Human-caused climate change worsened floods that have killed hundreds of people and displaced millions in Cameroon, Chad, Niger, Nigeria and Sudan this year, according to a study published on Wednesday.

The intense rainy season has unleashed a humanitarian crisis across large areas of the Sahel region bordering the Sahara desert.

A new analysis by the World Weather Attribution (WWA) network of scientists found warming driven by the use of fossil fuels had exacerbated the flooding in Sudan.