Assessing virtual water flows from small-scale and large-scale agriculture in global trade

Non-technical SummaryWater is a shared global resource, yet its movement is often invisible.When a country imports products, it also imports 'virtual water', the water used to produce those products.While agriculture accounts for 85% of global water transfers, we have lacked a clear understanding of who is actually moving this water: large industrial farms or small-scale farmers?Our study shows that small-scale agriculture plays a disproportionately large role in global virtual water flows, compared to its volume of crop production involved in trade. Technical SummaryMost global virtual water flows come from agri-food sectors, describing how commodity demand in one country drives water use in others.Despite their significance, virtual water flow assessments have largely overlooked the distinct roles of small-scale versus large-scale agriculture, hindering the development of targeted water and food security policies in both producing and consuming countries.To address this gap, we estimate the contributions of small-scale and large-scale agriculture to crop production and virtual water embedded in trade (export) using detailed hybrid multi-regional input-output tables spanning 55 countries.We reveal that, although small-scale agriculture accounts for only 17% of the total crop production involved in trade (in tonnes), its role in virtual water flows is disproportionately large, accounting for 22% of blue and 30% of green virtual