One Third of
World's Population 2.7 Billion People
Will Experience Severe Water Scarcity By 2025,
Says New Study
Groundwater Aquifers Dropping at Alarming Rates and Conflicts Over Water
One third of the world's population will experience severe water
scarcity within the next 25 years according to a new study by a leading
global water organization. The study, which is the first to look at the
complete cycle of use and reuse of the world's fresh water, finds that
the water sources that supply the world's wells, lakes, and rivers are
The study was conducted by the International Water Management Institute,
a research center of the Consultative Group on International
Agricultural Research (CGIAR), and appears in the March issue of the
International Journal of Water Resources Development, a leading
refereed journal on issues of global water resources. It is being
released jointly with Future Harvest, a CGIAR-sponsored organization
that educates the public about the links between global peace, the
environment, and agriculture.
"Water scarcity is now the single greatest threat to human health, the
environment, and the global food supply," said David Seckler, director
general of the Water Institute and an author of the study with Randolph
Barker and Upali Amarasinghe. "It also threatens global peace as
countries in Asia and the Middle East seek to cope with shortages."
The study, Water Scarcity in the Twenty-First Century, projects water
supply and demand for 118 countries over the 19902025 period. The study
examines on a country-by-country basis not only how much water is
withdrawn by the four major sectors that use water‹agriculture,
industry, households, and the environment‹but also how much water
remains to be used and how much returns to the ground to "recharge"
aquifers. In recent years, as more water has been used to support
growing populations in each of these sectors, there has been less water
available to recharge groundwater supplies.
"Water scarcity is already a major destabilizing force within countries
because different sectors of the economy are vying for scarce water
resources," said Seckler. "Within the next 25 years, there is great
potential for more water conflict not just within countries but between
them. Historically, Egypt has threatened to go to war to protect its
water supplies if necessary. And just last week, President Gaddafi of
Libya warned that, 'the next Middle East war would be over dwindling
The study divides the countries into four categories.* The first
category includes those countries that are most water scarce and in 2025
will not have enough water to maintain 1990 levels of per capita food
production from irrigated agriculture and meet industry, household, and
environmental needs. The countries, defined as facing "absolute water
scarcity," include 17 countries in the Middle East, South Africa, and
the dryer regions of western and southern India and northern China,
which account for more than 1 billion people today and are projected to
account for as many as 1.8 billion in 2025. The study notes that while
India and China will not have major water problems on average, there
will be massive regional variations in water availability.
The second category includes countries that have sufficient potential
water resources to meet projected 2025 requirements, but will have to
more than double their efforts to extract water to do so. Twenty-four
countries, mainly in Sub-Saharan Africa, are defined as extremely water
scarce and include some 348 million people today and are projected to
include some 894 million in 2025. Because it will be extremely difficult
for these countries to find the financial resources to build enough
water development projects, such as dams and irrigation systems, they
are classified as having "economic water scarcity."
The remaining countries of the world are in categories three and four
and include North America and Europe. For these countries, there will be
substantially less pressure on water supplies with moderate needs to
increase water development efforts.
This study notes that those who will suffer most will be the people in
the world's poorest nations. Already the women and children of these
countries walk great distances to retrieve water for cooking, drinking,
and other household needs, farmers are losing their land as water
sources decline, and wildlife is disappearing as wetlands dry up.
The single greatest impact of water scarcity will be on the food
supplies of the poor. To meet the world food supplies in 2025, the study
provides two scenarios‹a "business as usual scenario" where no increases
in irrigation efficiency are foreseen, and a scenario where irrigation
efficiency is dramatically increased. Under the business-as-usual
scenario, 60 percent more water will be required for irrigation to meet
the world food supplies in 2025. Even if irrigation efficiency is
greatly increased, between 13 and 17 percent more water will be needed
and still 2.7 billion people will remain short of water. The study uses
the United Nations "medium" projection for population growth.
*Please note attached chart showing the countries that appear in each
"Recent Future Harvest-sponsored research indicates that conflicts today
are occurring primarily in the poor agrarian countries of the world.
These are the same countries that will face severe water shortages,"
says Barbara Alison Rose, director of operations of Future Harvest.
"Although nations have been able to manage water supplies peacefully,
for the most part, this study suggests that without real action this may
not be the case in the future."
"Many countries, including China, India, Pakistan, Mexico and nearly all
of the countries of the Middle East and North Africa, have literally
been having a free ride over the past two or three decades by rapidly
depleting their groundwater resources," said Seckler. "This could have
catastrophic results in terms of limiting their ability to produce
enough food to feed their populations."
The report suggests that the main solution to the groundwater problem is
to replenish groundwater aquifers, not reduce irrigation, which will
reduce food production. The best way to do this is to capture more water
above the ground during the wet season and allow it to percolate down
into the aquifer and then pump it to provide water in the dry season.
This can be accomplished through the use of percolating ponds or small
reservoirs that capture rainwater. Also, pump systems around large
bodies of water can inject water down into the aquifer. This is an
approach being used in California.
Another approach may be more effective. This is to increase rice paddy
irrigation in the wet season. "The irony is that people think rice
paddies waste a lot water when they are one of the best ways to maintain
healthy groundwater levels," said Seckler. "The deep percolation losses
of paddy irrigation recharge aquifers and replenish stream flows."
The opposite problem, of rising water tables of polluted and
oversalinized water, is also a severe problem in most of the arid areas
of Asia and the Middle East. It is particularly acute in Pakistan.
Rising water tables kill crops by waterlogging and adding a deadly level
of salt to the soil. With this rising water often comes raw sewage,
polluting villages and other water sources. What is required in this
situation is more efficient irrigation to reduce the amount of drainage
water, while simultaneously keeping salts below the root zone of plants
and periodically flushing them out of the system altogether.
"There is astonishing little attention to the threat of groundwater
depletion in the world by engineers or policymakers," said Seckler. "The
main focus is on surface water issues, but it is high time people began
focusing on how to solve the water problems beneath our feet. Few seem
to understand the magnitude and complexity of the groundwater problem."
The Sri Lanka-based International Water Management Institute undertakes
research to foster sustainable increases in the productivity of water
through better management of irrigation and other water uses in river
builds public understanding of the role of agriculture in international
issues through research and outreach on behalf of the 16 centers of the
Consultative Group on International Agricultural Research (CGIAR).