Runaway Global Warming

Discussion in 'Earth Science' started by Facial, Jul 11, 2014.

  1. Facial Valued Senior Member

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    Some suggest that there are many feedbacks which would cause a runaway global warming. I myself pondered what the possibility there could be for earth to 'bifurcate' into what Billy T calls a "hot, stable state." On the other hand, other scientists suggest otherwise:

    http://pubs.giss.nasa.gov/abs/ru00200g.html

    http://www.columbia.edu/~jeh1/mailings/2013/20130415_Exaggerations.pdf

    I do tend to believe that because the sun progressively becomes hotter over millions and billions of years, the tendency for a thermal runaway is inevitable but only on the long-term time scales. The oceans, after all, do contain about 700 times the mass of the atmosphere and the absorption by water vapor looks broad across the IR spectrum, making arguably more powerful than CO2 itself as a pure gaseous phase. Thus it is tempting to deduce that earth must have a runaway greenhouse coming up in the future with uncontrolled burning of fossil fuels and carbonate rocks, but I keep reading otherwise in the professional literature.

    I would like this thread to universally link to other posts in other threads with more, err, grim prospects on the planet's future, because I know some key players (iceaura, Billy T, etc.) have already elucidated this. I'm a senior member here too, but I've been only looking occasionally on SF and the search engine sucks...
     
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  3. sculptor Valued Senior Member

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  5. billvon Valued Senior Member

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    Probably. Increase insolation by 100 watts/sq m and the temperature rises enough that you might see that sort of runaway. Of course we are talking a billion years from now. After that happens the Earth will rapidly lose its water to space, and will cool down again - at least until the Sun enters red giant phase and incinerates the planet.
     
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  7. sculptor Valued Senior Member

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    Anthropogenic "Runaway global warming" is a myth, a fiction, a fantasy--- a tale "told by knaves to make trap for fools".
     
  8. KitemanSA Registered Senior Member

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    Or just something that hasn't happened yet.
     
  9. sculptor Valued Senior Member

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    OK
    Lemme try a different approach:

    If you wanted to create runaway global warming, how would you go about achieving that goal?
     
  10. Truck Captain Stumpy Registered Senior Member

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    well you could allow commercial industry to dump atmospheric contaminants, GHG's, and other known facilitators of global warming without any restrictions
    then support a slash and burn policy as well as urbanization for any forested/natural areas that contain biological material that is not utilised by people (like cows, crops, etc)

    What is the intent of the exercise?

    IF there is someone that can prove there is no such thing as Anthropogenic Global Warming?

    IF anyone thinks that they have the ability to prove that AGW is not real, then I know a site to visit: http://dialoguesonglobalwarming.blogspot.com.au/p/10000-global-warming-skeptic-challenge.html

    the are offering a $30,000.oo reward to anyone who can use the scientific method to prove that AGW doesn't exist, which is what I think certain people might be driving at.

    If I am wrong, then I apologize.

    If I am correct... perhaps you should prove it by trying for the prize.
    the contest is spelled out... and easy.
    all you have to do is PROVE it.
     
  11. sculptor Valued Senior Member

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    None of which has nor could even come close to matching atmospheric CO2 concentrations of the past. During which times we did not have runaway global warming.
    So what you offer(so far) ain't likely to create runaway global warming. (kinda like insisting on playing a tuba in a string quartet?)


    Being as we were most likely in a (rather rare) grand solar maximum during much of the recent rise in atmospheric CO2 concentrations, proving which is responsible for what percentage of the paltry amount of global warming remains problematic.
    Absent such knowledge, predicting runaway global warming from a potentially faulty hypothesis remains a really silly investment in science fiction.
     
  12. billvon Valued Senior Member

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    Not really. We know that AGW is responsible for 1.6 to 2.4 watts per square meter of warming. Solar forcing is responsible for about .2 watts per square meter.
     
  13. sculptor Valued Senior Member

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    I find that a curious thing to "know".

    (which is my polite way of expressing doubt)

    ..................
    You are aware that the harbor at Venice froze over during the maunder minimum? (1709?)

    On the one hand, we have historical evidence (of something as yet undefined---but most likely a result of a weak sun)
    On the other hand we have what seem to me to be ludicrously low estimates of solar influence.
     
  14. Trippy ALEA IACTA EST Staff Member

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    Estimates based on measurements made by satellites which can be correlated with measures of solar activity.
     
  15. sculptor Valued Senior Member

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    which means that we have 30 or so years of data, much of which was collected during a grand maximum.
    hardly a representative sampling of solar output over longer periods of time
     
  16. Trippy ALEA IACTA EST Staff Member

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    Okay, however, the evidence we have:

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    Suggests that the solar flux during (for example) the maunder minimum, was the same as, or close to, the solar flux observed during modern solar minima regardless of the modern grand maximum.
     
  17. sculptor Valued Senior Member

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    curious conclusion there trippy

    now we have an assumed lack of change of solar flux, and a dichotomous freezing of the harbor at venice, and noted change of vegetation zones which remain below those of the medieval warm period.

    I suspect that the assumption is in error
    .............
    you know of the work of Ilya G. Usoskin?
     
  18. billvon Valued Senior Member

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    No, we have a known _change_ in solar flux.
    All of which correspond to the observed solar forcing, based on the relationship between sunspots and total insolation.
     
  19. Trippy ALEA IACTA EST Staff Member

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    What's so curious about it? It's what the evidence says.

    Straw man hypothesis - I made no such claim. The claim I did make was that the change in solar flux observed during the maunder minimum was likely to have been within the range (but at the low end) of the values obsevred in the modern grand maximum.

    You seem to be confusing average values with instaneous ones.

    Maybe you should look into the role duty cycles have in heating, as well as the role long term averages (for example - the black line in the first graph) play in climate change and how the differe from short term variations and instantaneous values.

    Suspect all you want - the proof is there for anyone to examine.

    You haven't understood what I have said.

    I am not questioning whether or not we're in a grand maximum.
    I'm not questioning whether or not the average solar activity is higher than it has been in the past.
    Those points are red herrings to the point that I am making.

    The point that I am making is this - if you examine solar activity during the solar MINIMA between cycles then the range of activity includes the level of activity during the maunder minimum, and on that basis it does not seem unreasonable to infer that insolation observed during the maunder minimum was within the range observed today even though it was at the low end.
     
  20. sculptor Valued Senior Member

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    I suspect that I do see your point. Not instantaneous at all, but the steady pounding(if you will) of the unrelenting cold resulting from a weak sun that drags us deeper and deeper into "a little ice age". Residuals piled on residuals.
    I also suspect that my limited understanding is leading me to grasp at phraseology which fails to express what I sense/see as a driving force in heat or cold. The aforementioned Venice harbor freezing wasn't instantaneous to the beginning of the maaunder, but 1/2 a century into the freezing.

    One of the things I have studied since about the time I attended Bucky Fuller's design school at siu is the behavior of frost lines within building envelope insulation. As the frostline moves toward the interior, there is ever less insulation between the interior temperatures and the freezing temp. of the frostline, and if there is moisture within the insulating envelope, this can lead to rotting the frame. This past winter's heating of habitable space became increasingly harder to maintain economically as the frostline encroached ever more toward the interior of buildings, not because we had record low temperatures, but because we had record low maximum temperatures. This environment did not allow nor encourage the frostline to retreat toward the outside.

    One of our recent minima had higher solar activity as evidenced by sunspots than during some of the maxima within the maunder grand minimum.

    On these points, I suspect that we do indeed agree. And, within that , it seems obvious why we are not cooling significantly with the lower solar activity of the recent 2 solar cycles. The minima may be weak, but not of significant weakness nor time to have a serious effect.(yet)

    (More later----the river is still in flood stage, and my wife and i are going kayaking through the flooded riverine forest---great fun, I do not do well in the sun, so we get to kayak in the shade through the flooded ravines.)
     
  21. Trippy ALEA IACTA EST Staff Member

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    in·stan·ta·neous
    adjective \ˌin(t)-stən-ˈtā-nē-əs, -nyəs\
    : happening very quickly : happening in an instant
    Full Definition of INSTANTANEOUS
    1: done, occurring, or acting without any perceptible duration of time <death was instantaneous>
    2: done without any delay being purposely introduced <took instantaneous corrective action>
    3: occurring or present at a particular instant <instantaneous velocity> ​


    I mean Instantaneous in the third context rather than the first. So it's the actual measurement occuring at a particular time.

    Understood, and this is the point that I was making in regards to long term average value, which drives climate, versus the instantaneous measurement made at any particular time. It's also related to the point I was alluding to regarding duty cycles.

    This winters cold temps were restricted to those parts of North America affected by the destabilization of the arctic polar vortex. As I understand it, even in North America people living in different areas had different experiences of winter.

    in 2009 there were 260 Spotless days. In 2008 there were 200 Spotless days. In fact here's a SOHO image from September 2008:

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    Here's a graph showing the top nine spotless years in the last 50 years:

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    Now, let me repeat what my assertion was: Instantaneous insolation (IE insolation as measured at a particular moment) during solar minima that occured within the period that insolation data has been collected approached, or was the same as that observed during the maunder minimum. A corrollary of that is that during solar minima there were periods during which solar activity approached, or was the same as that during the maunder minimum: Spotless days.

    On this I have seen some interesting comparisons between the last two solar cycles and the lead in to - I think it was the Dalton or the Sporer minimum - the one that occured around the end of the 19th century.
     
  22. sculptor Valued Senior Member

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    the circa 1900 "minimum" (which wasn't much of a minimum) remains largely un-named, though some refer to it as the gleisberg

    steady diminution of solar activity from 1000ad through maunder
    steady encroachment of the cold from medieval maximum
    nice rise since maunder ---dalton(circa 1800)---

    here's Usoskin't longer series:

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    .........................................
    .........................................................................
    I see that we've steadily drifted away from discussing "runaway global warming".
    Does that mean that no-body corresponding in here believes that soundbite nonsense?
     
  23. andy1033 Truth Seeker Valued Senior Member

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    Its amazing that people are still on about this. Cycles exist and we are always moving between two ends of it.

    None of the effects that gore said has come into reality. He was a snake oil salesman and with his science moron crew tried to con the world.
     

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