Around the World
The Sahara Desert is massive — but it wasn't always a desert. What caused it to transform from a lush, green landscape into the arid expanse it is today, roughly 5,000 years ago?
A
A massive volcanic eruption that blocked sunlight
B
A gradual shift in Earth's orbital tilt that reduced monsoon rainfall
C
Overfarming by ancient civilizations
D
A meteor impact near the Atlas Mountains
E
The drying of the Mediterranean Sea
