Deserts could turn powerhouses
A UN report, however, points out that deserts worldwide are facing serious challenges due to global climate changes and high water demands.india Updated: Jul 19, 2006 15:10 IST
Deserts across the world are facing considerable challenges due to global climate changes, high water demands, tourism and salt contamination of irrigated soils, a new UN report said on Monday.
"Desert margins and so called 'sky islands' - mountain areas within deserts that have been important for people, wildlife and water supplies for millennia - are under particular threat," said the 187-page report 'Global Deserts Outlook', released by the United Nations Environment Programme (UNEP) on World Environment Day.
"Global and regional instability, leading to more military training grounds, prisons and refugee holding stations, may also be set to modify the desert landscape."
"These intrusions import many people into deserts, generate considerable income and help upgrade infrastructure but have large environmental footprints particularly with respect to water. In an insecure and competitive world, this kind of investment will continue, even grow," it says.
Not all the changes need be harmful. Some may have clear benefits for indigenous people and other desert residents, and even the wider world.
Most deserts have sunlight and temperature regimes that surprisingly favour possible sites for shrimp and fish farms in locations like Arizona to the Negev desert in Israel.
Meanwhile, some experts believe deserts could become the carbon-free powerhouses of the 21st century. They argue that an area of 800 by 800 km of a desert like the Sahara could capture enough solar energy to generate all the world's electricity needs and more.
The report, prepared by experts from across the globe, traces the history and astonishing biology of the deserts and assesses likely future changes in deserts.
It also flags policy options that may help governments and relevant bodies deliver a more sustainable future for these extraordinary regions.
Said Shafqat Kakakhel, UNEP's deputy executive director: "There are many popular and sometimes misplaced views of deserts, which this report either confirms or overturns. Far from being barren wastelands, they emerge as biologically, economically and culturally dynamic while being increasingly subject to the impacts and pressures of the modern world".
"They also emerge as places of new economic and livelihood possibilities underlining yet again that the environment is not a luxury but a key element in the fight against poverty and the delivery of internationally-agreed development goals such as the Millennium Development Goals."
According to the report, almost one quarter of the earth's land surface - nearly 33.7 million sq km - has been defined as 'desert' in some sense.
These deserts are inhabited by over 500 million people, significantly more than previously thought.
Water is a vital and limiting factor in deserts. Many life forms exist in limbo, suddenly bursting into fruit and reproducing in vast numbers in response to 'rain pulses', it said.
Meanwhile, scientists are also screening desert plants for promising medicinal compounds. Some, found in the Negev, are known to hold anti-cancer and anti-malarial substances.
Others, from the deserts of Argentina, Arizona and Morocco, are effective against diseases like uterine cancer and infectious diseases. Essential oils from two plants found in the deserts of Morocco appear to enhance the growth and the efficiency of feed conversion in poultry.