报告题目: |
全球变化科学紫荆论坛(第253期): Pastoralism delayed the collapse of the Green Sahara |
报告人: |
Dr Chris Brierley |
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UCL Dept. of Geography, University College London
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报告时间: |
2018-06-26 09:30 |
报告地点: |
清华地学系蒙民伟科技大楼南楼S808 |
主办单位: |
地球系统科学系 |
简介: |
During the early Holocene, northern Africa was relatively humid and supported a large human population. Around 5,500 years ago (5.5 ka) the regional climate deteriorated and the population declined substantially. Evidence suggests these changes were coeval, but it is unclear whether or not humans influenced this ecological collapse. Using a climate-vegetation model driven by global forcings, we forecast the length of the Holocene African Humid Period (AHP). The model indicates that the system was most likely to collapse between 7-6 ka, which is at least 500 years before the observed collapse. Archaeological and ethnographic evidence from northern Africa, suggests that the shift from hunter-gatherer to pastoralist societies around 7 ka was an effective adaptation to the orbitally-driven regional environmental changes. |
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