When the Sahara was Green
By: Christian Jimenez/Arab America Contributing Writer
When people think of the Sahara, they usually think of an arid desert region that is bone-dry and lifeless due to the lack of rainfall and inescapable heat. However, this was not always the case as the Sahara of 10,000 years ago was once covered in water and grasslands, making North Africa green.
The Current Climate of the Sahara
Photo: Wikipedia
In the modern age, when people think of North Africa, they usually think of the great Sahara Desert, which covers around 3.6 million square miles or 9.4 million square kilometers. This massive size can only be appreciated when looking at the globe, as it easily dominates the upper third of the African continent, engulfing around eleven countries stretching from Morocco in the west to Egypt in the east and as far south as the Sahel countries of Chad, Sudan, Niger, Mauritania, and Mali. Interestingly enough, most of these 9.4 million square kilometers aren’t covered in the region’s iconic sand dunes as most people believe, as this environment covers only around 15 percent of the total land area. In fact, most of the Sahara is actually covered in a variety of landscapes such as mountains, plateaus, salt flats, basins, and depressions.
However, despite this variety of geographical features, the Sahara is still a rather inhospitable place to live due to its amount of rainfall as it only reaches around 3 inches or less in a given year, with some areas receiving no rainfall for years on end. This lack of rainfall means that the only dense areas of settlement in the Sahara Desert are where there are permanent sources of water such as oases, aquifers, rivers, and lakes. The importance of these permanent sources of water can be seen in the Nile River where it flows north toward Egypt, helping to support around 100 million people.
However, the influence of the Sahara still affects Egyptians due to the Nile being surrounded by this desert, forcing 95 percent of Egypt’s population to live on only 7.7 percent of the country’s territory, as the Egyptians are relegated to mostly living on the banks of the Nile or in the Nile Delta. In places without these permanent water sources, populations are very scarce and are inhabited by somewhat nomadic peoples such as the Bedouins and the Berbers. In fact, there are only around 2.5 million inhabitants in the Sahara, which is less than one person per square kilometer. This is in comparison to the United States, which despite being around the same size as the Sahara, contains up to 92.9 people per square kilometer, showing just how inhospitable it is for life in North Africa. In addition to this, the Sahara’s lifeless conditions are expanding south due to factors such as climate change and desertification, which could be caused by overgrazing and unsustainable agricultural practices. Scientists have recorded this expansion of the Sahara to be around 10 percent since the year 1920. However, the Sahara was not always this inhospitable and expanding desert, as the region once had a grassland-type ecosystem not too long ago.
The Sahara’s Green Past
As recently as 6,000 years ago, there was no desert to speak of as the region was dominated by vast grasslands containing large inland bodies of water, such as an enlarged Lake Chad. The reason for the Sahara not being anywhere near as arid as it is today was because of the wobbling in the tilt of Earth’s orbital axis. This change in Earth’s tilt caused changes in the angle of solar radiation, allowing more solar energy to hit the atmosphere during the West African monsoon season, which in turn caused more precipitation in North Africa. This change in precipitation is a phenomenon that has occurred at countless intervals in Earth’s history and is called the African Humid Periods, with the next cycle of more rainfall occurring 10,000 years from now. However, during the most recent African Humid Period, there was the growth of flora such as grasses, which in turn attracted herbivores and carnivores south of the Sahara. This means that the Sahara of the past probably didn’t look that much different from today’s Sub-Saharan Africa’s grassland environments.
This wetter environment would have also made it possible for the habitation of human hunter-gatherer groups, who left signs of their habitation through their cave paintings that they left throughout the region, mostly in countries such as Algeria, Libya, and Niger. These cave paintings would contain animals common in the African savannahs, such as hippos, crocodiles, giraffes, elephants, etc. In addition to this, when looking at these rock paintings archeologists discovered and classified distinct time periods of Saharan rock art with the time period of 12,000 to 6,000 years ago being called the Large Wild Fauna period.
This is in contrast with the later painting periods of the Pastoral, Horse, and Camel periods as it would show paintings of livestock rather than wild animals around 7,200 to 1,000 years ago. The difference in the content of the paintings around 7,000 to 6,000 years ago shows that the large animals that dominated the Sahara were beginning to disappear as the Sahara began to dry, and the people living there would have to rely on pastoralism. The reason for this drying event has been the continuing wobbling in Earth’s tilt, causing the African monsoons to go back south towards West Africa, which caused desertification in the region. This process was further accelerated by the dying of plants, which used to add moisture into the atmosphere due to transpiration. The desertification of the Sahara was, therefore a rather rapid event causing many people to flee the encroaching desert by either fleeing south towards Sub-Saharan Africa, north towards the Mediterranean, or towards permanent sources of water such as the Nile.
Conclusion
Desertification is one of the major events of African history as many people fled the approaching sands of the ever expanding Sahara, a phenomenon that is still occurring today. However, the end of the last African humid period has also helped other regions such as Egypt, which increased its population, and with the advent of agriculture were able to become one of the first civilizations in the world. I also believe that in the future with more green policies such as more sustainable practices we can stop the encroaching Sahara, and hopefully allow our descendants to enjoy the next time the Shara becomes green in another 10,000 years time.
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