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 t a time when drought in the United States, Ethiopia,
and Afghanistan is in the news, it is easy to forget that far
more serious water shortages are emerging as the demand for water
in many countries simply outruns the supply. Water tables are
now falling on every continent. Literally scores of countries
are facing water shortages as water tables fall and wells go
dry.
 We live
in a water-challenged world, one that is becoming more so each
year as 80 million additional people stake their claims to the
Earth's water resources. Unfortunately, nearly all the projected
3 billion people to be added over the next half century will
be born in countries that are already experiencing water shortages.
Even now many in these countries lack enough water to drink,
to satisfy hygienic needs, and to produce food.
By 2050, India
is projected to add 519 million people and China 211 million.
Pakistan is projected to add nearly 200 million, going from 151
million at present to 348 million. Egypt, Iran, and Mexico are
slated to increase their populations by more than half by 2050.
In these and other water-short countries, population growth is
sentencing millions of people to hydrological poverty, a local
form of poverty that is difficult to escape.
Even with
today's 6 billion people, the world has a huge water deficit.
Using data on overpumping for China, India, Saudi Arabia, North
Africa, and the United States, Sandra Postel, author of Pillar
of Sand: Can the Irrigation Miracle Last?, calculates the
annual depletion of aquifers at 160 billion cubic meters or 160
billion tons. Using the rule of thumb that it takes 1,000 tons
of water to produce 1 ton of grain, this 160-billion-ton water
deficit is equal to 160 million tons of grain or one-half the
US grain harvest.
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At average
world grain consumption of just over 300 kilograms - one third
of a ton per person per year, this would feed 480 million people.
Stated otherwise, 480 million of the world's 6 billion people
are being fed with grain produced with the unsustainable use
of water.
Overpumping
is a new phenomenon, one largely confined to the last half century.
Only since the development of powerful diesel and electrically
driven pumps have we had the capacity to pull water out of aquifers
faster than it is replaced by precipitation.
Some 70 percent
of the water consumed worldwide, including both that diverted
from rivers and that pumped from underground, is used for irrigation,
while some 20 percent is used by industry, and 10 percent for
residential purposes. In the increasingly intense competition
for water among sectors, agriculture almost always loses. The
1,000 tons of water used in India to produce 1 ton of wheat worth
perhaps $200 can also be used to expand industrial output by
easily $10,000, or 50 times as much. This ratio helps explain
why, in the American West, the sale of irrigation water rights
by farmers to cities is an almost daily occurrence.
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In addition
to population growth, urbanization and industrialization also
expand the demand for water. As developing country villagers,
traditionally reliant on the village well, move to urban high-rise
apartment buildings with indoor plumbing, their residential water
use can easily triple. Industrialization takes even more water
than urbanization.
Rising affluence
in itself generates additional demand for water. As people move
up the food chain, consuming more beef, pork, poultry, eggs,
and dairy products, they use more grain. A US diet rich in livestock
products requires 800 kilograms of grain per person a year, whereas
diets in India, dominated by a starchy food staple such as rice,
typically need only 200 kilograms. Using four times as much grain
per person means using four times as much water.
Once a localized
phenomenon, water scarcity is now crossing national borders via
the international grain trade. The world's fastest growing grain
import market is North Africa and the Middle East, an area that
includes Morocco, Algeria, Tunisia, Libya, Egypt, and the Middle
East through Iran. Virtually every country in this region is
simultaneously experiencing water shortages and rapid population
growth.
As the demand
for water in the region's cities and industries increases, it
is typically satisfied by diverting water from irrigation. The
loss in food production capacity is then offset by importing
grain from abroad. Since 1 ton of grain represents 1,000 tons
of water, this becomes the most efficient way to import water.
Last year,
Iran imported 7 million tons of wheat, eclipsing Japan to become
the world's leading wheat importer. This year, Egypt is also
projected to move ahead of Japan. Iran and Egypt have nearly
70 million people each. Both populations are increasing by more
than a million a year and both are pressing against the limits
of their water supplies.
The water
required to produce the grain and other foodstuffs imported into
North Africa and the Middle East last year was roughly equal
to the annual flow of the Nile River. Stated otherwise, the fast-growing
water deficit of this region is equal to another Nile flowing
into the region in the form of imported grain.
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It is
now often said that future wars in the region will more likely
be fought over water than oil. Perhaps, but given the difficulty
in winning a water war, the competition for water seems more
likely to take place in world grain markets. The countries that
will "win" in this competition will be those that are
financially strongest, not those that are militarily strongest.
The world
water deficit grows larger with each year, making it potentially
more difficult to manage. If we decided abruptly to stabilize
water tables everywhere by simply pumping less water, the world
grain harvest would fall by some 160 million tons, or 8 percent,
and grain prices would go off the top of the chart. If the deficit
continues to widen, the eventual adjustment will be even greater.
Unless governments
in water-short countries act quickly to stabilize population
and to raise water productivity, their water shortages may soon
become food shortages. The risk is that the growing number of
water-short countries, including population giants China and
India, with rising grain import needs will overwhelm the exportable
supply in food surplus countries, such as the United States,
Canada, and Australia. This in turn could destabilize world grain
markets.
Another risk
of delay in dealing with the deficit is that some low-income,
water-short countries will not be able to afford to import needed
grain, trapping millions of their people in hydrological poverty,
thirsty and hungry, unable to escape.
Although there
are still some opportunities for developing new water resources,
restoring the balance between water use and the sustainable supply
will depend primarily on demand-side initiatives, such as stabilizing
population and raising water productivity.
Governments
can no longer separate population policy from the supply of water.
And just as the world turned to raising land productivity a half
century ago when the frontiers of agricultural settlement disappeared,
so it must now turn to raising water productivity. The first
step toward this goal is to eliminate the water subsidies that
foster inefficiency. The second step is to raise the price of
water to reflect its cost. Shifting to more water-efficient technologies,
more water-efficient crops, and more water-efficient forms of
animal protein offer a huge potential for raising water productivity.
These shifts will move faster if the price of water more closely
reflects its value. 
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worldwatch.org; website www.worldwatch.org