What exactly does ‘systems thinking’ have to do with the nexus approach to water, soil and waste? It comes down to the fact that nexus problems are usually very complex, and systems thinking can help us work through and understand this complexity. Nexus problems are complex because they deal with many different interactions between the numerous parts of the nexus. They are complex because they try to combine water, soil and waste management in some efficient way. And they are complex because they are concerned with human behaviour as it affects the consumption of resources.

Systems thinking can help us manage this complexity because it gives us a structured way of thinking about the whole system rather than its parts, and about connections rather than just content. Systems thinking comes with a large set of mathematical formalities for looking at systems in a rigorous way, and offers us a considerable toolkit of techniques relevant for studying nexus problems, including systems dynamics, integrated assessment, simulation and modelling, and many more.