When a shopper walks into a supermarket almost anywhere, they will typically find a multitude of imported foods and produce from all over the world. Behind this abundance and choice is a system of international supply chains – largely invisible – linking farmers and fields in producer countries to shops in destination markets. To buy a bag of Pakistan-grown rice in a UK supermarket, for example, a consumer is not only reliant on a kilo of grains travelling halfway round the world; that shopper is also indirectly dependent on the resources – land, freshwater, energy, labour – used to produce, process, transport and store it. This resource use can be said to be ‘embedded’ in the end-product; where that embedded resource is water, this is referred to in the academic and policy literature as ‘virtual water’. The overall water-related impacts from the production or supply of a good, or from all production or consumption by a defined actor or within a defined area, make up what is termed its ‘water footprint’.
This paper explores the increasing water footprints associated with international food and agriculture trade, and the challenges this presents for water security, environmental sustainability and international relations (see Preface for background on the concept of ‘fair water footprints’). Pressures on water sources from overexploitation, pollution and a changing climate and hydrological system mean that addressing water scarcity is emerging as a critical environmental challenge. Accounting for the virtual water hidden in traded products, as well as understanding the impacts of water footprints on producers, exporters and importers, is important for improving the sustainability of water use and the security of resource supplies.
Scale is an important part of the challenge. The global food system accounts for almost 70 per cent of freshwater withdrawals, making it the largest consumer of the world’s finite water resources. Growing populations, rising living standards and shifting dietary preferences, coupled with a corporatized international trading system, have dramatically increased the water footprints of the food and agricultural sector in recent decades. It is estimated that the trade in virtual water nearly trebled between 1986 and 2022. Although data on the topic are typically compiled on an ad hoc basis by academic researchers – so no official international datasets on water footprints exist – it is reasonable to assume that virtual water demand has continued to grow since 2022.
Given the often-uneven power dynamics between producers and consumers, this paper argues that responsibility for water use cannot be confined to the local level, such as within farms or specific river basins. International investors, importers and retailers of food products will have to transform how they interact with, and value, water, to make trade more sustainable and conducive to environmental and societal resilience.
Responsibility for water use cannot be confined to the local level. International investors, importers and retailers of food products will have to transform how they interact with, and value, water, to make trade more sustainable and conducive to environmental and societal resilience.
Such actors not only influence markets but also bear risks themselves from overexploitation of water. Social tensions over access to and competition for fertile land and freshwater can disrupt exports; so, too, can abrupt government policy shifts intended to conserve water in producer countries. States and corporations that have acquired or have access to foreign land for export-oriented agriculture could be subject to legal challenges over worsening local water stress. As well as climate and environmental shocks, political or social tensions could also create or aggravate supply-chain bottlenecks, destabilize prices and exacerbate food insecurity globally. As has been seen all too often this century, the impacts of crop failures or trade disruptions in one or more critical places can reverberate worldwide.
Recent geopolitical turbulence – including export restrictions, supply-chain fragmentation and tariff impositions – presents its own challenges and opportunities for food trade and hence sustainable water use. Increasing protectionism could restrict the flow of food products to international markets at the same time as droughts, floods and competition for water reduce harvests and worsen food security. Export restrictions in response to societal or political pressure to improve food security could push up international prices, as was seen in many countries when food price inflation surged owing to concerns around grain supplies following Russia’s invasion of Ukraine in 2022. Such crises tend to deepen global inequalities and create conditions for political upheaval and geopolitical tension.
With the above landscape in mind, this paper examines the impacts of global food and agricultural production – with a focus on traded food products – on water security, environmental sustainability and economic resilience. The paper also outlines the food and agriculture sector’s global water dependencies and explores how water footprints vary between foods. Two country case studies – covering Morocco and Pakistan – are also presented. These offer examples of how the link between agricultural trade and water security functions in practice, and identify the specific water sustainability challenges each country faces. Finally, the paper identifies gaps in knowledge about water footprints for food crops and agricultural products, and surveys existing literature and emerging tools and standards that could help drive fairer and more sustainable water use.
