Unique water scarcity footprints and water risks in US meat and ethanol supply chains identified via subnational commodity flows

Within the US, supply chains aggregate agricultural production and associated environmental impacts in specific downstream products and companies. This is particularly important for meat and ethanol, which consume nearly half of global crop production as feed and feedstocks. However, lack of data has thus far limited the ability to trace inputs and impacts of commodity crops through domestic supply chains. For the first time, we use a commodity-flow model to link spatially distributed water resource impacts of corn and soy to individual meat and ethanol processing facilities. This creates transparency in the supply chains, illuminating substantial variation in embedded irrigation water and water scarcity footprints among meat and ethanol processed at different facilities. By calculating unique blue water scarcity footprints for end-products, we show that beef processed in Iowa or Illinois, for example, has fewer water impacts than chicken processed in California and pork processed in Oklahoma. We find that over 75% of irrigated feed embedded in meat is consolidated in six companies and 39% of irrigated feedstock for ethanol is consolidated in five companies, with potentially negative impacts to supply costs and risk management. This subnational variation and consolidation of impacts in key supply chains creates opportunities for producers and consumers of agriculture-based products to make management, investment, and sustainability decisions about those products.