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A satellite image of the Sahara, the world's largest hot desert and third largest desert after Antarctica and the Arctic. Desert greening is the process of afforestation or revegetation of deserts for ecological restoration (biodiversity), sustainable farming and forestry, but also for reclamation of natural water systems and other ecological systems that support life.
The modern, arid Sahara. The Sahara was not a desert during the African humid period. Instead, most of northern Africa was covered by grass, trees, and lakes. The African humid period (AHP; also known by other names) was a climate period in Africa during the late Pleistocene and Holocene geologic epochs, when northern Africa was wetter than today.
The Sahara (/ s ə ˈ h ɑːr ə /, / s ə ˈ h ær ə /) is a desert spanning across North Africa.With an area of 9,200,000 square kilometres (3,600,000 sq mi), it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.
Climate scientists used models to show historic intervals of a green, vegetated Sahara Desert that occur every 21,000 years. The Sahara Desert—Yes, That One—Remarkably Grows Green Every 21,000 ...
Satellite images released by NASA show pockets of plant life popping up all over the Sahara Desert after an extratropical cyclone drenched a large swath of northwestern Africa on Sept. 7 and Sept. 8.
As with the subsequent Mousterian Pluvial (c. 50,000 to 30,000 years ago), the Abbassia Pluvial brought wet and fertile conditions to what is now the Sahara Desert, which bloomed with lush vegetation fed by lakes, swamps, and river systems, many of which later disappeared in the drier climate that followed the pluvial.
The precession of the equinoxes is regarded as the most important orbital parameter in the formation of the "green Sahara" and "desert Sahara" cycle. A January 2019 MIT paper in Science Advances shows a cycle from wet to dry approximately every 20,000 years.
In 15,000 BP, the West African Monsoon transformed the landscape of Africa and began the Green Sahara period; greater rainfall during the summer season resulted in the growth of humid conditions (e.g., lakes, wetlands) and the savanna (e.g., grassland, shrubland) in North Africa. [2] Between 5500 BP and 4000 BP, the Green Sahara period ended. [2]