Scale-dependency of the Water-Food-Energy Nexus

Recent years have shown increased awareness that the use of the basic resources water, food, and energy are highly interconnected (referred to as a ‘nexus’). Spatial scales play a major role in nexus analyses, and can be related to the physical characteristics and dependencies between nexus resources. In fact, water, food and energy are very different in terms of absolute magnitude of production, as well as in the extent to which they are traded. The differences in trade extent can partly be explained by physical differences: high value, high density, geographically concentrated resources are traded more. We show how input-output dependencies are more relevant at local to national scales, whereas the continental and global scales are important due to physical and virtual trade. We combined various insights into an overview of which spatial scales are most relevant for each nexus resource, based on physical characteristics, input-output dependencies, virtual trade, and potential future changes due to socio-economic trends, climate change impacts and climate change mitigation.