- Hamet Fall Diagne
- BBC Africa
Image Credit, Jorge Fernandez
Desertification is defined by the United Nations Convention to Combat Desertification (UNCCD) as “land degradation in arid, semi – arid and arid sub-humid areas due to various factors, including climatic variations and human activities.”
Soil degradation is again defined as the reduction or disappearance of the soil’s biological or economic productivity.
“The poorest countries are always the most vulnerable to drought,” said Ibrahima Thiaw, UN Under-Secretary-General and Executive Secretary of the UN Convention to Combat Desertification, at the opening ceremony of COP15 in Abidjan last month.
According to the organizers of the Fifteenth Conference of the Parties (COP15) to the UN Convention to Combat Desertification, 41% of the earth is globally endangered, and for Africa this rate reaches around 45%.
On the continent, the Sahel region, the Kalahari Desert and the Horn of Africa are the areas with the strongest dynamics of desertification due to frequent droughts and soil erosion.
Elsewhere in the world, China and Australia are also affected by this phenomenon.
What are the causes of desertification?
They are due to several factors related to extreme climatic variation or human activity. Accentuated by global warming, a consequence of greenhouse gas emissions associated with human activity, humans are indirectly responsible for it. We can quote:
Population growth: the population of some desert areas is increasing. The places where mining and tourism grow, people are attracted to the jobs. An increasing population puts greater pressure on the environment for resources such as wood and water.
Harvesting of wood: in developing countries, many families still use wood for cooking. The increase in the population in desert areas leads to an increased need for firewood. When the soil is cleared of forest, the roots of the trees no longer hold the soil together, which is therefore more vulnerable to erosion.
Overgrazing : the increase in population leads to the exploitation of larger desert areas. Sheep, cattle and goats graze the vegetation. The soil is then exposed to erosion.
Soil erosion: it is exacerbated by overgrazing and deforestation. Population growth is the primary cause of soil erosion. However, there is also water erosion because water flowing on the surface, under the influence of rain, can cause a displacement of the materials that make up the soil;
Soil acidity: Excess nitrogen released to soil using fertilizer creates acidic soils that damage plant growth.
Climate change: the global climate is getting warmer. In desert areas, conditions are not only warmer but also drier. On average, it rains less today in the desert areas than 50 years ago.
Image Credit, Getty pictures
An illustration photo shows desertification in Ouahigouya, Burkina Faso.
What are the consequences of desertification?
They go beyond the environmental framework to influence the socio-economic domain.
When we talk about soil degradation, Ibrahima Thiaw points out that ” our recent research has revealed that one in two people in the world is affected by the loss of soil productivity. Up to 40% of the earth’s surface experiences some form of soil degradation. ”
“Economic risks are serious, up to half of global GDP could be affected in the long run,” he concludes.
He also mentions among the consequences of the loss of fertile land the intensification of migration and the increase in poverty as well as social unrest and insecurity.
Soil degradation also promotes disease and famine.
Particularly affected by the desertification of agriculture caused by the absence of fallow in the crop cycle, the African population often migrates south in search of fertile land.
According to the UN, 50 million people worldwide could be displaced over the next 10 years due to desertification.
Environmentally, soil degradation emits carbon, exacerbates climate change and loss of biodiversity.
However, this process of desertification in the world is not irreversible according to Ibrahima Thiaw.
” Land degradation is not inevitable. Repair is possible. Each unit of money invested in land reclamation can generate up to 30 times its value. Worldwide, up to 50 points of GDP can be achieved by 2050. ”
Image Credit, Madalin Olariu
Amina J. Mohammed, UN Under-Secretary-General and Chair of the UN Group on Sustainable Development, believes that ” we must immediately revise our food production system, which is responsible for 80% of deforestation and 70% of water needs.
Some measures can help reduce desertification:
Water management : for example, dams can help store water during the rainy season. This water can then be used during the dry season for irrigation.
Promote green energies (solar, wind and biogas) to replace wood fuel;
Plant more trees : tree roots hold the soil together and help reduce soil erosion by wind and rain.
Improve soil quality : We can achieve this by fighting deforestation and overgrazing. Set-aside of soil and the use of organic manure or compost to fertilize crops should be encouraged.
The use of sand fences, lip belts, forest areas and windbreaks can also prevent soil erosion.
However, involving local people and educating them on the facts of climate change and desertification remains one of the most sustainable strategies to hope, in the long run, to fight soil degradation effectively.