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
