Fungal Climate Engineering: How a New Frontiers in Microbiology Review Positions Fungi at the Heart of Climate Action
- Gauri Khanna
- 6 hours ago
- 4 min read
Too long to read? Go for the highlights below.
Ectomycorrhizal forests can store up to 70% more below-ground carbon than forests lacking these fungal partners, suggesting significant untapped potential for fungi in nature-based climate solutions.
Mushroom species such as Pleurotus ostreatus can degrade up to 95% of polycyclic aromatic hydrocarbons in controlled conditions, pointing to a powerful enzymatic toolkit for cleaning polluted land.
The global market for mycelium-based materials is projected to exceed USD 5 billion by 2032, signalling rapid commercial interest in fungal biotechnology beyond food and medicine.
Carbon Stored Underground: The Mycorrhizal Advantage
A comprehensive review published in Frontiers in Microbiology in February 2026 by Karunarathna and colleagues makes a compelling case for repositioning mushroom-forming fungi as central actors in climate change mitigation, rather than peripheral curiosities of forest ecology.
The authors focus initially on carbon sequestration, the process by which carbon dioxide is drawn from the atmosphere and locked into the soil. Ectomycorrhizal (ECM) fungi, species such as Boletus, Amanita, and Laccaria that form intimate partnerships with tree roots, are identified as particularly important. Their thread-like hyphal networks channel an estimated 20 to 30% of the carbon fixed by host plants into the soil, where it can persist for decades. ECM-dominated forests, common across boreal and temperate regions, are estimated to hold up to 70% more below-ground carbon than forests relying on other mycorrhizal types, though the authors are careful to flag that this figure reflects a broad ecological pattern shaped by multiple interacting factors rather than a simple causal relationship.
Some ECM species have developed especially durable strategies. The melanised hyphae of Cenococcum, for example, resist decomposition, while Cortinarius secretes peroxidase enzymes to access nitrogen without fully breaking down the organic matter surrounding it. These approaches collectively contribute to what researchers describe as mineral-associated organic carbon, a recalcitrant pool that can persist in soils for centuries.
In agricultural landscapes, arbuscular mycorrhizal fungi (AMF) play an analogous role. They are partners to roughly 80% of herbaceous crops and produce glomalin, a sticky glycoprotein that binds soil particles into stable aggregates lasting up to 42 years. Glomalin-associated proteins account for around 4 to 5% of agricultural soil carbon. Field trials suggest that AMF inoculation can increase carbon sequestration by 30 to 50% over three years, and that conservation tillage, which limits soil disturbance and supports AMF colonisation, raises soil organic carbon by 15 to 20% compared to conventional methods. This intersection of fungal networks and agricultural practice represents one of the more immediately actionable findings the review presents.
Enzymatic Detectives: Cleaning Up Pollution Through Mycoremediation
The second major mechanism the review addresses is mycoremediation, the use of fungal enzymatic systems to break down persistent environmental pollutants. White-rot fungi produce an arsenal of ligninolytic enzymes, including laccases, manganese peroxidases, and lignin peroxidases, originally evolved to decompose recalcitrant plant polymers. These same enzymes can attack a remarkable range of industrial contaminants.
Pleurotus ostreatus, the oyster mushroom familiar to many as an edible species, can degrade up to 95% of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil under laboratory conditions. PAHs are a class of toxic compounds released by the combustion of fossil fuels and found widely in industrial sites. Trametes versicolor has demonstrated over 90% removal of bisphenol A, an endocrine-disrupting chemical used in plastics manufacturing. Ganoderma lucidum can degrade phenanthrene and pyrene, two persistent PAHs, at rates exceeding 99% within 30 days in optimised settings.
The review is admirably candid about the limitations of these figures. Nearly all high-efficiency results come from sterile laboratory conditions, with single contaminants, ideal temperature and moisture, and no competition from native microbial communities. Field applications consistently produce lower and more variable results. The authors emphasise that moving from laboratory promise to reliable remediation in complex soils requires a fundamental shift towards ecology-centred approaches, including designing stable fungal-bacterial consortia and understanding how introduced fungi interact with existing soil communities. The broader context of fungi solving plastic and pollution problems is one the review situates within a rigorous framework of caution.
Materials, Bioenergy, and the Circular Economy
Beyond remediation, the review synthesises evidence for fungi as platform technologies within a circular bioeconomy. Mycelium composites, grown by binding agricultural residues with fungal hyphae from species such as Ganoderma and Pleurotus, produce biodegradable materials suitable for packaging, construction insulation, and textile alternatives. These mycelium-based materials can replace expanded polystyrene, saving up to 90% of embodied energy, and decompose in soil within weeks rather than persisting for centuries like petrochemical plastics.
White-rot fungi also pretreat lignocellulosic agricultural residues, unlocking fermentable sugars for bioethanol production. Spent mushroom substrate, the leftover growing medium after harvest, can be applied as a soil amendment that sequesters an estimated 0.5 to 2.0 tonnes of carbon dioxide equivalent per hectare per year, while simultaneously improving soil structure and microbial diversity.
The review's principal contribution is not the accumulation of impressive statistics but its insistence on rigour. Fungi mediate an estimated 15 to 20% of terrestrial carbon sequestration annually, a figure that carries significant uncertainty and depends on modelling assumptions difficult to validate across diverse ecosystems. By flagging these uncertainties alongside the opportunities, Karunarathna and colleagues make a stronger, more credible case for integrating fungi into climate policy than optimistic projections alone could achieve.