Desertification

Desertification is when fertile land slowly turns into desert. This happens because of both natural processes and things people do. The main reason is the loss of plants that help keep the soil in place.

When plants disappear, the soil can be blown away by wind or washed away by rain. This leaves behind dry, hard land that cannot grow food. Places where this happens often have poor communities that struggle to grow enough food.

Areas most affected by desertification are in Africa, like the Sahel region, parts of Asia such as the Gobi Desert and Mongolia, and some parts of South America. Drylands cover about 40–41% of Earth's land and are home to more than 2 billion people. This process can cause sand and dust storms, make food harder to get, and increase poverty.

We can help fight desertification by improving soil quality, planting trees, managing how animals eat the land, and making deserts greener again. The study of desertification grew out of a big drought in the Sahel during the 1980s.

Definitions

Desertification is the slow process where soil becomes drier and less able to support plants. It happens in dry areas because of both natural changes and things people do. One main cause is when people cut down too many trees, farm in ways that harm the land, or when there are long periods without rain.

Many people have tried to define desertification in different ways. A common way to describe it is when fertile land turns into desert because of things like cutting down forests, drought, or bad farming practices. This shows how human actions and natural events work together to damage the land.

Causes

See also: Deforestation § Causes

The main reason deserts form is when plants and trees disappear from land. Without plants, the soil can blow away in the wind or wash away in heavy rain. This leaves the ground dry and hard, making it hard for new plants to grow.

People can speed up this process in several ways. Farming, raising animals, and cutting down trees for wood all take away plants that protect the soil. Climate changes, like long dry periods, can also make deserts grow. Scientists believe that both natural changes in the Earth's climate and human actions together cause deserts to spread. For example, in some places, human actions are the bigger cause, while in others, natural weather patterns play a larger role. As the world gets warmer, dry areas are likely to become drier and turn into deserts faster. This affects many people, especially in areas where resources are already limited.

Effects

Dust and sand storms are becoming more common because of desertification. When the land turns to desert, there is more loose sand and dust for the wind to pick up, creating storms. These storms can make people sick, damage water supplies, and stop transportation. They can also change the climate in ways that make desertification worse.

Desertification is also making it harder to grow enough food. As the world’s population grows, we need more food, but desertification is reducing the amount of good land available for farming. This can lead to conflicts between people who depend on the land for their living. It also pushes people to move from rural areas to cities, often leading to poverty and crowded living conditions. Many dryland areas, especially in developing countries, are struggling because the land can no longer support their communities.

Geographic areas affected

Drylands cover about 40–41% of Earth's land and are home to more than 2 billion people. Experts think that around 10–20% of these dry areas have already become less fertile. This means that between 6 and 12 million square kilometers of land is affected by desertification. About 1–6% of people living in drylands live in areas that have turned into desert.

The Sahel region in Africa shows how climate change and human actions lead to desertification. This area has a dry, hot climate with little rain—only 100 to 600 mm each year. Because of this, droughts are common. Over the past 50 years, the Sahel has lost about 650,000 km² of farmland.

In the Gobi Desert area, which spans Northern China and Southern Mongolia, desertification is happening very fast. Each year, over 3,600 square kilometers of grassland turns into desert. In Mongolia, about 90% of the grassland is at risk. Most of this is caused by people, like overgrazing with animals and cutting down trees. Warmer temperatures and less rain make the problem worse.

South America is also at risk. About 25% of its land is dry, and much of it has lost its fertility because of deforestation and overgrazing. In countries like Bolivia, Chile, Ecuador, and Peru, 27 to 43% of the land is at risk. In Argentina, Mexico, and Paraguay, more than half of the land can no longer be used for farming. In Central America and parts of Mexico, desertification has led to unemployment, less food, and people having to move to new places.

Reversing desertification

See also: Deforestation § Control

There are ways to help stop and even fix desertification. Some of these ways need help from leaders and money, while others just need people to make smart choices.

One big challenge is that using good farming methods can cost more than it helps individual farmers, even though it’s good for everyone and the environment. Another problem is that sometimes leaders don’t make enough effort or have enough money to support projects that bring back damaged land.

Improving soil quality

Main article: Soil regeneration

We can help poor soil by giving it water and making it richer. One way to protect soil is by planting rows of trees and bushes called windbreaks. These block wind and keep soil from blowing away.

Some soils, like clay, can become hard without enough water. Special ways of digging, like making small trenches along the land, help water stay in and protect the soil. Plants like certain types of beans and trees can also make soil healthier by adding important nutrients.

Desert greening

Main article: Desert greening

See also: Afforestation

Different deserts need different ways to bring them back to life. In some very dry places, like the Rub' al Khali desert in Saudi Arabia, we can grow crops using seawater without needing fresh water.

A successful method called Farmer-managed natural regeneration has helped bring back trees and land in Niger. This simple method lets local trees grow by carefully cutting back unwanted plants. This not only helps the soil but also gives more space for crops to grow.

China has created a huge “green wall” to fight desert spread. This big project has planted billions of trees, which has helped reduce desert land and sandstorms. Because of this success, similar plans are being made in Africa to help stop the Sahara desert from growing.

Better managed grazing

Restoring grasslands can help store carbon from the air. One way to manage grazing is by using fences to move animals from one small area to another often. This lets the grass grow better. Some believe this can even help with carbon in the soil, but others say it doesn’t fix desertification.

Agrivoltaics

Researchers in China found that putting solar panels over crops in dry areas can help the land. The panels give shade, block wind, and help keep soil moist, which is good for plants. This method is being tested on a large scale to help fight desertification.

History

Further information: Historic desertification

The world's most famous deserts formed slowly over time through natural processes. For much of history, these deserts grew and shrank without any help from humans. Some old deserts, now quiet and covered in plants, stretch even beyond where deserts are today, like the huge Sahara.

We have clues from the past showing that serious land damage happened many centuries ago in dry areas, especially around the Mediterranean, the Mesopotamian Valley, and the Loess Plateau in China, where many people lived.

The first known talk about this topic started not long after the French colonization of West Africa. Researchers were asked to study how the Sahara Desert might have grown long ago. Today, people began studying desertification more closely during the tough 1980s drought in the Sahel.