Consumption-Based Accounting for Tracing Virtual Water Flows Associated with Beef Supply Chains in the United States.

Enhancing the environmental sustainability of food systems requires an understanding of both production- and consumption-based impacts. As food supply chains become increasingly complex and connected, they also present a unique context in which to understand the environmental impacts of consumption. This is critical for understanding the disconnect between production- and consumption-based impacts of food systems and ultimately designing, evaluating, and implementing interventions for improving security, resilience, and sustainability of food systems. Using publicly available datasets and an optimization-based framework, we present a county-to-county level network model of beef supply chains in the United States. The model is used to connect and attribute the consumption-based impacts of beef consumption to production in distant locations, specifically focusing on water-based impacts. We specifically focus on the beef system because of its importance in the diet of U.S. consumers and in environmental sustainability discourse. The findings from this work show the spatial disconnect between the consumption and production counties with approximately 22 billion m 3 of blue virtual water being transferred for the year 2017, mainly from the northern and southern plains toward the coasts. These results highlight the importance of understanding environmental impacts from both production and consumption perspectives.