Burying wood waste harvested from sustainably managed forests just 2 metres underground has “huge potential for carbon capture” and, as a result, could be a low-tech, sustainable, and relatively simple way to achieve net-zero emissions. That is according to research from the US-based Cornell University, published in Nature last week.
Led by Yiqi Luo, Ning Wei and Benjamin Houlton, the study “Large CO2 removal potential of woody debris preservation in managed forests found that between now and 2100, burying debris could remove 770 and 937 gigatones of carbon dioxide from the atmosphere, which in turn could result in a reduction in global temperatures of up to 0.42 degrees Celcius.
“Based on my knowledge, this is the most effective and the least expensive, and possibly the most sustainable way to capture carbon,” Luo said, adding that if the United States – the largest producer of forest products – buried two-thirds of its debris underground, it could achieve net-zero by 2050. “There’s huge potential,” he said.
As it stands, most debris left behind through the timber harvesting process is either burned for fuel or left to decompose. Luo stresses that debris placed in the ground preserves the carbon in the soil and prevents it from escaping into the atmosphere. “(That’s because) soil is an excellent natural insulator and can naturally deplete oxygen to prevent wood debris from decomposition and carbon dioxide release.”
“So, if we bury the wood 2 metres deep, the wood can be preserved there for hundreds, or even thousands of years.”
Focusing on managed forests, sawmills, and discarded furniture, which the authors claim is the most significant source of woody debris, the method could also be applied to urban maintenance, orchards and farms. “The practice could also incentivise the removal of fire from forests in areas of high wildfire risk, reducing the amount of fuel for fires (all the while) capturing carbon,” the New York-based researchers said.
‘Wood Vaulting’: The climate solution you’ve never heard of!
Last year, Wood Central reported that the process, also known as wood vaulting, was already being deployed by the US Forest Service to remove excess vegetation and reduce wildfire risk within at-risk forests. It comes as scientists and climate tech companies alike say wood vaulting could help store some of the carbon dioxide equivalent, in the form of flammable vegetation, that the Forest Service must deal with in the coming years — an estimated 2.2 billion metric tons. That’s roughly equivalent to the CO2 emissions from cement production worldwide in 2016, and as much as forests globally removed from the atmosphere last year.
“There’s more wood in the forest than markets for it to go,” said research forester Nate Anderson, who studies product supply chains for the Forest Service’s Rocky Mountain Research Station in Missoula. Valuing the carbon stored in wood vaults could change that. If done correctly, burying the debris could help limit the release of greenhouse gases that warm the atmosphere and contribute to climate change. “I don’t see any reason why it can’t be quite significant and reach millions of tons of carbon dioxide sequestered per year, in the U.S. alone,” said Sinéad Crotty, the director of the nonprofit Carbon Containment Lab.
