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Desertification, climate change and sustainable development Introduction • Desertification is a creeping global problem Deserts cover about 30 % of the earth’s land, and situated mainly between tropical and subtropical regions north and south of the equator, at about 30 north and 30 south latitude. Furthermore, determining which changes are natural and which are human caused is difficult because little is known about the long-term natural dynamics of arid lands. 5/24/2017 2 Topics of Discussion • The causes of desertification and the consequences of desertification • The measures combating the world desertification • Desertification and global climate change • Desertification and sustainable development • Legal aspects for combating desertification 5/24/2017 3 5/24/2017 4 Definitions and classifications • A desert is an area where evaporation exceeds precipitation. Precipitation is typically less than 25 centimeters a year and is often scattered unevenly throughout a year The classification of deserts based on the level of rainfall combined with different average temperatures. There are tropical, temperate and cold deserts. 5/24/2017 5 Climate graphs showing typical variations in annual temperature and precipitation in tropical, temperate and polar deserts 5/24/2017 6 The causes of desertification Overgrazing on fragile arid and semiarid rangelands Deforestation without reforestation Surface mining without land reclamation Irrigation techniques that lead to increased erosion Salt buildup and waterlogged soil 5/24/2017 7 The causes of desertification Farming on land with unsuitable terrain or soils Soil compaction by farm machinery and cattle hoofs Wind factor 5/24/2017 8 The consequences of desertification Worsening drought Famine Declining living standards Swelling numbers of environmental 5/24/2017 refugees 9 The measures combating the world desertification • Each world region has its own unique mix of activities to combat the desertification. Some areas are subject to deforestation or salt buildup due to irrigation, while others suffer from exploitative cropping that depletes soil fertility and aggravates erosion, or from overuse of the land by grazing animals. There is a spectrum of problem evaluations and proposed solutions. 5/24/2017 10 The most effective ways to combat desertification Drastically reduce overgrazing Reducing deforestation and increasing reforestation Reduce the destructive forms of planting, irrigation and mining Rationale land use Restoring soil fertility by planting trees and grasses with anchor the soil and hold water 5/24/2017 11 Desertification and global climate change • Climate change could worsen the effects of desertification. According to the United Nations Framework Convention on Climate Change (FCCC), "countries with arid and semi-arid areas or areas liable to floods, drought and desertification ... are particularly vulnerable to the adverse effects of climate change 5/24/2017 12 Desertification and sustainable development Land degradation affects the quantity and quality of freshwater supplies. Drought and desertification are associated with lower water levels in rivers, lakes, and aquifers. For example, unsustainable irrigation practices can dry the rivers that feed large lakes; the Aral Sea and Lake Chad. 5/24/2017 13 Legal aspects for combating desertification • The Convention to Combat Desertification was formulated in 1992. This convention has been ratified by more than 60 countries. Along the way, however, the term desertification has been critiqued as being geographically limited. 5/24/2017 14