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Cathleen,
While I agree with your desire to preserve trees in areas with high-rise developments your letter in the Times and your posting online do not pass scientific muster.
First, trees are not the best form of carbon sink in the lower mainland. Rather, peat bogs like Burns Bog in Richmond or the bogs in the Derby Reach area are the best form of carbon sinks. Unlike trees, which ultimately release carbon when they die, peat bogs permanently fix carbon (in the form of peat). On an acre-by-acre basis the protection and preservation of peat bogs should be your first choice if the reduction of greenhouse gases was your primary concern.
Furthermore, trees do not store carbon dioxide as described in your letter. Trees use carbon dioxide in their metabolism. During metabolic processes small volumes of carbon dioxide will be retained in the leaves and needles of a tree but your 231 cm diameter western red cedar does not store 734 kg of carbon dioxide. Your tree will metabolize large quantities of carbon dioxide over the course of a year, but the vast majority of that carbon dioxide is returned to the atmosphere through metabolic processes and the decomposition of lost biomass. Carbon sequestering occurs when carbon is bound into woody materials (lignins) that form the structural component of trees. Elemental carbon makes up about 25% of the mass of a live tree and about 50% of a dried tree (50% of the mass of a live tree is water).
Of note, you may want to check the numbers you cite. I’m not sure what resource you used to get your numbers but they seem a bit odd and may have accidentally been reversed. Carbon makes up 12/44 th of the weight of carbon dioxide so if you had 2,686 kg of carbon dioxide it would contain 733 kg of carbon which is almost exactly the reverse of the numbers you quote in your posting.
Regarding carbon sequestering, a 147 cm diameter tree may hold the carbon equivalent of 3206 kg of carbon dioxide but at that point it will not remove carbon dioxide from the atmosphere at anywhere near the rate of a young tree. Trees sequester carbon dioxide as they gain biomass and when they stop gaining biomass they cease to sequester carbon dioxide. For most conifers the maximum rate of carbon sequestering occurs somewhere between 5 and 20 years into their life cycle. After that time the rate of carbon sequestering goes down. Once a tree is mature it ceases to serve as a carbon sink and becomes a source of carbon compounds to the atmosphere. Ultimately, when a tree dies, unless the wood is preserved, the carbon will be returned to the carbon cycle. Ironically for climate change calculations, a significant percentage of the biomass is decomposed anaerobically resulting in the production of methane. Since methane has a 21 times greater effect on global warming than carbon dioxide the anaerobic degradation of plant biomass can sometimes result in an increased in net forcing than if the plants had never sequestered the carbon dioxide equivalents in the first place.
Just to summarize, if you were carrying out cold-blooded greenhouse gas math the best approach would be to cut down all the trees on the lot; build your structure with the mature wood you cut (thus preserving the wood and preventing its decomposition); and then plant a large number of native conifers to replace the trees you cut down. Thus you would have prevented the decomposition of the mature trees and the young trees would quickly reach their maximum carbon sequestering years. I’m going to guess, however, that this approach would not get the environmental seal of approval 
A final note..this is one that I would have thought LFP would have caught, Councillors Richter and Bateman did not abstain on the vote, but rather both voted against the high-rise proposal.
Cheers,
Blair
Cathleen & Blair, is the Dickson Pit as written about by THE PROVINCE a bog or similar that the Township just sold? Any Environmental consequences or considerations?
http://www.kimrichter.com/Blog/2...sh-
langley.html
LFP,
I'll write more on this one later. I have worked extensively in that area and can give you the quick overview now.
The property is a really mixed bag. The southeast is higher than the north. There used to be a road access from that area (off 104) but the road is usually blocked. Part of the northeast of the property is still listed as an active gravel pit (when I last heared it was still in use as a source for emergency sand for sand bags). This side is quite hilly and is about 20 m to 30 m higher than the rest of the property. That area is sometimes used by the Scouts for camping and often used by local teens for drinking. The property drops down to the east where it borders onto an old mill and the GVRD parkland (it has been proposed as a natural park for nearly forever).
The north central and northwestern portion of the site is a flat labrador tea/hard hack bog. It backs onto cranberry farms and is quite the beautiful bogland. Ecologically it is an important area and I can't imagine how you could develop it since the ground is so wet. This area can be accessed via a path that originates at the old mill and goes to the edge of the cranberry fields. It would be quite the slog to get there from the south as the bog is well established and full of happy critters.
The south-central part of the property includes an upland wetland that has a semi-permanent pond near the gravel pit and lower down is a combination bog/wetland. The west of the pond can be accessed from the end of 216th Street as there is a right-of-way there that is not well known. It varies from really wet to, you-are-going-to-get-muddy but is a haven for birds and other wildlife.
Regards,
Blair
Blair,
Perhaps you also feel that concrete, glass, and brick contribute more to disposing of carbon dioxide than cedar trees. Good grief!
Hugger,
Carbon is sequestered in trees only so long as the tree maintains its lignin content. Once a tree ceases to grow it ceases to sequester additional carbon. When the tree dies virtually all its carbon is returned to the environment as the tree decays. If you build a building with wood then that wood is preserved and does not decay, then the carbon does not return to the carbon cycle.
As for my previous posting I specifically indicated that the building be composed of wood, not brick, nor concrete.
'Ecologically it is an important area and I can't imagine how you could develop it since the ground is so wet.'
When I read this statement all I can see is the permit for 10,000 truck loads of fill.
I'm with you on this Blair, but unfortunately the Mayor and some of his boys seem to have this thing called 'fill deposits' and that would be a very quick fix for the low and boggy area and future plans for the property. Don't underestimate the damage that they can do.
Thanks Blair. I'll recommend to my friends that they cut down their cedars and use all the wood to cover their land with standing planks.
I havn't seen too many wood surfaced high rises in my whole lifetime though. They would make great Roman Candles though.
Hugger,
Might I recommend you re-read my first posting because frankly I am tired of people attributing things to me that are not correct and it is clear that you need to re-read my original posting. Right at the outset I made clear where I stood on the issue as I wrote: "I agree with your desire to preserve trees in areas with high-rise developments".
The later discussion was to demonstrate a problem with the argument being put forward. The argument in the posting was a repetition of a common fallacy in the climate change debate and so my argument was deliberately exaggerated to make a point. I made it clear that the argument was based ONLY on greenhouse gas emissions and not other ecological concerns by stating: "if you were carrying out cold-blooded greenhouse gas math". It is sad you missed all that but it is not too late to go back and re-read what I wrote. After that I will welcome any further comments or criticisms you may have.
As for your final point, I was only being partially facetious as wood and bamboo are now being reconsidered for major construction. Might I suggest you take a look at some of the modern building techniques being used in other parts of the world. The use of bamboo as a substitute for metal in bridges is no longer a wild idea but is being put into practice in China with tremendous results. In the most recent example a highway bridge over a major river was built completely of bamboo. The new multi-purpose center in Langley is going to be an all-wood construction to demonstrate to naysayers like you that wood is a viable alternative to other materials in major construction.
Willy,
Frankly I am even more worried that they will just turn it into more cranberry fields. It would be too expensive to fill the entire site if they were only going to build a residence and so some of the bog might be preserved but if they go for cranberries they could use the entire site.
Blair, you continue to wax incessantly on a subject that is not all that complicated.
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