Nexus Strength: A Novel Metric for Assessing the Global Resource Nexus

The limited access to natural resources is a major constraint for sustainability at various spatial scales. This challenge has sparked scholarly interest in the linkages or nexus between resources, with a view to helping anticipate unforeseen consequences, identify trade-offs and co-benefits, and find optimal solutions. Yet, despite decades of research, limitations in the scope and focus of studies remain. Recently constructed multiregional input-output (MRIO) databases, which cover the global economy and its use of resources in unprecedented detail, allow systematically investigation of resource use by production as well as consumption processes at various levels and garner new insights into global resource nexus (GRN) issues. This article addresses the question of how to prioritize such issues. Using the MRIO database, EXIOBASE, we address the GRN considering five key resources: blue water, primary energy, land, metal ores, and minerals. We propose a metric of nexus strength, which relies on linear goal programming to rank industries and products based on its associated combined resource use and various weighting schemes. Our results validate current research efforts by identifying water, energy, and land as the strongest linkages globally and at all scales and, at the same time, lead to novel findings into the GRN, in that (1) it appears stronger and more complex from the consumption perspective, (2) metals and minerals emerge as critical, yet undervalued, components, and (3) it manifests with a considerable diversity across countries owing to differences in the economic structure, domestic policy, technology, and resource endowments.