Executive summary by darmansjah
A desert roughly the size of the United States
SAND TO SAND
Sandstone spires reach through Saharan dunes in Chad’s Karnasai Valley. Wind and storms are gradually eroding the rock formations and returning them to sand.
A Tuareg strides across the windblown sands of Tassillin-Ajjer, a plateau in southeast Algeria. Eroded
NORTH AFRICA It is the iconic desert, The Sahara is the largest hot desert in the world, covering 3.3 million square miles (8.6 million sq km) of North Africa. Towering golden sand dunes roll aross its midsection. Summer temperatures routinely soar above 120ᵒF (49ᵒC). The environment was not always so hostile. For several thousand years, from about 8500 B.C. to 5300 B.C., a wetter climate supported savannahs, acacia forests, and even swamps. Giraffes, hippos, and elephants flourished. When drier conditions returned, most of the animals and people moved out. Now, the reverse may be occurring. A more humid climate, possibly the result of global climate change, is bringing greenery back to the fringes.