Sheffield University researchers report that mycorrhizal fungi — which form vast networks with plant roots — may account for roughly 36% of the world’s annual atmospheric carbon uptake, storing an estimated 13 gigatons per year. A single network in Michigan covers about 91 acres, highlighting how extensive these systems can be. The study warns that agriculture and other human activities threaten soil ecosystems and urges leaders to adopt soil-protection and conservation measures to preserve this natural carbon sink.
Underground Allies: Mycorrhizal Fungi May Store ~36% Of Annual Atmospheric Carbon — A ‘Blind Spot’ For Climate Policy
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Researchers from Sheffield University report that powerful networks of mycorrhizal fungi may be capturing and storing a surprisingly large share of the planet’s atmospheric carbon each year. The study highlights a vast, mostly unseen partnership between fungi and plants that helps move carbon from the air into the soil — and warns that human activity could disrupt that natural service.
What the research found
Mycorrhizal fungi form extensive underground networks on every continent, living in a symbiotic relationship with plant roots. Plants convert atmospheric carbon into sugars through photosynthesis; fungi consume some of those sugars and, in the process, help transfer and store carbon in soils and fungal tissue.
According to the report, these fungal systems may account for roughly 36% of the world’s annual atmospheric carbon uptake. The researchers estimate that fungal carbon banks sequester about 13 gigatons of carbon each year — a quantity the authors say is comparable to the annual CO2 emissions produced by China.
A single giant fungal network in Michigan spans roughly 91 acres, The Hill reported, illustrating how large and interconnected some of these systems can be.
“Mycorrhizal fungi represent a blind spot in carbon modeling, conservation, and restoration — the numbers we've uncovered are jaw-dropping, and when we're thinking about solutions for climate we should also be thinking about what we can harness that exists already,”
— Professor Kate Field, Sheffield University
Why this matters
If confirmed and incorporated into carbon accounting, these findings could change how scientists, policymakers, and land managers estimate natural carbon sinks and design climate solutions. However, the service provided by fungal networks is vulnerable: intensive agriculture, land conversion, and other human activities can degrade soil ecosystems and reduce their ability to store carbon.
The researchers cite a United Nations warning that up to 90% of soils could be degraded by 2050 if current trends continue, underscoring the urgency of protecting soil health.
What the researchers recommend
The report calls on governments and global leaders to recognize and protect subterranean ecosystems as part of climate policy. Practical steps include promoting soil conservation, limiting practices that destroy soil structure and biodiversity, and integrating fungal carbon storage into restoration and conservation planning.
“When we disrupt the ancient life support systems in the soil, we sabotage our efforts to limit global heating and undermine the ecosystems on which we depend,” Professor Field added.
Protecting and restoring soil — and the fungal networks within it — could be a cost-effective, natural complement to emissions reductions and technological carbon removal.
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