Desertification is the process of land losing its greenness in dry areas of the world. A formal definition of desertification is ‘Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.’

The United Nations Convention to Combat Desertification (UNCCD) provides The following formal definition of desertification:

Desertification

Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.

Land degradation 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

Desertification can cause major health, socio-economic and environmental problems. 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.

Desertification is caused by multiple interacting factors. The exact mix of factors varies strongly by location.

Climate change is a strong factor that is rapidly exacerbating desertification and its risks to society and the environment.

Unsustainable land management also contributes to desertification. Examples include:  deforestation, over-cultivation, over-irrigation of farmland, Overgrazing by livestock. 

Rural depopulation can also lead to desertification. In areas that have been traditionally maintained by farming communities, abandonment causes the land to deteriorate.

Climate change’s impacts can contribute to desertification in a number of ways, including:

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

Unsustainable management of the land by humans can contribute to desertification. Examples 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.

lDesertification occurs in arid, semi-arid and dry sub-humid areas of the world, 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 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.

Desertification also occurs in Europe, in the drylands of the south. Affected countries include Cyprus, Italy, Romania and Spain.

Desertification risks are accelerating in Europe. According to a European Court of Auditors report (2018), an estimated 14% of land in southern, central and eastern Europe was highly vulnerable to desertification. Less than a decade later – in 2017 – the figure was 25%. This represents an increase of 177 000 km² – an area equivalent to the size of Greece and Slovakia combined.

The TERRASAFE research project is investigating how to combat desertification in vulnerable regions of southern Europe and Tunisia.

Yes. There are many 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.

The TERRASAFE research project is investigating a range of solutions to desertification in southern Europe and Tunisia. These are: a wood-based gel, soil sensors, a biochar-compost mix, compost, artificial soils, and social innovations to revive depopulated rural communities and economies of southern Europe.