Desertification can leave communities without food, water, fuel-wood and with poor livestock (© UN Photo)
Every minute an area of land the size of a football pitch is lost to degradation through desertification and drought.
It is estimated that around one third of the world’s surface could now be suffering the consequences of desertification – affecting around 1.5 billion people globally and ruining 24 billion tonnes of fertile soil each year.
However, studies show that as much as two billion hectares of degraded land and forest globally has the potential for restoration.
As RTCC marks Desertification Week – highlighting this important issue – we examine what desertification is and what techniques could be used to combat it.
What is desertification?
Defining desertification can be complex – with over 100 different definitions existing within scientific literature.
Many people believe the phase was first coined by French scientist Andre Aubréville in 1949. He used the term to describe the human-induced degradation that transformed the African savannah into desert.
Later definitions have shifted between human and natural causes and the term has been used to describe both the process and the end result.
On its formation the United Nations Convention to Combat Desertification (UNCCD) defined desertification as “land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities”.
This definition leaves it open for people to argue that the process is both a natural phenomenon and one exacerbated by human activities.
What causes it?
Unsustainable land-use is one major cause of desertification. This includes issues of over-cultivation, over-grazing, deforestation and poor irrigation practices.
Over-cultivation of land removes the soil’s nutrients, poor irrigation practices flood the land and raise the soil’s salt content and over-grazing leads to soil erosion.
Migration and mining are other human activities that cause land to be damaged.
With increases in population, more houses are built, more animals needed and more trees are uprooted worsening the problems.
What does it have to do with climate change?
Natural occurrences including drought and climatic change also contribute towards desertification. Climate change could exacerbate desertification through alteration of spatial and temporal patterns in temperature, rainfall, solar radiation and winds.
Hotter and drier conditions from climate change could extend the area prone to desertification northwards to areas not currently at risk. In addition, the rate of desertification could increase due to increased erosion, salinisation and fire hazards and reductions in soil quality.
Soil erosion can contribute to sand storms sometimes thousands of kilometres away (© Expom2uk/Creative Commons)
Where in the world does it occur?
Desertification occurs on all continents across the world except for Antarctica.
A large majority of dryland population live in the developing world, where desertification can have the hardest impacts due to populations already suffering from poverty. The situation is said to be worst in the drylands of Asia and Africa.
What are the impacts of desertification?
More than 2 billion people in developing nations occupying dryland areas are said to suffer from desertification.
Desertification can lead to the loss of biological or economic productivity of croplands, pastures and woodlands.
This can limit communities’ access to vital resources including food, water, fuel-wood, and livestock.
Loss of vegetation can also increase the formation of large dust clouds that can cause health problems in densely populated areas – sometimes thousands of kilometres away.
Desertification heightens the effects of climate crises from drought to flash flooding – as water is less able to be absorbed into the soil.
At its most extreme desertification can lead to and exacerbate social crises including conflict and can drive migration away from desertified land. For example many experts estimate that some 60 million people could be forced to move in areas of sub-Saharan Africa by 2020 due to desertification if current trends persist.
Can desertification be combated and how?
Most people agree that desertification is irreversible. This is due to the extremely expensive nature of techniques used to reverse desertification which has already occurred.
For this reason, much of the discussion on combating desertification is based on prevention rather than rehabilitation of land.
There are several land management techniques which help to halt deforestation (© geographyalltheway.com/Creative Commons)
The main techniques used to prevent desertification involve sustainable land-management and effective policy approaches – with large interventions needed at both local and global levels.
These interventions must promote alternative livelihoods and conservation techniques to protect drylands as desertification is beginning or ongoing – for example more sustainable agricultural and grazing practices.
Once land is desertified some measures can help to rehabilitate the land and restore lost ecosystem services.
Restoration methods could include establishing seed banks, restocking of soil organic matter and organisms, the reintroduction of selected species, installing counter erosion measures including terracing, controlling invasive species, chemical and organic nutrient replenishment and reforestation.
For more on Desertification Week:
- UNCCD’s Chief Luc Gnacadja calls for world leaders to show ambition on desertification at Rio+20.
- Why is desertification such an important issue?