14 March 2023

Can soil fungi counteract climate change?

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Fungi appear to accelerate plant growth by promoting CO2 removal. A Texas company wants to explore this potential in the market for emission credits

by Matteo Cavallito

 

Revitalizing the presence of fungi in the forest microbiome to accelerate tree growth and carbon sequestration. That’s the goal of Funga, an environmental services company based in Austin, Texas, which is leading an arguably unprecedented initiative: the launch of new CO2 removal projects using soil microorganisms. The deal, worth about $4 million, involves a set of funders that includes Azolla Ventures, Trailhead Capital, Better Ventures and Shared Future Fund.

“Funga, founded by Dr. Colin Averill, Ecologist and Climate Scientist, combines modern DNA sequencing and machine learning technology with breakthrough research on the forest microbiome,” according to a statement released by the U.S.-based company. “This approach allows Funga to put the right native, biodiverse communities of mycorrhizal fungi in the right place.”

The link between fungi and carbon

Fungi play an essential role. Forests, Euronews recently pointed out, rely in fact on the invisible but crucial presence of these microorganisms: any handful of soil, for example, can contain a sequence of hyphae – the cellular filaments that form the vegetative body of fungi – that are capable of extending over a hundred kilometers. But also to interact with plant roots by providing nutrients and absorbing CO2.

The U.S. company’s initiative stems, by its own admission, from the results of a research by the Swiss Federal Institute of Technology in Zurich. The investigation, published in the journal Nature Microbiology, claimed that the reintroduction of soil microbial biodiversity can accelerate plant growth by 64 percent while in turn driving up carbon sequestration.

From microorganisms to carbon market

The potential of fungi has long attracted the interest of scientists. In November 2021, for example, a study conducted by a team of researchers led by Luiz A. Domeignoz-Horta, a microbiologist at the University of Massachusetts and the Department of Evolutionary Biology at the University of Zurich, had shown a positive correlation between the presence of these microorganisms in the soil and the soil’s lower tendency to release CO2.

The reasons are unclear, but the scientists hypothesized that the fungi are able to produce enzymes that are in turn crucial in building more stable blocks of organic compounds.

The agreement with the funders, Funga told Euronews, will allow the company to develop its software and datasets, expand its soil restoration projects, and monetize CO2 removal. The idea, in short, is to enhance the capture of the element by creating emission credits to be sold on the carbon market. Fungas goal, the news agency further details, is to sequester at least three billion tons of carbon dioxide through forest regeneration by 2050.

The potential of forests

It is too early to assess the potential of the initiative. “The carbon offsetting industry has come under intense scrutiny in recent weeks, with more than 90 per cent of projects approved by the world’s leading certifier, Verra, found to be largely worthless,” Euronews wrote. The reference goes back to a survey published in January and carried out by the British newspaper The Guardian, the German weekly Die Zeit, and the nonprofit organization SourceMaterial, which highlighted the extent of uncertainty still surrounding the emissions credit market sector.

What is certain, in any case, is that the carbon sequestration capacity of forests remains robust enough to make them an important ally in tackling climate change.

This idea now inspires several mitigation strategies starting with agroforestry, which is the development of an agricultural system that combines traditional activities – such as crops and livestock – with the planting and management of trees. This practice, said a report by Woodland Trust, an organization promoting the restoration of Britain’s forests, increases soil carbon by helping to meet climate and nature commitments. According to the study, in particular, “establishing silvopastoral agroforestry on 30% of UK grassland would result in net zero emissions from the grassland sector by 2050, and a net sequestration rate of 21 million tonnes of CO2 equivalent per year by 2062.”