Eternal Canopies: The Pan-African Forest Heritage
Africa’s forests are among the oldest living systems on Earth. The Congo Basin rainforest, the continent’s green heart and the world’s second-largest tropical forest after the Amazon, covers roughly 3.7 million square kilometres across ten countries, with the Democratic Republic of Congo alone holding 155 million hectares of closed-canopy forest. Beyond the Congo, significant blocks persist in West Africa (Upper Guinea rainforest in Liberia, Côte d’Ivoire, Ghana, Sierra Leone), Central Africa’s coastal forests, the Eastern Arc mountains of Tanzania and Kenya, the Albertine Rift montane forests, and the dry miombo woodlands stretching from Angola to Mozambique. Together, these ecosystems once accounted for more than 17% of global forest cover and stored an estimated 180 billion tonnes of carbon in biomass and soil.
For millennia, these forests expanded and contracted with natural climate swings, reaching their maximum extent around 8,000–5,000 years ago during the African Humid Period. Indigenous and local communities shaped them through low-intensity fire, selective harvesting, and agroforestry long before colonial boundaries were drawn. Colonial and post-colonial logging, industrial agriculture, and mining dramatically accelerated fragmentation in the 20th century, yet until the early 2000s, the continent’s intact forests remained a robust net carbon sink, absorbing roughly 1.2–1.5 billion tonnes of CO₂ equivalent per year—more than the annual emissions of the entire European Union at that time.
The Great Flip: From Global Sink to Continental Source
Between 2010 and 2025, a quiet but catastrophic reversal occurred. High-resolution satellite monitoring and ground inventories now confirm that Africa’s tropical forests have shifted from a net carbon sink of approximately 0.4–0.5 PgC yr⁻¹ (petagrams of carbon per year) to a net source emitting between 0.2 and 0.6 PgC yr⁻¹, depending on the year and methodology. This means that, for the first time in recorded history, the continent’s forests release more carbon than they absorb.
The primary drivers are well documented: agricultural expansion (especially cocoa, oil palm, rubber, and soy), artisanal and industrial logging, mining (coltan, diamonds, gold, cobalt), fuelwood and charcoal demand, and infrastructure corridors. Degradation—selective logging and edge effects—accounts for roughly 70% of the carbon loss, while outright deforestation accounts for the remainder. The Democratic Republic of Congo alone lost 5.1 million hectares of primary forest between 2002 and 2024, an area larger than Costa Rica. When peatlands in the central Congo Basin began drying and burning after drainage, an additional pulse of centuries-old carbon was released into the atmosphere.
Heat Beyond Tolerance: Extreme Thermal Stress on African Trees
African forests evolved under relatively stable equatorial temperatures, rarely exceeding 32–34 °C even during past warm periods. Since 2015, however, prolonged heatwaves combined with severe droughts have pushed leaf and soil temperatures into lethal ranges. The 2015–2016 El Niño, the 2019–2020 drought, and the 2022–2024 multi-year dry spells caused widespread canopy browning, hydraulic failure, and elevated tree mortality, particularly among shallow-rooted understorey species.
Montane forests face an even bleaker outlook. Warming rates at higher elevations are 1.5–2 times faster than at sea level, and cloud bases are rising, stripping moisture-dependent mossy forests of their life-sustaining mist. Species such as the African rosewood (Hagenia abyssinica) and giant heathers in Ethiopia and Kenya are already retreating upslope with no higher ground left to colonise.
The Desert Bites Back: Desertification and Savanna Encroachment
While the humid core shrinks, arid forces advance from the margins. The Sahara and Kalahari deserts are expanding southward and northward, respectively, at rates of 0.5-3 km per year in some sectors. In the Sahel, woody cover declined by 18 % between 1985 and 2020. Dry forests and woodlands are being replaced by open savannas or shrublands with far lower carbon density. In North Africa, remnant forests in Morocco’s Middle Atlas and Algeria’s Kabylia have shrunk to isolated patches amid rampant fuelwood harvesting and wildfire.
Mitigation Pathways: Halting the Haemorrhage
Efforts to reverse the trend are multiplying, though the scale of the loss still dwarfs them. The African Forest Landscape Restoration Initiative (AFR100) has mobilised commitments to restore 130 million hectares by 2030. Jurisdictional REDD+ programmes in Gabon, the Republic of Congo, and the Democratic Republic of Congo have begun issuing verified carbon credits at scale, with Gabon becoming the first African nation to receive results-based payments under the Central African Forest Initiative (CAFI) in 2021 and again in 2024–2025.
Community-based approaches—Farmer-Managed Natural Regeneration in Niger, Ghana, and Mali—have regrown tens of millions of trees on degraded farmland at almost no cost. Agroforestry systems integrating high-value native trees with cocoa or coffee are expanding in Liberia and Cameroon, simultaneously raising farmer incomes and restoring carbon stocks.
Adaptation Imperatives: Building Forests for a Hotter Century
Restoration must now be designed for 2–4 °C warmer conditions. Assisted migration of drought-tolerant provenances, enrichment planting with pioneer and fire-resistant species, and the creation of riparian buffer corridors are emerging strategies. Protected-area networks are being re-evaluated to include climate refugia—cool, wet valleys and peatland cores that will remain habitable longest.
Carbon Markets and Green Finance: Promise and Peril
Africa hosts some of the world’s most significant voluntary carbon projects, yet controversy surrounds integrity, permanence, and equity. Leakage, double-counting, and overstated baselines have undermined confidence in specific market segments. At the same time, sovereign carbon deals and emerging compliance pathways under Article 6 of the Paris Agreement offer the potential to mobilize hundreds of billions in finance if governance improves.
Toward 2050: Two Futures
One future sees Africa’s forests stabilise and begin recovering as a managed, mosaic landscape of intact core areas, restored corridors, and climate-smart agroforestry, sequestering 0.5–1 PgC yr⁻¹ again by mid-century while supporting hundreds of millions of livelihoods.
The other future is continued collapse: primary forest reduced to isolated fragments by 2050, peatlands essentially drained and burning, montane endemics extinct, and the continent becoming one of the most significant terrestrial carbon sources on Earth, accelerating global warming in a vicious feedback loop.
The choice remains open, but the window is closing fast. The reversal is not yet irreversible—but it will be soon.
