What this is about:
The world’s tropical rainforests, once known as the lungs of the Earth, are losing their ability to store carbon. New satellite data show that vast forest regions are now emitting more CO₂ than they absorb.
Why you should read this:
Because this tipping point is one of the most alarming signs of global climate change. What was once our greatest natural ally is now turning into an additional source of warming.
From Carbon Sink to Carbon Source
Research from the National Centre for Earth Observation at the Universities of Leicester, Sheffield, and Edinburgh shows that since 2010, African forests have shifted from being a carbon sink to a net emitter. Once they absorbed more CO₂ than they released, but now they are losing around 106 billion kilograms of biomass each year—about the weight of 106 million cars, according to The Guardian.
This shift is not limited to Africa. All the world’s major rainforest regions—the Amazon, Southeast Asia, and Africa—are now releasing more carbon than they store. The causes are the same everywhere: deforestation, forest degradation, and increasingly intense wildfires.
Tropical Rainforests Under Pressure
In South America, the eastern Amazon, particularly the states of Pará and Mato Grosso, has been hit hardest. Due to deforestation, drought, and fires, this part of the rainforest now emits more CO₂ than it absorbs. Only forests managed by Indigenous communities largely remain carbon sinks, although these areas, too, are under growing pressure from illegal logging and new roads.
In Africa, the change is even more dramatic. Outside the most intact core of the Congo Basin, tropical forests are rapidly losing biomass. Forests in the Democratic Republic of Congo, Madagascar, and parts of West Africa are becoming thinner and drier. As a result, the African continent as a whole now emits more CO₂ than it captures.
In Southeast Asia, the pattern is similar. In regions such as Malaysian Borneo, logged or degraded forests remain net emitters for at least a decade after clearing. The decay of dead trees and soil organic matter releases more carbon than young vegetation can take in.
Fire-Prone Northern Forests
It’s not only the tropics that are losing their role as carbon sinks. In the boreal forests of Canada, Alaska, and Siberia, increasingly severe wildfires are driving a similar shift. In dry areas such as parts of Canada’s Northwest Territories, young forests have become net carbon sources due to repeated fires. These blazes destroy not only vegetation but also long-stored soil carbon that previously escaped combustion.
More and more often, massive wildfires—from the Amazon to Australia—are turning forests into temporary but immense CO₂ sources. During extreme fire years, scientists speak of “super-emitters”: ecosystems that release in a few weeks what would otherwise take decades to absorb.
Regional Contrasts
The picture is not entirely bleak. In the Amazon, many Indigenous territories remain carbon sinks thanks to careful forest management. And the central, peat-rich heart of the Congo Basin still stores vast amounts of carbon. Yet at the forest edges, trees are disappearing so quickly that Africa’s overall carbon balance has tipped toward net emissions.
A Race Against Time
Scientists warn that current climate policies are not keeping pace with this transformation. Professor Heiko Balzter of the University of Leicester stresses that policymakers urgently need to strengthen protection for tropical forests.
Brazil’s Tropical Forest Forever Facility (TFFF) aims to mobilize over $100 billion to pay countries for preserving their forests. So far, however, only $6.5 billion has been pledged—far too little to reverse the trend.
In Short
The forests that once stabilized the climate are now destabilizing it. Deforestation, degradation, and fire have turned several of the world’s largest forest regions into net emitters of greenhouse gases.
Without swift action to halt forest loss, fund sustainable alternatives, and empower Indigenous communities, the world risks losing its most powerful natural ally in the fight against climate change.
