Wooden buildings have double the climate benefit than their cement and steel counterparts: They produce less greenhouse gas emissions and can even act as a carbon sink.
A new study from the Yale School of Forestry and Environmental Studies in the US and the Potsdam Institute for Climate Impact Research in Germany has found that replacing cement and steel with wood in new housing and commercial buildings can have two major benefits for the climate.
First, it would cut the high greenhouse gas emissions associated with cement and steel production by at least half. Second, it could turn urban buildings into carbon sinks that store the carbon dioxide taken up from the air by trees that are harvested and used as engineered timber. For example, a five-storey residential building structured in laminated timber can store up to 180 kilograms of carbon per square meter. This is three times more than the above-ground biomass of natural forests with high carbon density.
However, the study authors stress that the potential of timber construction should only be realized under two conditions: the harvested forests must be sustainably managed and the wood from demolished timber buildings must be preserved on land in various forms.
“Trees offer us a technology of unparalleled perfection,” says Hans Joachim Schellnhuber says, co-author of the study and Director Emeritus of PIK. “They take CO2 out of our atmosphere and smoothly transform it into oxygen for us to breathe and carbon in their trunks for us to use. There’s no safer way of storing carbon I can think of. Societies have made good use of wood for buildings for many centuries, yet now the challenge of climate stabilization calls for a very serious upscaling. If we engineer the wood into modern building materials and smartly manage harvest and construction, we humans can build ourselves a safe home on Earth.”
Image credit: Carey Ciuro via Flickr