Over one third of the world’s land surface (38 percent) is threatened with desertification, according to a new study published in the International Journal of Life Cycle Assessment. The study found that eight of fifteen eco-regions are threatened by desertification, including coastal areas, the prairies, the Mediterranean region, the savannah, the temperate steppes, the temperate deserts, tropical and subtropical steppes, and the tropical and subtropical deserts.
“The greatest risk of desertification (7.6 out of 10 on a scale produced using various desertification indicators) is in the subtropical desert regions – North Africa, the countries of the Middle East, Australia, South West China and the western edge of South America”, said Montserrat Núñez, lead author and a researcher at the Institute of Agro Food Research and Technology (IRTA). Many of these regions have already experienced pockets of desertification.
This is the Guadalquivir River as it passes through Seville, one of the areas most at risk of desertification in Spain. Photo by: Nesta Vázquez.
The remaining areas scored less but are still at-risk. The Mediterranean and the tropical and subtropical Steppes scored 6.3 out of 10, while coastal areas and prairies scored 4 out of 10.
“Unsustainable land use may lead to soil becoming degraded. If this happens in arid, semi-arid and dry sub-humid regions, such as Spain, this degradation is known as desertification, and the effects can be irreversible, because they lead to areas becoming totally unproductive”, explains Núñez. Unsustainable land use includes over-grazing, over-cultivation, and deforestation. Scientists are further worried that climate change is exacerbating desertifcation worldwide.
Researchers employed the Life Cycle Assessment which analyzes the full environmental impacts of an activity, such as mining or logging. The researchers looked at four main signs of sensitivity to desertification: aridity, erosion, over-exploitation of aquifers, and the risk of fire.
“This makes it possible to satisfactorily evaluate the impact of desertification of a particular human activity, and compare the impact of the same activity in a different place, or the impact of different activities carried out in the same place,” explains Núñez.
Citation: Núñez, Montserrat; Civit, Bárbara; Muñoz, Pere; Arena, Alejandro Pablo; Rieradevall, Joan; Anton, Assumpció. “Assessing potential desertification environmental impact in life cycle assessment” International Journal of Life Cycle Assessment 15(1): 67-78, enero de 2010.
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