Hydroclimate variability was the main control on fire activity in northern Africa over the last 50,000 years

North Africa features some of the most frequently burnt biomes on Earth, including semi-arid grasslands Sahel and wetter savannas immediately to south. Natural fires are fuelled by rapid biomass production during wet season, its desiccation dry season ignition frequent lightning strikes. Today, fire activity decreases markedly both north Sahel, where rainfall is extremely low, almost eliminating over Sahara, south forest too burn. Over last glacial cycle, vegetation cover northern varied dramatically in response gradual astronomically-forced insolation change, changes atmospheric carbon dioxide levels, abrupt cooling events Atlantic Ocean associated with reorganisation Meridional Overturning Circulation (MOC). Here we report results a study into impact these climate African 50,000 years (50 kyr). Our reconstructions come from marine sediments strong age control that provide an uninterrupted record charcoal particles exported continent. We studied three sites latitudinal transect along northwest margin between 21 9°N. exhibit distinct relationship past activity. At southernmost site (GeoB9528-3, 9°N), decreased intervals increasing humidity, while our northernmost (ODP Site 658, 21°N) clearly demonstrates opposite relationship. The middle transect, offshore present day southern today (GeoB9508-5, 15°N), exhibits “Goldilocks” hydroclimate, wherein fluxes peak under intermediate conditions supressed transition more arid or humid conditions. remarkably consistent predictions fire-productivity hypothesis developed conceptual macroecological models supported empirical evidence modern Feedback processes operating fire, undoubtedly complex but temperature suggested be main driver temporal change globally, precipitation-evaporation balance perhaps secondary influence Holocene tropics. However, there only sparse coverage composite records upon which those interpretations based. conclude hydroclimate (not temperature) exerted dominant burning tropics well before (from at least 50 ka).