A farming technique practised for centuries by villagers in West Africa, which converts nutrient-poor rainforest soil into fertile farmland, could be the answer to mitigating climate change and revolutionising farming across Africa. A global study by researchers has for the first-time identified and analysed rich fertile soils found in Liberia and Ghana. They discovered that the ancient West African method of adding charcoal and kitchen waste to highly weathered, nutrient poor tropical soils can transform the land into enduringly fertile, carbon-rich black soils which the researchers dub ‘ African Dark Earths ’. Similar soils created by Amazonian people in pre-Columbian eras have recently been discovered in South America — but the techniques people used to create these soils are unknown. Moreover, the activities which led to the creation of these anthropogenic soils were largely disrupted after the European conquest. Encouragingly researchers in the West Africa study were able to live within communities as they created their fertile soils. This enabled them to learn the techniques used by the women from the indigenous communities who disposed of ash, bones and other organic waste to create the African Dark Earths.