Desertification: an introduction

Desertification threatens our food supply, environment, income – and even lives. We break down the meaning, causes and impacts of this urgent problem, and introduce five promising solutions.

 

What is desertification?

In short, desertification is the process of land losing its greenness in dry areas of the world.

The land becomes less able to provide a home for nature, and less able to support crops. Patches and stretches of bare soil emerge where plants once grew. This may occur gradually, or suddenly after a major disturbance, such as a wildfire.

You’ll often see the following, more formal, definition of desertification. This provides a useful starting point for understanding more about what’s going on here:

It comes from the United Nations Convention to Combat Desertification (UNCCD) (an international agreement that helps countries manage land degradation and drought).

But what does it actually mean? This blog breaks it down for you.

 

What is land degradation?

‘Degradation’ might seem a loose term, but that’s because it covers a broad set of changes that can contribute to desertification. These include:

• The soil retaining less water for plants
• The soil storing less carbon and fewer nutrients
• The soil becoming saltier and less suitable for many crops
• The soil becoming hard and difficult to plough
• The soil erodes and becomes blown or washed away more easily

In sum, degradation refers to a decline in the health of soils that reduces the value of land for humans and nature.

 

What are the impacts of desertification?

Desertification carries major health, socio-economic and environmental risks. These include:

• Health: desertification can lead to dust storms and floods that threaten human lives and cause ill health.
• Food insecurity: desertification makes it much harder for farmers to grow crops and graze livestock, which adds to uncertainty about food supply.
• Water scarcity: more water may simply run off the land, reducing the water available to crops or the amount of water seeping into natural underground stores.
• Poverty: the loss of livestock and reduced crop yields can lead to the loss of livelihoods and contribute to wider economic losses for the affected region or country.
• Biodiversity loss: desertification lowers the variety of plants and can create space for invasive species to move in and cause further harm to local biodiversity. In turn, animals that rely on the plants, such as pollinating insects and grazing mammals, suffer.
• Increased wildfires: desertification increases the chances of wildfires in some areas, adding to health issues, livelihood losses, contamination of water resources and damage to transport infrastructures.
• Displacement and migration: in extreme conditions, the loss of livelihoods may contribute to people’s decisions to move away from affected areas.
• Energy and transport: dust storms and flooding can also damage energy infrastructure, such as wind and solar farms, and transport infrastructure, including railway lines – disrupting daily life and businesses.

 

Where is desertification happening?

It occurs in the arid, semi-arid and dry sub-humid areas of UNCCD’s definition, and which are collectively known as drylands.

While land degradation can occur anywhere in the world, typically it is only classed as desertification if it is in drylands.

Drylands, as the name suggests, receive relatively little rain or snow each year. Their soils are typically drier than in other regions. Around 40% of the Earth’s land area is drylands, and most are in Africa and Asia.

You also find drylands in southern Europe, where they cover a third of land area. Affected countries include Cyprus, Italy, Romania and Spain.

Research suggests that less than 10% of drylands is undergoing desertification – but the problem affects around 20% of people who live in dryland regions.

Scientists are still unsure of the exact extent and severity of desertification, however. This is because it is a complex process that strongly depends on local conditions and because reliable data is often lacking.

Available evidence nonetheless highlights the growing urgency of desertification, especially as extreme weather events, such as prolonged droughts and intense storms, increase in number and size under climate change.

 

 

 

What are the main causes of desertification?

Desertification is caused by multiple interacting factors. The exact mix of factors varies strongly by location, adding to its complexity

But what do they include? Let’s first think back to the climatic variations in UNCDD’s definition.

Climate change is rapidly exacerbating desertification and its risks to society and the environment. Factors include:

• Warmer land surfaces that cause more water to evaporate from the soil.
• Reduced rainfall and longer droughts that dry out the soil.
• Torrential rainfall that erodes soil.
• Wildfires that consume plants and impact soil health.

Meanwhile, human activities that also contribute to desertification include:

• Deforestation. Logging and wood extraction decreases soil protection, disturbs soil structure and disrupts water, carbon and nutrient cycles, increasing erosion and other risks.
• Over-cultivation: Intensive farming, and especially frequent soil mobilisation, a lack of crop rotations and an over-reliance on agrochemicals, decreases soil health.
• Over-irrigation: Feeding crops with large volumes of poor quality water can lead to soil becoming too salty (‘salinisation’).
• Overgrazing. Excessive grazing by livestock strips the land of plants and nutrients.

 

 

Can you prevent desertification?

Yes. In many cases, we have solutions to prevent, slow down, and even reverse desertification.

These range from traditional measures, such as adding compost to soil, to high-tech innovations, like digital soil sensors for moisture that help farmers water their crops efficiently.

Given the huge variation in the nature, causes and contexts of desertification, however, no one-size-fits-all solution exists. A suite of solutions will typically be needed that addresses the specific problems at a local, national and global level.

At the local level, land managers have many options for improving the quality of soil and managing water effectively.

The problem, however, is that we don’t have a clear understanding of how effective or economically feasible many of these measures are beyond specific locations or contexts, or over longer timescales. This means that landowners can’t always tell if a measure is right for them. Further, policymakers don’t always know which measures to promote more widely.

This is where TERRASAFE comes in.

 

How does TERRASAFE plan to combat desertification?

TERRASAFE is our ambitious 5-year international research project that began in June 2024. We bring together:

• scientists from many disciplines
• local communities (including landowners and local authorities) in five desertification-prone regions of southern Europe and north Africa
• five businesses that produce innovative solutions to desertification

Our collective goal? To help answer: what works to combat desertification where and why?

We will compare the impacts of five innovative measures (see our diagram below) and traditional/organic practices against current practices in the face of four different threats:

1. soil degradation due to soil organic matter loss
2. soil degradation due to salinisation
3. water scarcity for irrigation
4. forest decline

TERRASAFE’s mission is to empower the communities and the businesses with our insights.

We will share our findings and approach with you, to help other communities across the world combat desertification too – and support livelihoods, health and nature for generations to come.

 

 

Keen to know more?

Accompany us on our research journey – as we discover how land managers can arm themselves against desertification.

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