The peatlands, which span the Democratic Republic of Congo and the Republic of Congo, are the largest in the tropics and cover 17m hectares (42m acres). They store a vast amount of carbon – the equivalent of three years of global fossil fuel emissions. They are also threatened by logging and oil and gas exploitation.
“We know today that these peatlands are very close to that tipping point where they could release billions of tonnes of carbon to the atmosphere,” said Prof Simon Lewis, from the University of Leeds, UK, and University College London, and a senior author of the study. “We don’t know exactly how close but we do know that for the last couple of decades, droughts have been getting longer in the centre of the Congo basin.