A vast peatland in the Congo Basin has been mapped for the first time. But if climate change or human activity dries out the peatland, huge amounts of carbon dioxide would be released into the atmosphere.
Scientists have discovered the world’s largest tropical peatland in the Congo Basin. The Cuvette Centrale peatlands cover close to 150,000 square metres, an area larger than England. The discovery is significant because the peatlands lock in 30 billion tonnes of carbon, making the region one of the most carbon-rich ecosystems on Earth.
The discovery of the vast peatland is newsworthy in and of itself. “It is astonishing that in 2016 discoveries like this can still be made,” said co-leader of the study Greta Dargie of University College London in a statement.
The UK-Congolese research team spent three years exploring remote tropical swamp forests to find samples of peat for laboratory analysis. Their research, published earlier this month Nature, combined the peat analysis with satellite data to estimate that the Congo Basin peatlands store the equivalent of three years of the world’s total fossil fuel emissions.
“These peatlands hold nearly 30 per cent of the world’s tropical peatland carbon, that’s about 20 years of the fossil fuel emissions of the United States of America,” said co-leader Simon Lewis of the University of Leeds.
Peat is an organic wetland soil made from part-decomposed plant debris, more commonly found in cool environments. Healthy peatlands act as carbon sinks, removing carbon from the atmosphere through plant growth.
Further decomposition of the peat is prevented by its waterlogged environment, locking up carbon. Year-round waterlogging is needed for peat to form in the tropics.
But if peatlands dry out, either through changes in land use such as drainage for agriculture or reduced rainfall from climate change, further decomposition resumes, releasing carbon dioxide into the atmosphere.
Professor Lewis said: “Peatlands are only a resource in the fight against climate change when left intact, and so maintaining large stores of carbon in undisturbed peatlands should be a priority. Our new results show that carbon has been building up in the Congo Basin’s peat for nearly 11,000 years.
“If the Congo Basin peatland complex was to be destroyed, this would release billions of tonnes of carbon dioxide into our atmosphere.”
Image credit: Simon Lewis, University of Leeds
