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March 27, 2003-3
Copyright © 2003 Earth Policy Institute
Deserts Advancing, Civilization Retreating
Janet Larsen
The coalition forces advancing northward
from Kuwait to Baghdad are traversing the site of the world's first
civilization—ancient
Sumer. More than 5,000 years ago, the Sumerians inhabited the rich
land between the Tigris and Euphrates Rivers, part of the legendary
Fertile Crescent. There they developed a sophisticated irrigation
system, built the first cities, devised a written language, and
invented the wheel.
Yet the Fertile Crescent as now seen in press coverage of the war
in Iraq appears to be anything but fertile. Strong winds ripping
across the dusty floodplains of the Tigris and Euphrates and the
surrounding area catch fine dust and sand, creating choking storms
that impede movement, impair visibility, and threaten human health.
Once-fertile land is now desert.
Unfortunately, this situation is not unique. The pressure of the
world's 6.2 billion people is slowly turning productive land into
desert on every continent. Cultivation of marginal land has eroded
soils, while some 3 billion cattle, sheep, and goats have pushed
pastures beyond their sustainable limits. All told, desertification
plagues up to one third of the earth's land area, affecting more
than 1 billion people in 110 countries.
Although deserts regularly expand and contract, the acceleration
of human-induced desertification is fast undermining rural economies.
Each year, deserts claim millions of hectares of cropland and rangeland.
Africa—with
almost half its land area at risk—is
most vulnerable, but satellite images and on-the-ground reports
confirm that desertification is widespread throughout the world's
drylands.
In the Sistan basin shared by Afghanistan and Iran, windblown dust
and sand have buried more than 100 villages. A former oasis that
only five years ago supported at least a million cattle, sheep,
and goats is now nearly barren. As overgrazed pastures turn to sand,
hundreds of thousands of livestock have perished, and villagers
have abandoned the area.
To the north, along Afghanistan's Amu Darya River, destruction of
protective vegetation has exacerbated the effects of drought and
allowed the formation of a sand dune belt that is some 300 kilometers
(186 miles) long and 30 kilometers wide. These dunes, moving up
to 1 meter per day, are blocking roads and swallowing villages no
longer shielded by local forests.
In Kazakhstan, overtaxed farmland is being abandoned as productivity
falls. Overplowing of marginal land during a Soviet attempt to boost
grain harvests in the 1950s led to widespread wind erosion of soil.
Since 1985, Kazakhstan has abandoned half of its 25 million hectares
of grainland.
In China, desertification threatens the livelihoods of millions
and racks up direct annual economic losses of roughly $6.5 billion,
including the cost of reduced farm productivity. A report from the
U.S. Embassy in Beijing entitled "Desert Mergers and Acquisitions"
reveals that in northwest China, prolonged dry weather, overgrazing
of pastures, and rampant harvesting of wild plants have loosened
sand on the edges of the country's third and fourth largest deserts.
Strong winds are pushing destabilized dunes southward from the 5-million-hectare
(12-million-acre) Bardanjilin Desert toward the 3-million-hectare
Tengry Desert, literally laying ground for a merger.
A similar situation exists in China's Xinjiang Autonomous Region.
Excessive upstream dam building and water withdrawals for agriculture
have dried up the Tarim River. As a result, large poplar groves
and other vegetation that once served as a barrier between the Taklimakan
and Kumtag deserts have died off. Now the two deserts are moving
steadily toward each other, and they too may merge.
These problems are not isolated, nor are they purely local in scope.
Massive dust storms originating in China and Mongolia have traveled
as far east as the continental United States. Two countries directly
in the path of the suffocating dust, Japan and South Korea, have
teamed up with China to promote rehabilitation of the degraded lands
that feed these ocean-traversing storms.
The secretariat of the United Nations Convention to Combat Desertification
has projected that without concerted efforts to arrest and reverse
desertification, Asia could lose one third of its arable land. In
South America, arable land area could shrink by one fifth. In Africa,
two thirds of the arable land could be lost, reinforcing poverty
and food insecurity and quickly adding to the ranks of environmental
refugees.
Nigeria, Africa's most populous country, loses some 350,000 hectares
of land—about
half the size of the U.S. state of Delaware—to
the encroaching Sahara Desert each year. Desertification from a
combination of excessive population pressure, poor land management,
overgrazing, and drought affects over half the land in 10 of Nigeria's
northern states, which have a combined population of 29 million.
As deserts expand, the competition between farmers and pastoralists
for the remaining productive land intensifies.
In Kenya, over 80 percent of the land is vulnerable to desertification—land
that supports nearly a third of the country's 32 million people
and half of its 28 million cattle, sheep, and goats. Unprecedented
population growth has led to inappropriate land use and accelerated
deforestation. People and their livestock have been forced onto
marginal lands, and farmers have reduced fallow periods, furthering
soil degradation.
The means of combating desertification varies among countries, depending
on local climatic and social conditions. Efforts to turn back the
deserts and break the cycle of poor land management and poverty
hinge on raising the incomes of the 1 billion people worldwide who
live on less than $1 per day. Reduced family size and education
also play key roles in lowering pressure on the land and fostering
stewardship.
Though desert margins are particularly at risk, any land that is
completely cleared of vegetation is vulnerable to desertification.
Restoring vegetation in vulnerable areas can stabilize soils so
that they do not blow away. Realizing this, the Chinese government
has launched the world's largest tree planting project in an attempt
to stop the encroaching desert.
To prevent wind and water erosion, farmers can practice conservation
agriculture. No-till or low-till farming can replace intensive plowing,
maintaining soil organic matter and moisture. Conservation agriculture
is practiced on some 60 million hectares worldwide, primarily in
the United States and South America, but it has great potential
to reduce soil erosion and raise crop yields in dry regions in Africa
and the Middle East.
Careful management of livestock is necessary to protect the integrity
of grasslands. In China, where grasslands are grazed and trampled
by 161 million goats, 137 million sheep, and 128 million cattle
and buffalo, some local governments have banned goats from feeding
on open land. Villagers may receive subsidies to keep their flocks
in the farmyard, feeding them with cut forage.
Alternative energy also has a role to play in preventing land degradation.
In developing countries, where some 2 billion people rely on wood
and crop residues for cooking, simple devices like solar cookers
can relieve pressure on the land. And wind turbines can provide
clean energy while serving as windbreaks.
The United Nations Environment Programme conservatively estimates
that between 1978 and 1991, some $300-600 billion in income was
lost worldwide because of the failure to combat desertification.
Other analyses have estimated that the benefits from slowing desertification
and rehabilitating degraded lands are at least 2.5 times higher
than the costs of letting sands take over. A world where productive
land area is shrinking while human demands grow is not a recipe
for ecological stability or economic progress.
Copyright
© 2003 Earth Policy Institute
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FOR ADDITIONAL INFORMATION
From Earth Policy Institute
Lester R. Brown, Eco-Economy:
Building an Economy for the Earth (New York: W.W. Norton
& Company, 2001).
Lester R. Brown, Janet Larsen, and Bernie Fischlowitz-Roberts,
The Earth Policy Reader
(New York: W.W. Norton & Company, 2002).
Lester R. Brown, "World's Rangelands Deteriorating
Under Mounting Pressure," Eco-Economy
Update, 5 February 2002.
Lester R. Brown, "Dust Bowl Threatening China's
Future," Earth Policy Alert,
23 May 2001.
From Other Sources
H.E. Dregne and Nan-Ting Chou, "Global
Desertification Dimensions and Costs," in Degradation and
Restoration of Arid Lands (Lubbock, Texas: Texas Tech. University,
1992).
Hari Eswaran, Paul Reich, and Fred Beinroth, "Global
Desertification Tension Zones," in D.E. Stott, R.H. Mohtar, and
G.C. Steinhardt (eds.), Sustaining the Global Farm (2001),
pp. 24-28.
M. Kassas, "Desertification: A General Review,"
Journal of Arid Environments, vol. 30, 1995, pp. 115-118.
P.F. Reich et al., "Land
Resource Stresses and Desertification in Africa," in: E.M. Bridges
et al., (eds.), Responses to Land Degradation, Proceedings
of the 2nd International Conference on Land Degradation and Desertification,
Khon Kaen, Thailand (New Delhi: Oxford Press, 2001).
United Nations Environment Programme (UNEP), Global
Environment Outlook 3 (London: Earthscan Publications Ltd.,
2002).
UNEP, Status of Desertification and Implementation
of the United Nations Plan of Action to Combat Desertification
(Nairobi: 1991), p. 74.
UNEP, Afghanistan: Post-Conflict Environmental
Assessment (Switzerland: 2003).
Mohan K. Wali et al., "Assessing Terrestrial Ecosystem
Sustainability: Usefulness of Regional Carbon and Nitrogen Models,"
Nature & Resources, vol. 35, n. 4, October-December 1999,
pp. 21-33.
LINKS
Secretariat of the United Nations Convention to
Combat Desertification (UNCCD)
http:/www.unccd.int
UNCCD country listings and reports
http:/www.unccd.int/
convention/ratif/doeif.php
United Nations Food and Agriculture Organization
http:/www.fao.org
U.S. Department of Agriculture - Natural Resources
Conservation Service World Desertification Vulnerability Map
http:/soils.usda.gov/use/worldsoils/
mapindex/desert.html
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