15yr Slow Down In Global Warming - Sceptics Say Weather Simulation Models Are Wrong

Discussion in 'Earth Science' started by common_sense_seeker, Sep 27, 2013.

  1. common_sense_seeker Bicho Voador & Bicho Sugador Valued Senior Member

    Messages:
    2,623
    The IPCC is due to issue the latest report on Friday but ahead of the release there's been some divided opinion due to the slowing of the global warming rate in the last 15 years. Is it right for the IPCC to insist that human CO2 contributions are the cause of our changing weather? Climate sceptics claim warming pause backs their view

    Please Register or Log in to view the hidden image!



     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. kurros Registered Senior Member

    Messages:
    793
    This claim is incorrect. The sensitivity estimates have hardly changed since 1979. From wikipedia (which agrees with claims made in a talk given by a climate scientist to our physics department last week):

    -----------
    (http://en.wikipedia.org/wiki/Climate_sensitivity#Consensus_estimates)

    Consensus estimates

    A committee on anthropogenic global warming convened in 1979 by the National Academy of Sciences and chaired by Jule Charney[10] estimated climate sensitivity to be 3 °C, plus or minus 1.5 °C. Only two sets of models were available; one, due to Syukuro Manabe, exhibited a climate sensitivity of 2 °C, the other, due to James E. Hansen, exhibited a climate sensitivity of 4 °C. "According to Manabe, Charney chose 0.5 °C as a not-unreasonable margin of error, subtracted it from Manabe’s number, and added it to Hansen’s. Thus was born the 1.5 °C-to-4.5 °C range of likely climate sensitivity that has appeared in every greenhouse assessment since..."[15]
    Chapter 4 of the "Charney report" compares the predictions of the models: "We conclude that the predictions ... are basically consistent and mutually supporting. The differences in model results are relatively small and may be accounted for by differences in model characteristics and simplifying assumptions."[10]
    In 2008 climatologist Stefan Rahmstorf wrote, regarding the Charney report's original range of uncertainty: "At that time, this range was on very shaky ground. Since then, many vastly improved models have been developed by a number of climate research centers around the world. Current state-of-the-art climate models span a range of 2.6–4.1 °C, most clustering around 3 °C."[9]
    --------------

    The model average (of something like 50 independent models) is still around 3 °C sensitivity; this is not an extreme predicition. The higher outliers predict upwards of 8 °C sensitivity, though this is thought unlikely (when they say the span is 1.5 - 4 °C, they mean 68% of the models predict values within this range). Regardless, 3 °C is still concerning.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. common_sense_seeker Bicho Voador & Bicho Sugador Valued Senior Member

    Messages:
    2,623
    I would take the Guardians report more seriously than Wikipedia incidentally. He's specifically referring to the 2007 report, which you haven't quoted from. I'm assuming that there has been a slight reduction in the predicted global temperature rise since the last report. Prove me wrong if you like but quote from the last report and the latest one please.

     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. origin Trump is the best argument against a democracy. Valued Senior Member

    Messages:
    9,796
    So basically you are saying that if each year is not warmer than the previous year there is no global warming. That is silly. I think we can agree that winter is coming and January is going to be cold in the northern hemisphere. However this week has been warmer than last week - do you think that is evidence that winter is not coming this year?
     
  8. Grumpy Curmudgeon of Lucidity Valued Senior Member

    Messages:
    1,876
    common_sense_seeker

    Your(and your chosen cite's)characterization of the meaning of the report is at odds with real climate scientist's understanding and multiple other reports. Disprove what? You've just not "proven" anything needing to be disproved. You are obviously a pathetic climate change denier looking for any evidence you can find that you can distort to try supporting your preconceived conviction that man couldn't possibly be responsible for what man has done to the Earth's environment. If you all put as much energy into trying to educate yourself on the facts of climate change as you put in the pursuit of idiocy we wouldn't have to spend any energy debunking said idiocy.

    Grumpy

    Please Register or Log in to view the hidden image!

     
  9. Aqueous Id flat Earth skeptic Valued Senior Member

    Messages:
    6,152
    I suppose you could argue that climate scientists should insist that CO[sub]2[/sub] is not rising. But then that would be a lie wouldn't it. :bugeye:
     
  10. common_sense_seeker Bicho Voador & Bicho Sugador Valued Senior Member

    Messages:
    2,623
    I'm not a "climate change denier" and *do* think that the IPCC does have the general gist correct; that human CO2 output is contributing to global warming. It's the lack of an understanding of the natural cycles which contribute to climate change as well which worries me. There's a clear millennial cycle within the ice core data which is currently ignored by the IPCC as far as I'm aware. There's more natural cycles which aren't included in the simulation models New paper finds lunar-tidal cycles influence climate (Jul 2013):
     
  11. kurros Registered Senior Member

    Messages:
    793
    There is some planetary dynamics stuff that was not included in previous reports, but are now included in the most recent one, if I remember the aforementioned talk correctly. I will get back to you in 2 days when said report is accessible online. As for your concern that I did not mention the 2007 IPCC 4th assessment report, if you look in the very next paragraph from the one I quoted you will find direct reference to it:

    -----------------------
    (http://en.wikipedia.org/wiki/Climate_sensitivity#Intergovernmental_Panel_on_Climate_Change)

    Intergovernmental Panel on Climate Change

    The 1990 IPCC First Assessment Report estimated that equilibrium climate sensitivity to CO2 doubling lay between 1.5 and 4.5 °C, with a "best guess in the light of current knowledge" of 2.5 °C.[16] This used models with strongly simplified representations of the ocean dynamics. The IPCC supplementary report, 1992 which used full ocean GCMs nonetheless saw "no compelling reason to warrant changing" from this estimate [17] and the IPCC Second Assessment Report found that "No strong reasons have emerged to change" these estimates,[18] with much of the uncertainty attributed to cloud processes. As noted above, the IPCC TAR retained the likely range 1.5 to 4.5 °C.[4]
    Authors of the IPCC Fourth Assessment Report (Meehl et al., 2007)[19] stated that confidence in estimates of equilibrium climate sensitivity had increased substantially since the TAR. AR4's assessment was based on a combination of several independent lines of evidence, including observed climate change and the strength of known "feedbacks" simulated in general circulation models.[20] IPCC authors concluded that the global mean equilibrium warming for doubling CO2 (a concentration of approximately 540 parts-per-million (ppm)), or equilibrium climate sensitivity, very likely is greater than 2.7 °F (1.5 °C) and likely to lie in the range 4 to 8.1 °F (2 to 4.5 °C), with a most likely value of about 5 °F (3 °C). For fundamental physical reasons, as well as data limitations, the IPCC states a climate sensitivity higher than 8.1 °F (4.5 °C) cannot be ruled out, but that agreement for these values with observations and "proxy" climate data is generally worse compared to values in the 4 to 8.1 °F (2 to 4.5 °C) range.[20]
    --------------------
     
  12. common_sense_seeker Bicho Voador & Bicho Sugador Valued Senior Member

    Messages:
    2,623
    Okay, I'll look forward to it.

    Here's another interesting article which supports my case Global warming believers are feeling the heat
     
  13. kurros Registered Senior Member

    Messages:
    793
    I'm afraid that article is again total rubbish. It just says the same thing as the first one, with no better support for its claims. You really should stop reading this tabloid trash and find some legitimate sources.
     
  14. common_sense_seeker Bicho Voador & Bicho Sugador Valued Senior Member

    Messages:
    2,623
    I'm a lot more impressed with the two different newspapers' take on the subject than your Wikipedia source.

    Btw I don't agree with the conclusion given at the end of the last article:

    Due to the 18.6 yr tidal cycle which has been linked to climate change (see post#7), it suggests to me that a renewed increase in global warming is just around the corner.
     

Share This Page