Close
Did pastoralism hold back desertification of the Sahara?
8 October 2018
Nature Communications report of 香港六合彩中特网 Geography study
During the African humid period (AHP), before the desertification of the Sahara, evidence points to human population expansion in northern Africa and the introduction of pastoralism.
A new paper in聽Nature Communications聽by 香港六合彩中特网 Geography鈥檚 Dr Chris Brierley and Professor Mark Maslin, with Dr Katie Manning of King鈥檚 College, London, examines the possible role of this population growth in the subsequent ecological collapse.
A聽model is developed to predict the effects of orbital forcing during the Holocene on climate-vegetation feedback聽and the drying of the Sahara. It is concluded that the natural end of the AHP should have been around 6,000 years ago, about 500 years聽earlier聽than suggested by reconstructions of聽actual聽climate change. So why the difference in timing?
While it has been suggested that increases in Saharan pastoralism around 6000 years ago accelerated desertification,聽a beneficial relationship is actually indicated聽by evidence for how pastoralists interact with the environment. It seems that the Saharan population did the right things to combat desertification at a most sensitive time - increasing pastoralism became an effective adaptation to environmental change. The system, therefore, stayed 'green' for longer.
Such a process exemplifies how humans can live sustainably with the Earth System聽and shows how efforts such as the聽World Initiative on Sustainable Pastoralism聽offer real promise in holding back aridification, rather than simply assuming the inevitability of climate changes.