Blackwater lakes and rivers in the Congo Basin are releasing carbon up to 3,500 years old into the atmosphere, according to a study by the Swiss Federal Institute of Technology Zurich (ETH Zurich). Previously, scientists believed this carbon was stored in the surrounding peatlands. The research contradicts the assumption that old peat carbon remains trapped underground, suggesting that some tropical peatlandlands could potentially become major carbon sources. The study also revealed that microbes in the region are breaking down peat into pe2, which then seeps into the Earth's atmosphere. The findings were published in the journal journal, journal Science.