Transcript Desertification, climate change and sustainable development

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.
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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
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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.
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Climate graphs showing typical variations in annual
temperature and precipitation in tropical, temperate
and polar deserts
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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
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The causes of desertification
 Farming on land with unsuitable terrain or
soils
 Soil compaction by farm machinery and
cattle hoofs
 Wind factor
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The consequences of
desertification
 Worsening drought

Famine

Declining living standards
 Swelling numbers of environmental
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refugees
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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.
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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
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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
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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.
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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.
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