Kenya’s CO2-to-Stone Trees Offer Breakthrough in Climate Fight

Researchers have discovered that certain Kenyan fig trees, specifically Ficus wakefieldii, can convert atmospheric CO2 into stone, offering a novel approach to carbon sequestration. This finding, presented at the 2025 Goldschmidt Conference, could transform climate change mitigation strategies. This article explores the science, impacts, and scalability of this natural solution.

In Kenya’s coastal forests, Ficus wakefieldii trees, aided by symbiotic bacteria, convert CO2 into calcium carbonate, a stable mineral that locks carbon in soil for centuries. Unlike traditional tree sequestration, where CO2 is released upon decay, this process mineralizes carbon into stone-like deposits, preventing re-emission. The discovery, led by the University of Zurich, identifies these trees across Kenya, Tanzania, and Uganda, with potential for broader application.

The process involves bacteria in the tree’s roots converting CO2 into calcium oxalate, which transforms into calcium carbonate. This not only sequesters carbon but also raises soil pH, enhancing fertility and supporting vegetation growth. A single hectare of these trees can sequester 10 tonnes of CO2 annually, equivalent to removing 2,000 cars’ emissions. The soil enrichment also boosts agricultural yields by 15%, benefiting local farmers.

Economically, the discovery supports rural communities. Scaling these forests could create jobs in conservation and agroforestry, with Kenya’s government planning to expand plantations by 500 hectares by 2030. The carbon credit market offers additional revenue, with each tonne of sequestered CO2 valued at $30–50. However, establishing these forests requires investment in land and maintenance, estimated at $10 million for initial scaling.

Environmental benefits are profound. The process locks away 1.5 million tonnes of CO2 annually across existing forests, supporting Kenya’s Paris Agreement commitments. Unlike mechanical carbon capture, it requires no energy-intensive infrastructure, reducing emissions further. However, critics question the process’s efficiency compared to industrial solutions, noting that scaling requires vast land areas, potentially competing with agriculture.

Challenges include land availability and biodiversity risks. Expanding plantations could encroach on farmland, raising food security concerns. Monoculture risks, as seen in other reforestation projects, could reduce biodiversity if not managed carefully. The government is piloting mixed-species plantations to address this, integrating native trees to maintain ecological balance.

Community engagement is critical. Local farmers are trained in agroforestry techniques, ensuring economic inclusion. Public campaigns highlight soil fertility benefits, gaining support from rural communities. Indigenous knowledge informs planting strategies, enhancing resilience. Critics, however, caution that without equitable land access, benefits may favor large landowners.

Globally, the discovery aligns with nature-based solutions like mangrove restoration in Iraq. The UN Environment Programme supports scaling such initiatives, emphasizing their low-cost, high-impact potential. However, skepticism persists about over-relying on natural systems, as industrial solutions offer faster deployment. Collaboration with global research institutions could optimize bacterial strains for broader application.

Long-term success depends on monitoring and policy support. Satellite imagery tracks forest expansion, while soil sensors measure carbon sequestration. Kenya’s climate plan includes incentives for farmers adopting these trees. Scaling globally requires addressing land-use conflicts and ensuring carbon markets fairly compensate developing nations.

Conclusion

Kenya’s CO2-to-stone trees offer a groundbreaking, natural solution to climate change, with significant environmental and economic benefits. Addressing land, biodiversity, and equity challenges is essential for scalability. Policy support and global collaboration will determine whether this discovery becomes a cornerstone of climate action.

Source: Sustainablity Times