Update 6: February 5, 2002-2
Copyright © 2002 Earth Policy Institute
World's Rangelands Deteriorating Under Mounting Pressure
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 table)
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.
Copyright ©
2002 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, "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