What caused the deforestation in Central Africa between 2,500 and 2,000 years ago? According to recent publication, the farming Bantu peoples caused the large-scale clearing opening the way to the savannah. But researchers form the Institut de Recherche pour le Developpment (IRD), together with experts from France, Belgium, Germany, UK, Australia, US, Cameroon e Gabon contest this argument in Science magazine.

The fragmentation of the Central African forest was caused by a drastic climate change. Ancient deforestation was caused by a period a phase of general desiccation that spread from the equatorial region to the edges of the Sahel.

It was only 500 years later, around 2,000 years ago, that Bantu colonization became widespread. The first Bantu, arrived in the earlier centuries, merely took advantage of the fragmentation of the forest to penetrate these areas and start planting crops.

The first  Bantu started settling around 4,000 years ago. It was a semi-nomadic neolithic civilization, practicing pottery and stone polishing. , and cleared small parts of the forest fringe for. They did the slash-and-burn farming, but there were few of them to really impact the forests. They just learnt to use iron when the major forest fragmentation was already ongoing, 2,500 years ago.

Most of Bantu settlements in the Congo Basin, according to radiocarbon dates established on pottery, stone or iron tools, started 2,000 years ago, and its peak is estimated between 1,900 and 1,600 years ago, when the forest were re-expanding, according to the paleo-environmental studies.
 
In the Holocene, forest cover was much wider than today. Then, around 4,000 years ago, they started to make place for savannah. 2,500 years ago, a second disturbance impacted on Central African forests, caused by storm rainfalls and a shortened wet season. The erosion stripped many ancient soils and the sediments were carried away by the Congo River to the sea. These submarine deposits are rich in aluminum and potassium and this led to the theory of the large-scale clearing by Bantu settlers as  an explanation for deforestation in Central Africa.

If it is true that currently, human activities have a devastating impact on the natural forests, 2,500 years ago Bantu settlement was very smal and the available tolls were insufficent to cause large-scale clearing in the Congo Basin. Scientist think therefore that the massive deforestation can be explained with a major change in the climate of the sub-region.