The world’s largest terrestrial carbon sink is losing its grip on the climate fight.
A landmark UN-backed scientific assessment has warned that the Congo Basin rainforest could soon shift from absorbing carbon dioxide to emitting it, as deforestation accelerates across Central Africa. The warning, delivered by a panel of 177 scientists ahead of COP30 in Belém, Brazil, marks one of the starkest climate alerts ever issued for the region.
The 800-page report paints a troubling picture of a forest system under mounting pressure from logging, slash-and-burn agriculture, charcoal demand and weak governance. Scientists say the basin now absorbs roughly 600 million tonnes of CO₂ annually, down sharply from an estimated 1.5 to 4.5 billion tonnes two decades ago. That collapse in absorption capacity signals that the rainforest’s ability to regulate the global climate is rapidly weakening.
Stretching across more than 300 million hectares in six Central African countries, the Congo Basin is the world’s second-largest rainforest after the Amazon rainforest and plays a critical role in stabilising rainfall patterns across the African continent. Scientists estimate the forest recycles around 70 per cent of its own rainfall, influencing weather systems as far north as Egypt.
“The Congo Basin stands at a decisive crossroads,” warned Lee White, the panel’s envoy and former environment minister of Gabon. He cautioned that unless deforestation is brought under control within the next decade, the damage could become irreversible.
Alarmingly, scientists say parts of the basin have already crossed the line and become net carbon emitters due to heavy forest loss, echoing trends already observed in sections of the Amazon.
The warning arrives as global attention increasingly shifts toward the role of tropical forests in carbon markets and climate finance. The panel is calling for major expansion of forestry carbon credit projects, stronger regional coordination among Congo Basin nations, and large-scale public and private investment to protect standing forests.
“With the right incentives, through carbon markets and other mechanisms, the Congo Basin should receive tens of billions of dollars for carbon storage,” the report states.
That recommendation could significantly reshape Africa’s carbon markets landscape. As demand for high-integrity nature-based carbon credits rises, the Congo Basin is emerging as one of the most strategically important regions for future carbon asset development.
Yet despite its global ecological importance, the basin has historically attracted far less international forest finance than the Amazon or forests in Southeast Asia. At COP30 preparations, momentum has begun to build around mechanisms such as Brazil’s Tropical Forest Forever Facility, which has already secured billions in pledges with the Democratic Republic of the Congo among key beneficiaries.
Scientists behind the report argue that climate finance alone will not be enough. They are also urging governments to strengthen governance systems, curb illegal logging, support sustainable agriculture and create economic alternatives for communities dependent on forest clearing and charcoal production.
For Africa’s rapidly evolving carbon markets sector, the report sends a clear signal: the future credibility of global climate action may depend heavily on whether the Congo Basin can remain a carbon sink rather than become the next major climate tipping point.
