The water footprint of staple crop trade under climate and policy scenarios

Trade in staple crop commodities has become increasingly important in the global food system,with ramifications for both food security andwater resources sustainability. It is thus essential to understand how thewater footprint (WF)of staple crop trademay change in the future. To this end,weproject international staple crop trade and itsWFunder climate andpolicy scenarios for the year 2030.Weuse theH08 global hydrologicmodel to determine the impact of climatic changes to staple crop yields and evapotranspiration.Using the yield changes projectedwith theH08model, we estimate the bilateral trade of staple crops using theGlobalTradeAnalysis Projectmodel.We combine these projections to obtain the total and blueWFof agricultural trade and globalwater savings (GWS) across scenarios. This approach enables us to determine the direct impact of climate change and trade liberalization—together and in isolation—on theWFof staple crop trade. Importantly, we show that trade liberalization leads to greaterWF,making it a potentially important adaptationmeasure to a changing climate, although future work is needed to distinguish high resolution cropwater use,water stress, and commodity transfers.

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