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Ice core data shows 27% increase in CO2

  1. Nov 25, 2005 #1


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  2. jcsd
  3. Nov 26, 2005 #2
    27% above averge? What is the standard deviation first?
  4. Nov 26, 2005 #3
    Apparently, going from the first post, 27% higher than any previous point. Not 27% above the average.
  5. Nov 27, 2005 #4
    Hi Patty, sorry for neglicting this thread, I was having the discussion here:


    and here:



    Bottom line: known problems with the ice, the open snow-ice ("firn") at the first ~80 meters in which the air freely passes tends to dampen shorter gas spikes. For the Greenland cores we are talking about century scale fluctuations but those cores only go back to some 120 thousand years. The continental Antarctic cores (Vostok, Dome-C) are much older but the spike problem is on millenium scale due to the slow accumulation. This means that we cannot see shorther higher CO2 spikes in the ice cores. However,

    Leaf stomata of certain species (the Stomata Density or count per mm) react on CO2 as well, the more CO2 the less stomata per mm. However, this branch of science is juvenile and regarded with great suspicion, which is logical because indeed it shows a much larger variation in CO2 than the ice cores do. One proxy (Jay Bath) suggest a possible CO2 concentration in the order of magnitude of 500ppmv in the dark ages after the fall of the Roman Empire (currently some 375ppm) but the Author, Lenny Kouwenberg, starts doubting her own findings perhaps avoiding the controversy.

    Here is the PhD thesis in question:

  6. Nov 27, 2005 #5
    Hi Andre,

    Don't feel obliged to point me towards other threads. I was merely correcting kant's misunderstanding of what the OP said.
  7. Nov 28, 2005 #6
    But others may like to click on links too.
  8. Dec 13, 2005 #7
    Here is an article about a short term study of CO2 in the atmosphere and it's effects on trees.

  9. Dec 14, 2005 #8


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    I don't understand... If the global warming was caused by high amounts of CO2, then the trees would have a lot of extra CO2 for photosynthesis. But of course if it is hotter, that would mean more water vapour, meaning less water that the trees can suck up. More water vapor also means more clouds, which increase the Earth's albedo, and cool the Earth. More water vapor also means more precipitation (correct assumption?), meaning more water for trees to suck up...

    We don't know what is stronger, and what is weaker.
  10. Jan 5, 2006 #9
    There is a study done with plants in an increased CO2 environment. The plants have a smaller stomata, leading to a decrease in transpiration. Less transpiration, less water being sucked up, less nutrients in the plant from the soil.

  11. Jan 5, 2006 #10


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    Yes, stomata on leaves is a good indicator of CO2 in the air. But if the stomata are smaller, and there is less transpiration, isn't there more water in the plant than, so the plant doesn't need as much water front the ground?
  12. Jan 6, 2006 #11
    Exactly. If the plant does not draw water from the ground, it doesn't draw nutrients from the ground either. Which leads to less nutritious plants.
  13. Jan 6, 2006 #12
    The stomata story may be a bit different. It's not the size but the count of stomata per area that changes and only for certain species other may not react. There is not one study about stomata reaction to CO2 but many, it could fill libraries.

    Stomata studies show some consistency with ice cores but they also show a much bigger variation than the ice cores.

    This PhD thesis especially interresting albeit that the author did not really want to challenge ice core wishdom:



    Full thesis (6 MB)


    Note especially ch5 and 6 about a possible high CO2 level in the early medieval period that dwarfed whatever there is in the ice cores.
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