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Growing desertification
worldwide threatens to swell by millions the number of poor
forced to seek new homes and livelihoods. And a rising
number of large, intense dust storms plaguing many areas
menace the health of people even continents away,
international experts warn in a new report.
Thick storms rising out of the Gobi Desert affect much of
China, Korea and Japan and even reduce air quality over
North America, according to
Ecosystems and Human Well-Being:
Desertification Synthesis. The report is based on
information generated for the
Millennium Ecosystem
Assessment (MA), a $22 million, four-year global study by
1,300 experts from 95 countries.
“An increase in
desertification-related dust storms is widely considered to
be a cause of ill-health (fever, coughing, sore eyes) during
the dry season,” says the report. “Dust emanating from (the
Gobi desert) and the Sahara has also been implicated in
respiratory problems as far away as North America and has
affected coral reefs in the Caribbean.”
The report shows infant
mortality in drylands in developing countries averages about
54 children per 1,000 live births, 10 times that of
industrial countries. Importantly, the rate in such drylands
is twice as high as that of other, non-dryland regions in
developing countries.
The authors rank
desertification – land degradation in drylands as a result
of climatic factors and human activities – among the world’s
greatest environmental challenges, destabilizing societies
by deepening poverty and creating environmental refugees who
can often add stress to areas that may not be degraded.
Desertification has other
strong adverse impacts on non-drylands as well. In addition
to dust storms, biophysical impacts include downstream
flooding, impairment of global carbon sequestration
capacity, and regional and global climate change.
“Given the size of population
in drylands, the number of people affected by
desertification is likely larger than any other contemporary
environmental problem,” says the report.
Occupying more than
four-tenths (41%) of the world’s land area, drylands are
home to over two billion people, among them some of the
world’s most impoverished, dependant on the environment for
basic needs. Indeed, half of all people living in poverty
are in drylands.
Impacts of desertification
are exacerbated by political marginalization of the dryland
poor, and the slow growth of health and education
infrastructure.
“The cross boundary nature of
the problem makes desertification a global concern – one
that receives too little attention,” says co-author Zafar
Adeel, Assistant Director of the United Nations University
water academy in Canada, the UNU International Network on
Water, Environment and Health.
Population growth,
globalization and desertification
Desertification is not the
result of drought alone, as often believed, says co-author
Gregoire de Kalbermatten, of the UN Convention to Combat
Desertification. “Drylands experience frequent droughts
without harm. However dryland ecosystems are fragile and
human activity can increase their vulnerability to seasonal
fluctuations and droughts.”
“Population growth,
inappropriate policies, and some aspects of globalization
are the main drivers that lead to unsustainable pressure on
dryland ecosystems,” he says.
Adds co-author Uriel Safriel
of Hebrew University of Jerusalem, a visiting professor at
the University of Maryland: “For centuries pastoral people
lived in such regions with minimal impact. This ‘harmony’
was a default result of smaller populations, low stocking
rates, and large areas to forage on. The conversion of
rangelands to croplands reduced the available pasture and
the collection of firewood by many, not necessarily just the
pastoralists, reduced range quality. The lesson is that
increasing population pressure not accompanied by management
practices compatible with the new population size, is the
cause of degradation.”
As populations in drylands
increase, especially in urban areas, water scarcity
increases in tandem. Drylands contain 43% of the world’s
cultivated lands, much of it dependent on water from sources
typically located outside drylands.
The low average water
availability in drylands today (1,300 cubic metres per
capita per year, already below the threshold of 2,000
considered a minimum for meeting human needs), is expected
to fall further due to a combination of pressures in and
around the drylands including population growth, reduced
freshwater availability due to global warming and drought,
and economic growth.
As well, inappropriate
economic policies, including agricultural subsidies
totalling US$ 300 billion in 2002, can contribute to
desertification.
“Studies have shown that
trade liberalization, macroeconomic reforms and a focus on
raising production for exports can lead to desertification,”
the report says. “Such distortions to international food
markets drive down prices and have often seriously
undermined the livelihoods of food producers in many poorer
countries.”
“These practices eventually
lead to decreased land productivity and a downward spiral of
worsening degradation and poverty,” says Prof. Safriel.
An Environmental
Danger of Unknown Scope
Desertification diminishes
plant and animal biodiversity, while flooding from denuded
plains affects areas adjacent to drylands.
Despite the importance of its
global impacts, the exact extent of desertification is
unknown. Nor is it known accurately how fast it is
increasing. Based on three studies in the past 15 years, an
estimated 10 to 20% of world drylands are degraded, with a
much larger fraction at risk of future desertification.
“Bridging the wide gaps in
determining the extent and understanding the processes of
desertification are urgent requirements in order to develop
policies that are sound from economic and scientific
standpoint” says Mr. de Kalbermatten.
A Millennium-Long
Challenge
“The Millennium Development
Goals, a suite of objectives globally agreed by world
leaders in 2000 to be met by 2015, cannot be met without
addressing the problem of desertification effectively,” says
Dr. Adeel.
Effective policies and
sustainable agricultural practices can reverse the decline
of drylands. Chief among these are measures that protect
soils from erosion, salinization and other forms of
degradation. Proper land use management policies are needed
to protecting existing vegetative cover from overgrazing,
over-exploitation, trampling and unsustainable irrigation
practices.
Finally, creating viable
livelihood alternatives for drylands populations should
become part of national strategies to combat desertification
and poverty reduction.
The greatest vulnerability is
ascribed to sub-Saharan and Central Asian drylands. For
example, in three key regions of Africa—the Sahel, the Horn
of Africa, and Southeast Africa—severe droughts occur on
average once every 30 years. These droughts triple the
number of people exposed to severe water scarcity at least
once in every generation, leading to major food and health
crises.
About the MA
The report released today is
the third of seven reports of the world's largest study of
changes to Earth's ecosystems and the impact of those
changes on humans.
Involving some 1,360 of the
world's leading experts, the MA is a partnership among
several international organizations, including the
Convention on Biological Diversity, U.N. Convention to
Combat Desertification, Ramsar Convention on Wetlands,
Convention on Migratory Species, five UN agencies (WHO, FAO,
UNESCO, UNEP, UNDP), the World Bank, and IUCN. It is
supported by 22 of the world’s leading scientific bodies,
including The Royal Society of the U.K. and the Third World
Academy of Sciences.
The MA’s work is overseen by
a 45-member board of directors, co-chaired by Dr. Robert
Watson, Chief Scientist of The World Bank, and Dr. A. H.
Zakri, Director of the United Nations University’s Institute
of Advanced Studies. The multi-stakeholder board is composed
of the international organizations plus government
officials, the private sector, NGOs and indigenous peoples.
The Assessment Panel, which
oversees the technical work of the MA, includes 13 of the
world’s leading social and natural scientists. It is
co-chaired by Ms. Angela Cropper of the Cropper Foundation,
and Prof. Harold Mooney of Stanford University. Dr. Walter
Reid is the Director of the Millennium Ecosystem Assessment.
Major funding was provided by
the Global Environment Facility, the United Nations
Foundation, the David and Lucile Packard Foundation, and The
World Bank. The MA Secretariat is coordinated by the United
Nations Environment Programme (UNEP).
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