Like Rome was not built in a day, Sahara, the great desert of the world, was not turned desert in a day. The once green Sahara turned to desert over thousands of years rather than in an abrupt shift as believed earlier. As per the extensive studies, it appears that Sahara turned into desert slowly & steadily due to the increasing global warming. The study of ancient pollen, spores and aquatic organisms, give ample of indication of confirmation of this theory.
The findings about one of the biggest environmental shifts of the past 1,000 years, challenge past beliefs based on the evidence in marine sediments that a far quicker change created the world’s biggest hot desert. The hypothesis of a sudden shift may be astonishing but it is well taken up by the researchers working in this field.
The scientists studying in the remote Lake of Yoa, found the region had once had grassy & scattered acacia trees, ferns and herbs. The salty lake is renewed by groundwater welling up from beneath the desert. A gradual drying due to shift I monsoon rains linked to shift in the power of sun meant large amounts of dust started blowing in the region about four thousand years ago which gave birth the desert.
The great desert- Sahara, now covers up an area similar to size of the United States. This theory of understanding on scientific basis regarding the formation of the Sahara may help climate modelers to improve the forecasts of what is in store from global warming. Apart from that the abrupt conversion of desert theory may rest aside only to understand that it took thousands of years to become a desert due to our own negligence.