The Sahara is already the largest hot desert in the world, covering most of North Africa. Yet it isn’t staying the same size—it’s still expanding. Scientists say the Sahara has grown by about 10% in the past century, and the reasons are both natural and human.
One cause is climate change. Rising global temperatures mean more heat and less rainfall in the region. Without enough rain, plants and grasses die, leaving bare soil that quickly turns to desert sand. Winds then carry this sand further, spreading the desert.
Another cause is human activity. In many areas, people cut down trees for firewood or overgraze land with livestock. Without plants to hold the soil together, the land becomes dry and eroded. Slowly, fertile farmland turns into barren desert—a process called desertification.
The Sahara’s expansion has real effects on people. Farmers in countries like Niger, Chad, and Sudan struggle to grow crops, and entire villages sometimes move in search of better land. International projects now focus on planting millions of trees in Africa’s “Great Green Wall,” a huge effort to stop the desert from swallowing more land.
The Sahara may look endless, but its edges are constantly changing. It’s a reminder of how fragile our environment is—and how human choices and global climate shape even the biggest landscapes on Earth.
Bigger than the entire United States
Covering about 9 million sqkm, the Sahara is larger than the whole USA, including Alaska.
Sandstorms can cross the Atlantic
Dust from the Sahara travels thousands of kilometres, even fertilising soils in the Amazon rainforest.
The desert hides dinosaur fossils
Palaeontologists have found fossils of giant dinosaurs and crocodiles buried under the Sahara’s sands.