Ancient chemical discovered ‘leaking’ in African lakes

A significant threat to global climate stability has emerged from the Democratic Republic of Congo, where two vast lakes are actively releasing carbon that has been sequestered in surrounding peatlands for millennia.

This startling discovery, made by researchers from ETH Zurich and published in Nature Geoscience, challenges long-held assumptions that tropical peatlands securely store carbon for thousands of years.

Lakes Mai Ndombe and Tumba are now understood to be emitting up to 40 per cent of their carbon dioxide from ancient peat deposits, some dating back over 3,000 years, rather than from more recent plant matter.

Lead author Travis Drake expressed surprise at the findings, stating: "We were surprised to find that ancient carbon is being released via the lake." Co-author Matti Barthel added: "The carbon reservoir has a leak, so to speak, from which ancient carbon is escaping."

While the precise mechanism by which this ancient carbon moves from the peatlands into the lakes remains unclear, scientists warn the phenomenon could intensify with ongoing climate change or shifts in land use, such as the conversion of forests to cropland, which exacerbates drought conditions.

Peat, formed from accumulated dead plant material, typically remains stable and carbon-locked in water-logged environments. However, when it dries out, organisms that break down plant material revive, causing the stored carbon to seep back into the atmosphere.

The swamps and peatlands of the Congo Basin are globally significant, covering just 0.3 per cent of the Earth's land surface yet holding a third of the carbon stored in all tropical peatlands, making the region a critical global carbon reservoir.

Despite its immense ecological importance, the Congo Basin remains one of the world’s least-studied major forest regions, underscoring the urgent need for further research to comprehend how its vast ecosystems are evolving.