The U.N. Convention to Combat Desertification defines the phenomenon as “land degradation in arid, semiarid and dry subhumid areas resulting from various factors, including climatic variations and human activities”. It is a global phenomenon, which affects drylands as a result of the excessive exploitation of ecosystem services and the diminishing reserves of water due to climate change. Drylands are a valuable resource: the CGIAR research programme on drylands reports they cover more than 40% of the globe and are inhabited by more than 1/3 of the world’s population. The process of desertification destroys each year 12 million ha of productive land, where 20 million tons of grain could have been harvested. Furthermore, desertification may affect also non-drylands with dust storms, downstream flooding and climate change.
Desertification is particularly threatening in Africa, where two-thirds of land is desert of drylands. While this land is used for agriculture and food production, almost three-fourths of it is degrading. Frequent and severe periods of drought have been affecting the continent in recent years, and particularly the Horn of Africa and the Sahel.
Two-thirds of the African continent is desert or drylands and it is estimated that nearly three-fourths of those desert and drylands are degrading. 485 million people are already suffering the impacts of this process of desertification, which makes sterile lands previously used for agriculture and food production and triggers processes of displacement and migration.