United Nations Report: Deserts threatened by global warming

Monday, June 5, 2006 

Libyan Desert: The world's deserts are under threat, says UNEP.

A new report, titled "Global Deserts Outlook," has been released on World Environment Day by the United Nations Environment Programme (UNEP). The report suggests that the world's deserts face dramatic changes as a result of global climate change: high water demands, tourism and salt contamination of irrigated soils. Desert margins and mountainous areas within deserts that have been important for people, wildlife and water supplies for millennia, are under particular threat, say UNEP.

2006 is the United Nations' International Year of Deserts and Desertification. Yet deserts could become the "carbon-free power houses of the 21st century," some experts believe. They argue an area 800 by 800 km of desert, such as the Sahara, could capture the solar energy to generate all the world's electricity needs - and more.

The report, prepared by experts from across the globe, flags options that may help governments and relevant bodies deliver a more sustainable future for the Earth's desert regions.

"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," said Shafqat Kakakhel, UNEP's Officer in Charge and Deputy Executive Director.

"If the huge, solar-power potential of deserts can be economically harnessed the world has a future free from fossil fuels. And tourism based around desert nature can, if sensitively managed, deliver new prospects and perspectives for people in some of the poorest parts of the world," said Mr Kakakhel.

Almost one-quarter of the earth's land surface – some 33.7 million square kilometres – has been defined as "desert" in some sense. These deserts are inhabited by over 500 million people, significantly more than previously thought. In many parts of the world desert cores remain pristine, representing some of the planet's "last remaining areas of total wilderness," stated the UNEP in a news release.

Desert species are on the brink of extinction the Global Deserts Outlook reports. At risk animals include various species of Gazelle, Oryx, Addax, Arabian Tahr and the Barbary sheep as well as one of the falconers favourite prey, the Houbara. "At greatest risk are the few patches of dry woodlands associated with desert mountain habitats which may decline by up to 3.5 per cent per year," said the study.

As a result of their valuable water supplies being diverted to domestic or agricultural use, desert wetlands, fed by the large rivers crossing deserts, are probably the most threatened ecosystem. Probable impacts include those created by roads, settlement expansion and other infrastructure developments around areas of desert montane. By 2050 the report estimates that desert wilderness - those areas where there are no nearby roads - will decline from just under 60 per cent of the current total desert area to just over 30 per cent.

The pharmaceutical potential of desert plants has yet to be tapped, suggests the report. Scientists across the globe are analysing many desert plants for potential medicinal compounds - including anti-cancer and anti-malarial substances, antioxidants, as well as appetite suppressants.

Impact of climate change

The Intergovernmental Panel on Climate Change (IPCC), who advise governments and the United Nations, have reported that temperatures in deserts could rise by an average of as much as five to seven degrees by 2100. The problem, UNEP say, will almost certainly be compounded by the melting of glaciers - whose waters sustain many deserts.

The impacts of climate change include the transformation of semi-arid rangelands into deserts, UNEP reports. They say water supplies are under threat from salinization and pollution by pesticides and herbicides, and that rising water tables beneath irrigated soils has led to more salinization of soils.

In some coastal areas ground-water supplies have been contaminated as seawater invades subsurface waters, the report shows. Large rivers that run through deserts have supported desert people for millennia, but many have been dammed, with water loss downstream having led to serious impacts on flood plains and river ecology.

Sources

• "Global Deserts Outlook Launched on World Environment Day" — UNEP News Release, June 5, 2006

• "Deserts 'need better management'" — BBC News, June 5, 2006