New research from the Future Ecosystems for Africa program at the University of the Witwatersrand in South Africa, has created the most accurate maps yet of where reforestation can effectively combat climate change.
The study identifies 195 million hectares globally where tree restoration will deliver maximum climate benefits without harming communities or ecosystems.
The study, published in Nature Communications and drawing from 89 previous research projects, provides the most comprehensive mapping yet of areas where reforestation can deliver optimal climate benefits while supporting wildlife habitat, food production, and freshwater availability.
The 195 million hectares identified – roughly equivalent to the combined area of South Africa, Namibia, Botswana and Zimbabwe – is a 71 to 92% drop in previous estimates of the total land area available globally for reforestation projects. However, it represents a substantial and realistic opportunity for reforestation to contribute meaningfully to climate goals while protecting communities and ecosystems.
“Previous studies often failed to address how afforestation could have negative effects on biodiversity and human well-being, especially for poor people living in remote rural areas often targeted for reforestation,” says Archibald, who leads the Future Ecosystems for Africa (FEFA) programme at Wits University. The research emphasises that negative impacts are more likely when communities lack secure land rights and depend heavily on natural resources.
“The drop from previous estimates is due to layers that previous maps haven’t been able to incorporate, because the research was still nascent at the time. It accounts for the albedo effect, for example, which means restoring tree cover can, in some locations, actively heat the Earth rather than cool it by affecting how much sunlight is absorbed or reflected. It also excludes native grasslands and other ecosystems where carpeting the land with trees would harm biodiversity and exacerbate fire regimes.”
This distinction is particularly important for Africa, where natural grasslands and savannas are often inappropriately converted to forests, harming biodiversity and worsening fire regimes. African countries contribute less than 5% of global carbon emissions yet face disproportionate climate impacts while holding enormous potential for nature-based solutions.
The research directly supports the Roadmap for Just Systems Transformations for Africa’s People and Nature, a continent-wide collaboration between FEFA, Conservation International and partners aimed at accelerating investment in Natural Climate Solutions that benefit both mitigation goals and local livelihoods.
«In areas that are non-forest ecosystems, increasing tree cover is not always appropriate and must explicitly consider historical natural state,» the study emphasises, challenging simplistic tree-planting approaches that ignore ecological complexity.
Professor Forrest Fleischman from the University of Minnesota and co-author of the study says policies must consider land rights and community dependence on natural resources, particularly in countries where political rights aren’t respected.
“African scientists must now rise to the challenge and provide guidance on appropriate landscape management and restoration activities in non-forest ecosystems. That is the goal of the Africa Roadmap,” says Archibald.
As policymakers prepare for upcoming UN Climate negotiations, the research provides a timely reminder that tree-planting alone cannot solve climate change. Only by restoring and protecting forests alongside aggressive industrial decarbonisation can reforestation make meaningful progress toward safe climate limits.
The study was co-funded by the Nature Conservancy and the Oppenheimer Generations Research and Conservation as part of the FEFA programme’s mission to prioritise African-informed solutions in ecosystem conservation.
