Update 23: March 27, 2003-3
Copyright © 2003 Earth Policy Institute
Deserts Advancing, Civilization Retreating
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
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