The largest desert on
Earth stretching from the Atlantic Ocean to the Red Sea on the
African continent. Countries which lie within the Sahara Desert are
Morocco,
Algeria,
Tunisia,
Libya,
Egypt,
Mauritania,
Mali,
Niger,
Chad, and
Sudan. The
Nile River and the
Niger River cross through it.
Scientists believe that 4,000 years ago the Sahara region had a much wetter climate with a
savanna environment. The tilting of the Earth's
axis caused an abrupt change in
climate and
vegetation (such as more sunlight and an amplified
monsoon season) causing the
desertification of the Sahara region.