Why all this discussion about wood?
Well, on October 15, 2012, the United Nations Economic
Commission for Europe (UNECE) held the Green Life of Wood – Life CycleAssessment Workshop which was tasked to review the environmental impacts of
wood from “cradle to cradle.” I have seen a few Youtube videos on the benefits
of transforming wood into biofuel – a claimed carbon-neutral system through a
balance of carbon sequestration during tree growth/re-growth and carbon release
during combustion. The presentation by
Nicolas Mainville, a Greenpeace Canada representative, points out the potential
for carbon mis-accounting, especially for large material exports between North
America and Europe. This, along with the
potential environmental trade-off with regard to high water demands and potential
water quality impacts due to urban runoff and air quality impacts of combustion
makes me less-than-enthusiastic about biofuels in general, let along wood
biofuels (see earlier comments in the post Energy
from your toilet...).
Sylvain Labbe proposed a series of taxes to provide a financial
protection against a wood-industry related Tragedy of the Commons. I studied this is solution/theory extensively
in school. Theoretically the market
system will balance out negative environmental impacts provided sufficient
economic drivers. The problem in
implementation is “taxes” – they are politically unpopular, difficult to
establish and then, as shown by the insanely complex US tax legal system, can
be relatively easy to circumvent to loop-hole around. Also, there arises the question of how a
market functions when the system has limited to no resources to draw upon… Here
I pointedly make an example of attempts for water trading/banking and function
of the Australian water markets during the 12 year drought that recently ended.
I love the idea of the economic market-based solution, but I have difficulty relying on that model.
Still, I like the idea of non fossil fuel sources of energy and pushing for sustainable building materials. Every technology and emerging solution has a slow start-up and sustainable wood, may indeed be sustainable in the long term. I continued my research on specific trees that are proposed to be sustainable and found:
·
Cork oak, a slow-growing tree used to create cork,
can be harvested/stripped up to 16 times during its 200 year lifetime. Cork is
used for wine bottle stoppers and certain building materials.
· Poplar, a fast-growing species of tree that produces soft, light weight wood used for biofuel and/or materials constructed for light-weight and cheapness rather than durability.
·
Pongamia pinnata / karum tree / poonga-oil tree,
a fast-growing, drought hardy evergreen that thrives in hot-dry climates and
supposedly does not require pest control and as a non-food crop can be grown on
marginal lands.
·
Bamboo is an incredibly light, tough building material that can be harveted within 3-5 years (compared to 10-20 years for most soft woods). Bamboo is used for scaffolding, fences, bridges, furniture, flooring and bricks. Bamboo is a popular sustainable wood, with draw-backs. It is water thirsty. It is a key food for the endangered Giant Panda and improper harvesting can be harmful. It growth like a weed and can become an invasive plant if not maintained properly.
· Teak, an exotic hardwood from Asia, has a reputation of being sustainable. Native trees have become engangered by overharvesting - there are a few sustainble farmed options, but in general, environmentally sound teak is hard to come by - Burma is the only country that still exports teak from natural forests, mostly illegal.
Articles also looked at the sustainability of Ash (typically
only farms because forests have been destroyed), Pine (same as Ash), Mahogany
(mostly endangered), and a variety of other woods. The jury is out on wood as a
sustainable building material and possible biomass, but this research definitely
opened my eyes to the need to be very careful about all wood purchases made in
the future!
