- The UN Decade for Deserts and the fight against Desertification: Impact and role of drylands
The UN Decade for Deserts and the fight against Desertification: Impact and role of drylands
When land degradation happens in the world's drylands, it often creates desert-like conditions. Drylands are home to more than 2.1 billion people (2005 Millennium Ecosystem Assessment); for every three people, one calls drylands home, and growth rates in these areas are faster than in any other ecological zone.
Drylands meet the basic needs of a significant proportion of the world, but are under threat. They harbor some of the world's most valuable and rarest biodiversity. They are major contributors to the world's breadbasket, considering that one in every three crops under cultivation today has its origins in the drylands. They are valuable indigenous food vaults because the wild ancestors and relatives of these plants still grow there. Drylands support 50% of the world's livestock, are wildlife habitats and account for nearly half of all cultivated systems (2005 Millennium Ecosystem Assessment).
Drivers of land degradation
There is no linear cause-effect process that leads to land degradation in the drylands, but its drivers, which interact in complex ways, are known. They change over time and vary by location. The direct drivers are climatic, especially low soil moisture, rainfall patterns and evaporation. The indirect drivers are mostly human derived, and include poverty, technology used, global and local market trends and sociopolitical dynamics. Poverty is both a cause and consequence of land degradation.
Food Security – World's Breadbasket at Risk
Drylands take up 41.3% of the land surface, and up to 44% of all the world's cultivated systems are in drylands. These lands have been largely used as rangelands, which are habitats for wildlife and currently support 50% of the world’s livestock. Sadly, these lands are increasingly being converted into cropland (2005 Millennium Ecosystem Assessment).
Poverty – Few Comforts in Life
The livelihoods of nearly 1 billion of the poorest and most marginalized people, who live in the most vulnerable areas, are threatened by desertification. The Millennium Assessment found that the well-being of dryland peoples is lower than that of people in other ecological systems. Infant mortality rates are highest and gross national product (GNP) per capita is lowest.
Water scarcity affects between 1-2 billion people, most of whom live in drylands. Under the climate change scenario, nearly half of the world's population in 2030 will be living in areas of high water stress. In some arid and semi-arid areas, it will displace up to between 24 million and 700 million people (2009 World Water Development Report, Water in a Changing World).
Drylands play a vital role in local, but also global climate regulation. These regions store approximately 46% of the global carbon share (2005 Millennium Ecosystem Assessment).
Natural regeneration of vegetation cover and soils in arid areas takes 5-10 times longer than in favorable areas with greater and more regular rainfall. Between 1983 and 2003, approximately 16% of the land improved, of which 20% is cropland and 43% rangeland (2010 GEF-STAP, Report of the Scientific and Technical Advisory Panel to the Fourth GEF Assembly).
Sustainable Land Management – a Solution
Applying sustainable land management (SLM) practices helps to combat desertification and recover and rehabilitate land. SLM can be used to rehabilitate degraded drylands to store carbon from the atmosphere in order to achieve land degradation neutrality (LDN).