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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
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    • CommentAuthortony
    • CommentTimeJun 29th 2012
     
    How do we measure CO2 or Carbon? There seems to be a lot of confusion about how to measure carbon emissions. Do we measure CO2 or just the Carbon (simplistic 44 to 12 ratio between these) ignoring methane completely.

    Then the biggie do we count in CO2 from biological sources? or from wood and biomass, or digesters? etc. This is another biggie (as you all know I think it should all be counted in)

    Without an agreed standard method of measuring carbon emissions how can we realistically even talk about reducing them?

    This whole thing is a jolly can of worms.

    Discuss!!!
    • CommentAuthorEd Davies
    • CommentTimeJun 29th 2012 edited
     
    Posted By: tonyThen the biggie do we count in CO2 from biological sources? or from wood and biomass, or digesters? etc. This is another biggie (as you all know I think it should all be counted in)

    Why? It's already in the current biosphere. The immediately concern is, of course, the amount of COâ‚‚ in the atmosphere but that's pretty much directly controlled by the total amount in the biosphere so that's what we need to keep an eye on. If burning the biomass doesn't make a long term difference to the amount of material in the land vegetation (i.e., replacements are grown rather than leaving the land deforested or otherwise with less vegetation) then it doesn't matter (much).

    It's the release of carbon from reservoirs which wouldn't otherwise be participating in the rapid exchange of carbon with the atmosphere which is the concern.

    To put it another way, the wood and biomass would have rotted, anyway.
    • CommentAuthorRobL
    • CommentTimeJun 30th 2012
     
    Does wood have to rot or be burnt and make CO2? These guys suggest burying wood deep underground, to lock the carbon away for "thousands" of years:
    http://www.cbmjournal.com/content/3/1/1
    • CommentAuthorGavin_A
    • CommentTimeJun 30th 2012 edited
     
    Posted By: RobLDoes wood have to rot or be burnt and make CO2? These guys suggest burying wood deep underground, to lock the carbon away for "thousands" of years:
    http://www.cbmjournal.com/content/3/1/1" rel="nofollow" >http://www.cbmjournal.com/content/3/1/1

    the problem being that any wood we're 'locking away' like that is being offset by the coal we'd be burning instead, and that coal really is locked away well out of the active carbon cycle.

    it's possibly something for 100 years down the line if we're no longer burning fossil fuels at all,but right now it's madness.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012 edited
     
    I am with Tony, we should count all carbon combustion equally and measure it in tonnes of CO2.
    As for trees rotting and producing methane, do they do it at the same rate as burning that same tree? Is burnt biomass replaced with new growth at the same rate? Is offsetting CO2 really the way to reduce atmospheric CO2?
    • CommentAuthorJoiner
    • CommentTimeJun 30th 2012
     
    And hasn't this been covered in the MASSIVE biomass thread?

    Or is Tony actually asking a very specific question regarding a very important distinction?

    I suspect the latter. :wink:
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012 edited
     
    Posted By: SteamyTeaI am with Tony, we should count all carbon combustion equally...

    Again, why? It seems to me to completely miss the point.

    It's like trying to estimate the rate a pond is filling up from a stream but rather than just looking at the amount of water flowing in the stream instead including the water swirling from the south half of the pond to the north half without taking any notice of the amount swirling from the north half to the south half (the north half being analogous to the atmosphere and the south half to the land and sea carbon reservoirs).

    Last night I edited my post above to read “...then it doesn't matter (much).” I added “(much)” because the timing of carbon emissions and the short-term movement of carbon from the land/sea to the atmosphere and back does matter a bit but in the long run it's the cumulative addition of carbon to the overall active system that matters.
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012
     
    Posted By: RobLDoes wood have to rot or be burnt and make CO2? These guys suggest burying wood deep underground, to lock the carbon away for "thousands" of years:

    Without getting sidetracked on the sense and practicality of that particular suggestion, I think it is reasonable to count any carbon which is put into long-term storage, away from interaction with the atmosphere, as a negative emission.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012 edited
     
    Posted By: Ed DaviesAgain, why

    So that emissions and sequestration can be accurately accounted for.
    Which is what you suggest in your second post.

    Trouble with biomass burning is that there is an assumption that for every tonne of CO2 produced, an equal amount will be captured and stored. Why should that be, is there evidence to show that this is actually happening.
    • CommentAuthorJoiner
    • CommentTimeJun 30th 2012
     
    Apparently, which is why the biomass burning issue thread came about and went on for so long. :sad:
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012 edited
     
    Is it still going, should it be linked to here, or the other way around :bigsmile:
    • CommentAuthortony
    • CommentTimeJun 30th 2012
     
    I didn't really want to discuss this but it is crucial, as I see it the ability of the biosphere to remove carbon is fixed at any point in time so it all carbon added should be counted.

    We talk about emissions -- if something is emitted the should be counted.
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012
     
    Emitted from where to where? I think it's emissions into the overall biosphere which should be the concern.

    Talking about just the atmosphere is pointless as we can't easily account for flows between the atmosphere and the land/sea. Those flows are very large compared with the releases of fossil carbon and reach a new equilibrium pretty quickly (a few years, I think) with about 40% of any extra carbon finishing up in the atmosphere, the other 60% being split between the land and oceans somehow.

    It's the flows in and out of the overall biosphere (combination of land life, sea life and dissolved carbon, and atmospheric carbon) which is key. Natural flows in are mostly COâ‚‚ from volcanoes and out is laying down of carbon on the sea bed. These flows are much smaller than those within the biosphere, that is between the land, sea and atmosphere. It's the balance of these smaller flows which we are upsetting by re-introducing fossil carbon into the biosphere. Therefore, to a first approximation, it only makes sense to worry about emissions which are upsetting that balance.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012
     
    Not sure if I am following you completely there Ed, but, as weather seems to be affected by atmospheric CO2, anything that releases it into the atmosphere, even for a short time, allows more energy to be stored in the atmosphere. This leads to greater variation in the weather from the previous norm (however/whenever you want to measure that).
    So it is the atmospheric concentration change that is important, not the overall amount that has been transferred. Of have I missed your point.
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012
     
    Posted By: SteamyTeaSo it is the atmospheric concentration change that is important, not the overall amount that has been transferred. Of have I missed your point.

    As you say, it's the amount of COâ‚‚ in the atmosphere which matters and burning a log you dragged in from the woods behind your house emitting a kilogram of COâ‚‚ or burning some oil or coal emitting a kilogram of COâ‚‚ will have the same immediate effect. However, burning that log has left a hole in the land vegetation which can be filled by a plant which absorbs that kg back again. Obviously one silly little log is difficult to account for - it's the principle of the thing. If we stopped burning logs then the level of COâ‚‚ in the atmosphere would go back to normal pretty quickly (within a few years) and, anyway, the effect of human log burning is pretty small compared with the large flows of carbon between the land and atmosphere.

    On the other hand, that kilogram of COâ‚‚ from a fossil source does not have a hole to run to. It'll increase the amount of carbon in the atmosphere by 1 kg immediately but about 600 g of that will be absorbed by the land and ocean pretty quickly (increasing their overall carbon mass). The remaining increase of 400 g in the atmosphere will stay there for a long time (hundreds of years). Of course, the individual carbon atoms will move back and forwards pretty quickly (the residence time of a COâ‚‚ molecule in the atmosphere is about 5 years on average, IIRC) but the total amount in the whole biosphere has increased by the 1 kg and 400 g of that is the atmosphere's long-term share.

    It's the long-term cumulative effect of slowly increasing the total amount of carbon accessible to the atmosphere which is the problem.
    • CommentAuthortony
    • CommentTimeJun 30th 2012
     
    I dont follow the logic at all. but if your last sentence is true the it would follow that all and any reductions in the amount of combustion would be beneficial.
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012
     
    I'm finding this conversation really quite frightening and dispiriting.

    From where I'm sitting it looks like some educated, intelligent, interested people don't have even a quite elementary understanding of such a prominent issue. Maybe I'm bad at explaining the matter but really, after all this time, it's not something which should need explaining. Of course, maybe I've misunderstood something myself - perhaps somebody else will pop along later and put me right. However, I do think my understanding is close enough to right that blank incomprehension on anybody else's part is not totally my fault.

    Of course, the typical press coverage is pretty appalling but you don't have to dig very deep to get a better idea.

    What else can I usefully say?
    • CommentAuthorSeret
    • CommentTimeJun 30th 2012
     
    You just can't treat carbon from geological sequestration the same as carbon that's come from biological sequestration. The two are entirely different animals. The problem isn't the carbon that's always been in the carbon cycle, it's the carbon we're adding to the cycle that is the issue.

    Biomass should have a CO2e rating, but due to the formation of soot, oxides of nitrogen, etc, not from its actual carbon IMO. Any carbon that has been shifting through the carbon cycle any time between now and the industrial revolution should be zero-rated. Carbon sequestered before then and foolishly dug up and released by us should be counted in full.
    •  
      CommentAuthorDamonHD
    • CommentTimeJun 30th 2012
     
    I'm with Ed and Seret on this, entirely.

    Plus a little bit more needs to be added to the CO2e to allow for processing and transport.

    But basically biomass burning remains, in my books, zero carbon.

    Rgds

    Damon
    • CommentAuthorRobL
    • CommentTimeJun 30th 2012
     
    Yes, biomass burning is zero carbon. Something will grow in its place - I don't think anyone disputes that.
    However burying biomass for extended periods is negative carbon.

    It's common to protect woodland/rainforests, funded by carbon offsetting, preventing logging and deforestation. I see it as a natural progression of this to artificially enhance woodland capability of long term carbon storage. Maybe somebody will pay to have wood buried in the future, whilst maintaining the health of the forest?
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012 edited
     
    I think I am starting to see where I may have been misunderstood.
    I am not saying, and never have, that burning fossil fuel instead of burning biomass is better, good, lower CO2. I think some people have misunderstood me here.
    What I have said is that any burning is a bad thing, and if it is carbon based, it adds to atmospheric CO2.
    I then go on to say that sequestration is a method of reducing atmospheric CO2. So if there is a choice between burning timber, and sequestering it, then why not sequester it (in buildings, deep mines, bottom of oceans, where ever it will cause no harm).
    That does not mean I have been saying that we are better off burning coal, oil or gas, I want that to stop as well.

    As for the 'hole left in the ground to grow something in'. It is not as simple as that. You cut a tree down, you can't plant another one in the same place as there is either a stump there, no soil (removing soil releases CO2 as well) or it has something less useful growing there, like grass or a rose. So if you start to calculate, and it was done endlessly on the two biomass threads, you soon find to meet even a fraction of our energy needs, you need to expand the growing area rapidly, it does not go into equilibrium, sadly.
    I think I mentioned that if you cut a forest down and sequester that timber and replaced it with PV, you would be better off in both long term energy production and CO2 terms. Not that I am suggesting that we must do this, or that it is even desirable.
    Trouble with biomass is that it is even worse that wind when it comes to energy density per square meter, and that is the problem. It also does not distinguish where it gets its atmospheric CO2 from, nor is growth rate a straight line to atmospheric CO2.

    Where I think you may have got confused in my thinking is that I have not been clear enough about alternative methods of generation to repay all combustion. What I did say, with regard to that paper about burning gas as against biomass, is that I agree that for each kWh from gas or each kWh from biomass, you are better off burning gas and offsetting that with carbon sequestration (which was what the paper was about), but it is better not to burn the gas or the timber if you can.
    Is that clearer?
    • CommentAuthorEd Davies
    • CommentTimeJun 30th 2012 edited
     
    Posted By: SteamyTeaI am not saying, and never have, that burning fossil fuel instead of burning biomass is better, good, lower CO2. I think some people have misunderstood me here.

    I don't think anybody thought you were suggesting that burning fossil fuel is actually better than burning biomass, only that the the two are roughly equivalent.

    What I, and I think Seret and DamonHD, would assert is that burning biomass is essentially zero carbon apart from some second-order issues to do with timing, processing and secondary combustion products.

    (Burning biomass is a lost opportunity to sequester it. Burning fossil fuels is a lost opportunity to leave it in the ground.)
    •  
      CommentAuthorSteamyTea
    • CommentTimeJun 30th 2012
     
    Those second order issues are pretty big I think, the timing being the really big one with respect to CO2, but another thread for that :wink:
    • CommentAuthortony
    • CommentTimeJul 1st 2012 edited
     
    So when it comes to measuring carbon emissions almost all emissions from wood and biomass are ignored, is that how we have managed to reduce carbon emissions so nicely during the last few years then?
    • CommentAuthorEd Davies
    • CommentTimeJul 1st 2012 edited
     
    Going back to the original question:

    Posted By: tonyThen the biggie do we count in CO2 from biological sources? or from wood and biomass, or digesters? etc. ...

    Count for what? I've been assuming something like “count as emissions for the purposes of laws intended to mitigate global warming” but maybe Tony had something else in mind.


    Edit: Ahah, just seen Tony's post. So he's asking not whether they should or shouldn't count but literally are they counted now. Fair question. I imagine not but don't know for sure.
    • CommentAuthorSeret
    • CommentTimeJul 1st 2012
     
    Posted By: SteamyTeaSo if there is a choice between burning timber, and sequestering it, then why not sequester it (in buildings, deep mines, bottom of oceans, where ever it will cause no harm).


    As much as we all want long-term sequestration to work and solve all our problems, it's looking more and more likely from what I've read that it both won't work and will be too expensive. Which is a severe bummer IMO, as the problem is going to be immensely harder to solve without it.

    I hope I'm wrong on that, but I don't think we're going to see any sequestration on a meaningful scale any time soon.
    •  
      CommentAuthorDamonHD
    • CommentTimeJul 1st 2012
     
    I think we should go on trying, but should not bank on it.

    Rgds

    Damon
    •  
      CommentAuthorSteamyTea
    • CommentTimeJul 1st 2012
     
    Go along with that.
    Probably best not to get the Banks involved :devil:
    • CommentAuthorJoiner
    • CommentTimeJul 1st 2012
     
    SteamyTea: "Those second order issues are pretty big I think, the timing being the really big one with respect to CO2"

    Absolutely, totally, incontrovertably, which is why MAN-MADE crap is the deciding factor in whether or not we've well and truly friggin well made a complete balls-up of the planet.

    Left to itself, the planet could cope with having every volcano on its surface having a go at the same time, but only because it would be able to utilise its resources to do that in its own time - millenia - whereas adding mankind into the mix rather buggers up the sums because it (mankind) has its own agenda, survival.

    Parable of the day (it being Sunday)...

    Give a team of guys an axe each and let them work their way through a rainforest. By the time they (or more probably their grandchildren) reach the other side they'd be able to just turn around and work their back across the forest and it would take them the same amount of time, and continue the same cycle throughout time.

    But give the same team of guys a chain-saw each and suddenly the rainforest has a big problem.

    Mankind's "problem" was the Industrial Revolution and the advances in medicine that have seen us living longer.

    The Earth's "problem" started when we crawled out of the swamp and decided to live on the land.
    •  
      CommentAuthorSteamyTea
    • CommentTimeJul 1st 2012
     
    I think the problem started when we anthologised nature. There was an interesting programme about animals on the radio during the week. The main thing was not about the 'gay' penguins, but how the researchers/press put that label on them.
    Playing Devils Advocate, what is the planet for?
   
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