The 26 major nexus frameworks in literature.

The water-energy-food (WEF and its variants) nexus addresses the intricate linkages between human and natural systems to ensure sustainable management of natural resources without compromising economic, social, and environmental well-being. Despite this, the WEF nexus has been mainly approached as a focused biophysical system connecting those three dimensions. This review maps the extent to which the WEF nexus has been conceptualised and the consideration of additional dimensions linked to environmental and social outcomes. The aim is to broaden the WEF nexus concept to enhance its applicability to human, planetary, and sustainable development outcomes. Of the identified nexus frameworks, approximately 50% are sectorally unbalanced, as they centralise one or more resource node(s). Water and energy are key nexus nodes in most frameworks. The second most popular framing is water-energy-food-climate, followed by water-energy-land (WEL) and water-energy-food-land-ecosystems. In addition, the current WEF nexus approach is biased towards input-oriented conceptualisation. It fails to make explicit linkages to outcome- and impact-based dimensions, such as politics, gender, environment, planetary health and the economy. This limits its relevance and practical application in decision-making and policymaking for addressing sustainability and developmental challenges. Models and tools should be improved to be more holistic, including WEF resources and other linked resources, and should be useful for monitoring all sustainability outcomes (economic, social, and environmental). We propose a conceptual broadening of the WEF nexus to a WEF+ nexus, with the “plus” representing added outcomes-based dimensions such as environment, climate, people, planet and health. This conceptual broadening balances WEF resource securities with human, planetary and sustainable development outcomes.