Desertification
Desertification is a type of gradual land degradation of fertile land into arid desert due to a combination of natural processes and human activities.[2] This spread of arid areas is caused by a variety of factors, such as overexploitation of soil as a result of human activity and the effects of climate change.[3][4] Geographic areas most affected are located in Africa (Sahel region), Asia (Gobi Desert and Mongolia) and parts of South America. Drylands occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people.[5] Effects of desertification include sand and dust storms, food insecurity, and poverty.
Not to be confused with Decertification or Desertion.
Humans can fight desertification in various ways. For instance, improving soil quality, greening deserts, managing grazing better, and planting trees (reforestation and afforestation) can all help reverse desertification.
Throughout geological history, the development of deserts has occurred naturally over long intervals of time.[6] The modern study of desertification emerged from the study of the 1980s drought in the Sahel.[7]
Definitions[edit]
As recently as 2005, considerable controversy existed over the proper
definition of the term "desertification." Helmut Geist (2005) identified more than 100 formal definitions.[8] The most widely accepted of these was that of the Princeton University Dictionary which defined it as "the process of fertile land transforming into desert typically as a result of deforestation, drought or improper/inappropriate agriculture". This definition clearly demonstrated the interconnectedness of desertification and human activities, in particular land use and land management practices. It also highlighted the economic, social and environmental implications of desertification.
However, this original understanding that desertification involved the physical expansion of deserts has been rejected as the concept has further evolved since then.[9] Desertification has been defined in the text of the United Nations Convention to Combat Desertification (UNCCD) as "land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities," according to Hulme and Kelly (1993).[10]
There exists also controversy around the sub-grouping of types of desertification, including, for example, the validity and usefulness of such terms as "man-made desert" and "non-pattern desert".[11]
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This article incorporates from Desertification. United States Geological Survey. Retrieved 4 May 2021.
