Can Fungi help reduce Climate Changes?

Fungi, with their remarkable abilities, present a potential solution to address the pressing issue of climate change. These organisms play a crucial role in the environment and offer various benefits in mitigating climate change. One key contribution of fungi is their ability to sequester carbon dioxide, thereby reducing greenhouse gas levels in the atmosphere. Recent research conducted by the University of Sheffield unveiled the astounding finding that fungi might be responsible for absorbing approximately 36% of global fossil fuel emissions.

Beneath the Earth's surface lies an extensive network of fungi, storing over 13 gigatons of carbon worldwide. This storage capacity is roughly equivalent to 36% of annual global fossil fuel emissions. Previously, the true extent of carbon storage by mycorrhizal fungi, which form symbiotic relationships with almost all land plants, was not fully understood. These fungi transport carbon, which plants convert into sugars and fats, into the soil. The discovery of their significant role in storing carbon emphasizes their potential in addressing climate change and achieving net-zero emissions. Scientists are now exploring ways to enhance the soil's carbon storage capacity beneath our feet.

Mycorrhizal fungi have been vital in supporting terrestrial life for at least 450 million years. They form vast underground networks, even extending beneath roads, gardens, and buildings on every continent. A team of international scientists, including experts from the University of Sheffield's School of Biosciences, conducted a meta-analysis of numerous studies on plant-soil processes. Their research, published in Current Biology, revealed that an estimated 13.12 gigatons of carbon dioxide are transferred from plants to fungi annually. This process transforms the soil into a massive carbon pool, making it the most effective carbon capture and storage unit globally.

The amount of carbon stored by fungi represents approximately 36% of yearly global fossil fuel emissions, surpassing the annual emissions of China. Consequently, researchers are advocating for fungi to be incorporated into biodiversity and conservation policies due to their critical role in reducing carbon emissions. If current trends persist, the United Nations warns that 90% of soils could be degraded by 2050, leading to catastrophic consequences for climate change mitigation, rising temperatures, and the productivity of crops and plants.

Professor Katie Field, a co-author of the study and an expert in plant-soil processes at the University of Sheffield, highlights the significance of mycorrhizal fungi. She emphasizes that these fungi are often overlooked in carbon modeling, conservation efforts, and ecological restoration.

She Explains, “Mycorrhizal fungi represent a blind spot in carbon modelling, 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.”

The researchers are now delving into the longevity of carbon storage by fungi in the soil and further exploring the multifaceted role played by fungi in Earth's ecosystems.

Dr. Heidi Hawkins, the study's lead author from the University of Cape Town, notes that while forests have received substantial attention as a natural means of mitigating climate change, little focus has been given to the fate of the considerable amounts of carbon dioxide moved from the atmosphere to mycorrhizal fungi through photosynthesis.

Dr Hawkins adds, “A major gap in our knowledge is the permanence of carbon within mycorrhizal structures. We do know that it is a flux, with some being retained in mycorrhizal structures while the fungus lives, and even after it dies. Some will be decomposed into small carbon molecules and from there either bind to particles in the soil, or even be reused by plants. And certainly, some carbon will be lost as carbon dioxide gas during respiration by other microbes or the fungus itself.”

Professor Toby Kiers, a senior author from Vrije University Amsterdam and co-founder of the Society for the Protection of Underground Networks, underscores the global effort to comprehend the role of fungi in Earth's ecosystems.

“The paper is part of a global push to understand the role that fungi play in Earth’s ecosystems. We know that mycorrhizal fungi are vitally important ecosystem engineers, but they are invisible to most people. Mycorrhizal fungi lie at the base of the food webs that support much of life on Earth, but we are just starting to understand how they actually work. There’s still so much to learn.”

Ongoing research, led by the University of Sheffield's School of Biosciences, is now investigating the specific role of mycorrhizal fungi in soil carbon and nutrient cycles. By simulating future climates in specialized outdoor field experiments, this study, funded by NERC, aims to enhance our understanding of the critical contributions of soil fungi, alongside other microbes, in transferring carbon below ground and how these processes will be affected by future climate change.