The Global Desertification - The Situation, and the Challenges for Japan -
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2. What Are the Major Causes of Desertification?
"Climatic variations" and "Human activities" can be regarded as the two main causes of desertification.
- Climatic variations：Climate change, drought, moisture loss on a global level
- Human activities：These include overgrazing, deforestation and removal of the natural vegetation cover(by taking too much fuel wood), agricultural activities in the vulnerable ecosystems of arid and semi-arid areas, which are thus strained beyond their capacity. These activities are triggered by population growth, the impact of the market economy, and poverty.
Source: WORLD ATLAS OF DESERTIFICATION SECOND EDITION (UNEP, 1997)
Population levels of the vulnerable drylands have a close relationship with development pressure on land by human activities which are one of the principal causes of desertification. The table below shows the population in drylands by each continent and as a percentage of the global population of the continent. It reveals a high ratio especially in Africa and Asia.
There is a vicious circle by which when many people live in the dryland areas, they put pressure on vulnerable land by their agricultural practices and through their daily activities, and as a result, they cause further land degradation.
*Includes New Zealand and neighboring islands Source: Aridity zones and dryland populations: an assessment of population levels in the world's drylands with particular reference to Africa(UNDP/UNSO, 1997)