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August 2008




No food without water

The recent World Food Summit, held in Rome by the United Nations Food and Agriculture Organization (FAO), provided a forum for active debate about the role of high oil prices, biofuels, changing consumption patterns and erratic weather in driving up the prices of basic foods. But oddly, participants paid less attention to the alarming decline in the availability of water over the last few decades.

They did acknowledge the importance of breeding higher yielding crop varieties that require less water but did not address the critical question of where the extra water for more productive and efficient food, fiber and energy crops will come from.

Raising the warning flag

In 2007, the International Water Management Institute (IWMI) reported that many countries already face severe water scarcity, either because they lack available fresh water or because they have not invested sufficiently in water infrastructure, such as dams and reservoirs. Those findings were presented in a 5-year study called The Comprehensive Assessment of Water Management in Agriculture, which brought together some 700 specialists to examine the impacts of water policies and practices over the last 50 years. The study emphasized that water scarcity mainly affects developing countries, where most of the world’s approximately 840 million undernourished people live.

“The causes of water scarcity,” says Colin Chartres, IWMI’s director general, “are much the same as those that account for the food price crisis.” Fresh water, like food, is steadily being used up, as rising demand exceeds a finite supply. It takes a liter of water to produce every calorie of food we consume. Thus, a typical Western diet involves the use of 2,500 to 3,000 liters per day.

By 2030, earth’s population will have grown from 6 billion people today to about 8.5 billion. To feed those additional people will require more than 2,000 cubic kilometers of additional fresh water. Finding so much water will be extremely difficult, since current water usage for food production has already reached 7,500 cubic kilometers per year and supplies are growing scarce.

According to The Comprehensive Assessment, there simply will not be enough water to feed the world’s growing population within 25 years, unless profound changes take place in the way we use water and raise its productivity (that is, produce “more crop per drop”). “That doesn’t leave us much time to ward off the profound impacts of water scarcity – far less than the longer term efforts needed to combat climate change,” Chartres notes. “Yet, most countries have done little so far about the impending water crisis. That must change if we are to keep the current food price crisis from becoming a perpetual food deficit.”

Improving water productivity in agriculture

In the 8 years since the United Nations Millennium Development Goals were formulated, the water agenda has centered mainly on drinking water and sanitation. The water used for those purposes comes from the same sources as that for agriculture. So, as developing countries urbanize and improve their living standards, increasing competition for drinking water will put growing pressure on agriculture’s water supplies. “Improved drinking water and sanitation are vital for raising health and living standards in the developing world, Chartres points out. “But they must not come at the price of continued neglect of the need to improve water productivity in agriculture.”

Better water storage is among the potential solutions. Take the case of Ethiopia, which is typical of many sub-Saharan African countries in terms of water resources and management. Its water storage capacity is only 38 cubic meters per person, compared to almost 5,000 cubic meters per person for Australia, an amount that may prove inadequate in the face of expected climate change impacts.

Africa will need new large and medium-sized dams to deal with its critical lack of water storage capacity, Chartres explains. But other, simpler solutions must be part of the equation as well, such as construction of small reservoirs, sustainable use of groundwater systems (including artificial groundwater recharge) and rainwater harvesting for small vegetable gardens.

Once farmers have better year-round access to water, they will be better able to maintain local food security, using simple supplementary irrigation techniques. Further increases in water productivity could come from the redesign of both the physical and institutional arrangements of some large and often dysfunctional irrigation schemes. Safe, risk-free re-use of waste water from growing cities will also be needed. Of course, those actions must be taken in parallel with the development of drought- tolerant crops and improvement of the infrastructure and facilities needed to get fresh food to markets.

As in other areas of agricultural research and development, support for the provision and improved management of water resources has declined steadily since the Green Revolution of the 1960s to 1980s. “Significant investment in both research for development and water infrastructure is essential,” says Chartres, “if we are to avoid the dire consequences for world agriculture of worsening water scarcity.”

Related Resources

The Comprehensive Assessment of Water Management in Agriculture critically evaluates the benefits, costs, and impacts of the past 50 years of water development, the water management challenges communities are facing today, and solutions people have developed. The results will enable better investment and management decisions in water and agriculture in the near future and over the next 50 years. The assessment is produced by a broad partnership of practitioners, researchers and policy makers. - CGIAR


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 Article courtesy ©CGIAR - Consultative Group on International Agricultural Research


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