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CO2 Puzzle

Discussion in 'Environmental Discussion' started by TimBikes, Mar 16, 2007.

  1. TimBikes

    TimBikes New Member

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    I'm puzzled by this - I'm wondering if anybody can explain why anthropogenic CO2 emissions are rising at an exponential rate:

    Link here

    Yet the atmospheric concentration of CO2 is rising at a linear rate:

    See link:

    Note that the first chart is ANNUAL emissions, NOT CUMULATIVE emissions. Since CO2 has an atmospheric life of something like 50-100 years, one would expect a cumulative emissions chart to be even more drastically exponential. So why should the annual increase in atmospheric levels be linear. I understand that the human contribution of CO2 is extremely small in regard to the total atmospheric CO2 - just not sure that is the whole answer.
     
  2. tcjennings

    tcjennings New Member

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    1. Your first graph is total carbon emissions, which will include all of CO2, CH4, CFCs, HFCs, etc. The second graph is only CO2.

    2. The earth's carbon cycle is still taking up about half of the carbon we put up, and it's the remaining half that is accumulating the atmosphere and causing a radiative effect.
     
  3. Betelgeuse

    Betelgeuse Active Member

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    Also, if you look over the same range in both figures, the first one is also roughly linear.
     
  4. KMO

    KMO Senior Member

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    The atmospheric CO2 graph doesn't look linear to me. It's accelerating. See, it goes up 100ppm in the first 10 years, and maybe 180ppm in the last 10. Look at it from an angle, and the curve is obvious. It could easily be a close-up of an exponential curve - it's over a very short timespan.

    And looking at the emission curve, if you just look at the 1960-2000 region covered by the first graph, that's pretty linear, or even flattening off (I've heard the flattening off attributed to the collapse of the USSR).

    On the other hand, the graphs are looking at different things - the first is a rate, the second is a total amount. If the rate were to stay constant, the CO2 might go up linearly. If the rate went up linearly, the CO2 might go up quadratically.

    Mainly what you're seeing there is a difference in scale. What you need to do is rescale the emission curve to the right time period, then convert it to a total cumulative emissions, rather than emission rates.
     
  5. DFWPrius

    DFWPrius New Member

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    Not only is just CO2 on one chart compared to total carbon on the other. It is also scale
    Total carbon in on a 200 year scale and CO2 is on just 40 years scale chart.

    Its not apples to apples.

    I am not saying your wrong, it just you do not have data on both charts matched so
    you can use them to work input points of the data.

    Try some internet mining for data, its can be done.

    Good luck on your search and keep looking.
     
  6. TimBikes

    TimBikes New Member

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    <div class='quotetop'>QUOTE(DFWPrius @ Mar 16 2007, 10:29 AM) [snapback]406848[/snapback]</div>
    I agree with all of you that there is a time scale difference and this is not apples to apples (I haven't found any cumulative emissions data) - but I'm not sure that or the other explanations are very compelling here. Again, this is annual emissions, not cumulative and the rates of change are dramatically different.

    If you look at the charts, atmospheric CO2 goes from about 315 to 370 ppmv (1960-2000), a 17% increase.

    On the same timescale, you see ANNUAL (again, not cumulative) CO2 emissions go from about 2500 to 6500 mmt/yr, a 160% increase. Because of the long atmospheric life of CO2 the cumulative increase would have to be much, much greater, but it is apparently not influencing the atmospheric concentration much.

    Even on a shorter timescale (say 1990-2000) it looks like atmospheric CO2 goes up by about 4% while ANNUAL (again - not CUMULATIVE) emissions, go up about 8% over the 10 year span. And earlier (1960-1970) it looks like about 3% increase in atmospheric CO2 vs. 40% increase in annual emissions.

    So the only explanations I can come up with are:
    - the measurements are wrong (I'm certain this is not the case)
    - most of the CO2 we are producing is not staying in the atmosphere
    - the amount we are producing is so tiny as compared to the total that it is barely moving the needle and possibly related to that, something greater that humans is driving the bulk of the annual increases and we are just layering on a small portion of the overall increase.

    OK - these are just a layperson's thoughts so I don't claim they are accurate. But I have yet to see anything that addresses the mismatch between annual emissions increases and increases in atmospheric concentrations of CO2.
     
  7. tcjennings

    tcjennings New Member

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    QED. I said that in post #2.

    Really? Where have you looked? Because the fact that only about 45% of anthropogenic emissions stays aloft is fairly well known. Otherwise we'd have CO2 concentrations at about 425 ppmv today!

    This is math anyone can do: the data behind the graphs you cite indicate 224.3 GtC in the 1960-2003 timeframe. At the same time, the Atmospheric CO2 went up 59.27 ppmv. It only takes about 126 GtC to account for that increase, which means the ~99 GtC extra we put up in the air was taken in by natural sinks.
     
  8. KMO

    KMO Senior Member

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    <div class='quotetop'>QUOTE(TimBikes @ Mar 16 2007, 06:24 PM) [snapback]406903[/snapback]</div>
    Totally wrong comparison.

    The point is the rate of increase. In 1960-70 it was going up maybe 100ppm a decade. By 1995-2005 it was going up about 180ppm a decade. So the 160% increase of emission rate goes with an 80% increase of CO2 growth rate. As a hand-wavey check, acknowledging that we're looking at we're looking at quite tight timescales, and haven't tried smoothing the data, that passes the smell test.

    Try thinking about it in terms of money. If you start off with $300,000 in the bank with a salary of $25,000, and then you get a payrise to $65,000, you don't expect your savings to suddenly jump to $800,000, do you? But your savings will certainly start going up faster.

    Do you now understand why your comparing the wrong things?

    <div class='quotetop'>QUOTE(TeeSeeJay @ Mar 16 2007, 09:45 PM) [snapback]406954[/snapback]</div>
    Exactly. Most of the rest is being absorbed by the ocean. The ocean is getting measurably more acidic, with a resulting impact on sealife. If that keeps going, there will be a whole other set of problems on top of warming.

    Maybe next we'll see ocean acidification denialists. :rolleyes:

    Unfortunately, as the earth warms, the ocean will begin to belch its CO2 back out again...
     
  9. TimBikes

    TimBikes New Member

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    <div class='quotetop'>QUOTE(TeeSeeJay @ Mar 16 2007, 02:45 PM) [snapback]406954[/snapback]</div>
    OK - let's not get snippy here - you did say that - but it wasn't clear to me that even with that being the case the annual output was fully accounted for in the annual atmospheric increase. I have been looking for the underlying data for the charts for some time but have never seen it. I have seen the data for the annual rates of emissions but never accumulated. Obviously it exists. If you could provide a link it would be appreciated. I'm not disputing your conclusions - just want to play with the numbers so I can make better sense of it myself. Gracias. <_<
     
  10. tcjennings

    tcjennings New Member

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  11. F8L

    F8L Protecting Habitat & AG Lands

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    <div class='quotetop'>QUOTE(TimBikes @ Mar 15 2007, 11:57 PM) [snapback]406652[/snapback]</div>
    Tim, I'm at the girlfriends house and getting ready to head out but I promise to lookinto this post as wellas your "watervapor" post in the other thread.They both look interesting. :)

    As for a quick idea on this one:

    Could it be the natural buffering system ofthe earth is changing the CO2 buildup curve? IE cations are combined to form other compounds and buffer the CO2. IE Ca combining with the CO2 and forming CACO3 or Carbonic acid or any number of organic chemical reactions. Obviously this is the natural way we recycle CO2 but there are cases where this buffering system loses enough cations and it cannot effectively buffer and we get acidification like we are seeing in the oceans and in lakes and streams allover the world, especially the eastern U.S..

    So in essense my uneducated guess would be that the excess CO2 is not showing up on the "radar" because it is being used up or transformed by this buffering system and wearing it down faster than it is going to be able to recharge itself. Remember what I was saying about ocean acidification and the problems that can present with CO2 uptake in calcifying organisism.

    Ok gotta go, gonna get in trouble. LOL

    *edit* her computer is so slow it didn't show all these responses before I typed all this out. :(
     
  12. TimBikes

    TimBikes New Member

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    <div class='quotetop'>QUOTE(TeeSeeJay @ Mar 17 2007, 06:56 AM) [snapback]407361[/snapback]</div>
    Thanks TeeSeeJay - sorry I snapped at you. ;)
    I will check this out when I have time.

    <div class='quotetop'>QUOTE(F8L @ Mar 17 2007, 12:22 PM) [snapback]407480[/snapback]</div>
    I'm kind of wondering something along the same lines.

    Anyway - I will admit this must be a sort of scientific "no-brainer" - in a sense as others have argued here. I admit I have never seen this discussed elsewhere - so I must be missing something- which is why I termed it a puzzle (for me anyway). I need to play with the numbers to make my own sense of it - it is probably also as TeeSeeJay and KMO suggest.
     
  13. redcane

    redcane New Member

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    <div class='quotetop'>QUOTE(TimBikes @ Mar 17 2007, 01:33 PM) [snapback]407198[/snapback]</div>
    If i recall my calculus, you can calculate the accumulated emissions from the area under the graph. Or just add up the heights off all the yearly data plots as best as you can read them from the graph.