The role of water circularity in the food-water-energy nexus and climate change mitigation

By 2050, the global Earth population will reach 10 billion, leading to increased water, food, and energy needs. Availability of water in sufficient quantities and appropriate quality is a prerequisite for human societies and natural ecosystems. In many parts of the world, excessive water consumption and pollution by human activities put enormous pressure on this availability as well as on food and energy security, environmental quality, economic development, and social well-being. Water, food/materials, and energy are strongly interlinked, and the choices made in one area often have consequences on the others. This is commonly referred to as the “water-food-energy” nexus. These interconnections intensify as the demand for resources increases with population growth and changing consumption patterns, and Humanity continues using a linear economy model of ‘take-make-dispose’. The nexus makes it difficult for governments, public and private organizations, and the public, to set and follow a clear path towards a sustainable economy i.e., “meeting the needs of the present without compromising the ability of future generations to meet their own needs”. Humanity best chance at mitigating climate change, and shortage of resources is to harness the value of water as much as possible.This paper reviews the latest publications about the water-food-energy nexus and climate change, putting numbers into perspective, attempting to explain why water circularity is part of the key factors to accelerate the transition from a linear economy to a circular economy, and to meet the UN Sustainable Development Goals, and how circularity can be implemented in the water sector.