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 economi
Source:United Nations University