RE: [GreenYes] Digest for greenyes@googlegroups.com - 4 Messages in 3 Topics
Jeffrey Morris
Norm,
Apparently you didn’t see my posting Garbage and Biomass Combustion Warning Labels about two weeks ago. Otherwise you would have known that my response to your claims regarding wood burning was in fact based on just the sort of comprehensive life cycle analysis and assessment that you indicate one should carry out in order to compare household energy sources. If you want to see the detail involved in our analysis, check out Appendix D: LCA Example – Clean Wood Waste Management in our recently completed life cycle assessment of waste management alternatives for the Vancouver, BC metropolitan region. You can download that report from the subscribers’ area of our website (www.zerowaste.com) or from http://www.belkorp.ca/Dr_Morris_Report.pdf .
I mainly focused on the emissions from combustion in my response to your claims because the environmental impacts from the upstream portions of the life cycle for wood are small compared to the combustion impacts. For wood combustion in wood stoves and furnaces at home the combustion climate change impacts are nearly 5 times the upstream impacts. For the human respiratory impacts wood combustion impacts are over 75 times the upstream impacts; for human carcinogenicity impacts wood combustion impacts are more than 330 times upstream impacts; and for ecosystems toxicity wood combustion impacts are 14 times larger than upstream impacts. These estimates are from our Consumer Environmental Index (CEI) model that we created for our WA State Department of Ecology. That report is available at our website, along with a brief description of the study. Our article (Scott Matthews - Carnegie Mellon University School of Engineering and Green Design Institute and me) on the CEI is almost through the peer-review process and will soon be available in the Journal of Industrial Ecology published by Yale University.
The life cycle inventory and assessment data for the CEI are the basis for my rebuttal of your claims that wood burning at home is environmentally beneficial. The CEI covers all forms of household fuels – natural gas, fuel oil, coal, wood, and bottled gas. It also covers electricity. It turns out that because trees uptake heavy and transitional metals from the soils where they grow, just as they uptake (i.e., sequester) carbon dioxide from the air, wood combustion emits heavy metals at a rate per Btu that is comparable to coal and much higher than natural gas. In addition, the lignin in wood contributes to the formation of some rather nasty organic compounds when wood is burned. (Recall that wood provides the source for the solvent turpentine.) All in all, in terms of human health and ecosystem impacts wood is as dirty as coal and much dirtier than natural gas. So while wood is somewhat lower in GHG emissions than natural gas per Btu of heat energy (not a lot because it takes a lot of wood to generate then same Btus as a little natural gas, and as the report I referenced in the first paragraph above makes clear, there are substantial GHG emissions from the upstream activities required to prepare wood for combustion whether in an industrial furnace or boiler or home wood stove or furnace), the human health and ecosystem damages from wood combustion far outweigh its small GHG benefits versus the gaseous fuels.
And it is important to acknowledge that wood combustion has GHG benefits relative to gaseous fossil fuels only if the biogenic carbon dioxide emitted when wood is burned is re-sequestered by new tree growth. According to recent EPA information, it takes more than a hundred years to re-sequester the carbon released when wood is burned. That makes it almost impossible for wood to be a serious energy source unless we start re-planting temperate and tropical forests at such a rate that their land area is expanding rather than shrinking. Furthermore, on a 20-year time horizon that expansion would essentially be non-feasible for wood to be available as a significant energy source while at the same time new tree growth was sequestering carbon at a rate high enough each year to offset the biogenic carbon emissions from wood combustion. In other words, wood emits carbon just as fossil fuels do when combusted. All that carbon counts towards global warming. It is only the assumed offset from new tree growth that gets wood combustion off the global warming hook. Expand wood combustion in any significant way and that offset becomes less than the carbon emissions from wood burning.
Finally, I haven’t done the life cycle analysis of wood versus electricity for home heating. But I’m betting that the environmental impacts of using electricity for home heating, even given the loss of more than 2/3rds of the heat energy in generating electricity from fuels, is better than using wood. In short, wood is a nasty, dirty fuel for use only in the most dire of circumstances.
Jeffrey Morris
Norm Ruttan <normr...@iwastenotsystems.com> Nov 22 05:40AM -0800
Hi Jeffrey,
Thanks. You make some good points.
I used the wood pellet stove eg only to illustrate that biomass is not
all black and white, and was not completely black and white in the
1990's when I bought my stove.
Please note that wood stoves, and wood pellet stoves have a very
different emissions profile. http://www.treehugger.com/files/2007/04/ask_treehugger_12.php
And if we were going to compare natural gas to locally produced wood
pellets, smokestack emissions are just one part of the equation.
For the wood pellets, we need to look at the whole sawmill/wood chip
industry to tally up the gross and net effect on the earth. And we
need to know if the wood pellets are a byproduct, or a direct source.
In my case, my pellets are hardwood sourced from the Quebec hardwood
mills. However last winter I ran out of pellets, and the source was
pine beetle killed standing wood from British
Columbia, which I assume
came cross country by train. Different source, different energy
profile, different conservation profile, different assessment.
Ditto for the natural gas industry, so for eg. we need to include the
gas drilling industry, the pipeline industry, etc.
For eg. the folks who live near natural 'sour gas' wells in Alberta
would not compare natural gas so favourably to wood.
http://www.cbc.ca/canada/edmonton/story/2009/11/13/ercb-lifts-sour-gas-suspension.html
Then we need to understand that the natural gas is finite, and will in
a few (dozen? hundred?) years run out as the gas accumulated by the
earth of its history is exhaustible. Whereas wood is renewable, to the
point that we use it in a sustainable way (not clearcutting
Massachussetts for eg).
http://www.eponline.com/Articles/2009/11/11/Massachusetts-Studies-Biomass-Sustainability-before-Setting-RPS-Criteria.aspx
In my case, it's a moot point. I don't have access to natural gas.
So I would need to look at propane, fuel oil, electrical, or solar
(which industry has its own emissions from manufacturing,
transportation, installation, etc). In 1997 when I bought my wood
pellet stove, none of the others were attractive to me. Solar is good,
except I live in Canada
and cold winter nights don't work well for
solar except in a super-insulated house (mine is a solar house built
in the 70's).
Again though, I'd have to do a complete 'full cost assessment' for
each of the above, not just look at local emissions.
It will be good for the industry/EPA to do/publish some of those
assessments.
In any case, the cat is out of the bag. Wood waste from New York is
currently travelling by ship across the Atlantic,
to co-fuel coal
fired electricity plants in Europe (to reduce
Greenhouse Gas
Emissions). Expect a lot more of this. Co-generation at pulp and paper
mills is common.
The trick will be to steer it in a more, rather than less sustainable
direction.
Norm
Justin Stockdale
While I can certainly not dispute your excellent "scientific" analysis, I do not think that your process even begins to comprehend the dire consequences related to the production of the "better" fuel sources you cite. It may be well and good that wood is an inferior fuel source in terms of emissions at the source of heat production, but the impacts of oil, gas and coal production on the environment are not at all limited to GHG. Take a drive through SW Wyoming, or central Appalachia or the north slope of AKand witness the dramatic and real impacts of these sources of energy. While I also will not (and have not) supported the industrial use of biomass for fuel, the use of cord wood for residential heat production is a wholly different matter. The few Americans who continue to rely on wood to heat our homes are typically conscientious gatherers and not clear cutters. For instance, my cut for this winter consists solely of dead and down trees, and not a clear cut of a local old growth forest. While impossible to substantiate, I suspect that those who rely on wood have similar ethics to myself.
You may argue that GHG emissions trump all other environmental concerns? If this is the case, then debating the implications of a particular fuel source is relatively inconsequential. The greater impact will be achieved in efficiency of use including no flue systems and improvement to heat retention and holding capacities of structures. Heat loss is the greater enemy...the fuel source is secondary. If we look at a more complete picture which includes immediate habitat loss and segmentation, ground water contamination and consumption and waste management and waste toxicity... Electric heat for example relies on a grid system which now ignores their impact in the name of green energy...in NM, a proposed high voltage transmission line is to bisect a national wildlife refuge on the rocky mountain flyway and a wilderness area in the name of green energy to heat and cool the homes of Phoenix. While the power may be somewhat benign the distribution comes at an unacceptable cost.
I have said this before on this list...we all need to remember that we each live within the confines of our own particular bubble...only when we begin to explore the balance of this country and the world can we begin to understand the implications of our beliefs. A no burn policy may make sense in Seattle, but take a look at West Virginia and the deep consequences of coal and try to prove that coal is a better source of heat for my home!
In The Spirit of Debate,
Justin Stockdale
Jeffrey Morris wrote:
--
You received this message because you are subscribed to Google
Groups "GreenYes" group.
To post to this group, send email to Gree...@googlegroups.com
To unsubscribe from this group, send email to
GreenYes+u...@googlegroups.com
To change email delivery options visit http://groups.google.com/group/GreenYes?hl=en
Jeffrey Morris
Justin,
You apparently missed the references to the life cycle analysis on which I am basing my conclusions. The impacts covered by those life cycle analyses include not only climate change but also human toxicity, human carcinogenicity, human respiratory disease, ecosystem toxicity (which is definitely related to habitat viability), acid rain (definitely related to the acidity of the oceans and other water bodies), and water bodies eutrophication (also related to habitat viability). In addition, all these impact calculations include emissions from the extraction, refining, production and transportation of fuels (those activities in the fuel life cycle are what the word “upstream” refers to).
I am not disparaging your ethics, but I am wondering about the extent to which you were paying attention or have examined the sources I mentioned that are the basis for my conclusions. Please re-read and you’ll see that I didn’t suggest using coal. What I did say was that wood is as dirty as coal, and more than twice as dirty as natural gas. So I’m suggesting that wood burning should not replace gaseous fuels in the near term, and that we continue to use natural gas or other gaseous fuels until we can ramp up our solar and other truly renewable and clean energy sources. I would also suggest that you figure out how to replace your wood based heating system with something better for your immediate environment as well as our global environment.
Thanks for taking time to make comments!
Jeffrey Morris
Norm Ruttan
I'm unable to spend time with your report immediately, but will review
it asap. It sounds as if it's exactly what I've been looking for.
One thing that jumped out at me from your note below, is that given
what you've said about combustion of wood, should we be concerned
about prescribed burns which are used by conservation agencies (Parks
Canada, National Park Service, Forestry Departments, etc) to simulate
the natural regime that existed in much of North America over the
millenia?
Once I get a chance to review your work, I'll respond in more detail.
Regards, Norm
On Nov 23, 8:22 pm, "Jeffrey Morris" <jeff.mor...@zerowaste.com>
wrote:
>
> Apparently you didn't see my posting Garbage and Biomass Combustion Warning
> Labels about two weeks ago. Otherwise you would have known that my response
> to your claims regarding wood burning was in fact based on just the sort of
> comprehensive life cycle analysis and assessment that you indicate one
> should carry out in order to compare household energy sources. If you want
> to see the detail involved in our analysis, check out Appendix D: LCA
> metropolitan region. You can download that report from the subscribers'
> I mainly focused on the emissions from combustion in my response to your
> claims because the environmental impacts from the upstream portions of the
> life cycle for wood are small compared to the combustion impacts. For wood
> combustion in wood stoves and furnaces at home the combustion climate change
> impacts are nearly 5 times the upstream impacts. For the human respiratory
> impacts wood combustion impacts are over 75 times the upstream impacts; for
> human carcinogenicity impacts wood combustion impacts are more than 330
> times upstream impacts; and for ecosystems toxicity wood combustion impacts
> are 14 times larger than upstream impacts. These estimates are from our
> Consumer Environmental Index (CEI) model that we created for our WA State
> Department of Ecology. That report is available at our website, along with
> a brief description of the study. Our article (Scott Matthews - Carnegie
> Mellon University School of Engineering and Green Design Institute and me)
> on the CEI is almost through the peer-review process and will soon be
> available in the Journal of Industrial Ecology published by Yale University.
>
> The life cycle inventory and assessment data for the CEI are the basis for
> my rebuttal of your claims that wood burning at home is environmentally
>
> Norm Ruttan <normrut...@iwastenotsystems.com> Nov 22 05:40AM -0800
> Hi Jeffrey,
>
> Thanks. You make some good points.
>
> I used the wood pellet stove eg only to illustrate that biomass is not
> all black and white, and was not completely black and white in the
> 1990's when I bought my stove.
>
> Please note that wood stoves, and wood pellet stoves have a very
> And if we were going to compare natural gas to locally produced wood
> pellets, smokestack emissions are just one part of the equation.
>
> For the wood pellets, we need to look at the whole sawmill/wood chip
> industry to tally up the gross and net effect on the earth. And we
> need to know if the wood pellets are a byproduct, or a direct source.
> In my case, my pellets are hardwood sourced from the Quebec hardwood
> mills. However last winter I ran out of pellets, and the source was
> pine beetle killed standing wood from British Columbia, which I assume
> came cross country by train. Different source, different energy
> profile, different conservation profile, different assessment.
>
> Ditto for the natural gas industry, so for eg. we need to include the
> gas drilling industry, the pipeline industry, etc.
>
> For eg. the folks who live near natural 'sour gas' wells in Alberta
> nsion.html
> Then we need to understand that the natural gas is finite, and will in
> a few (dozen? hundred?) years run out as the gas accumulated by the
> earth of its history is exhaustible. Whereas wood is renewable, to the
> point that we use it in a sustainable way (not clearcutting
> stainability-before-Setting-RPS-Criteria.aspx