There is an urgent need to put water stewardship at the edge of public and private discussion. In the food system, few big corporations handle the import-export of fundamental food commodities (e.g., wheat, maize, soy). Despite the role of transnational corporations has been identified as pivotal for CO₂ targets and forest conservation, as well as for the aquaculture system, their possible engagement in corporate water stewardship in the agricultural system has received limited scholarly attention: to date, there remains a poor understanding of the critical role played by Transnational Corporations (TNCs) in driving and managing the water use in the food production system (which account for the 70% of freshwater use worldwide). This knowledge gap limits the extent to which sustainable water management can be targeted at the most critical production sites and consumers.

With our study, open access on Earth & Environment Communications, we fill this knowledge gap by focusing on the emblematic case of the Brazilian soy to explore the magnitude of TNCs’ role in managing (and thus stewarding) global water resources within the food system.

We propose the virtual water trade (VWT) assessment as a viable tool to quantify both the pressure on water resources (i.e., water footprint m³) and the water risk (drought probability in this study) associable with TNCs’ trade to top-ten importing countries over the period 2004-2018.

The VWT is a metric to reconnect the water footprint of consumption locations to production locations through the international trade of agricultural goods, which virtually displaces water resources from the site of production to that consumption.

So far, the VWT has been studied through a country-scale perspective, by means of trade matrices between countries available from the FAO datasets. These studies have pursued important results, highlighting inter-dependencies between countries for food security and water footprint.

Thanks to the availability of the recently released high-resolute data of trade between the producer localities and the importer country from Trase, we seized the opportunity to couple trade data at the municipality scale with hydrological and crop models that can estimate crop water requirement at the high-resolution of 5x5 arc mins. Thanks to this high spatial resolution, our study highlights the influence of the sub-national climatic heterogeneity on water footprint and water risk associated with each trading corporation and importing country. 

The findings of our study highlight the importance of a transnational corporation for achieving water stewardship and sustainable supply chains to support water resource security at municipal and international scales.  

The evidence of water risk vulnerability for companies will increasingly engage TNCs in this kind of collaborative process; this paper gave us the opportunity to contact the nine mentioned companies in relation to the findings of our study. This was a great opportunity to directly communicate to companies our results about their supply. Among them, we received feedback from the Cargill company, which indeed acknowledged its role in water resources management and its recent collaborative work with the World Resources Institute in the direction of water stewardship.

Our paper represents an invitation for more research across scientific disciplines on how to engage with TNCs in ways that help meet the Sustainable Development Goals, and that ensure both transparent decision-making and improved regulation.