World running out of water to meet food security, warn scientists

Posted: 17 August 2004

Global water use must be reduced to meet the demand for food production, otherwise it will be impossible to meet the UN development goal of halving the 840 million undernourished people by 2015, warn experts.

"For several decades, the increase in food production has out-paced population growth. Now much of the world is simply running out water for more production," says the report, Water: More Nutrition per Drop, issued during the World Water Week conference in Stockholm. "The additional water requirements to alleviate hunger and under-nourishment by 2025, would be equivalent to all water withdrawn to support all aspects of society use today," warns the report.

Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
"The basic problem is that food is the main global consumer of water, with irrigation taking 70 per cent or more of all the water we use, apart from huge volumes of rainwater," says Anders Berntell, SIWI's Executive Director. "The bottom line is that we've got to do something to reduce the amount of water we devote to growing food today."

"By 2020 world cereal demand will increase by 40 per cent, but the world has a finite supply of water," says Mr Frank Rijsberman, Director General the International Water Management Institute (IWMI). "Today's production patterns are unsustainable, involve large scale groundwater over-exploitation and widespread river depletion, and pose a major threat to biodiversity and aquatic ecosystems. There are increasing levels of environmental degradation and loss of production potential due to water pollution from agricultural chemicals, water logging and salinisation."

Less meat, more water

Difficult choices will have to made in the next few years as pressure from the world's growing population for more food leads to greater water consumption and increased environmental degradation, say the water experts.

Influencing peoples' eating habits away from meat and diary products could be one possible solution to conserving water and the environment.

Water and Food

  • A kilogram of grain-fed beef needs at least 15 cubic metres of water
  • A kilo of lamb from a sheep fed on grass needs 10 cubic metres
  • A kilo of cereals needs from 0.4 to 3 cubic metres

Far more water is needed for animals that feed on grain, and also for those which depend on grazing, than for grain crops. For example, it takes approximately 7000 litres of water to produce 1 kilo of beef in a developed country, while to produce enough flour for one loaf of bread requires approximately 550 litres.

'Virtual water'

Increasing the trade of 'virtual water' - or trade in food from water abundantcountries to water scarce ones could be another way forward. "The transport of virtual water is huge. Australians were astonished to find that although their country is short of water, they're net exporters of water in form of meat," explains Berntell.

As cities are predicted to use 150 per cent more water by 2025, an increase in the use of wastewater for irrigation is also an option. Reducing agricultural subsidies in the west could also be a way to give cash-strapped farmers in developing countries greater opportunity to manage water in a more efficient and economical way.

Moreover, say the experts, the best solution to free up water for the environment is to improve water productivity. This means increasing crop yields by extracting more value from each drop used. This can be achieved through introducing improved crop varieties, better farming practices and small scale, low cost technologies that have the potential to safeguard the environment while also doubling yields of staple crops in developing countries.

The World Water Week conference is held annually in Stockholm, Sweden, and is organised by the Stockholm International Water Institute. This year it runs from August 15-21.

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