Snowmelt runoff provides important seasonal water resources for irrigated agriculture. However, the hydrological processes that form snowmelt runoff are particularly sensitive to climate change, which has already begun to alter the spatial and temporal patterns, as well as the magnitude of snowmelt runoff.
In this study, we built an integrated framework to characterize the virtual transfer of irrigation snowmelt runoff and climate-induced snowmelt risks embodied in international trade throughout the global supply chain. We integrate historical sub-annual irrigation surface water consumption in the past three decades (1985-2015) primarily using the Global Crop Water Model, high spatial-temporal resolution snowmelt and rainfall runoff simulations from the TerraClimate dataset under both 2°C and 4°C warming scenarios, and a global multi-regional input–output model of trade named the Global Trade Analysis Project (GTAP).
The risks of climate-induced snowmelt are virtually transferred via international trade throughout the global supply chain. Globally, 16% of snowmelt runoff used for irrigation is embodied in trade, and 70% of this embodied snowmelt is exported by just five countries.
Countries depending on agricultural imports fed by snowmelt will have to find substitutes for these imports, including domestic production. The biggest impacts on agricultural imports, according to this model, will be felt by Germany and the UK. Net snowmelt exporters mainly include South Asia (Pakistan and India), East Asia (China), Argentina and the USA.
Global trade transmits climate risks to regions where they did not otherwise exist and thus distributes those risks across more regions. For countries exporting at-risk agricultural products, though such crops are not utilized for local food supply, their production remains financially critical for local farmers’ livelihoods. The worldwide diffusion of the snowmelt risk will, therefore, spread the need for climate adaptation.