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dam-l Populations Outrunning Water Supply/LS
NEWS FROM THE WORLDWATCH INSTITUTE
Worldwatch News Brief 99-9
POPULATIONS OUTRUNNING WATER
SUPPLY AS WORLD HITS 6 BILLION
Lester R. Brown and Brian Halweil
(Third in a series of reports on global population issues leading up to the Day
of 6 Billion, October 12, 1999. Additional information and resources can be
found at <www.worldwatch.org/alerts/pop2.html>.)
As world population approaches 6 billion on October 12, water tables are falling
on every continent, major rivers are drained dry before they reach the sea and
millions of people lack enough water to satisfy basic needs.
Water tables are now falling in China, India, and the United States, which
together produce half the world's food. Historically, irrigated farming has
been plagued with waterlogging, salting, and silting, but now, with the advent
of powerful diesel and electrically powered pumps, it is also threatened by
aquifer depletion.
In China, water tables are falling almost everywhere that the land is flat.
Under the North China Plain, the country's breadbasket, water tables are falling
by 1.5 meters, or roughly 5 feet, per year. Where wells have gone dry, farmers
have been forced either to drill deeper, if they can afford it, or to abandon
irrigated agriculture, converting back to lower-yield rainfed farming.
In India, a country whose population hit 1 billion on August 15, the pumping of
underground water is now estimated to be double the rate of aquifer recharge
from rainfall. The International Water Management Institute, the world's
premier water research group, estimates that India's grain harvest could be
reduced by up to one fourth as a result of aquifer depletion. In a country
adding 18 million people per year, this is not good news.
In the southern Great Plains of the United States, depletion of the Ogallala
aquifer has already led to irrigation cutbacks. Texas, Oklahoma, Kansas, and
Colorado have been losing irrigated land over the last two decades. Texas, for
example, has lost irrigated land at roughly one percent per year since 1980.
Rivers running dry provide an even more visible manifestation of water shortages
as growing populations take more water. The Yellow River, the cradle of Chinese
civilization, first ran dry in 1972. Since 1985, it has run dry for part of each
year. In 1997, it failed to reach the sea during 226 days, or roughly 7 months
of the year.
During the dry season, the Ganges River has little water left when it reaches
the Bay of Bengal. India, with more than a billion people taking the lion's
share of the water, is leaving too little for the farmers of Bangladesh during
the dry season.
In central Asia, the Amu Darya, one of two rivers that once fed the Aral Sea, is
now drained dry by farmers in Turkmenistan and Uzbekistan. As the Sea has shrunk
to scarcely half its original size, the rising salt concentration has destroyed
all fish, eliminating a rich fishery that once landed 100 million pounds of fish
per year.
Similarly, the Colorado, the major river in the southwestern United States,
rarely ever makes it to the Gulf of California. The fishery at its mouth that
once supported several thousand Cocopa Indians has now disappeared.
Today the Nile, like many other major rivers, has little water left when it
reaches the sea. Even though virtually all the water in the river is now
claimed, the population of the three principal basin countries-Egypt, the Sudan,
and Ethiopia, where most of the water originates-is projected to increase from
153 million today to 343 million in 2050, generating intense competition for
water.
Hydrologists estimate that when the amount of fresh water per person in a
country drops below 1,700 cubic meters per year the country is facing water
stress. In her new book, Pillar of Sand: Can the Irrigation Miracle Last,
Worldwatch senior fellow Sandra Postel reports that the number of people living
in countries experiencing water stress will increase from 467 million in 1995 to
over 3 billion by 2025 as population continues to grow. In effect, these people
will not have enough water to produce food and satisfy residential and other
needs.
Postel estimates the current world water deficit -- the excess of water pumping
over recharge from rainfall --at 160 billion tons per year. Since it takes
1,000 tons of water to produce 1 ton of grain, this water deficit is equal to
160 million tons of grain, a quantity only slightly less than annual world grain
exports of 200 million tons.
Ironically, the excessive grain supplies that have depressed world grain prices
in 1999 are partly the result of overpumping. If falling water tables were
stabilized by a cutback in pumping, the resulting decline in grain production
would likely drive prices off the top of the chart.
As water becomes scarce, the competition for water between cities and
countryside intensifies. In this competition, farmers almost always lose. In
North Africa and the Middle East, the region ranging from Morocco in the west to
Iran in the east, virtually every country is experiencing water shortages. As
cities grow, countries take water from agriculture to satisfy expanding urban
water needs. The countries then import grain to offset the water losses.
Given that importing one ton of grain is equal to importing 1,000 tons of water,
this is the most efficient way for water-short countries to import water. Last
year the water required to produce the grain and other farm products imported
into this region was roughly equal to the annual flow of the Nile River. With
more and more countries looking to the world market for food, spreading water
scarcity may soon translate into world food scarcity.
It is often said that the competition for water among countries may take the
form of military conflict. But it now seems more likely that the competition for
water will take place in world grain markets. It is the countries that are
financially strongest, not those that are militarily the strongest, that are
likely to win in this competition.
If the world could move from the U.N. medium population projection of nearly 9
billion in 2050 to the low projection of less than 7 billion, water stresses
would be greatly alleviated, making the water problem much more manageable. If
the world stays on the current population trajectory, a growing share of
humanity may simply lack the water needed for a decent life.
-END-
LESTER R. BROWN is president and BRIAN HALWEIL is staff researcher at Worldwatch
Institute, a Washington, D.C.-based research organization.
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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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