A multi-level approach to the energy-water-food nexus: From molecule to governance

The energy-water-food (EWF) nexus is an approach to resource management that highlights the inextricable relationship that exists among three essential resources. The EWF nexus is aimed at fostering interlinkages, limiting trade-offs and exploiting synergies that exist amongst these resources. Adopting the nexus approach is key to sustainable development, as it can alleviate resource insecurities and harness collaboration between sectors. Several EWF nexus-related studies have exhaustively analysed the different levels of decision-making within the nexus. However, these studies have failed to account for the multi-level relationship that exists among the different levels of the nexus, as most have adopted a level-based approach. This review study presents a novel multi-level approach to addressing the EWF nexus-related challenges. The study analyses the multiple levels that exist within the EWF nexus. The three levels identified are the molecule, process, and governance levels. The study goes on to show how communication amongst all three levels not only impacts the performance of the system but is crucial for decision-making as the three stages are intrinsically related such that the decisions at one level directly influences the others. The study starts by reviewing the various molecular-level changes that can be made in each of the EWF resources to enhance their performance. Then a review of the set of modelling and analytical tools that have been applied to the process and governance levels are presented. Finally, a novel decision-making pyramid integrating all three levels is presented and discussed using the case of a greenhouse food production system.