Human Activities May Have Formed The Desertification Of Sahara, A New Study Claims
Sahara was then a fertile and grassy landscape 10,000 years ago. A new study indicates that its transformation into a world's largest arid desert was due to human activities.
The findings of the study were published in Frontiers in Earth Science. The study was led by archaeologist Dr. David Wright from Seoul National University.
In the previous studies, they indicated that the desertification of Sahara was due to changes in the Earth's orbit or natural changes in vegetation. On the other hand, this conclusion was not confirmed by some researchers.
Dr. Wright explained that in East Asia, there are long accepted theories of how Neolithic populations changed the landscape so greatly that the monsoons ceased accessing the inland. He theorized that human-driven ecological and climate change has formed the Sahara Desert. He noted the evidence of these causes was documented in North America, Europe and New Zealand, according to Phys.org.
In the study, Dr. Wright discovered the first appearances of pastoralism in the Saharan region. He compared this with records indicating the expansion of scrub vegetation. This suggests an ecological change towards desert-like conditions. He found that way back 8,000 years ago, the pastoral communities began spreading westward in the regions near the Nile River. It also had an increase in scrub vegetation.
Pastoralism involves raising livestock such as goats, camels, yaks, cattle, sheep and llamas. It is a successful approach to sustaining a population on less productive land and could adjust well to the environment. The herds mostly are in search of green and clean pasture as well as water.
However, pastoralism influences the ecology. Once the vegetation diminished by the growing livestock, the albedo, which is the amount of sunlight that contemplates the surface of the Earth, was heightened.This has the effect of the atmospheric conditions that lessen the monsoon rainfall. It triggered desertification as well as loss of vegetation that ultimately swept over the whole of Sahara.
Meanwhile, Dr. Wright put emphasis on the significance of this study. He said that the innuendos for how humans change ecological systems have a direct influence on whether humans will be able to survive indefinitely in arid environments.