Owing to rising populations, increasing per capita water use, environmental flow requirements, and climate change, our results suggest that by 2050 there will be significant threats to water availability for agriculture in many regions of the world. If rising agricultural demands and the full spectrum of climate change effects are taken into account, threats to water availability will be considerably more pronounced. It is therefore likely that, unless broad changes are made to the way environmental and water resources are governed, conflicts over water for agriculture will increase markedly by the middle of the twenty-first century. Changes in governance may include reforming the policies and institutions that manage and allocate water, improving access to water in the poorest regions of the world, enhancing ecosystem services, recognizing water as an economic good in order to promote efficiency use, improving rain-fed and irrigation infrastructure to increase "crop per drop", and making agriculture more resilient to changes in climate. In the light of these threats to water for agriculture, and therefore to global food availability, it is important—and urgent—that water planning efforts be coordinated and integrated across sectors, particularly in the most vulnerable regions.

© 2013 United Nations