Currently, the developing and relatively underdeveloped countries are also vigorously developing their economy, and the emerging economies have become an important force to drive the recovery of global economy. As the developing countries, particularly those located in arid and semi-arid regions such as Africa and China, haven’t yet broken away from the extensive development mode in which they have to win economic growth by enormously consuming various resources including land, the hazardous degree of land degradation and its control difficulty are increased.
(II) Land degradation control faces new challenges due to many factors such as human activities and climatic change
Climatic change has been the severest environmental problem and the most complicated global challenge so far. According to the fourth scientific assessment report issued by the United Nations Intergovernmental Panel on Climate Change (IPCC), the earth’s climate is undergoing some significant changes mainly characterized by global warming, precipitation pattern change and frequent extreme climate events. The average temperature of global surface increased by 0.74℃ and will increase by 1.1~6.4 ℃ in 2100 in estimation. Climate change accelerates global land degradation, particularly such frequent extreme climate events as continuous drought, flood and storm lead to more vulnerable ecosystem and significantly declined land productivity. In addition, drought does not only appear in some new regions, but also causes those regions easily vulnerable to drought to suffer more frequent and worse land degradation.
Due to the impact of climate change and the superimposition effect produced by artificially damaged forest, overgrazing, blind reclamation and unreasonable land use, the whole world, especially the arid and semi-arid regions, is facing a severer challenge to combat land degradation. According to the figures announced by the United Nations Environment Programme (UNEP), excessive human activities and climate change have led to serious land degradation in arid regions covering 41% of the global area. Currently, more than 110 countries and over 1 billion people in the world are being threatened by land desertification, and 135 million people may face the danger to become homeless. This indicates that the global land degradation control is confronting new and serverer challenges in the context of climate change, human disturbances and other influencing factors.