Desertification occurs when the soil of an arid area is drained of its organic substance due to various factors, including human activities such as intensive livestock farming.
Important notes on desertification
- Sustainable land management, for example through the reforestation of degraded land, can help to avoid, reduce or even reverse desertification;
- The difference between desertification and land degradation is purely geographical. Land degradation can occur anywhere in the world. When it occurs in arid areas, it is considered as desertification;
- Despite the strong assonance that suggests a simple spelling mistake, desertification and desertification are two distinct processes. The latter consists of the expansion of the line of pre-existing deserts.
Deforestation, unsustainable agricultural practices and overgrazing are among the major direct causes of desertification. These practices drive soil erosion, put pressure on water resources and result in the loss of biodiversity. Consequently, the soil loses much of its stable organic substance, hummus, and becomes less solid, less able to capture light and heat, to nourish the microorganisms it usually harbours, and to provide plants with a range of metals important for their growth. Desertified soil is virtually dead soil.
On a different note, there is a complex relationship between desertification and climate change. The two processes, both individually and in combination, impact the health of ecosystems and biodiversity. This results in ecosystems failing to perform such important functions as production of food and drinking water, climate and tidal regulation, pollination and pest control. As ecosystems are depleted, vital educational, cultural and recreational values are also lost.
On the one hand, human-caused climate change, particularly through increased air temperature at the soil surface, evapotranspiration and decreased precipitation, has probably played a role in desertification in some arid areas. On the other hand, desertification exacerbates climate change through the effects of shrinking vegetation cover, greenhouse gas fluxes and often a reduction in the albedo effect, i.e. the ability of a surface to reflect solar radiation back into the atmosphere. A reduction in the albedo effect fuels a vicious cycle of rising temperatures, thus worsening the ongoing disruption of the climate.