Astronomically controlled aridity in the Sahara since at least 11 million years ago

The Sahara is the largest hot desert on Earth. Yet timing of its inception and response to climatic forcing debated, leading uncertainty over causes consequences regional aridity. Here we present detailed records terrestrial inputs from Africa North Atlantic deep-sea sediments, documenting a long sustained history astronomically paced oscillations between humid arid 11 million years ago. We show that intervals strong dust emissions heart continent predate both intensification Northern Hemisphere glaciation oldest land-based evidence for Saharan by millions years. find no simple long-term gradational transition towards an increasingly climate state in northern Africa, suggesting aridity was not primary driver gradual Neogene expansion African savannah C4 grasslands. Instead, insolation-driven wet–dry shifts were common past Myr, identify three distinct stages sensitivity this relationship. Our data provide context evolutionary outcomes Africa; example, fossil hominid bipedalism at least 4 Myr. Pulses have been entering since Ma, result cycles conditions according terrigenous input record ocean core off west Africa.