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dam-l Water stress threatens food supplies, regional peace--new book/LS
Saturday, July 17, 1999
Emerging Water Shortages Threaten
Food Supplies, Regional Peace
Spreading water shortages threaten to reduce the global food supply by more
than 10 percent. Left unaddressed, these shortages could lead to
hunger, civil unrest, and even wars over water, reports a new book from the
Worldwatch Institute.
Irrigation accounts for two thirds of global water use, but less than half
that water reaches the roots of plants. "Without increasing water
productivity in irrigation, major food-producing regions will not have
enough water to sustain crop production," said Sandra Postel, author of
Pillar of Sand: Can the Irrigation Miracle Last? The book was funded by the
Wallace Genetic Foundation and by the Pew Fellows Program of the
Pew Charitable Trusts.
"Some 40 percent of the world's food comes from irrigated cropland," said
Postel, "and we're betting on that share to increase to feed a growing
population." But the productivity of irrigation is in jeopardy from the
overpumping of groundwater, the growing diversion of irrigation water to
cities, and the buildup of salts in the soil.
"Our civilization is not the first to be faced with the challenge of
sustaining its irrigation base," said Postel, director of the Global Water
Policy
Project in Amherst, Massachusetts, and a senior fellow at the Worldwatch
Institute. "A key lesson from history is that most irrigation-based
civilizations fail. As we enter the third millennium A.D., the question is:
will ours be any different?"
Today, irrigation problems are widespread in the grain-growing regions of
central and northern China, northwest and southern India, parts of
Pakistan, much of the western United States, North Africa, the Middle East,
and the Arabian Peninsula.
Water tables are dropping steadily in several major food-producing regions
as groundwater is pumped faster than nature replenishes it. The
world's farmers are racking up an annual water deficit of some 160 billion
cubic meters-the amount used to produce nearly 10 percent of the
world's grain. The overpumping of groundwater cannot continue indefinitely.
Eventually the wells run dry, or it becomes too expensive to pump
from greater depths.
Meanwhile, the amount of irrigated land per person is shrinking. It has
dropped 5 percent since its peak in 1978, and will continue to fall. At the
same time, one in five hectares of irrigated land is damaged by salt-the
silent scourge that played a role in the decline of ancient Mesopotamian
societies.
So much water is being diverted for irrigation and other human uses that
many major rivers now run dry for large portions of the year-including
the Yellow in China, the Indus in Pakistan, the Ganges in South Asia, and
the Colorado in the American Southwest. The Yellow River, the cradle
of Chinese civilization, ran dry for a record period in 1997, failing to
reach the sea for 226 days.
With population growing rapidly in many of the most water-short regions,
water problems are bound to worsen. The number of people living in
water-stressed countries is projected to climb from 470 million to 3
billion by 2025, the study notes. Already many countries do not have enough
water to meet domestic demands for food, creating a source of potential
political instability.
Water-short countries are increasingly turning to the world grain market.
In the swathe of countries from Morocco across North Africa and the
Middle East to Iran, virtually every nation is facing water shortages as
rising populations draw against a limited supply and as irrigation water is
diverted to satisfy growing urban demand. To meet their food needs, these
countries are importing grain. (Importing a ton of wheat is the
equivalent of importing 1,000 tons of water.)
Last year, the water required to produce the grain and other farm products
imported into the region was equal to the annual flow of the Nile River.
And this deficit is growing year after year. Jordan is importing some 91
percent of its grain, Israel 87 percent, Libya 85 percent, Saudi Arabia 50
percent, and Egypt 40 percent.
"As water shortages continue to mount, it is dangerous to presume, as many
officials do, that there will be enough exportable grain to meet the
import needs of all water-short countries at a price they can afford," said
Postel. "Most of the growth in water-stressed populations will be in
South Asia and sub-Saharan Africa, where the majority of the world's poor
and malnourished are today."
In five of the world's hot spots of water dispute-the Aral Sea region, the
Ganges, the Jordan, the Nile, and the Tigris-Euphrates-the population of
the nations within each basin is projected to climb between 44 and 75
percent by 2025. Some 260 rivers flow through two or more countries, but
in most cases there is no treaty among all the parties that sets out how
that river water should be shared. In the absence of water-sharing
agreements, tensions are bound to rise.
Irrigation's heavy water demands are also damaging the health of the
aquatic environment-shrinking wetlands, reducing fish populations, and
pushing species toward extinction. "Using water as inefficiently as we do
today, meeting the food demands of the projected 8 billion people in
2030 would result in costly losses of ecological services that the economy
depends upon," Postel said.
To meet the challenges of a water-short world, Postel proposes a "Blue
Revolution" to dramatically boost water productivity. "Most farmers
today irrigate the way their predecessors did hundreds of years ago," said
Postel. "Just as raising land productivity helped meet food needs during
the last half of this century, boosting water productivity will be the
agricultural frontier during the next century. The challenge today is to
substitute technology and better management for water."
Postel describes a diverse and creative mix of "Blue Revolution" strategies:
Farmers in India, Israel, Jordan, Spain and the United States have
shown that drip irrigation systems that deliver water directly to crop
roots can cut water use by 30 to 70 percent and raise crop yields by
20 to 90 percent.
In the Texas High Plains, farmers using highly efficient sprinklers
raised their water efficiency to more than 90 percent while
simultaneously increasing corn yields by 10 percent and cotton yields
by 15 percent.
Rice farmers in an area of Malaysia saw a 45 percent increase in
their water productivity through a combination of better scheduling their
irrigations, shoring up canals, and sowing seeds directly in the
field rather than transplanting seedlings.
Farmers in California's Imperial Valley are lining canals, recycling
farm runoff and selling the saved water to southern California cities.
Israel is now reusing 65 percent of its domestic wastewater for crop
production, freeing up additional freshwater for households and
industries.
Postel shows that a special effort is needed to lift the water productivity
of millions of very poor farmers who cannot afford some of the more
advanced technological solutions. "Helping small-scale farm families raise
their incomes and improve their food security can be a powerful engine
of economic growth in the world's poorest regions," Postel said.
In Bangladesh, farmers have purchased 1.2 million treadle pumps, a
human-powered device that allows users to pump previously inaccessible
groundwater. These pumps, which to an affluent Westerner look remarkably
like a Stairmaster exercise machine, cost $35 but typically return
more than $100 in the first year of operation. In Kenya, Chad, Zambia and
India, farmers are combining indigenous water-management
techniques with inexpensive new technologies like low-cost sprinklers,
bucket-drip systems, small-scale pumps, and check dams.
For the "Blue Revolution" to succeed, Postel says, it is up to governments
and water authorities to adopt new rules of the game for irrigation.
Government subsidies totaling at least $33 billion a year make it cheaper
to waste water than to conserve it. Legal barriers often make it difficult
for farmers to sell any water they save through conservation practices. And
the failure to regulate groundwater overpumping leaves the world
vulnerable to sudden cutbacks in food production as water tables drop to
greater and greater depths.
FOR MORE INFORMATION CONTACT:
Worldwatch Institute
1776 Massachusetts Ave NW
Washington, DC 20036
telephone: 202 452-1999
fax: 202 296-7365
e-mail worldwatch@worldwatch.org
or visit our website www.worldwatch.org
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Lori Pottinger, Director, Southern Africa Program,
and Editor, World Rivers Review
International Rivers Network
1847 Berkeley Way, Berkeley, California 94703, USA
Tel. (510) 848 1155 Fax (510) 848 1008
http://www.irn.org
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