Humans delayed the onset of the Sahara desert by 500 years

Humans did not accelerate the decline of the 'Green Sahara' and may have managed to hold back the onset of the Sahara desert by around 500 years, according to new research led by UCL. The study by a team of geographers and archaeologists from UCL and King's College London, published , suggests that early pastoralists in North Africa combined detailed knowledge of the environment with newly domesticated species to deal with the long-term drying trend. It is thought that early pastoralists in North Africa developed intricate ways to efficiently manage sparse vegetation and relatively dry and low fertility soils. Dr Chris Brierley (UCL Geography), lead author, said: "The possibility that humans could have had a stabilising influence on the environment has significant implications. We contest the common narrative that past human-environment interactions must always be one of over-exploitation and degradation.  "The fact that societies practising 'pastoralism' persisted in this region for so long and invested both economically and ideologically in the local landscape, does not support the scenario of over-exploitation. Our study shows that increasing human population and sustainable pastoralism did not accelerate - and may even have delayed - the decline of the 'Green Sahara'." Around 8,000 years ago, the Sahara wasn't desert, but instead was a vibrant ecosystem that supported hunter-gatherers and fisherfolk. The 'Green Sahara' -   the colloquial term for the African Humid Period - was the period in which North Africa became much wetter than it is today thanks to a series of monsoons.