Since the 1960s, the world food system has responded to a doubling of the world population, providing more food per capita at progressively lower prices. Global nutrition has consistently improved. This performance was possible through a combination of high-yielding seeds, irrigation, plant nutrition and pest control. In the process, large quantities of water were appropriated for agriculture. As population keeps increasing, albeit at a slower rate, more food and livestock feed need to be produced in the future and more water applied to this purpose. Water withdrawals for irrigation in developing countries are expected to increase by an aggregated 14 percent until 2030, while irrigation water use efficiency is expected to improve by an average 4 percent. Water-scarcity stress is foreseen to grow locally and in some cases regionally and a number of countries will have to rely more on trade for their food security.
While food production is satisfying market demand at historically low prices, an estimated 777 million people in developing countries do not have access to sufficient and adequate food because they do not have the resources to buy it or, in the case of subsistence farmers, to produce it. In spite of the overall improvement in the nutritional situation, the absolute number of undernourished people is reducing at a much slower rate than had been anticipated. The 1996 World Food Summit (see Annex 1)set a target of reducing the number of chronically hungry people to about 400 million, but current projections indicate that this figure may be achieved fifteen years later than targeted, i.e. by 2030, unless decisive policy and financial action is taken.
Irrigated agriculture will by necessity claim large quantities of water to produce the food required to feed the world. Irrigation-water management has a long way to go to adapt to the new production requirements and reconcile competing claims from other economic sectors and calls for environmental protection. However, water-saving technologies are available and can significantly reduce the waste of water. In addition, the political, legal and institutional framework to support improved water productivity in irrigated agriculture also shows signs of adaptation. Water-management trends point to empowering stakeholders, with a priority for the poor and the marginalized. At the same time, the water needs for human health and for the aquatic environment call for closer attention. The message from agriculture, which will remain globally the largest water user, is cautiously optimistic.
At the start of the twenty-first century, agriculture is using a global average of 70 percent of all water withdrawals from rivers, lakes and aquifers. The Food and Agriculture Organization (FAO, 200b) anticipates a net expansion of irrigated land of some 45 million ha in ninety-three developing countries (for a total of 242 million ha in 2030) and projects that agricultural water withdrawals will increase by some 14 percent from 2000 to 2030 to meet future food production needs. The analysis indicates a projected annual growth rate of 0.6 percent, compared with the 1.9 percent observed in the period from 1963 to 1999.
Only a part of agricultural water withdrawals are effectively used in the production of food or other agricultural commodities; a large proportion of water may not reach the crop plants because it evaporates or infiltrates during conduction, evaporates from the soil in the field, or is used by non-productive growth such as weeds. Irrespective of the actual outcomes, it is important to highlight the fact that water allocations for agriculture will face increasing competition from other higher utility uses – municipal, industrial uses and calls for water to be left in the environment. Under these circumstances it is crucial that the role of water in securing food supply is understood and the potential for improving overall agricultural productivity with respect to water fully realized.
In this report, the facts about past, present and future water demand in food production and food security are discussed. For the purpose of discussion, three groups of countries are identified: developing countries, industrialized countries and countries in transition. Developing countries call for special attention because demographic growth rates are high and the potential demand for food is not yet satisfied. This group of countries is considered in regional groupings, that is: sub-Saharan Africa, Near East/North Africa, Latin America and the Caribbean, South Asia and East Asia. It should always be kept in mind that aggregate and average figures tend to hide as much as or more than they reveal. Water problems are always local or, at most, regional in nature, and may vary over time. Countries with large territories also have a large diversity of situations, including arid and humid regions and plains as well as mountains.
This section is largely based on FAO’s technical report World Agriculture: Towards 2015/2030, the most recent edition of FAO’s periodic assessments of likely future developments in world food, nutrition and agriculture. The report provides information on a global basis, with more detailed emphasis on ninety-three developing countries. The section also relies extensively on the data, information and knowledge provided by FAOSTAT, the FAO statistical database, and AQUASTAT, FAO’s information system on water and agriculture. The contribution of the International Water Management Institute (IWMI) in the preparation of this section is acknowledged with thanks. National values of key indicators in 251 countries are presented in Table 1. The significance of each indicator is highlighted in the relevant part of the discussion by reference to this table.
Table 1 National values of key indicators on agriculture, food and water