Fungi are prodigious decomposers, but of their many biochemical achievements, one of the most impressive is this ability of white rot fungi to break down the lignin in wood. Based on their ability to release free radicals, the peroxidases produced b white rot fungi perform what is technically known as “radical chemistry.” “Radical” has it right. These enzymes have forever changed the way that carbon journeys through its earthly cycles. Today, fungal decomposition — much of it of woody plant matter — is one of the largest sources of carbon emissions, emitting about eighty-five gigatons of carbon to the atmosphere every year. In 2018, the combustion of fossil fuels by humans emitted around ten gigatons.
That is from the new and excellent book by Merlin Sheldrake, Entangled Life: How Fungi Make Our Worlds, Change Our Minds & Shape Our Futures.