November 9, 2011
Proposals to remove the carbon dioxide caused by burning fossil fuel from the atmosphere include letting commercially managed forests grow longer between harvests or not cutting them at all.
An article published in the journal Forests says, however, that Pacific Northwest trees grown and harvested sustainably, such as every 45 years, can both remove existing carbon dioxide from the air and help keep the gas from entering the atmosphere in the first place. That’s provided wood is used primarily for such things as building materials instead of cement and steel – which require more fossil fuels in their manufacture – and secondarily that wood wastes are used for biofuels to displace the use of fossil fuels.
“When it comes to keeping carbon dioxide out of the atmosphere, it makes more sense to use trees to recycle as much carbon as we can and offset the burning of fossil fuel than it does to store carbon in standing forests and continuing burning fossil fuels,” said Bruce Lippke, University of Washington professor emeritus of forest resources.
Lippke is one of eight co-authors of the article in Forests. It is the first to comprehensively calculate using woody biomass for bioenergy in addition to using wood for long-lived products. The article focuses on the extra carbon savings that can be squeezed from harvesting trees if bioenergy is generated using wood not suitable for long-term building materials. Such wood can come from the branches and other debris left after harvesting, materials thinned from stands or from plantations of fast-growing trees like willow.