More than one-third of worldwide annual emissions are being sequestered into the soil by fungi!

Did you know that the largest organism in the world might actually be a fungus? The enormous Armillaria ostoyae fungus spans about 10 square kilometres of intricate underground roots underneath the Malheur National Forest in Oregon, weighing an estimated 35,000 tons and earning it the nickname of 'Humongous fungus'.

This isn't just a one-off incident, either. Many fungi grow to exceptional sizes; we just don't notice them because they're hidden underground, forming an ecosystem with plant roots and microbes in the soil. And for this reason, scientists think they might be a crucial part of the carbon cycle we continue to overlook daily.

In fact, recent research has shown that the massive underground network of such fungi could end up storing about 13 gigatons of carbon annually. This is the shocking equivalent of 36% of total global fuel emissions — more than China emits annually!

When plants convert carbon into sugar and fat equivalents, these mycorrhizal fungi vault them into the soil. And this type of fungi is everywhere in the world, from underneath roads to gardens to houses.

"We always suspected that we may have been overlooking a major carbon pool," remarks Dr Heidi Hawkins, the study's lead author.

"Understandably, much focus has been placed on protecting and restoring forests as a natural way to mitigate climate change, but little attention has been paid to the fate of the vast amounts of carbon dioxide that are moved from the atmosphere during photosynthesis by those plants and sent belowground to mycorrhizal fungi."

However, this discovery is only the tip of the iceberg. We need a ton more research to determine how long this sequestered carbon actually stays locked in the soil. Furthermore, how severely are these silent carbon warriors affected by soil degradation?

"Soil ecosystems are being destroyed at an alarming rate through agriculture, development and other industry, but the wider impacts of disruption of soil communities are poorly understood. 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," notes Katie Field, co-author of the study.

"More needs to be done to protect these underground networks — we already knew that they were essential for biodiversity, and now we have even more evidence that they are crucial to the health of our planet."

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