June 17, 2005
Environmental degradation is threatening the health and
livelihoods of two billion people living in arid regions round
the world, says an international team of researchers.
They say
that desertification — the irreversible degradation of drylands
due to climatic factors and human activities — is among the
world's greatest environmental challenges.
The
researchers published their findings yesterday (16 June) in a
report of the Millennium Ecosystem Assessment, a US$22 million
study by an international partnership of scientists, UN
agencies, the World Bank and the World Conservation Union (IUCN)
(see
Healthy ecosystems 'critical in fight against poverty').
According
to the report, desertification is spreading because of climate
change and population growth, both of which have led to pressure
on resources such as water for irrigating fields. It says that
43 per cent of the world's cultivated land is in drylands.
Half of the
world's poor live in drylands, and the infant mortality rate in
these areas is twice as high as that in other regions of
developing countries, says the report.
"Desertification is not due to lack of knowledge and science,
but to a lack of proper governance," says co-author Uriel
Safriel, a professor at the Hebrew University of Jerusalem,
Israel.
Safriel
explains that the knowledge needed to generate sustainable
incomes from drylands is available in the world's scientific and
engineering communities, yet doesn't reach the people affected.
"The reason
is either that their own governments are not very efficient or
that the donor countries are not investing their systems in a
proper way," he says.
Safriel and
colleagues note in their study that desertification is a global
problem, affecting not only drylands but also regions distant
from them. Dust from the Gobi and Sahara deserts has, for
instance, been linked to respiratory problems in North America
and has affected coral reefs in the Caribbean Sea.
Nevertheless, the report says there are still "serious gaps in
our knowledge of the seriousness of desertification".
The study
suggests that 10-20 per cent of drylands are already degraded,
with those in sub-Saharan Africa and Central Asia most
vulnerable to further desertification.
It adds
that the 'least dry drylands' are those most at risk. These
areas are often identified as possible areas for growing crops
to meet increasing demand for food. However, converting them to
agriculture introduces stresses that can lead to irreversible
damage and desertification.
The authors
say policymakers need to consider what are the most appropriate
and sustainable livelihoods for people living in drylands, which
cover 40 per cent of the planet's land area.
They
recommend taking steps to prevent future desertification rather
than attempting to reverse it, a costly option that is prone to
failure. Measures to protect soils from erosion, to manage water
resources sustainably and to maintain vegetation can all help
prevent desertification.
"The global
population has to find better ways to use the good areas for
agriculture, and use land less suited to agriculture for other
livelihoods," says Safriel.
The
transportation of goods between drylands and non-drylands would
need to be improved so that people living in drylands can import
agricultural goods from other areas.
The authors
point out that agricultural land needs more water than urban
environments, and that water used in cities could be recycled
and used on crops.
Although
the drylands do not have much water, they do have other natural
resources that can be exploited.
"Drylands
could generate solar energy for non-dryland areas," suggests
Safriel.
by Catherine
Brahic,
SciDev.Net |