An advertisement currently played over and over on television extolls the virtues of wood for building which, despite being given some credence through its sponsorship by Planet Ark, does require clarification.
The scene is set in a forestry nursery, where the narrator stresses these seedlings soak up carbon from the atmosphere as they grow, and when eventually used to build houses, that carbon is safely stored.
This message is only partly true, and the seedlings are undoubtedly used in plantations specifically to supply our insatiable demand for timber, but not all will end up as house frames. A large percentage will be used for garden fences, out-door decking and even for paper manufacture, all of which have short life spans, and will be disposed of in land-fill or burned, releasing the carbon back into the atmosphere within just a few short decades.
If a particular plantation tree is deemed worthy of being cut for house construction, just what percentage of that tree will be stored? Well, not much as it happens, and the following figures are very generous. Less than 40% of the average plantation tree is taken to the mill, 60% comprising the stump, root system and crowns, is left behind to be burned or to rot in the ground.
As well, after reaching the mill, a surprisingly small portion of the log provides timber. At an Upper House land use inquiry in 2013, respected local mill owner, the late Spiro Notaras, explained the salvage rate for smaller logs averages about 28%. That's about a quarter of each log actually becoming lumber, and while the remaining 70-75% is not always wasted, either burned to generate heat or electricity, it's still releasing carbon dioxide back into the atmosphere.
So, at best only about 10% of a tree's mass the ends up being stored in buildings.
This would seem to be one of many good arguments to stop logging native forests, but instead we are currently clear-felling them at a financial loss. Where's the logic?
- John Edwards
This article was originally published in the VOICES FOR THE EARTH column in The Daily Examiner on August 5, 2019