Early warning signals of the termination of the African Humid Period(s)

Martin H Trauth; Asfawossen Asrat; Markus L Fischer; Peter O Hopcroft; Verena Foerster; Stefanie Kaboth-Bahr; Karin Kindermann; Henry F Lamb; Norbert Marwan; Mark A Maslin; Frank Schaebitz; Paul J Valdes

doi:10.1038/s41467-024-47921-1

Early warning signals of the termination of the African Humid Period(s)

Nat Commun. 2024 May 7;15(1):3697. doi: 10.1038/s41467-024-47921-1.

Authors

Martin H Trauth¹, Asfawossen Asrat^{2

3}, Markus L Fischer⁴, Peter O Hopcroft⁵, Verena Foerster⁶, Stefanie Kaboth-Bahr⁷, Karin Kindermann⁸, Henry F Lamb^{9

10}, Norbert Marwan¹¹, Mark A Maslin¹², Frank Schaebitz⁶, Paul J Valdes¹³

Affiliations

¹ University of Potsdam, Institute of Geosciences, Potsdam, Germany. [email protected].
² Botswana University of Science and Technology, Department of Mining and Geological Engineering, Palapye, Botswana.
³ Addis Ababa University, School of Earth Sciences, Addis Ababa, Ethiopia.
⁴ University of Potsdam, Institute of Geosciences, Potsdam, Germany.
⁵ University of Birmingham, School of Geography, Earth & Environmental Sciences, Birmingham, United Kingdom.
⁶ University of Cologne, Institute of Geography Education, Cologne, Germany.
⁷ Freie Universität Berlin, Institute of Geological Sciences, Berlin, Germany.
⁸ University of Cologne, Institute of Prehistoric Archaeology, Cologne, Germany.
⁹ Aberystwyth University, Department of Geography and Earth Sciences, Aberystwyth, UK.
¹⁰ Trinity College Dublin, Botany Department, School of Natural Sciences, Dublin, Ireland.
¹¹ Potsdam Institute for Climate Impact Research, Member of the Leibniz Association, Potsdam, Germany.
¹² University College London, Geography Department, London, UK.
¹³ University of Bristol, Bristol Research Initiative for the Dynamic Global Environment, School of Geographical Sciences, Bristol, UK.

Abstract

The transition from a humid green Sahara to today's hyperarid conditions in northern Africa ~5.5 thousand years ago shows the dramatic environmental change to which human societies were exposed and had to adapt to. In this work, we show that in the 620,000-year environmental record from the Chew Bahir basin in the southern Ethiopian Rift, with its decadal resolution, this one thousand year long transition is particularly well documented, along with 20-80 year long droughts, recurring every ~160 years, as possible early warnings. Together with events of extreme wetness at the end of the transition, these droughts form a pronounced climate "flickering", which can be simulated in climate models and is also present in earlier climate transitions in the Chew Bahir environmental record, indicating that transitions with flickering are characteristic of this region.

Abstract

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