A Climate Skeptic

The thought experiment that made him one:

I think any physical scientist should be extremely skeptical that a long-term stable system is dominated by positive feedback. Systems dominated by positive feedback — and we are talking about incredibly high implied feedback percentages to get to these catastrophic forecasts — don’t tend to be very stable, but it is Michael Mann himself who has argued over and over with his hockey stick chart that past temperatures have only varied in very narrow ranges for thousands of years. Not the behavior one would expect of a system dominated by strong positive feedbacks.

To me, this thought experiment demonstrated that it was more likely that net climate feedbacks were zero or even negative (if only half of past warming was due to man, and half due to nature, it would imply a sensitivity around 0.7C). In either case, the resultant warming would be far from catastrophic. To believe the IPCC forecasts, one would have to believe there were either really long time delays, or natural and manmade cooling factors off-setting the warming. These have all been debated and I won’t go into them today, but I didn’t find the higher forecasts of 5-10C to be at all credible.

I don’t, either.

40 thoughts on “A Climate Skeptic

  1. Sigivald

    Michael Mann himself who has argued over and over with his hockey stick chart that past temperatures have only varied in very narrow ranges for thousands of years.

    That argument always stuck out at me, too – because I knew about the medieval climactic optimum and little ice age, from my historical bent, before Global Warming was the new hotness.

    (And don’t even start with the paleogologists and the very old, very high CO2 levels with … no particular indications of radically higher temperatures.

    The Mann/IPCC-style models never worked.)

  2. George Turner

    Some of the climate scientists argued that the feedback isn’t “feedback”, it’s “amplification.” They are quite wrong on that because amplification, to avoid forming unstable positive feedback, can’t have the output be the same thing as the input while also having the output hooked directly to the input. The climate’s input isn’t CO2, it’s sunlight raising the temperature T of point X, and then that warmth makes more water vapor feedback to further increase temperature T of point X – which further raises temperature T of point X, ad infinitum. That’s positive feedback, and it’s not stable.

    1. Bart

      Such a system can be stable, IF it is assumed that the water vapor response is instantaneous. For example, suppose you have a system of the form

      dT/dt = -a*T^4 + S + b*H2O
      H2O = H2Oeq + k*(T – Teq)

      where

      T = temperature
      S = solar input
      H2O = water vapor
      H2Oeq = H2O content at Teq
      Teq = equilibrium temperature

      The perturbation equation reads

      dD/dt = (-c + b*k)*D

      where D is the delta temperature, and c = 4*a*Teq^3. This system is stable as long as c is greater than b*k.

      However, if you start adding lags into the H2O response, then you start skating on thin ice.

      I do not know the response of H2O to temperature. I do, however, know the response of CO2 to temperature. It is, to a very high degree of fidelity for the last 56 years

      dCO2/dt = k*(T-To)

      where k is a coupling factor, and To is a reference baseline. You can see it directly here. Couple that equation with a temperature dynamic of the form

      dT/dt = -a*T^4 + S + b*CO2

      and, this system IS unstable for any b (sensitivity of temperature to CO2) greater than zero.

      1. Karl Hallowell

        and, this system IS unstable for any b (sensitivity of temperature to CO2) greater than zero.

        And T near 0. For higher T (there is a second such place where dT/dt = 0) where a*T^4 increases faster than S+b*CO2 with respect to T, then it is stable.

      2. Karl Hallowell

        dCO2/dt = k*(T-To)

        Also it’s d(ln(CO2))/dt = k*(T-To). The temperature sensitivity of CO2 is estimated in terms of doublings of CO2.

      3. Karl Hallowell

        Ok, I gave these formulas some real thinking rather than the garbage I gave it early tonight.

        Looking at the two formulas, I was wrong. I agree that your equation has a instability at dT/dt = 0. When one solves for the second derivative of temperature with respect to time while setting the first derivative to zero, one gets a positive value which indicates instability in this case (negative values would give opposite).

        But I don’t agree that your equation has any basis in reality. First, I still don’t like your rate of change of CO2 equation as a function of temperature. It ignores human contributions which happen to be on the same order of magnitude as the changes in CO2 quantity in atmosphere. That’s a huge oversight in the equation unless humanity activity happens to emit CO2 proportionally to the expression, T-To. Further, plant activity would tend to increase as temperature increases resulting in moderately greater absorption of CO2. So why should k>0 hold rather than the reverse?

        Second, I don’t buy this equation:

        dT/dt = -a*T^4 + S + b*CO2.

        Where’s the rationale for a rate of temperature increase term linearly dependent on CO2 concentration? It’s basically claiming that presence of CO2 introduces a proportional amount of heat into the system. And only with that term present do you actually get an instability. That indicates that there’s something wrong with the term since we don’t actually observe the instability in question (I think it would have a time scale on the order of days or hours, not decades).

        Instead, going on with our crude approximation, we should have something more like

        dT/dt = -a*(T_effective)^4 + S_effective.

        Here, T_effective is the temperature of the Earth as it appears to an observer in space. S_effective is similarly how much solar influx energy actually gets absorbed by Earth. There are no other terms because there are no other mechanisms (aside from really small stuff like geothermal and gravity tidal force heating) to change this energy balance. T_effective and S_effective would then be functions of T and CO2 concentration. Both nonnegative “effective” variables would IMHO decline in value as CO2 concentration increases because there is somewhat more insulation between the upper atmosphere and the lower atmosphere which both inhibits heat transfer from lower to upper and solar influx to the lower atmosphere.

        1. Bart

          ” It ignores human contributions which happen to be on the same order of magnitude as the changes in CO2 quantity in atmosphere.”

          Actually, total accumulate emissions over the years are about twice what is measured. As half of it is missing, at least that has been reabsorbed into other reservoirs, and the question becomes not what emissions have been, but how much is actually retained in the atmosphere. The notion that half is retained is merely an assumption, and a poor one, according to the data and the temperature relationship.

          As for having a basis in reality, it is what is observed. It is, from this, actually clear that humans are not responsible for the increase in atmospheric CO2 measured at least over the last 56 years – it would have occurred regardless of human activity. Nature shrugs off the tiny inputs of humankind in a vast, CO2 regulatory system. Dr. Murry Salby has given a series of lectures on this topic, one of which you can view here. Few believe him yet, but in time, as the relationship above continues to hold with declining temperatures, while human inputs keep accelerating, the truth will become undeniable.

          Bottom line: for the past 56 years, given the temperature record, I can tell you to a very close level of approximation what the CO2 record will be – you don’t really need to know human inputs at all. They are effectively superfluous. This type of response could easily be exhibited by a system analogous to

          dCO2/dt = (CO2eq – CO2)/tau + H
          dCO2eq/dt = k*(T – To)

          where H is human inputs, and tau is a time constant. If tau, is “short”, then H is severely attenuated by rapid sequestering, and CO2 will track the equilibrium level, which is set by temperature. In that case, you can neglect the first equation, and go directly to CO2eq for all practical purposes.

          “Second, I don’t buy this equation:”

          Doesn’t really matter. When you take the partial derivatives to derive the perturbation equation, it will be linear of the form

          dD/dt = -c*D + b*E

          where E is the delta CO2. Coupled with

          dE/dt = k*D

          the system is unstable for b greater than zero.

          1. MfK

            The term containing H2O assumes absorption only. Cloud formation, which is a function of H2O, atmospheric particulates, cosmic radiation, etc., on the sun-side of the earth acts to decrease S. The effect can be a reduction in S by as much as 10% on a monthly basis, and 1-2% in a matter of hours. Those factors overwhelm the absorption term, and are unpredictable (and unpredicted by any models I know of). The short answer is that “b” is not necessarily positive if you take into account clouds (and assume clouds = C*H2O). It is a stochastic function, and one of the main ones that shoots a simplistic analysis like this to smithereens.

          2. Bart

            The short answer is that “b” is not necessarily positive…”

            Well, yeah. That’s the point. And, if b is not positive, then there is no CO2 driven warming.

          3. Bart

            You see, it is a pair of fundamental errors at the very foundation of the AGW panic, and paints the entire brouhaha as an utter scientific fiasco, and a bubble poised to pop:

            1) We are not responsible for rising CO2 in the atmosphere at any level of significance
            2) The sensitivity of surface temperature to rising CO2 cannot, in the aggregate, be positive, or at least not significantly so, in the current state of the climate

            Note that the above does not deny the greenhouse effect. It merely says that, in the current state of the climate, it has lost its punch. It may very well be, almost assuredly is, in fact, that all things being equal, increasing CO2 should increase surface temperatures. But, all things decidedly do not remain equal in the vast feedback regulatory network of the modern Earth climate system.

          4. Karl Hallowell

            As half of it is missing, at least that has been reabsorbed into other reservoirs, and the question becomes not what emissions have been, but how much is actually retained in the atmosphere.

            In other words, the net increase in CO2 levels which are being claimed by AGW advocates as being a problem are half the cumulative human contribution to said CO2 levels (which incidentally is well within an order of magnitude). That’s a huge thing to gloss over. It’s like ignoring the vig of a gambling establishment and focusing instead on the give and take of luck.

            As to your perturbation equation, you only have part of the necessary terms (and lost the T^4 term altogether). Each derivative of D and E would be a linear expression of both D and E. And there are coefficient ranges which make that stable. You still have to rationalize your coefficient choices.

          5. Bart

            “…the net increase in CO2 levels which are being claimed by AGW advocates as being a problem are half the cumulative human contribution to said CO2 levels…”

            Not precisely. The fact that the increase observed is equal to approximately half of a virtual accumulation of total emissions does not mean that the increase is necessarily due to the emissions.

            Allow me to give an example. Suppose you have one of those old fashioned lavatories with separate hot and cold faucets. The cold water is turned on and, due to the drain being partially obstructed, water accumulates, and rises to the point at which the pressure at the drain forces outflow to balance the inflow, and an equilibrium volume is established. Now, let’s say we turn on a trickle of hot water and, at some time afterward, we measure the volume of the water, and find that the change from the previous equilibrium volume is 1/2 of the hot water we added. Can we then say that the rise was due to adding the hot water?

            Only if we can also say that the influx of cold water remained the same, and that is therefore the only possibility. If we do not know that, if we weren’t watching all the time, and there is a chance that someone else came in and turned the cold water faucet up, then we cannot say given the information presented thus far.

            This is easy to see in the reductio. Assume the cold water is really blasting in, and the drain is taking it out very fast, too. Then, adding a trickle of hot water is barely going to budge the level, no matter how long you wait. You would then have to conclude that someone did, indeed, turn up the cold water.

            That is what this comes down to: how fast do CO2 sinks take out the incoming CO2, and how dynamic are they? The drain in the lavatory is dynamic – it increases its outflow in response to an increase in the water level. Just so, the CO2 sinks in nature expand their uptake in response to how much CO2 is in the atmosphere. If they are very active, then you have to pump a whole lot of CO2 in to get a marginal increase in overall concentration. It is estimated that human inputs to the atmosphere are 3% or less of natural inputs from decaying vegetation, geologic activity, and so forth. That’s a pretty small part of the overall flow. A small increase in natural inflow, or decrease in outflow, can easily swamp the small amounts we put in.

            The observations indicate that the observed rise is very nearly, if not totally, accounted for by a temperature modulated source. The slope and the variations match. Moreover, the rate of change of CO2 in the atmosphere has stalled at the precise time that temperatures have stalled, while emissions have accelerated. See here. These data indicate that the CO2 “drain” is quite active, and we are not having a significant effect on overall levels in the atmosphere.

            “As to your perturbation equation, you only have part of the necessary terms (and lost the T^4 term altogether).”

            That’s what a perturbation equation is. It is a linearization of the differential equations about an equilibrium condition, and it can be used to diagnose stability properties at that equilibrium. The T^4 dependency is encapsulated in the sensitivity coefficient c = 4*a*To^3.

            “Each derivative of D and E would be a linear expression of both D and E.”

            As they are…

            “You still have to rationalize your coefficient choices.”

            The position of AGW advocates is that b is greater than zero. Anything less than or equal to zero, and AGW is by default not a problem.

            The k value is observed to be positive. A negative value would give you this – out of phase, and heading in the wrong direction.

            That’s all you need. For b and k greater than zero, the system is unstable. Ergo, AGW is not happening.

          6. George Turner

            I assume you’ve watched Dr. Murray Salby’s presentation, which basically got him fired for showing that CO2 levels follow temperature with a 90 degree phase lag?

            Youtube link

            His equations based on the CO2/temperature records are irreconcilable with the popular equations that try to make temperature a fairly simple function of CO2, given that the Earth’s temperature history isn’t a continuous exponential catastrophe.

          7. Bart

            Salby is my idol. And, it appears the Warmistas are persecuting him for daring to hold an informed opinion contrary to their not-so-informed one. I have no idea where he is now or how he is coping. He seems to have dropped out of popular view, and may have been successfully stifled. It reminds me of the scientists who were sent to the gulag for questioning Lysenkoism, and gives me a distinct chill.

          1. Bart

            Note that, in the plotted observations, you could add in a term proportional to the rate of human emissions from burning of hydrocarbons. That rate of emissions is essentially an affine function of time.

            However, to do that, you would have to reduce the scale factor for the temperature related term. And, if you do that significantly, the bumps and wiggles will no longer match very well, so there isn’t a lot of room for human emissions to affect things. The bumps and wiggles of human emissions do not match the bumps and wiggles of the observations at all.

            This “fingerprint”, if you will, then strongly implies that the rise is almost entirely due to the temperature dependent term. Given that the rate of sequestration is not really known, and it could be anything from fast to very fast, I would say that Occam’s razor suggests that the simplest and most likely dynamic going on is that human emissions have negligible impact overall on atmospheric concentration.

            How might this term come about? I have some ideas I put forward when I first realized all this, and which got picked up by this blog. I think treating the oceans as a steady state pipeline with uniform properties throughout the 1000 year THC is a grave error, and vast oversimplification of a very complicated transmission phenomenon.

  3. M Puckett

    If the climate were dominated by positive feedback, we wouldn’t be here to even have this debate, it would be academic and moot.

    That’s always been at the root of my informed skepticism.

      1. Bart

        It’s simply assumed that there is an overarching negative feedback which stabilizes things, so that internal positive feedback simply results in greater sensitivity to external disturbances.

        But, you know what they say about assumptions…

  4. Al

    It’s always boggling to me that this argument doesn’t carry more weight with the people involved or even interested outsiders. I keep deciding they much just not have had the correct background.

    A class in elementary differential equations (a 200 level class) isn’t always a piece of a BS. And although my course mentioned the problems of systems with net positive feedbacks and stability, it didn’t dwell on it.

    But the three main engineering branches (mechanical, electrical, and chemical) and -many- of their ‘child’ specialist disciplines have courses in control theory at the 300 or 400 (and 600+ and…) levels. Admittedly, they’re often focused on completely different time scales, but there’s an entire real realm of simple tests with extensive backgrounds. You -need- to know, or your electronics will emit magic smoke, your engines will behave erratically, and your chemical plant will make a very large crater with the added bonus of toxic smoke. Volcanos are a pretty good step change. And there are a variety of other shifts the just don’t make a lot of sense from a control theory standpoint.

    The standard retort is “But! Chaotic System!” and “Well, you can have unstable systems on -short- time scales!”

    Yeaaah. A simple drip from a faucet can be a chaotic system, that doesn’t make it that much tougher to have a solid grasp of a chemical plant’s dynamic response. Yet, they’ve bailed on that and insist on Monte Carlo simulations and then the weird “Average completely different models into a consensus, and we think this is valid because it sorta is valid for separate runs of one specific model.”

  5. dn-guy

    “We know that there has been about 0.7C of warming since the middle of the 19th century. ”

    Interesting, is rand endorsing Climate change here?

    1. Rand Simberg Post author

      There has never, ever, been a period of time on this planet in which the climate has not been changing, you imbecile.

      And I have never, ever, denied that the climate has been changing.

      But I know that I’ll have to continue to remind you of this, because you are an abject moron.

      1. dn-guy

        “I have never, ever, denied that the climate has been changing”

        That’s one of those bold universal statement’s the internet loves to jam down.

        1. Gregg

          “So you merely deny that Humans are changing the climate?”

          What are your thoughts and beliefs on this?

          Do you think climate has always been changing or do you think it’s supposed to be static?

          Do you have a temperature which you think the Earth should average out to?

          Do you think that CO2 has a major effect on climate?

          Do you think that the amount of Co2 that humans have injected into the atmosphere over the last 200 years has had a measurable impact on climate?

          If the answer tot he previous question is yes, what do you think that impact is? How much of an impact?

      2. George Turner

        Another swing and a miss.

        Humans have changed the climate, but so have cows and goats. The question is by how much, and the answer is “not a whole lot.” Do you think the Roman Warm period was caused by the emissions of Roman donkeys? Do you think the Medieval Warm period was caused by Viking oarsmen stirring up warm water from the deep ocean? Both effects seem to be larger than power plant emissions, based on the past temperatures – unless you see that the climate has a high level of natural variability, which some think might be linked to our planet orbiting a big giant roiling ball of fusion.

    2. Larry J

      Since the middle of the 19th century marks the end of the Little Ice Age, it’s hardly surprising that temperatures have risen. If they hadn’t, we’d still be in the Little Ice Age. What caused the Little Ice Age to start? What caused it to end? Gee, could it be that the climate changed on its own?

      From the Glacier Bay National Park website:

      Glacier Bay proper opens to the north off Icy Strait and branches for over 60 miles through increasingly deforested mountains to terminate in bare rock and glacial ice. The heart of the present Park, Glacier Bay was hidden under a vast ice sheet when the earliest Europeans paused briefly to chart the adjacent waters in the late 18th century. Eighty five years later, the American naturalist and writer John Muir found the glaciers had receded more than 30 miles, beginning the documentation of one of the most rapid glacial retreats ever recorded. Tlingit oral history along with subsequent investigation have established that this dynamic bay had been ice-free before, and was home to the Huna people who had inhabited it between periodic glacial advances for thousands of years. Since the latest reopening, the glaciers have continued to withdraw, and the land and waters thus unlocked have evolved a diverse array of flora and fauna in an ongoing display of marine and terrestrial succession.

      So, in the time between 1794, when Captain George Vancouver of the H.M.S. Discovery, along with Lt. Joseph Whidbey, describes Glacier Bay as “a compact sheet of ice as far as the eye could distinguish” to 1879 when John Muir noted that the glacier had receeded over 30 miles, we can safely say that the area had warmed substancially (unless you believe the National Park Service is a hotbed of Deniers, in which case you’re a flaming idiot). The end of the Little Ice Age took place between those dates (roughly 1850). Did humans do something to cause the end of the Little Ice Age?

      The Earth’s climate has changed constantly throughout geologic time, including periods before humans even existed. When the last major ice age ended some 15,000 years ago, the worldwide human population was quite low. How did that ice age end if humans weren’t the cause? Try learning and thinking for yourself for a change instead of making a fool of yourself spouting ignorant warmist talking points.

  6. Sam Dinkin

    10 degrees C is a large amount of extra emissivity. That’s more than a 3% increase in average temperature. Given emissivity rises at T^4, that would lead to a whopping 12.5% increase in emissivity. How can we possibly increase the optical depth enough to keep that many photons flying around the lower atmosphere when heat is emitting upward like crazy at the higher temperatures? Water vapor would need to overcome a damping factor that damps to the fourth power.

    Extraordinary claims require extraordinary levels of evidence to be believable.

  7. Paul Milenkovic

    Emissivity. Stefans-Boltzmann radiation law. Optical depth. Keep talking, I . . . love ya, man, I think we are soul mates.

    But 10 C is relation to -273C being the absolute temperature reference scale, I think that is a 1% change and the T that goes into T^4 is in Kelvins, the absolute temperature scale.

    Rand, for this bromance to get any farther, I think you will have to enable LaTeX equations into your Web site.

    1. Paul Milenkovic

      Hit the wrong button on the calculator — 10 C is 3 percent. Does bromance love mean “never having to say you are sorry”?

  8. Arizona CJ

    What first opened my eyes (I admit to being a AGW believer in the late 90′s) was the CO2-temperature graphs. They’;re beloved by the AGW crowd because they show a relationship (correlation) between the two, a very strong one. They use this to argue causation. Turns out, there’s a huge problem with that.

    The CO2-temperature graphs show a close tracking for the last 400,000 years (ice core data). If, as was done, the two are separated by height on the graph, only the relationship is evident. (and that, I suspect, is why they present it in that format)

    The real eye-opener is when you overlay the two lines. Then, you clearly see what isn’t easy to see on the most commonly used charts – a time lag. It varies from 2 to 10 centuries (it trends toward the lower limit in warming periods, the longer in cooling)

    It’s the time lag that’s the key. What it boils down to is the cause must come before the effect.

    Short version: it’s absolutely clear in both the Greenland and Antarctic ice cores that there is a relationship between CO2 and temperature. Temperature goes up, *then* CO2 does the same. Temperature goes down, so does CO2. The two, when graphed, do track each other. But it’s temperature, not CO2, that’s the leader; CO2 follows temperature (by several hundred years) not the other way around.

    This is most clearly evident at both the start and end of the most recent glacial era. At the end of the Eemian interglacial, temperature and CO2 diverged massively; CO2 continued to rise for several hundred years after the drop in temperature. Likewise, at the end of the last glacial era, temperatures rose several hundred years before CO2 began to rise. This is also true (though based on antarctic ice cores only) of the prior four glacial eras, so five glacial eras in all. It’s evident through the entire timeline not just at the glacial era interfaces, but it’s most obvious there.

    So, unless we want to assume violations of the law of cause and effect (or time-traveling CO2) then it’s abundantly clear that temperature drives CO2 levels, and not the other way around. This makes sense, because while it’s difficult to beleive that a gas that’s a tiny fraction of earth’s atmosphere (four tenths of one percent) could have a major impact on temperature, it’s very easy to see how temperature, through its effects on both geochemical and organic processes, could have an effect on trace gas levels. (and also, why there’s a time lag in this effect).

    Now, we get to the Eemian interglacial era (the last interglacial warm period prior to the one in which we live). CO2 levels then were lower than today, and also lower than our per-industrial levels, yet the climate then was both hotter and wetter, worldwide. This is seen clearly from the fossil record in many location on earth; hippopotamus fossils on the Thames in the UK, iguanas in Greenland, tropical shells in presently-temperate areas… and most glaring of all, raised coral islands worldwide. (surface level coral reefs in the Eemian, when sea levels were about 17 feet higher.) It’s true that in some cases raised coral islands are caused by geologic uplift, but that’s not the case with most. Yet, all over the globe, even in areas where it’s currently too cold for coral, we see raised coral islands of approximately the same height, all dating from the Eemian.

    The warmist claim is twofold. First, they denied (ahha, deniers!) that the Eemian was warmer than the present (Much as they currently still do regarding Holocene warm periods, such as the Medieval Warm Period, that was warmer than today) . Then, they adapted, and now the current commonplace AGW explanation for the Eemian is that this warmth (that they denied) was due to solar forcing, not CO2. If that were true, it would, amongst other things, negate the cause and effect they claim from the close tracking of CO2 and temperature.

    Some of the current warmist claims are that the Eemian was only warmer in non-polar regions, and was colder at the poles, and that’s why polar bears didn’t go extinct, and thus global temp averages weren’t warmer than today. Unfortunately for them, this doesn’t pass the snicker test; the ice cores, especially in Greenland, show this isn’t the case, and it also ignores the higher sea level. Even if every bit of Greenland ice (the only significant ice volume in the northern hemisphere) melted, it’d raise sea levels by about six feet. The sea ice on the arctic ocean is meaningless for sea level changes, because it could all melt and not raise sea levels at all (it’s floating, of course).

    So, that leaves Antarctic ice as the source of the majority of the Eemian high sea levels (the water had to come from somewhere, and that’s the only source large enough). So, taken to a logical conclusion, the current AGW claims for the Eemian can be summed up as “the ice melted because it got colder”. They can’t claim sublimation; precipitation was higher then, too.

    But, that makes just as much sense as time-traveling CO2.

    1. Arizona CJ

      I bungled the atmospheric percentage of CO2 above.

      I said “four tenths of one percent”. (I rounded to 400ppm). I was wrong (and mathematically inept – pesky decimal places!) It’s an order of magnitude less than that, .04 percent, not .4 percent.

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