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Global Warming Question

Discussion in 'Environmental Discussion' started by FL_Prius_Driver, Aug 12, 2011.

  1. cyclopathic

    cyclopathic Senior Member

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    from quick reading the point they are trying to make that not all positive feedbacks are accounted for in current models, and while the models may overestimate some of the known feedbacks they overall underestimate total.

    The negative feedbacks are even worse understood and not accurately represented in models. Agree at some point negatives s.a. Thermohaline disruption will kick in, however we do not know how long it would take, how effective they will be and to what is overall capacity to absorb they have. Any proxy reconstructions are in question as the rate we are warming now unprecedented.
     
  2. austingreen

    austingreen Senior Member

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    There are certainly non-linearities shown in the ice, but these are changes related to temperature not CO2 concentration. The op ed piece you pointed to quoted an article that said seinsitivity might be as high as 78% higher than historic. Now hanson has a number that is 114% higher than historic estimates, so that thing saying higher than 2.8 degrees C is certainly still lower than Hansen's estimate of 6. The high estimates have to find excuses on why there models do not fit temperature patterns, hanson's "explanation" is sulfur dioxide changes from emissions control is warping the data. I would say until the high models actually are predictive, hand waving on how much higher sensitivity is than historic measures seems like theories that should be rejected.

    Definitely a broad margin of error here. Rock weathering is fairly well understood. If we chop down the forests and kill the oceans much of the natural sequestration may go away. The rate greenland is warming was exceeded historically, and this is one reason many climate scientists believe there may be a tipping point.
     
  3. cyclopathic

    cyclopathic Senior Member

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    rejected?? def no; taken with the grain of salt? yes.

    there is no question that we are heating up at rates far exceeding historic, accelerated permafrost thawing alone is enough to cause it.
     
  4. tochatihu

    tochatihu Senior Member

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    Not entirely unrelated to the discussions here, more new things in Geophysical Research Letters:

    AGU journal highlights -- Aug. 18

    Take a peek at #1,3 and 4.

    This one

    News releases 2011

    refers to just one Greenland glacier, so your conclusions may vary.

    Anyway, all of this sort of stuff pops up on "Eurekalert", which I visit frequently along with "sciencedaily". Those interested in "what looks important" in earth system science publications might wish to do the same.

    The onerous alternative is to go through journals' tables of contents, one by one. There are many, I assure you. To stay reasonably current in terrestrial carbon cycling I read about 50 journals, and some stuff still threatens to slip through the cracks.

    My Fun Fact of the Day: Fossil fuel burn C emissions are now 8 or 9 petagrams per year. All of the CO2 respired by all terrestrial multicellular organisms is estimated as 10. This excludes bacteria and fungi. It includes eukaryotes from nematodes to elephants and, incidentally, people. Within a decade or so, burning 'business as usual', the fossil fuel C will be greater than respiration of all the critters on earth.*

    *Not including oceans. The data there look more fuzzy to me, but then again I am not an 'oceans' guy.

    I see that as something of a milestone, that has not been placed into wide view.
     
  5. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    That's good enough for a first order estimate. It indicates that burning all the coal should be the primary worry. It may sound backward, but I think the best action plan is to get a replacement for coal generated electricity developed first. "Replacement" really means the economics of alternative (non-polluting) make coal extraction.....and coal burning throughout the world more expensive than the alternative energy plants.

    Great Thanks to all who contributed.
     
  6. PriusSport

    PriusSport senior member

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    The simple answer is to move to a high elevation.
     
  7. SageBrush

    SageBrush Senior Member

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    Six ways to die ? Nah, just one for billions: starvation
     
  8. SageBrush

    SageBrush Senior Member

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    How long before the AGW denialists turn into 'god is MAD and wants BLOOD' nutjobs ? I say 10 years. It is one of the sorry ironies of these idiots that they spend a decade questioning science they cannot understand, but require no proof that disaster is god's will.
     
  9. mojo

    mojo Senior Member

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    Sagebrush ,
    From a lifelong left of Democrat.
    As a believer in astrophysics,I predict 10 years from now Earths temps will be much lower .
    Hopefully then you will realize how you have been duped by Enron, Goldman Sachs and Morgan Stanley.

     
  10. icarus

    icarus Senior Member

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    I'll take that bet Mojo, I'll also give you odds. (and I am not a betting man generally). It is you my friend that has been duped. It does surprise me however.

    Icarus
     
  11. SageBrush

    SageBrush Senior Member

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    Mojo,
    As a lifelong cynic of political parties, all I can tell you is that science is not a belief, and therein lies your fundamental [sic] problem.
     
    2 people like this.
  12. cyclopathic

    cyclopathic Senior Member

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    don't bother.. he will back out.

    It is like one of the Nasreddin stories, where he promises shah to teach donkey to speak (in 20 years); if not be beheaded. When confronted by friends over a stupid bet he points out: in 20 years either me or shah or donkey is going to be dead.
     
  13. MontyTheEngineer

    MontyTheEngineer New Member

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    Touching on the oxygen question again - our atmosphere is currently 21% O2. Since burning carbon turns one C and one O2 into one CO2, and we're talking about burning enough C to raise CO2 concentrations from 0.04% to 0.1% or so, then O2 concentration will go from about 21% to 20.95%. That's before you take increased photosynthesis into account, which will add oxygen back. Don't worry about it.
     
  14. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    I don't think anyone was worried about it directly. Part of the reason for the question was that very high CO2 concentrations would have many first order chemistry effects. O2 going down, Ocean pH going down, and others that are direct chemical effects. Which of these would be measurable?

    The other reason is what ecological effects could emerge with this high concentrations? If plant life has been optimized for about 300 ppm, what happens worldwide at 1500 ppm? Are there very non-linear effects at a certain ppm(s)?
     
  15. wjtracy

    wjtracy Senior Member

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    Monty- You are correct ...which means I overstated O2 loss in my prior calcs. Will edit. O2 loss is a little more than CO2 gain due to also burning the hydrogen in the hydrocarbons. Bottom line is the atmosphere is huge so even burning all the fossil fuels does not reduce the O2 much.
     
  16. austingreen

    austingreen Senior Member

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    Decrease in oxygen would be measurable but its unlikely this will greatly impact anything. With a tripping of CO2 the ocean would likely decrease ph by 0.5, down to around 7.65, and lead to changes in calcium carbonate concentration which will have the most affect on shells and skeletons of sea life .. No one really knows all the ocean buffering, but uptake currenly is around 25% of new carbon dioxide. More immediate changes with temperature lead to coral bleaching, and there are corals that survive well in high temperatures but these do not live on all reefs. Most of my diving has seen changes more related to direct pollutants versus the current small change in acidification.

    Plants are not optimized for a certain CO2 concentration. The fossil record shows wide variability, and this will change from plant to plant. As CO2 is higher there a plant produces fewer stoma, and loses less water. This should lead to more drought resistance and higher growth rates. In oceans higher acid concentration will lead to a different balance of minerals and shifts to different sea life. On land continued deforestation and polution, not caused by ghg are the major anthropological drivers.
     
  17. cyclopathic

    cyclopathic Senior Member

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    Oceans are far more sensitive to temp increases, as the 25-26C beautiful tropical water does not have enough oxygen to support majority of marine life. The increase in 1C will cause a major shift.

    Also the melting ice cups are of the big concern as w/o them there is nothing to drive thermohaline circulation, and oceans will go stagnant. This would put planet on fast track to another Permian-Triassic magnitude extinction.
     
  18. mojo

    mojo Senior Member

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    "Carbon Dioxide Enhancement

    The introduction of supplementary carbon dioxide into the greenhouse has been found to significantly increase the yields of greenhouse tomatoes and other vegetables. Supplementary carbon dioxide is most effective on days when the greenhouse has been shut up for several days with no ventilation. Maximum results can be achieved by injecting 1000-1500 ppm CO2 into the greenhouse using propane burners or other CO2 generators."
     
  19. wjtracy

    wjtracy Senior Member

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    Nice AG we like snorkling. Diving is a challenge we have not tried. In researching this thread, I found some references that suggested as much as 80% of excess CO2 could eventually (centuries) be taken up by land+sea. Hope this true. Seems to suggest focus on finding ways to take up CO2 (planting trees?) may be way to go assuming humans cannot reduce CO2 generation.
     
  20. mainerinexile

    mainerinexile No longer in exile!

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    The last time I taught Environmental Chemistry and checked the literature for this information, 97% of emitted CO2 was sequestered. In other words, 3% of emitted C was responsible for the increase in global CO2. So I don't think the 50% value mentioned is anywhere near correct.