Imported virtual water is physically scarcer than domestic water globally

To ease pressure on scarce domestic freshwater resources, countries can import virtual water, i.e., the volume of water consumed for producing traded products. However, if those foreign water resources are physically scarcer than domestic resources, engaging in virtual water trade shifts the burden of unsustainable water use beyond national borders. Here, we provide the first global, long-term comparison of the physical scarcity of imported and domestic water, measured by the overconsumed portion, for 158 countries and aggregated areas spanning 123 agricultural and 84 non-agricultural sectors from 1990 to 2019. We achieve this by combining global crop and hydrological modeling with a hybrid Multi-Regional Input-Output analysis. We find that 45% of virtual water is overconsumed, which remains broadly stable over the past three decades, despite marked growth in water consumption and trade. Importantly, we find clear global evidence that, for most countries over the study period, imported virtual water is physically scarcer than the water consumed domestically; only ten countries consistently import less scarce water. In addition, many regions import more virtual water from water-scarce regions than they export to those regions. This calls into question the prevailing narrative of virtual water trade as a solution to water scarcity. Our findings suggest that future virtual water studies should be complemented by a narrative that explicitly recognizes the role of virtual water trade in contributing to global water scarcity, thereby highlighting the need to identify trade and policy pathways to leverage virtual water trade in promoting sustainable water use.