GROUNDWATER DEPLETION EMBEDDED IN DOMESTIC TRANSFERS AND INTERNATIONAL EXPORTS OF THE UNITED STATES (Invited Presentation)

The United States plays a key role in global food security by producing and exporting agricultural products all over the world. Groundwater irrigation is increasingly important to the agricultural production of the United States. However, increased reliance on groundwater and prolonged unsustainable pumping of aquifers has led to groundwater depletion in many areas. How much groundwater depletion is embedded in domestic and international food exports of the United States? How much domestic and international agricultural commodity transfers rely on unsustainable groundwater use? To address these questions we quantify the amount of nonrenewable groundwater that is incorporated into agricultural commodities produced in the U.S. and transferred both within the country and exported internationally. We find that 26.3 km3 of nonrenewable groundwater was transferred domestically in 2000, with 2.7 km3 being sent abroad. In 2010, 34.8 km3 was transferred domestically and 3.7 km3 was exported. This indicates an increase of 32% in domestic transfers and 38% in international exports. In 2000, we find that 1,491,126 Ktons (340,407 million $USD) of agricultural products reliant on nonrenewable groundwater was domestically transferred, while 119,048 Ktons (47,036 million $USD) was exported. In 2010, the mass transfer of agricultural goods reliant on unsustainable groundwater decreased, but the value of agricultural commodities reliant on unsustainable groundwater use in national and international supply chains increased by 54% and 31%, respectively. Our results highlight the need for scientists, policy makers, and supply chain managers to consider the risks posed to global food supply chains from reliance on unsustainable groundwater use.