There is increasing interest in the water–food nexus, especially the restrictive effect of water on food
production in hot spots where irrigation stress is growing. However, little is known about the largerscale
implications of future irrigation shortfalls for global trade and economic welfare, as well as of the
potential buffering impacts of international trade on the local impacts of irrigation shortage. In this
paper, we utilize a recently developed model, GTAP-BIO-W, to study the economic effects of changes in
irrigation outlook for 126 river basins, globally by 2030. Projected irrigation availability is obtained from
the IMPACTWATER model, and imposed upon the present-day economy. Irrigation availability in 2030
is expected to drop by 30–60% in several key rivers basins, including: Hai He, Indus, Luni, and the Eastern
Mediterranean basin, leading to significant output declines in China, South Asia, and the Middle East. We
find that the regional production impacts of future irrigation water shortages are quite heterogeneous,
depending on the size of the shortfall, the irrigation intensity of crop production, the possibility of
expanding rainfed areas, as well as the crop mix. These changes in regional output significantly alter the
geography of international trade. To compensate for the loss of productivity caused by the irrigation
constraint, an estimated 7.6 million hectares of cropland expansion is needed to meet the demand for
food. In spite of the remarkable reduction of irrigation in some basins, the resulting welfare impact is
relatively modest as a result of the buffering capacity of global markets. The global welfare loss amounts
to $3.7 billion (2001 prices) and results from a combination of the reduction in irrigation availability as
well as the interplay with agricultural support policies.