|
The Surprising Results of a
Global Water Assessment
Ironically, solutions to global water scarcity may lie, not so
much in places where this resource is still abundant, but in a
region that is relatively dry - the African savannas. This was one
of the key findings of the Comprehensive Assessment of Water
Management for Agriculture, presented by IWMI Director General
Frank Rijsberman in a plenary session at World Water Week in
Stockholm during late August.
The Assessment, carried out over the last 5 years, brought
together more than 700 policy makers, researchers and development
specialists from 400 organizations to examine the current status of
water availability worldwide, based on the prevailing management
practices and policies of the last 50 years. Led by IWMI, the
Assessment was co-sponsored by the CGIAR, the Food and Agriculture
Organization (FAO) of the United Nations, the Ramsar Convention on
Wetlands and the Convention on Biological Diversity. The final
report of the Assessment will be published in November.
The greatest opportunities to deal with water scarcity,
according to David Molden, the IWMI scientist who led the research,
involve multiple strategies for producing more crops, livestock and
fish with water already in use, especially across the African
savannas. Most of the world's poor live there and in other
parts of the semi-arid tropics, where short dry spells are common
and soil fertility is declining.
"Since soils are fragile and rainfall is variable in the
savannas, making them more productive is not easy," Rijsberman
remarked. "But this year the World Food Prize is going to
Brazilian scientists who accomplished just that in their
country's vast savanna, called the Cerrados. The same miracle
needs to be repeated in Africa."
To transform rainfed agriculture in the African savannas and
other semi-arid lands, the Assessment argues, requires investment
in low-cost practices such as supplemental irrigation and water
harvesting with simple equipment - that is "buckets, not big
irrigation systems," as phrased in The Economist
magazine, one of many major media that reported on the
Assessment.
This transformation must start happening soon for two reasons.
First, water scarcity is an impending threat to the livelihoods of
the poor. Though natural resource analysts are sometimes accused of
exaggerating environmental perils, they rarely understate them.
Yet, that is precisely what happened at the start of the new
millenium. "Predictions in 2000 forecast that one third of the
world's population would suffer the effects of water scarcity
by 2025," said Rijsberman. "Our research findings show
the situation to be much worse. Already, in 2005 more than a third
of the population is affected by water scarcity."
A second source of concern is that the water requirements of
agriculture are huge. Up to 70 times more water is needed to grow
food than is consumed in drinking and other domestic uses, such as
cooking, washing and bathing. In general, it takes about one liter
of water to produce each calorie consumed as food. Depending on
their diets, humans indirectly consume 2,000 to 5,000 liters of
water in their daily meals.
To meet future food requirements, it is especially important
that water be used more efficiently in the production of livestock
and fish, but oddly their relationship to water management has been
neglected. For that reason a workshop held during World Water Week
included an ILRI presentation on livestock. In addition, a side
event was organized by the World Agroforestry Centre on the
importance of trees in water management.
As decision makers struggle to cope with the food-water dilemma,
"they will face many difficult choices entailing tradeoffs
between urban and agricultural users, food production and the
environment, and fishers and farmers," said Molden.
"There simply is not enough water to go around."
The Comprehensive Assessment, based on a combination of rigorous
science and broad public debate, will at least provide decision
makers with a coherent basis for planning and action.
Useful Links
|
