They believe, for example, that productivity gains can still be made in nonirrigated agriculture and by adding lighter, supplemental watering arrangements to crops that are primarily rain-fed. They point out that advances in plant genetics should increase food productivity and that local food crises can now be relieved by international trade in food grains. They also believe that charging fees for access to water will provide incentives to conserve the resource, although the transition will undoubtedly have a harsh side. And they assert that close managerial attention to water demand as well as its supply will lead to more rational use, thus saving large amounts of water for new needs. As Pillar of Sand makes clear, water problems do not really exist at the world level but at a great variety of regional and local levels.
Many problematic situations exist, notably in the Middle East.
But because water imbalances and their remedies are local and regional, the irrigation issue lacks the scope and also the intractability of the authentically global issue of climate change. That does not mean, however, that it does not deserve global attention. Peter Lydon is an associate at the University of California at Berkeley's Institute of Governmental Studies.