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Desertification ~. What is desertification?. "Desertification" is the process whereby productive land becomes so seriously eroded that any remaining soil loses nutrients essential to plant growth. The natural causes are manifold: drought, higher temperatures, lower water tables, and
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What is desertification? • "Desertification" is the process whereby productive land becomes so seriously eroded that any remaining soil loses nutrients essential to plant growth. • The natural causes are manifold: drought, • higher temperatures, • lower water tables, and • deforested land. • Erosion — especially wind erosion — does the rest. Swaziland: soil erosion causes ravines.(IDRC Photo: N. McKee)
The role humans play: • Human activity can play a considerable role in degrading land. For various reasons, including poverty and over-population, people are driven to- • destroy forest belts, • practice poor irrigation, and • use inappropriate agricultural methods such as slash and burn, shorter fallow periods, and soil nutrient mining. • Mexico: a farmer uses the slash and burn technique to clear a field.(IDRC Photo: P. Bennett)
The effects of desertification: • Wind erosion is suspected of contributing to the formation of more frequent and more intense hurricanes in the eastern Atlantic Ocean, the stress on the world’s food-producing capacity, air pollution, a global loss of biodiversity, and, of course, massive suffering for those robbed of their means of survival. • China: dune stabilization. The plants’ roots slow the movement of the sand. (IDRC Photo: D. Anton)
A growing problem: • Land degradation is increasing at an alarming rate. • UNEP estimates that – • 250 million people are directly affected by land degradation in dryland regions, and • more than one billion are at risk. • Drylands covers up to 40% of the Earth’s surface. • More than 110 countries are potentially at risk. • Egypt: a farmer in an arid field.(IDRC Photo: P. Bennett)
Drylands: • While drylands may conjure up images of unproductive land, the reality is quite the opposite. • Drylands are, in fact, a vital source of biological diversity. Medicines, resins, waxes, oils, and other commercial products originate in dryland species. In fact, these species supply one-third of all the plant-derived drugs in the US. • Kenya: farmer in cornfield.(IDRC Photo: P. Bennett)
Food grains: • Many of the world’s most important food grains — including wheat, barley, millet, and sorghum — originated in the drylands. • Wildlife, including large mammals and migratory birds, depend on drylands for their habitat. • Mali: woman winnowing grain.(IDRC Photo: P. St-Jacques)
The cost of desertification: • While the United Nations estimates that desertification costs US$42 billion a year, the annual cost to prevent land degradation is estimated at only US$2.4 billion, according to the UN. • The human cost is probably not only much higher, but is also impossible to estimate. Burkina Faso: dry, degraded soil.(IDRC Photo: S. Colvey)
Some consequences of desertification: • Desertification exacerbates poverty and political instability; • Entire communities suffer from water scarcity and famine; • Children (especially girls) cannot attend school because they're forced to walk long distances to get firewood; • Millions of people are displaced from their homes, creating severe pressures in the places in which they re-settle; • "Environmental refugees" endure extremely difficult living conditions, suffer a loss of cultural identity, and experience an undermining of their social stability; • Conflicts between neighbouring countries, even armed conflict, can result.
