The climate of the Sahara has altered climate during the prehistoric times:

• In the oasis of Bilma (Niger), there were craters with saline deposits, which are the remains of seas that covered the Sahara 100 million years ago
• 40 000 years ago, there were large lakes in the Sahara, populated semi-nomadic people
• 18 000 years ago, the Sahara was lush with jungle and vegetation
• Around 12,000 years before our time, its south-eastern boundary was close to the Tropic of Cancer
• Around 10,500 years before our time, the desert surface was less than half the current
• The further change in climate of this eco-region is continued to be changed around 8,500 years before our time. The Sahara was wet and covered steppe and savannah.
• Although the warming was rapidly increasing, the Sahara was still wet to 6,500 years before our time
• The Sahara became arid, 3000 years ago. Before that, it was grassland and had rich fauna.