Hence, putting the nexus approach into practice necessitates delivering solutions at multiple scales and in different contexts. Nexus approaches are relevant at all points on the development spectrum.