Desertification

Overview

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Desertification is a natural or human induced process in which fertile land becomes desert. The resulting loss of plant life leads to a decrease in overall bio productivity.[1] Barren soil becomes more susceptible to erosion and more vulnerable to evaporation and higher temperatures. The cause of this process is most often attributed to anthropogenic climate change, but a multitude of factors influence desertification. [2] Rapid desertification is expected to have drastic environmental, economic and political consequences.

Figure 1. Human Induced Desertification

Causes

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Desertification is most attributable to human activity and climate change. According to scientists, poorly managed livestock herds has led to overgrazing of grasslands. In addition, the expansion of agriculture and deforestation have decreased overall natural vegetation. In turn, loss of vegetation has led to a host of problems resulting in the degradation of land. The change from fully grassed lands to scattered shrubbery leaves land bare and susceptible to erosion. Unprotected soil surfaces are also prone to salinization by evaporation and water logging. [3] Nutrients are washed away, fauna dies from lack of nutrients or washes away as well. Scientists have identified several driving forces behind desertification. It is contended that a combination of multiple factors are at play. [2] Leading causes include:

• Agricultural activities
  

  Figure 2: Leading causes of desertification
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• Infrastructure extension
• Wood extraction and related activities
• Increased aridity
• Demographic factors
• Economic factors
• Technological factors
• Climatic factors
• Policy and institutional factors
• Cultural factors

Consequences

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Large scale effects on agriculture are expected, most predominately in nations already afflicted by poverty. Agricultural production will drop significantly, as there will no longer be fertile land to support crops. In addition to declines in crop production, vegetation loss affects grazing livestock. Changes in landscape are also predicted to bare significant declines in tourism. A myriad of negative impacts are expected, but none more forbearing than feeding a growing population with diminishing returns. [3]

Prevention and Reversal

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There are many techniques for the prevention and reversal of desertification. Many of these methods rely heavily on the availability and usage of water. Some look to reforestation as a means of re-greening deserts. Studies have indicated that extended wet periods can reverse historical environmental regimes. [4]

One of the most controversial proposals comes from Allan Savory, founder of the Savory Institute. Savory proposes a holistic approach to reversing desertification, relying on, not avoiding, livestock to re-green. Savory theorizes that through proper management, agriculture can be employed in a way to mimic nature and farmers can use sustainable farming to prevent further degradation.

References

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