Hidden underground around the world lie 110 quadrillion kilometers of arbuscular mycorrhizal fungal networks—webs of ultra-thin threads that, if connected in a single line, would stretch almost a billion times the distance between the Earth and the sun, according to new research published in Science on Thursday. These fungal communities form intimate relationships with plants, trading nutrients for carbon in a vast subterranean system.
This discovery underscores the potential for these mycorrhizal networks to significantly influence carbon sequestration. The fungi help plants access water and minerals while drawing down atmospheric carbon dioxide into soil, a process that could play a critical role in climate mitigation. The research quantifies the scale of this biological infrastructure for the first time, highlighting its capacity to store carbon over geological timescales.
The study did not provide specific emissions reduction figures, but it suggests that preserving these networks could enhance soil carbon storage by billions of tons annually. Investment in mycorrhizal research remains minimal compared to other climate technologies; no funding amounts were cited. The global fungal network represents a natural, low-cost tool for carbon capture, but its economic valuation has yet to be established in markets or policy frameworks.
Geopolitically, the findings align with international efforts under the Paris Agreement to protect terrestrial ecosystems. Countries with extensive agricultural lands—such as the U.S., Brazil, and India—could benefit from integrating fungal network conservation into land-use policies. However, the research did not address trade implications or specific national commitments.
Some scientists caution that the full extent of fungal networks remains unknown, and scaling up conservation measures may face practical challenges. The study’s authors note that industrial farming practices, including tillage and chemical fertilizers, can disrupt these delicate connections. While the discovery opens new avenues for climate action, its real-world impact depends on integrating knowledge into sustainable agriculture.