What is desertification and why is it important to understand?

This article has been updated.

When we think of deserts, regions such as the Middle East, Northern Africa or Central Asia may spring to mind. Yet desertification doesn’t just refer to deserts but the persistent degradation of dryland ecosystems due to factors including climate change and human activities.

It is a global issue with worldwide implications for biodiversity, socio-economic stability and sustainable development that could displace some 50 million people within the next 10 years, according to the United Nations (UN).

This year could prove to be pivotal in addressing the issue. Under the theme of Restoring Land, Restoring Hope, the 17th session of the Conference of the Parties (COP17) to the United Nations Convention to Combat Desertification (UNCCD) will be hosted in Mongolia in late August. On the agenda: forging solutions to the combined effects of land degradation, desertification and drought – estimated to cost the global economy $878 billion annually.

So what are some of the impacts of desertification on our planet and people – and how can we mitigate against it?

Desertification is a type of land degradation in which an already relatively dry land area becomes increasingly arid, degrading productive soil and losing its bodies of water, biodiversity and vegetation cover.

It is driven by a combination of factors, including climate change, deforestation, overgrazing and unsustainable agricultural practices.

The issue reaches far beyond deserts like the Sahara, Kalahari or Gobi. Three-quarters of Earth’s land became permanently drier in the past three decades. The UNCCD says that the equivalent of four football fields of healthy and productive land becomes degraded every second, with about 1 million km² becoming degraded every year. Droughts are becoming more frequent and more severe, and they are expected to affect three-quarters of people by 2050.

Currently, more than 2 billion people live in drylands, which are most prone to desertification, according to Earth.org. This number is projected to double by 2100.

Africa is the most affected region, with two-thirds of the continent being desert or drylands. In regions such as the Sahel – a belt of semi-arid savannah that’s home to 400 million people and stretches from Senegal, Niger, Mali and Chad to Sudan – desertification is rapidly spreading. Currently, more than 80% of the land in the region is degraded.

Central Asia’s drylands are among the most rapidly degrading and climate-vulnerable areas worldwide, according to the World Bank. China is also severely affected by desertification, especially in the north, northeast and northwest.

While some areas across China and Central Asia have long been classed as having a desert climate, desertification has continued, leading to hotter, wetter climates. In the mountains, a lack of snow has led to the gradual disappearance of glaciers, threatening water security that affects both people and agriculture.

COP17 host Mongolia, meanwhile, is also among the countries most affected by desertification, with 77% of its land already degraded.

But the issue affects many other regions. Over 30% of the land in the United States is affected by desertification, and a quarter of Latin America and the Caribbean is deserts and drylands.

In Europe, about 12% of EU territory is affected, with Spain, Cyprus and Greece among those having the highest percentage of land under diversification conditions. The EU has flagged more than 1 million km² as being at “elevated risk” of desertification – with many of these areas being outside the region currently considered as drylands.

According to the UNCCD, around 500 million people live in desertified areas. They can experience exacerbated poverty, lack of food security and poor health due to malnutrition and lack of access to clean water. They are also more vulnerable to climate change and extreme weather such as droughts and natural disasters. With their livelihoods at stake and a greater risk of conflict over declining resources, they may also face forced migration.

One of the most prominent examples of desertification is the Aralkum desert in central Asia. In the 1960s, the area was covered by the fourth-largest lake in the world, the Aral Sea. Since then, it has shrunk to a tenth of its former size, with only three small, highly salty lakes remaining. In Soviet times, its waters were used for irrigating a semi-desert region to grow cotton, leading to a drop in water levels. Climate change added further impetus to this over time, turning the dry seabed into a salt-covered desert, leaving fishing boats stranded, rusting and livelihoods destroyed.

There are a wide variety of approaches to address desertification, with many programmes underway around the globe.

Regions from China to Saudi Arabia and the EU are all stepping up action on the issue.

And worldwide, specific interventions are seeing success. Reforestation and afforestation, for example, is helping to revive degraded soil. In Uzbekistan, a regreening programme has planted trees and shrubs across one million hectares along the Aral desert. This includes the black saxual shrub, which is highly drought-resistant and can fix salt and sand, stopping it from being swept up and carried inland by sandstorms.

In the Sahel and Sahara region in Africa, the “Great Green Wall” – launched in 2007 by the African Union – aims to restore plant life across 100 million hectares of degraded land. Involving 22 African countries, this initiative will revive the land, store more than 250 million tonnes of carbon and create 10 million jobs by 2030.

Another big part of tackling land degradation is introducing sustainable land management practices, ranging from agroforestry to sustainable grazing - which can also improve crop yields and livelihoods.

Water management practices such as rainwater harvesting, drip-water irrigation and planting drought-resistant crops can address the impact of water scarcity. Other remedial steps include re-vegetation and restoring natural habitats such as wetlands or entire river beds.

With biodiversity loss and ecosystem collapse considered by the World Economic Forum's Global Risks Perception Survey the second-most pressing risk over the coming decade, it's vital the private sector plays its part in tackling desertification. The Forum and UNCCD have introduced a tool - the Land Degradation Neutrality: Strategic Intelligence Map - designed to guide businesses in evaluating risks and opportunities related to ecosystems.

This resource empowers corporations to align their operations with global land restoration goals, while mitigating supply chain risks and accelerating biodiversity protection.