Even after a tree is chopped down the timber continues to hold carbon, preventing it being released into the atmosphere. The more we can make things out of wood, known as ‘harvested wood products’, then the more carbon will be sequestrated. Building in wood is one of the easiest ways to capture carbon. The development of engineered timber products such as Cross Laminated Timber (CLT), enables wooden buildings to be built at a height and scale previously impossible.
The world’s tallest wooden building stands 18 storeys high in Vancouver, Canada but work is underway in Vienna, to build 24 storeys and in London a 25-storey building has been commissioned.
Building in timber also has a substitution impact, replacing steel and concrete two materials that have big climate change footprints. In fact the manufacture of concrete is responsible for 8% of global carbon emissions. Conversely 1 cubic meter of Cross Laminated Timber holds 1 ton of CO2.
Wood is five times lighter than concrete so instead of say 70 deliveries to a construction site of concrete in heavy goods vehicles (think air pollution) we can replace this with only 10 lorry loads of wood.