CTET 2 Social and Science Jan 2021 Paper

The Sahara desert is known for its undulating sand dunes, unforgiving Sun, and oppressive heat. But just 10,000 years ago, it was lush green plain region. Humans played a big role for this shift from woodland to wasteland. A new study suggests as humans spread West from the Nile river 8,000 years ago, they brought with them sheep, cows, and goats that overgrazed on the native vegetation.
This transformed the landscape and altered the local climate. This overgrazing led to drought. Drought stunted the growth vegetation, which further transformed the landscape, which worsened the drought, and eventually produced a hot, dry, dusty Sahara desert. Many cave paintings are found in the Sahara desert, which are found in mountains of Ennedi in Chad in the heart of Sahara desert.
These cave paintings are an important source to know more about how Sahara desert was in the past.