Warming Global Deserts Under Pressure of Tourism, Prisons

ALGIERS, Algeria, June 5, 2006 (ENS) - Global climate change, high water demands by prisons and tourism, as well as salt contamination of irrigated soils are changing the world’s deserts, finds a new report launched today by the United Nations Environment Programme (UNEP) to mark World Environment Day. The biggest casualties may be cities in the deserts of southwestern Asia and in the southwest United States.

Deserts will feel the pressure of global and regional instability, which the report forees will lead to more military training grounds, prisons and refugee holding stations.

A 4,800 bed male medium security prison planned near Tucson, Arizona next to an existing prison (Photo courtesy Arrington Watkins Architects LLC)

“There are many popular and sometimes misplaced views of deserts which this report either confirms or overturns," said Shafqat Kakakhel, UNEP deputy executive director. "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, Kakakhel said, citing the growing interest in deserts as prime locations for aquaculture and the source of novel drugs, herbal medicines and industrial products derived from the plants and animals adapted to these arid areas.

This is the United Nations International Year of Deserts and Desertification. The main World Environment Day celebrations for 2006 are being held in the Algerian capital Algiers with the theme “Don’t Desert Drylands!”

In the Algerian city of Ghardaia, World Environment Day celebrations centered on an international forum on desertification and sustainability as well as street festivities with a parade and dancing.

Traditional dance at the World Environment Day street parade in Ghardaia (Photo courtesy UNEP)

“If the huge, solar power potential of deserts can be economically harnessed the world has a future free from fossil fuels," said Kakakhel. "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."

Rising numbers of people are attracted to deserts for hiking, fishing and to view cultural artifacts. Countries are recognizing this and the number of desert conservation areas including national parks is set to climb. Popular sites include Joshua Tree National Park in North America, St. Catherine’s Monastery in Sinai, and Uluru, also called Ayers Rock, in Australia.

A series of large transboundary parks are being negotiated in southwestern Africa which should offer new levels of protection to the entire coastal Namib desert.

Some deserts areas are capitalizing on the low costs of land, mild winter temperatures and in some cases the availability of brackish water that may be too salty for plant crops to farm crustaceans and fish. Raised in closed systems that prevent evaporation, such farming can be more water efficient than crop production.

Most deserts have sunlight and temperature regimes that favor sites for shrimp and fish farms in locations such as Arizona and Israel's Negev desertl.

The UNEP report favors such shrimp and fish farm developments that could help relieve the pressure on mangroves and sensitive coastlines which are now being cleared for shrimp aquaculture.

UN communications director Eric Falt (far right) is welcomed to Ghardaia by (from left) Fehim Yehia, the Wali of Ghardaia, Ahmed Zerrouk, the secretary general of the Ministry of Land Management and the Environment in Algiers, and Fatima Bou Saleh, director of environment in Ghardaia. (Photo courtesy UN)

“The pharmaceutical potential of desert plants has yet to be tapped,” says the report.

Desert plants, from countries like China and India, are being exported for herbal treatments and medicines to places like Germany. The report expects this trade will grow.

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.

Hoodia appears to mimic the effect that glucose has on nerve cells in the brain, fooling the body into thinking it is full, even when it is not, thus curbing the appetite. (Photo courtesy South African Herbal Remedies)

Nipa, a salt grass harvested in the Sonoran desert of northwestern Mexico in the Colorado River delta, thrives on pure seawater. It produces large grain yields the size of wheat and could become a major global food crop. The UNEP report says nipa "could become this desert’s greatest gift to the world."

Water scarcity is the definition of a desert and UNEP warns that population growth and inefficient water use are, by 2050, set to move some countries with deserts beyond thresholds of water scarcity, particularly in Chad, Iraq, Niger and Syria.

By 2025, large rivers may fail, the report warns, mentioning the Rio Grande and Colorado Rivers in North America, the Gariep River in southern Africa, the Tigris and Euphrates in southwestern Asia, and the Amu Darya and Indus Rivers in central Asia.

Almost one-quarter of the Earth’s land surface – some 33.7 million square kilometers – has been defined as desert in some sense. These deserts are inhabited by over 500 million people, more than previously thought, the UNEP report shows.

The desert cores remain pristine in many parts of the world, representing some of the planet’s last remaining areas of total wilderness.

But the report warns that the desert fringes in many places suffer high pressures from human activities and include several of the most threatened terrestrial ecoregions of the world.

Some Key Facts from the Global Deserts Outlook

Climate Change

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."

Water supply is vital for human settlements and these are even more vulnerable to unsustainable withdrawals of water, and the report states that climate change as a result of human emissions of greenhouse gases is already affecting deserts.

The overall temperature increase of between 0.5 and two degrees C over the period 1976-2000 has been much higher than the average global rise of 0.45 degrees C.

The Dashti Kbir desert in Iran has seen a 16 percent fall per decade in rainfall during this same period; the Kalahari in South Africa a 12 percent decline and the Atacama desert in Chile, an eight percent drop.

In contrast Kizil Kum in Afghanistan and Uzbekistan and the Western Desert in Egypt have seen an four to eight percent rise over the same period.

A dune in the Kizil Kum desert, Uzbekistan (Photo courtesy Tour Elena)

Under scenarios developed by the Intergovernmental Panel on Climate Change (IPCC), the body of scientists advising governments and the United Nations, temperatures in deserts could rise by an average of as much as five to seven degrees C by 2071 - 2100, compared to the average in the period 1961-1990.

Many deserts will see declines in rainfall as great as 15 percent, with deserts in southerly latitudes especially vulnerable.

Most of the 12 desert regions, whose future climate has been modeled, are facing a drier future with rainfall in some cases forecast to be 10 to 20 percent lower by the end of the century.

This applies to the northern hemisphere deserts such as the Colorado and Great Basin region in the United States as well as Australia' Great Victoria desert, and South America's Atacama desert.

Only the Gobi desert in China is predicted to have rainfall increases of between 10 and 15 percent.

The problem will almost certainly be compounded by the melting of glaciers whose waters sustain many deserts such as the Atacama and Monte Deserts in South America.

The sprawling city of Phoenix, Arizona, population 3.8 million, gets its water supply from the Colorado River. Green lawns account for a large part of the water use. (Photo credit unknown)

The situation is being aggravated by overgrazing and the cutting of trees and other vegetation in these desert mountain realms thus reducing the capacity of these natural water towers.

Modeling of the impact on California’s irrigated farmlands, the Global Deserts Outlook says they are likely “to lose more than 15 percent of their value because of losses in snow pack.”

Other impacts of climate change include the turning of some semi-arid rangelands into deserts and the re-mobilization of dunes currently stabilized by vegetation as in the southwestern Kalahari Desert in southern Africa.

Wider Water Issues and Agriculture

Underground water supplies, some formed over the course of a million years, are increasingly being drained of water for agriculture and settlements, including retirement resorts.

In some parts of the world, such as Arizona, deserts are becoming increasingly attractive as places to live and to retire, but this often requires large pumping and water transfers.

Other water supplies are under threat from salinization and pollution by pesticides and herbicides.

Countries like the United Arab Emirates are also seeing a growth in retirees which will certainly increase water demand.

Desalination plants, which turn sea water into drinking water, are used in some counties like Saudi Arabia but they consume large amounts of energy in a world where energy prices are rising sharply.

The report suggests that ancient, ingenious methods of water management such as underground channels known as qanats and foggara in North Africa and karez in countries like Pakistan, might offer sustainable options for the future.

Biodiversity

“Large convoys of air conditioned caravans follow hunters across the deserts of Arabia, Kazakhstan and Sudan,” the report warns, urging action to protect wildlife in deserts.

Desert species on the brink of extinction or declining fast include various species of gazelle, oryx, addax, Arabian tahr and the Barbary sheep as well as one of the falconers favorite prey, the houbara.

A pair of Arabian oryx in the United Arab Emirates (Photo by Hartmut Jungius courtesy WWF-Canon)

Sky islands in deserts are plant and animal communities that have been isolated in mountain ranges when the deserts became rapidly more arid some 20,000 years ago.

Many hold unique and rare species that, like oceanic islands, have evolved in isolation. These include the rich pine and oak forests of the Moroccan Atlas Mountains; the Arabian tahr goat found in the Al Hajar Mountains near the Gulf of Oman and the wild olives and Saharan myrtles of Niger’s Air Massif.

“At greatest risk are the few patches of dry woodlands associated with desert mountain habitats which may decline by up to 3.5 percent per year,” adds the Global Deserts Outlook.

The report cites experts who fear that these woodlands areas, which made possible the great desert trades such as the Silk Road and the cross-Sahara trade, could be lost in less than 50 years unless urgent action is taken to protect and conserve them.

Global Deserts Outlook has been produced by UNEP’s Division of Early Warning and Assessment and is the latest in its series of Global Environment Outlooks at: http://www.grid.unep.ch/geo/

The full Global Deserts Outlook is online at: http://www.unep.org/wed/2006/english/ where there are also other language versions.