Desertification is one of the greatest environmental challenges we currently face. But what exactly is desertification? And what can we do about it? Read on to find out everything you need to know.
What is desertification?
The UN’s official definition of desertification is as follows: “Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities”.
So to summarise, desertification is when previously fertile land turns into infertile desert. As a result the soil becomes unable to support crops, livestock and wildlife.
A few desertification facts and stats
- A third of the Earth’s soil is severely degraded and fertile soil is being lost at a rate of 24 billion tonnes per year.
- Land degradation negatively affects over 3.2 billion people worldwide – that’s two fifths of the world’s population.
- One in three crops grown today is grown in dryland regions at risk of desertification.
What causes desertification?
There are a number of different factors that can lead to desertification. They are often inextricable from each other and work together to degrade the land.
A lack of vegetation
Trees, plants and their roots help to hold soil together. When an area doesn’t have this kind of vegetation, the soil is more prone to erosion. Wind and rain can blow and wash away the rock and soil more easily.
Droughts, deforestation and livestock farming have all led to a decrease in land vegetation.
Poor farming methods
Overgrazing – when farmers allow sheep, cattle and goats to deplete the vegetation – leads to soil erosion. We can also blame poor irrigation methods for land degradation and decreasing soil quality.
As the Earth’s temperature rises, desert regions are becoming hotter and drier. There’s less rain. And areas are experiencing an increased number of extreme weather events.
Droughts cause plants and trees to die. Flash floods can also wash away the top layer of soil. Coastal storm surges can salinate the land, making it less fertile.
Population growth contributes to all of the problems listed above. When there are more people in a region, greater demands are placed on its natural resources.
Farmers keep more livestock. They overuse the land, failing to allow adequate fallow periods or overusing fertilizers. Deforestation also increases. Particularly in the developing world, wood is regularly used as fuel for cooking.
What problems does desertification cause?
When previously fertile land turns into desert there are far-reaching consequences for both people and the planet.
When arable land becomes infertile, more trees are chopped down in an effort to find land on which to grow crops.
Desertification creates a kind of snowball effect. The less land available to humans, the more we’ll exploit it. This puts the natural world and wildlife at an even greater risk.
Human health and social effects
Desertification causes increased levels of migration. Populations move to find land that can provide the food and water they need. Conflict over land also increases.
When it comes to health effects, dusty desert air can cause respiratory diseases. Malnutrition will also become a more common problem as our food security comes under threat.
As land becomes less fertile, farmers make less money from farming. This leads to poverty. It will also affect world economies. US$42 billion is already lost every year because of desertification and land degradation.
Where is desertification happening?
One hundred and ten countries are at risk of land degradation. But it tends to be developing countries that are affected most badly.
The following regions provide just a few examples. Desertification is one of the most pressing environmental problems of our time, with Antarctica the only continent currently unaffected.
Desertification in Africa and the Sahara
The Sahel region in Africa is one of the worst affected places on Earth. It sits between the Sahara Desert and more southerly savannas and has experienced many devastating droughts.
As the population has grown, the region has also seen an increase in deforestation, illegal farming and land cleared for housing.
In 2014, the UN announced that 20million people in the Sahel were suffering from hunger and needed $2 billion in food aid due to desertification.
Desertification in Asia
When salt is present in water sources – and when that water is then used to irrigate crops – salt levels build in the soil. It reaches a point where the land turns into a saline desert.
This has been happening in Asia, specifically in Iraq, which has lost over 70% of its irrigated land because of salt accumulation.
Russia is facing similar problems. Experts think that irrigated land at the Volga River delta may only be usable until 2050, when salts will finally turn it into a desert.
Desertification in southern Europe
Southern European countries are also at risk of desertification, with Spain at the top of the list.
A study has shown that 74% of Spain is at risk of desertification. The regions of Murcia, Valencia and the Canary Islands – which comprise 18% of the country – are at high risk of irreversible land degradation.
Desertification is a serious problem. So what can we do to reverse the negative effects of land degradation? And how can we prevent the problem getting any worse?
There are a number of initiatives in operation. And they’re based around the following aims.
Improve farming practices
Experts believe that controlling grazing and rotating crops could help preserve soil quality and prevent soil erosion.
Giving less arable land over to livestock and instead using that land to grow crops is also more sustainable. Crop roots help to hold the soil together and reduce erosion.
Better irrigation practices are also important. Storing water in earth dams in the wet season, using stone circles that help to reduce water run-off, and drip irrigation techniques are also being used to reduce land degradation.
NGOs are working in developing countries to give the resources and knowledge that can help farmers to make these changes.
Repair degraded land
Restoring some natural vegetation and planting drought resistant shrubs is another way to reverse some of the effects of desertification.
The Great Green Initiative in the Sahel and Sahara aims to restore 100 million hectares of degraded land. A wall of trees, stretching from Senegal to Djibouti will help to prevent the desert from expanding any further.
The African Union came up with the idea in 2007 but currently, halfway through the project, only 4% of land has been planted. Progress has varied from country to country and it seems there is still a long way to go.
The battle against desertification is ongoing. One thing’s for sure. If we want to ensure our food supply and maximise the land available to humanity, nature and wildlife, reducing and reversing desertification has to be one of our top priorities.