[أسلمت لله 5]

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وهذه الويكيديا الذى يثق به الملاحدة تقول أن الصحراء كانت أرض خضراء قبل الآف السنين .

http://en.wikipedia.org/wiki/Sahara

People lived on the edge of the desert thousands of years ago[5] since the last ice age. The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles [6] survive, with half found in the Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs, including Afrovenator, Jobaria and Ouranosaurus, have also been found here.


The climate of the Sahara has undergone enormous variation between wet and dry over the last few hundred thousand years.[13] During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[14] The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps because of low pressure areas over the collapsing ice sheets to the north.[15]

Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara though, the drying trend was soon counteracted by the monsoon, which brought rain further north than it does today. The monsoon season is caused by heating of air over the land during summer. The hot air rises and pulls in cool, wet air from the ocean, which causes rain. Thus, though it seems counterintuitive, the Sahara was wetter when it received more insolation in the summer. This was caused by a stronger tilt in Earth's axis of orbit than today, and perihelion occurred at the end of July around 7000 BC.[16]


وهذه اشارة الى عودة الصحراء تريجيا إلى الإخضرار .

Recent signals indicate that the Sahara and surrounding regions are greening because of increased rainfall. Satellite imaging shows extensive regreening of the Sahel between 1982 and 2002, and in both Eastern and Western Sahara a more than 20-year-long trend of increased grazing areas and flourishing trees and shrubs has been observed by climate scientist Stefan Krِpelin.[21]


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