Hidden peat swamp in Central Africa stores 30 billion tons of carbon

A vast swamp forest in Central Africa contains enough carbon to equal two decades’ worth of U.S. fossil fuel emissions, scientists have found. 

The Congo Basin peatland — an area larger than New York State — has accumulated around 30 billion metric tons of carbon over the last 11,000 years, according to a study published Wednesday in the journal Nature.

The discovery makes the fate of this vast carbon sink an important consideration for climate projections and land conservationists. 

A team of U.K. and Congolese researchers spent three years roaming the Cuvette Centrale peatland to find samples of peat to test in their labs. They also analyzed satellite data to estimate the amount of carbon stored in the soil.

Five years ago, most scientists weren’t even aware of the 56,000-square-mile swamp, which is now considered the world’s largest tropical peatland. 

The Cuvette Central peatland.

The Cuvette Central peatland.

Image: university of leeds

Chunk o' peat.

Chunk o’ peat.

Image: University of Leeds

“The sheer expanse of these peatlands makes Central Africa home to the world’s most extensive peatland complex,” Greta Dargie, a geologist at University College London and co-author of the Nature study, said in a statement

“It is astonishing that… discoveries like this can still be made,” she said.

Peatlands are comprised of partially decomposed, wet plant material that piles up over thousands of years. Peat soil covers about 3 percent of the Earth’s surface, but it contains more carbon than is stored in all the plants and trees worldwide.

Because they absorb and lock in so much carbon, the destruction of peatlands poses a significant threat to the climate. 

In Indonesia and Malaysia, where farmers are draining and clearing peatland to make way for palm oil plantations, enough carbon is escaping into the atmosphere every year to equal emissions from nearly 70 coal plants, according to World Resources Institute.

In 2015, massive peatland fires in Indonesia made the country the world’s fourth-largest greenhouse gas emitter that year.

Image: world resources institute

Peatlands can also dry out naturally because of declining rainfall, which is happening more frequently because of human-driven climate change. 

“If the Congo Basin peatland complex was to be destroyed, this would release billions of tonnes of carbon dioxide into our atmosphere,” Simon Lewis, a professor at the University of Leeds in England and a study co-author, said in a statement. 

So far, however, the Cuvette Centrale peatland remains relatively intact and undisturbed.

The swamp forests are extremely remote and difficult to access, and many local communities depend on the forest system’s rivers and streams for fishing and sustenance, said Emma Stokes, who directs the Central Africa program for the Wildlife Conservation Society (WCS).

“There’s a certain natural protection already afforded to these areas,” she told Mashable by phone from Brazzaville, the Republic of Congo’s capital city.

A simplified map of the Congo Basin peatland: Peat swamp forest (pink); open water (blue); savanna (yellow); other tropical forest (green).

A simplified map of the Congo Basin peatland: Peat swamp forest (pink); open water (blue); savanna (yellow); other tropical forest (green).

Image: university of leeds

WCS works with the Republic of Congo to manage the Lac Tele Community Reserve, a legally protected peatland that covers about 1,700 square miles and has one of the world’s highest densities of western lowland gorillas. The government is also considering expanding the reserve to include an adjacent 1,930-square-mile area. 

Stokes said Wednesday’s study on the peatlands carbon content could play a crucial role in shaping the government’s future land-use development plans or economic decisions.

“We’re in a good position now,” she said. “But there’s certainly always a risk.”