Recent hydrological modelling1 and Earth observations2,3 have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation1,2,4, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world’s food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world’s population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.
C.D. acknowledges the funding support of the Belmont Forum (SAHEWS project, NERC NE/L008785/1), the Economic and Social Research Council through the Centre for Climate Change Economics and Policy, and the Natural Environment Research Council Fellowship (NERC NE/N01524X/1). T.K. was supported by the European Research Council Starting Grant LUISE (263522) and the Swedish Research Council Formas (grant number 231-2014-1181). M.J.P. acknowledges fellowship support from the Columbia University Center for Climate and Life. Y.W. is supported by a Japan Society for the Promotion of Science (JSPS) Oversea Research Fellowship (JSPS-2014-878). This paper was presented at the conference Virtual Water in Agricultural Products: Quantification, Limitations and Trade Policy (Lincoln, Nebraska, USA, 14–16 September 2016), sponsored by the OECD Co-operative Research Programme: Biological Resource Management for Sustainable Agricultural Systems (CRP). The CRP financially supported C.D. to participate in the conference. The opinions expressed and arguments employed in this paper are the sole responsibility of the authors and do not necessarily reflect those of the OECD or of the governments of its Member countries.
Extended data figures
Extended data tables
This table shows shows the GWD intensities for crops belonging to 26 major crop classes, by country for years 2000 and 2010. A large variability in GWD intensities across countries and crop classes may be found.
This table contains the extraction rates for food commodities.