Desertification in the Sahara

1999/10/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena

It has long been said that the Sahara was not at all a desert, among other things because fossil pollen has been discovered. Researchers at the Potsdam-Institut fuer Klimafolgenforschung have used the CLIMBER-2 model to conclude that desertification in the Sahara began 5,440 years ago (+/- 30 years).

The change seems to be quite violent, divided on two occasions. The first, the sweetest, between 6,700 and 5,500 years, and the second, the hardest, between 4,000 and 3,600 years, with a strong increase in summer temperature and a decrease in precipitation. The change was initiated by the change of the Earth's orbit and the change of the axis tilt, which was then 24.14 degrees and now 23.45 degrees.