Tracking water pressure on water-energy-food system in global trade

Water resources are a critical component of the water-energy-food (WEF) nexus, making it vital to examine the pressures on WEF systems from a water resource perspective. However, few studies have examined how international trade can cause water stress on local WEF systems. This study begins by compiling an inventory of water use within the WEF system, and further employs Multi-Regional Input-Output model and structural decomposition analysis to analyze the water usage in each country's WEF system driven by global consumption, the associated risk contributions, and the underlying drivers. The findings indicate that demand from Brazil, China, the United States, and Russia significantly increased water stress on the WEF system from 2010 to 2020. In most countries, external consumption contributes <20 % to WEF water risks. However, in countries where the external water risk contribution exceeds 20 % and overall water risk is lower, this external risk is often dominated by the electric energy sector. The study also shows that water stress induced by China, Germany, Japan, and the United States has a more diffuse impact on food systems in water-scarce countries compared to energy systems. In major consuming nations like China and the United States, the increase in global WEF water stress is primarily driven by rising domestic demand. Conversely, in developed countries such as Germany and Japan, changes in foreign production structures heighten the water stress on the global WEF system. This study identifies the primary modes of water stress transmission in global trade and explores potential mitigation strategies. Implementing local water-saving measures in countries with high water scarcity risks, supported by developed countries along the supply chain, is crucial for the integrated utilization of water resources and the sustainable provision and production of essential resources.