We Are Going Backwards: Africa's Forests Switch from Carbon Sink to Source After 2010
Major satellite study reveals continent's forests now releasing more carbon than they absorb, speeding up climate breakdown
Key Points
- ✓ Africa's forests shifted from absorbing 439 million tonnes of biomass annually (2007-2010) to losing 106 million tonnes per year (2010-2017)
- ✓ Tropical moist broadleaf forests in DR Congo, Madagascar, and West Africa experienced the greatest losses
- ✓ Deforestation around settlements, rivers, and roads drives the carbon emissions
- ✓ Solutions include stronger forest governance, REDD+ financing, and large-scale restoration through initiatives like AFR100
Africa's forests have crossed a critical threshold. After centuries of absorbing carbon dioxide from the atmosphere, the continent's forests now emit more carbon than they capture—a shift with profound implications for global climate action.
New research published in Scientific Reports tracked over a decade of forest changes across Africa using satellite data and machine learning. The findings reveal that between 2007 and 2010, Africa's forests gained 439 million tonnes of biomass annually. But by 2010-2017, this reversed to an annual loss of 106 million tonnes.
What Changed After 2010
The transition from carbon sink to carbon source happened rapidly. Researchers from the UK's National Centre for Earth Observation analyzed high-resolution satellite imagery covering the entire continent from 2007 to 2017.
2007-2010: Net gain of 439 million tonnes of biomass per year
2010-2015: Net loss of 132 million tonnes per year
2015-2017: Continued loss of 41 million tonnes per year
The driving force behind this reversal is deforestation in tropical moist broadleaf forests, particularly in the Democratic Republic of Congo, Madagascar, and West African nations. These dense forests store far more carbon than savannas—averaging 396 tonnes per hectare compared to just 45 tonnes per hectare in savannas.
Where the Carbon Loss Is Happening
The Congo Basin, home to the world's second-largest rainforest, experienced the most dramatic changes. While some areas within Equatorial Guinea, Gabon, and Republic of Congo showed biomass gains, overall forest loss dominated.
Deforestation in these regions typically occurs around settlements, rivers, and roads—patterns clearly visible in the satellite data. The research team mapped these changes at 100-meter resolution, detailed enough to detect forest disturbances as small as one hectare.
How the Research Was Conducted
The research combined multiple data sources to create the most detailed picture yet of African forest biomass:
- NASA's GEDI laser instrument measured forest height from the International Space Station
- Japan's ALOS PALSAR radar satellites tracked changes across the continent
- Machine learning algorithms processed 1.8 million laser measurements alongside radar data
- Over 10,000 ground-based forest plots validated the satellite estimates
Professor Heiko Balzter from the University of Leicester, who directed the study, emphasized the urgency: "If Africa's forests are no longer absorbing carbon, it means other regions and the world will need to cut greenhouse gas emissions even more deeply to stay within the Paris Agreement goals."
Implications for Climate Goals
Africa's forests and woodlands store approximately 59 petagrams (59 billion tonnes) of carbon in aboveground biomass. The loss of this carbon sink creates a significant gap in global climate calculations.
The Paris Agreement assumed that natural forests would continue absorbing substantial amounts of carbon dioxide. With Africa's forests now contributing to emissions rather than offsetting them, meeting the agreement's temperature targets becomes substantially harder.
What's Driving the Forest Loss
Population growth puts increasing pressure on forest resources for agricultural expansion, timber, and fuelwood. FAO statistics show harvested roundwood in Africa increased from 277 million cubic meters in 1961 to 768 million cubic meters by 2017.
Export demand, particularly from Asia, drives commercial logging for timber and agricultural commodities. Weak governance in some regions allows illegal logging to continue despite national and international commitments to forest protection.
Pathways to Reversal
Dr. Nezha Acil from the University of Leicester pointed to restoration initiatives like AFR100, which aims to restore 100 million hectares of African landscapes by 2030, as critical to reversing forest loss.
Satellite-enabled forest alert systems, already deployed in Kenya to combat illegal logging, offer technological solutions for better forest governance and enforcement. The REDD+ initiative provides financial incentives for countries that successfully protect their forests and reduce carbon emissions.
Dr. Pedro Rodríguez-Veiga, who led the analysis, stressed the need for collaboration: "Governments, the private sector, and NGOs must work together to fund and support initiatives that protect and enhance our forests. This isn't just a local issue—it's changing the global carbon balance."
The Glasgow Leaders Declaration on Forests and Land Use, signed at COP26, committed nations to halt net deforestation by 2030. Meeting this goal now requires intensified action, particularly in tropical moist broadleaf forests where carbon storage is highest.
Frequently Asked Questions
When did Africa's forests stop being a carbon sink?
The transition occurred between 2010 and 2015. Forests gained biomass through 2010, but by 2010-2015 showed net losses that continued through 2017.
Which African countries experienced the worst forest loss?
The Democratic Republic of Congo, Madagascar, and several West African nations saw the most significant deforestation in tropical moist broadleaf forests during this period.
How much carbon do Africa's forests store?
Africa's forests and woodlands contain approximately 59 petagrams (59 billion tonnes) of carbon in aboveground woody biomass.
What is causing African deforestation?
Multiple factors drive forest loss including population growth, agricultural expansion for commodity crops, timber harvesting, fuelwood collection, and export demand particularly from Asia.
Can savanna growth offset tropical forest loss?
No. While savannas showed some biomass gains from shrub encroachment, their lower carbon density (45 tonnes per hectare versus 396 tonnes per hectare in tropical forests) means gains cannot compensate for tropical forest losses.
What initiatives exist to protect African forests?
Key programs include AFR100 (aiming to restore 100 million hectares by 2030), REDD+ financial incentives for forest protection, satellite-based forest monitoring systems, and the new Tropical Forests Forever Facility announced at COP30.
