Using data and models to infer climate and environmental changes during the Little Ice Age in tropical West Africa

Abstract. Here we present hydrological and vegetation paleo-data extracted from 28 sites in West Africa 5? S to 19? N the past1000/PMIP4 IPSL-CM6A-LR climate model simulations covering 850–1850 CE period document environmental climatic changes that occurred during Little Ice Age (LIA). The comparison between shows a clear contrast area spanning Sahel savannah north, characterized by widespread drought, equatorial south, where humid conditions prevailed. Particular attention was paid Sahel, whose evolution progressive drying trend 1250 1850 CE. Three major features are highlighted: (1) detection of two early warning signals around 1170 1240 preceding onset LIA trend; (2) tipping point at 1800–1850 rainfall drop an degradation Sahel; (3) succession events punctuating LIA, one which dated 1600 long-term is associated with gradual southward displacement Inter-Tropical Convergence Zone induced radiative cooling impacts volcanic eruptions have punctuated last millennium.