Temperature History

Assuming Your Conclusion

20 Comments

I thought this was pretty interesting, and oh-so typical of climate science, from an article by Viscount Monkton:

The paper was based on a test of a widely-used climate model on the mid-Pleiocene warm period, 3 million years ago, when the Earth warmed in response to natural processes. Cores drilled from ocean sediment provide some evidence for atmospheric carbon levels and temperature at the time.

The team found that at that era, although CO2 levels were close to today’s 388 parts per million by volume, global temperature was 3 C° (5.5 F°) warmer than today. The paper assumes – without evidence – that the difference can only be fully explained by the long-term loss of ice sheets and changes in vegetation that caused the Earth’s surface to absorb more solar radiation. One of the authors said that today’s CO2 concentration of 388 ppmv might already be too high to prevent more than 2 C° (3.5 F°) of warming compared with pre-industrial times – the limit agreed as an aspiration by the recent Copenhagen accord.

The authors are concluding that there is therefore another 3C of warming we should see over time due to our current CO2 levels that has just not showed up yet because slow-response-time feedbacks like ice melting / albedo changes haven’t fully come into play.

I presume you see the problem.  This conclusion can only be drawn if either

1.  We know the value of every other climate forcing that was in play 3 million years ago, and know them to be identical to their values today, such that the only changed variable in the temperature system between then and now is CO2.  Of course, this is absurd — we can’t possibly know all the other forcings from 3 million years ago (we argue about what they are today) and there is a very low probability they were all of the same value as today to set up a nice controlled experiment.  – OR –

2.  We assume that the only major driver of climate, the one that dominates and makes all others irrelevant, is CO2.  This is not only not proven, it is not even reasonably true.

These guys, as is so often the case in climate, are assuming their conclusion.  “If we assume that CO2 is the primary driver of climate, then sensitivity of the climate to CO2 is high.”  Duh.

20 thoughts on “Assuming Your Conclusion”

  2. It is precisely that kind of logic that keeps the $research $gravy $train flowing into their labs.

    No global warming crisis, no hammerlock on the $$$$$$.

    A lesson to be learned by other science/medical researchers.

  3. Perhaps during the Pleistocene the earth was passing through a part of the universe in which the ether contained higher levels of phlogiston. That would easily explain how identical amounts of CO2 could have such disparate climate effects.

    As any reader of Real Climate or Tamino knows, models carefully constructed to maximize the climate sensitivity figure for CO2 will make no sense and completely fail to account for modern temperatures if the CO2 forcing factor is removed. This proves that CO2 is clearly the main factor.

    Also, the authors of this proxy study have failed to perform the required adjustments on the raw data. Given that we don’t know the time of day when the bubbles were formed, etc., we should use the general past temp correction factor:
    RAW DATA minus some random value between 0.1 and 1.0 depending on what it does to improve the slope of the historical curve

    That trick should remove the apparent discrepancy.

  4. Yes, but if we do assume that CO2 is the only important driver of climate, it makes it much simpler to fit in with everyone else in climatology who is raking in the big grant money. Who knew that “begging the question” could be so profitable and good for job security?

  5. ‘the authors of this proxy study have failed to perform the required adjustments on the raw data’~ g toby

    Translation: They didn’t fudge the numbers to fit the agw preconception.

    Figures georgie belives in phlogiston.

  6. Clearly Monkton is on to something. I agree with his view on AIDS too:

    “there is only one way to stop AIDS. That is to screen the entire population regularly and to quarantine all carriers of the disease for life. Every member of the population should be blood-tested every month … all those found to be infected with the virus, even if only as carriers, should be isolated compulsorily, immediately, and permanently.”

    What was the name of the paper anyway?

  7. Taking sides with Monckton is always a risk even if he’s occasionally right about something. He’s so weird, he’s a liability.

  8. AGW theory is circular and non-falsifiable.
    That takes out of the realm of science rather nicely.
    Rick, unfortunately, has it right about Lord M.

  11. Re Lord Monckton

    Christopher is what I would describe a a libertarian rationalist but with perhaps a somewhat contradictatory Catholic Faith.

    His views on AIDS have to be seen in the context of the time when they were composed some 30 years ago. In the UK at least, we were bombarded with a government inpired campaign that was swallowed hook line and sinker by the media. The slogan was don’t die of ignorance with the implication that we were all at risk. It was rather redolent of a similar campaign about VD during WW2.

    The implication was that the whole population was at risk which history showed it was not. How extreem, you view the measures proposed by Monckton depends upon how you value the millions of deaths from AIDS since. I would say he was right even though I doubt that I would have said so at the time.

    Cheers

    Paul

  13. The authors even mention the teeny little fact of the Panama Seaway back then, allowing a circumglobal warm current that is no longer with us. (Panama lifted 3 Mya, triggering heightened glaciation.) Their conclusion about climate sensitivity ignores this, absurdly enough.

  15. I’m looking at the Angry Physicist paper, trying to see if I can confirm they claims. For example, “[CO2] Re-emission is not reflection and can in no way heat up the ground-level air against the actual heat flow without mechanical work.” That sounds interesting. But I can’t figure out how they get there. Can anyone else?

  16. Is it possible that Monkton pulled this article out of his royal arse and posted it on a blog and y’all are simply buying into it?

  17. Xmas: Thank you for that Angry Physicist paper. I have almost finished it, and I feel humiliated that I did not see these things myself. For example, to answer my own question above, CO2 absorbs IR and gets warmer as a result. The CO2 does not reflect the heat back to the earth. So how can this heat return to the earth? Through conduction? The climate models set the conductivity of the atmosphere to zero. Through radiation? The math does not work out for back-radiation from a body at -40C even if we assume its a black cavity radiator. For this and many other reasons, the paper shows that the atmospheric greenhouse effect is contradictory to the established laws of physics.

    Not that anyone cares, of course. But thank you for the link.

  18. How silly… to assume that a direct comparison of climate between today and ~3My ago is reasonable. The continents were not in the same place! The ocean currents were quite different: http://www.nature.com/ngeo/journal/v2/n6/full/ngeo520.html Climate is complicated by many factors besides atmospheric chemistry. Without “adjusting” for the change in latitude of the location where the core samples were acquired over the past 3My, these scientists are bound to draw the wrong conclusions. That bit of ocean floor MOVED :-O

    As for the OT comments on IR back-radiation, this does take place. However, there can never be a net transfer of heat from a cool body to a warm one. The whole hypothesis of CO2 “warming” is often mis-stated, by hinges upon CO2 simply “slowing” the transfer of heat from the surface to outer space. A better analogy is blocking the airflow through your radiator with a postage stamp. Doubling CO2 = 2 postage stamps on radiator. If this makes your car over-heat, you have more serious issues than the reduced air-flow, or a serious lead-foot 😉

  19. wahoo:
    It sounds similar to conclusions in Hansen et al. “Target Atmospheric CO2: Where Should Humanity Aim?”
    (http://arxiv.org/ftp/arxiv/papers/0804/0804.1126.pdf)
    But as far as I can see that paper doesn’t single out a point 3 million years ago to compare with.
    Hansen similarly argues that variations in ice sheet cover and GHG concentrations can explain most of the observed variability in past climates.

  20. Target paper: http://www.nature.com/ngeo/journal/v3/n1/abs/ngeo706.html

    Abstract:

    Quantifying the equilibrium response of global temperatures to an increase in atmospheric carbon dioxide concentrations is one of the cornerstones of climate research. Components of the Earth’s climate system that vary over long timescales, such as ice sheets and vegetation, could have an important effect on this temperature sensitivity, but have often been neglected. Here we use a coupled atmosphere–ocean general circulation model to simulate the climate of the mid-Pliocene warm period (about three million years ago), and analyse the forcings and feedbacks that contributed to the relatively warm temperatures. Furthermore, we compare our simulation with proxy records of mid-Pliocene sea surface temperature. Taking these lines of evidence together, we estimate that the response of the Earth system to elevated atmospheric carbon dioxide concentrations is 30–50% greater than the response based on those fast-adjusting components of the climate system that are used traditionally to estimate climate sensitivity. We conclude that targets for the long-term stabilization of atmospheric greenhouse-gas concentrations aimed at preventing a dangerous human interference with the climate system should take into account this higher sensitivity of the Earth system.

    It seems Mr. Monkton confuses the author’s argument with their interpretation of its incidence.

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