Study claims previous estimates of desertification have failed to account for the growing impact from changing land use
Danny Bradbury, BusinessGreen, 11 Feb 2010
Over a third of the world's land could be turned into desert, according to a new report published in the International Journal of Life Cycle Assessment that warns increased rates of desertification could have a huge impact on global food and water supplies.
In a series of two papers, authors from the Institute of Agro Food Research and Technology (IRTA) included the impact of desertification in lifecycle analyses of land use impact to ascertain how much land was at risk.
They assessed aridity, erosion, the risk of fire, and overuse of aquifers, as parameters leading to desertification, and concluded that vast swathes of land are at risk of becoming irrevocably unproductive unless unsustainable land use practices are halted.
"Using geographical information systems, calculation of the characterisation of factors for the aridity variable shows that 38 per cent of the world area, in eight out of 15 existing eco-regions, is at risk of desertification," the authors said. "The most affected is the tropical/subtropical desert."
That area lies in North Africa, the Middle East, Australia, southwest China, and the western edge of South America, although the report warned that some coastal areas, the prairies, the Mediterranean region, the savannah, and the temperate, tropical and subtropical Steppes are also at risk.
Such widespread desertification would have crippling impact on national economies and global food production.
The scientists said that the report's conclusions varied from prior studies of desertification as previous lifecycle analyses looked primarily at the impact of climate change and failed to measure the effect of human activities such as cultivation or grazing.
However, there are some positive moves being taken to try and reclaim desert lands and make the process reversible. Two years ago, the Sah ara Forest Project was launched, with a plan to create renewable energy, water, and food in the desert region using concentrated solar power and sea water greenhouses. A "hedge" of sea water greenhouses - which condense and sea water into fresh water - would be created to help irrigate orchards planted in the desert region.