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February 5, 2002-2
Copyright © 2002 Earth Policy Institute
World's Rangelands Deteriorating Under Mounting Pressure
Lester R. Brown
In late January, a dust storm originating
in northwestern China engulfed Lhasa, the capital of Tibet, closing
the airport for three days and disrupting tourism. Such dust storms
are no longer uncommon. Dust storms originating in Central Asia,
coupled with those originating in Saharan Africa that now frequently
reach the Caribbean remind us that desertification of the world's
rangelands is ongoing.
Even though the damage from overgrazing is spreading, the world's
livestock population continues to grow, tracking the growth in human
population. As world population increased from 2.5 billion in 1950
to 6.1 billion in 2001, the world's cattle herd went from 720 million
to 1.53 billion. The number of sheep and goats expanded from 1.04
billion to 1.75 billion.
With 180 million pastoralists worldwide now trying to make a living
tending 3.3 billion cattle, sheep, and goats, grasslands are under
heavy pressure. As a result of overstocking, grasslands are now
deteriorating in much of Africa, the Middle East, Central Asia,
the northern part of the Indian subcontinent, Mongolia, and much
of northern China. Overgrazing of rangelands initially reduces their
productivity but eventually it destroys them, leaving desert. Degraded
rangeland, worldwide, totals 680 million hectares, five times the
U.S. cropland area.
Rangelands, consisting almost entirely of
land that is too dry or too steeply sloping to support crop production,
account for one fifth of the earth's land surface, more than double
the area that is cropped. Tapping the productivity of this vast
area depends on ruminants-cattle, sheep, and goats--animals whose
complex digestive systems enable them to convert roughage into food,
including beef, mutton, and milk, and industrial materials, importantly
leather and wool.
Some four fifths of world beef and mutton production, roughly 52
million tons, comes from animals that forage on rangelands. In Africa,
where grain is scarce, 230 million cattle, 246 million sheep, and
175 million goats are supported almost entirely by grazing and browsing.
The number of livestock, a cornerstone of many African economies,
often exceeds grassland carrying capacity by half or more. A study
that charted the mounting pressures on grasslands in nine southern
African countries found that the capacity of the land to sustain
livestock is diminishing.
Fodder needs of livestock in nearly all developing countries now
exceed the sustainable yield of rangelands and other forage resources.
In India, with the world's largest cattle herd, the demand for fodder
in 2000 was estimated at 700 million tons, while the sustainable
supply totaled just 540 million tons. A report from New Delhi indicates
that in states with the most serious land degradation, such as Rajasthan
and Karnataka, fodder supplies satisfy only 50-80 percent of needs,
leaving large numbers of emaciated, unproductive cattle.
China faces similarly difficult challenges. The northwest of China,
where there are no land ownership rights and no fences, has become
a vast grazing commons. Since the economic reforms of 1978, there
has been little incentive for individual families to limit the size
of their flocks and herds. As a result, livestock numbers have soared.
The United States, which has a comparable grazing capacity, has
98 million head of cattle while China has 130 million head. But
the big difference is in the number of sheep and goats: 9 million
in the United States, 290 million in China.
In Gonge County, for example, in eastern Qinghai Province, the local
grasslands can support an estimated 3.7 million sheep. But by the
end of 1998, the region's flock had reached 5.5 million--far beyond
its carrying capacity. The result is fast-deteriorating grassland
and the creation of a new desert, replete with sand dunes.
The mounting pressures on rangelands in the Middle East are illustrated
by Iran, a country of 71 million people. The 8 million cattle and
81 million sheep and goats that graze its rangelands supply not
only milk and meat, but also the wool for the country's fabled rug-making
industry. In a land where sheep and goats outnumber humans, and
where rangelands are being pushed to their limits, the current livestock
population may not be sustainable.
Land degradation from overgrazing is taking a heavy economic toll
in lost livestock productivity. In the early stages of overgrazing,
the costs show up as lower land productivity. But if the process
continues, it destroys vegetation, leading to the erosion of soil
and the eventual creation of wasteland. A U.N. assessment of the
earth's dryland regions, done in 1991, estimated that livestock
production losses from rangeland degradation exceeded $23 billion.
In Africa, the annual loss of rangeland productivity is estimated
at $7 billion, more than the gross domestic product of Ethiopia.
In Asia, livestock losses from rangeland degradation total over
$8 billion. (See ) Together,
Africa and Asia account for two thirds of the global loss.
Arresting the deterioration of the world's rangelands presents a
difficult challenge. One key to arresting the growth in livestock
populations is to stop the growth in human populations. Iran, recognizing
the threat of overgrazing and other population-related stresses
it was facing some 15 years ago, dropped its population growth from
4 percent a year to scarcely 1 percent in 2001, illustrating what
can be done with committed leadership.
Another key to lightening pressure on rangelands is the spreading
practice of feeding livestock crop residues that would otherwise
be burned, either because they are needed for fuel or because double-cropping
requires destruction of the residues. India has been uniquely successful
in converting crop residues into milk--expanding production from
20 million tons in 1961 to 80 million tons in 2001, and without
feeding grain. Its farmers did so almost entirely by using crop
residues and by stall-feeding grass cut and collected by hand.
China also has a large potential to feed corn stalks and wheat and
rice straw to cattle or sheep. As the world's leading producer of
both rice and wheat and the second-ranked producer of corn, China
annually harvests an estimated 500 million tons of straw, corn stalks,
and other crop residues. Feeding crop residues in the major crop-producing
provinces of east central China--Hebei, Shandong, Henan, and Anhui--has
created a "Beef Belt," whose beef output dwarfs that of the northwestern
grazing provinces of Inner Mongolia, Qinghai, and Xinjiang.
In rangeland reclamation, where successes are few, a promising low-cost
technique for reclaiming overgrazed and exhausted rangeland is being
developed at the International Center for Agricultural Research
in the Dry Areas (ICARDA) in Syria. ICARDA scientists have developed
a simple implement that slightly depresses the soil in double rows
20 centimeters (8 inches) apart. The implement seeds grass in these
twin depressions, which follow the contour of the land, enabling
them to trap rainwater runoff and restore vegetation.
It will take an enormous effort to stabilize livestock populations
at a sustainable level and to restore the world's degraded rangelands.
This will be costly, but failing to halt the desertification of
rangelands will be even costlier as flocks and herds eventually
shrink and as the resulting poverty forces large-scale migration
from the affected areas.
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Copyright
© 2002 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, "Dust Bowl Threatening China's Future," Earth
Policy Alert, 23 May 2001.
From Other Sources
M. Kassas, "Desertification: A General Review,"
Journal of Arid Environments, vol. 30, 1995, pp. 115-118.
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
United Nations Development Programme Office to Combat
Desertification and Drought
http:/www.undp.org/seed/unso
United Nations Food and Agriculture Organization
on-line database
http:/apps.fao.org
United Nations Secretariat of the Convention to
Combat Desertification
http:/www.unccd.int
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