The fungi act like blood vessels, moving water and nutrients from soil into plant roots.
Beneath the surface of every meadow, forest, and plain, a hidden circulatory system has been quietly sustaining life for millions of years — and for the first time, humanity has drawn its map. An international team of scientists, using artificial intelligence and data from 16,000 soil samples, has charted the global reach of mycorrhizal fungi: 110 trillion kilometers of living thread that moves water, nutrients, and four billion tons of carbon through the Earth each year. The discovery is as much a revelation as it is a reckoning, for the same map that shows where this network flourishes also shows where industrial agriculture is quietly erasing it.
- A fungal web stretching the equivalent of a billion Earth-to-Sun journeys has been mapped for the first time, forcing a reckoning with how little we understood about the planet's own life-support system.
- These mycorrhizal networks absorb 11% of all human-related CO2 emissions annually, making their accelerating destruction one of the least-discussed climate emergencies on Earth.
- Intensive farming has already cut fungal density in agricultural soils by half, severing ancient plant-fungi partnerships that took millions of years to evolve and cannot be replaced by synthetic fertilizers.
- Hotspots in South Sudan, Florida's Everglades, and the Tibetan plateau now stand as critical conservation frontlines, newly visible thanks to an interactive global map published alongside the research.
- Scientists and policymakers now hold, for the first time, a tool that transforms an invisible crisis into something that can be seen, measured, and — perhaps — defended.
Beneath the soil, invisible to every eye that has ever walked the Earth, lies a network of fungal threads so extensive that if laid end to end they would travel from our planet to the Sun a billion times over. This week, scientists published the first global map of that network — and what it reveals is both extraordinary and deeply unsettling.
The threads belong to mycorrhizal fungi, organisms that weave through soil and into plant roots in a partnership older than forests themselves. Plants provide the fungi with sugars; the fungi return water and nutrients. An international team led by the Society for the Protection of Underground Networks used AI, machine learning, and over 16,000 soil samples to finally render this system visible. Their findings, published in Science, confirm what ecologists long suspected: these fungi are the Earth's circulatory system, and they are in trouble.
The map shows that grasslands hold roughly 40 percent of the most common fungal type, with exceptional concentrations in South Sudan's floodplains, the Florida Everglades, and the Tibetan plateau. Beyond geography, the numbers carry a climate dimension that is difficult to overstate: these networks pull approximately four billion tons of CO2 into the soil each year — 11 percent of all human-related emissions — storing carbon in a mass estimated at 300 megatons, several times the weight of every living person combined.
Yet intensive agriculture is dismantling this system quietly and rapidly. Tilling, synthetic fertilizers, and pesticides have left farmland with fungal densities 50 percent lower than natural ecosystems. The ancient relationships collapse. The soil grows dependent on chemicals. The planet loses one of its most powerful carbon sinks.
The researchers have released an interactive version of the map as a conservation tool — a way to see, with clarity that was never before possible, both the architecture of what sustains us and the outline of what we are losing.
Beneath your feet, in the dark soil where nothing seems to move, lies a network so vast that if you stretched it into a single line, it would reach from Earth to the Sun a billion times over. Scientists have now mapped this hidden infrastructure for the first time, and what they found is both wondrous and fragile.
The network is made of mycorrhizal fungi—threadlike filaments called hyphae that bundle together into what we recognize as fungus. These aren't the mushrooms you see poking through the forest floor. Those are just the reproductive bodies. The real organism lives underground, woven through the soil in patterns so intricate that researchers estimate the total length of all these fungal threads on Earth stretches approximately 110 trillion kilometers. To put that in perspective, the distance from Earth to the Sun is about 150 million kilometers. This fungal network could make that journey a billion times over.
An international team led by the Society for the Protection of Underground Networks used artificial intelligence, machine learning, and data from more than 16,000 soil samples collected across the planet to create the first global map of this system. The results, published this week in the journal Science, reveal something that ecologists have long suspected but never fully visualized: these fungi are quite literally the circulatory system of the Earth. The hyphae act like blood vessels, moving water and nutrients from the soil into plant roots. In return, plants feed the fungi with sugars produced during photosynthesis. It is a partnership so fundamental that most plants cannot survive without it.
The map shows where these networks thrive and where they are collapsing. Grasslands harbor roughly 40 percent of the most common type of mycorrhizal fungi, called arbuscular mycorrhizae. Certain regions—the flooded pasturelands of South Sudan, the Everglades of Florida, the Tibetan plateau—show exceptionally dense concentrations. Mexico's mountainous regions contain considerable fungal networks, though the Baja California and Yucatán peninsulas have relatively sparse coverage. The visualization allows scientists and policymakers to see, perhaps for the first time, the true architecture of what lies beneath.
What makes this network crucial to human survival is its role in climate regulation. These fungi transport approximately four billion tons of carbon dioxide into the soil each year—equivalent to 11 percent of all human-related emissions. They are, in effect, a planetary carbon sink of staggering proportions. The total mass of carbon stored in these fungal networks is estimated at around 300 megatons, roughly four to six times the combined weight of every human being alive.
But there is a crisis unfolding in the soil. Intensive agriculture is destroying these networks at an alarming rate. Farmland shows fungal densities 50 percent lower than natural ecosystems. When farmers till the soil, apply synthetic fertilizers, and use pesticides, they disrupt the delicate relationships that have evolved over millions of years. The fungi cannot establish themselves. The plants lose access to the nutrients and water the fungi would have provided. The soil becomes dependent on chemical inputs. And the planet loses one of its most powerful tools for sequestering carbon.
The researchers have published an interactive map alongside their findings, allowing anyone to see the density and distribution of these networks across the globe. It is a tool designed for conservation, for understanding where these systems flourish and where they face the greatest threat. The map is also a kind of warning. For the first time, we can see what we stand to lose—not just an abstract ecosystem service, but a living infrastructure that holds the climate in balance and feeds the world.
Notable Quotes
These fungi are quite literally the circulatory system of the Earth, moving water and nutrients from soil into plant roots in exchange for sugars produced by plants.— International research team, Society for the Protection of Underground Networks
The Hearth Conversation Another angle on the story
When you say these fungi are Earth's circulatory system, what exactly are they moving through the soil?
Water, nutrients, and carbon. The fungi connect to plant roots and essentially become an extension of them—reaching into soil the roots alone could never access. In exchange, plants give the fungi sugars. It's a trade that's been happening for hundreds of millions of years.
And the carbon they're moving—that's actually being stored in the soil?
Yes. Four billion tons of it annually. The fungi pull carbon dioxide from the atmosphere through the plants, and then deposit it deep in the soil where it stays. It's one of the reasons losing these networks is so dangerous for climate.
The map shows farmland has 50 percent less fungal density. What happens when you farm?
Tilling breaks up the fungal networks. Synthetic fertilizers make plants less dependent on the fungi, so the fungi don't establish. Pesticides kill them directly. Over time, the soil becomes a dead medium that only works with chemical inputs.
So industrial agriculture is essentially dismantling the planet's carbon storage system?
It's worse than that. It's dismantling the system that feeds the plants in the first place. We've been treating soil as inert—just something to hold plants upright. But it's alive, and it's organized. We're only now learning to see it.
What does the map actually show someone looking at it?
Density. Where these networks are thick and healthy, and where they're sparse or gone. It's a visualization of invisible infrastructure. You can see that grasslands are fungal hotspots, that mountains in Mexico are rich with them, that farmland is a desert by comparison.
Can we restore what's been lost?
That's the question researchers are asking now. The map is partly a tool for that—showing where restoration might be possible, where the networks are still viable. But it requires changing how we farm, and that's not simple.