Roger Tattersall (aka Tallbloke) writes on his blog of a WUWT comment. Unfortunately WUWT gets so many comments a day that I can’t read them all (thank you moderators for the help). Since he elevated Dr. Robert Brown’s comment to a post it seems only fair that I do the same.
I saw this comment on WUWT and was so impressed by it that I’m making a separate post of it here. Dr Brown (who is a physicist at Duke University) quotes another commenter and then gives us all an erudite lesson. If Nikolov and Zeller feel they need to take any of the complaints on WUWT about the way they handle heat distribution from day to night side Earth seriously, they probably need to study this post carefully. this is also highly relevant to the reasons why Hans Jelbring used a simplified model for his paper, please see the new PREFACE added to his post for further elucidation.
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I can’t speak for your program, but I will stand by mine for correctly computing the ‘mean effective radiative temperature’ of a massless gray body as a perfect radiator. Remember, there is no real temperature in such of an example for there is no mass. It takes mass to even define temperature. (but most climate scientist have no problem with it and therefore they are all wrong, sorry)
I’d like to chime in and support this statement, without necessarily endorsing the results of the computation (since I’d have to look at code and results directly to do that:-). Let’s just think about scaling for a moment. There are several equations involved here:
is the total power radiated from a sphere of radius R at uniform temperature T. \sigma is the Stefan-Boltzmann constant and can be ignored for the moment in a scaling discussion. \epsilon describes the emissivity of the body and is a constant of order unity (unity for a black body, less for a “grey” body, more generally still a function of wavelength and not a constant at all). Again, for scaling we will ignore \epsilon.
Now let’s assume that the temperature is not uniform. To make life simple, we will model a non-uniform temperature as a sphere with a uniform “hot side” at temperature T + dT and a “cold side” at uniform temperature T – dT. Half of the sphere will be hot, half cold. The spatial mean temperature, note well, is still T. Then:
P’ = (4 \pi R^2) epsilon sigma ( 0.5*(T + dT)^4 + 0.5(T – dT)^4)
is the power radiated away now. We only care how this scales, so we: a) Do a binomial expansion of P’ to second order (the first order terms in dT cancel); and b) form the ratio P’/P to get:
P’/P = 1 + 6 (dT/T)^2
This lets us make one observation and perform an estimate. The observation is that P’ is strictly larger than P — a non-uniform distribution of temperature on the sphere radiates energy away strictly faster than it is radiated away by a uniform sphere of the same radius with the same mean temperature. This is perfectly understandable — the fourth power of the hot side goes up much faster than the fourth power of the cold side goes down, never even mind that the cold side temperature is bounded from below at T_c = 0.
The estimate: dT/T \approx 0.03 for the Earth. This isn’t too important — it is an order of magnitude estimate, with T \approx 300K and dT \approx 10K. (0.03^2 = 0.0009 \approx 0.001 so that 6(0.03)^2 \approx 0.006. Of course, if you use latitude instead of day/night side stratification for dT, it is much larger. Really, one should use both and integrate the real temperature distribution (snapshot) — or work even harder — but we’re just trying to get a feel for how things vary here, not produce a credible quantitative computation.
For the Earth to be in equilibrium, S/4 must equal P’ — as much heat as is incident must be radiated away. I’m not concerned with the model, only with the magnitude of the scaling ratio — 1375 * 0.006 = 8.25 W/m^2, divided by four suggests that the fact that the temperature of the earth is not uniform increases the rate at which heat is lost (overall) by roughly 2 W/m^2. This is not a negligible amount in this game. It is even less negligible when one considers the difference not between mean daytime and mean nighttime temperatures but between equatorial and polar latitudes! There dT is more like 0.2, and the effect is far more pronounced!
The point is that as temperatures increase, the rate at which the Earth loses heat goes strictly up, all things being equal. Hot bodies lose heat (to radiation) much faster than cold bodies due to Stefan-Boltzmann’s T^4 straight up; then anything that increases the inhomogeneity of the temperature distribution around the (increased) mean tends to increase it further still. Note well that the former scales like:
P’/P = 1 + 4 dT/T + …
straight up! (This assumes T’ = T + dT, with dT << T the warming.) At the high end of the IPCC doom scale, a temperature increase of 5.6C is 5.6/280 \approx 0.02. That increases the rate of Stefan-Boltzmann radiative power loss by a factor of 0.08 or nearly 10%. I would argue that this is absurd — there is basically no way in hell doubling CO_2 (to a concentration that is still < 0.1%) is going to alter the radiative energy balance of the Earth by 10%.
The beauty of considering P’/P in all of these discussions is that it loses all of the annoying (and often unknown!) factors such as \epsilon. All that they require is that \epsilon itself not vary in first order, faster than the relevant term in the scaling relation. They also give one a number of “sanity checks”. The sanity checks suggest that one simply cannot assume that the Earth is a ball at some uniform temperature without making important errors, They also suggest that changes of more than 1-2C around some geological-time mean temperature are nearly absurdly unlikely, given the fundamental T^4 in the Stefan-Boltzmann equation. Basically, given T = 288, every 1K increase in T corresponds to a 1.4% increase in total radiated power. If one wants a “smoking gun” to explain global temperature variation, it needs to be smoking at a level where net power is modulated at the same scale as the temperature in degrees Kelvin.
Are there candidates for this sort of a gun? Sure. Albedo, for one. 1% changes in (absolute) albedo can modulate temperature by roughly 1K. An even better one is modulation of temperature distribution. If we learn anything from the decadal oscillations, it is that altering the way temperature is distributed on the surface of the planet has a profound and sometimes immediate effect on the net heating or cooling. This is especially true at the top of the troposphere. Alteration of greenhouse gas concentrations — especially water — have the right order of magnitude. Oceanic trapping and release and redistribution of heat is important — Europe isn’t cold not just because of CO_2 but because the Gulf Stream transports equatorial heat to warm it up! Interrupt the “global conveyor belt” and watch Europe freeze (and then North Asia freeze, and then North America freeze, and then…).
But best of all is a complex, nonlinear mix of all of the above! Albedo, global circulation (convection), Oceanic transport of heat, atmospheric water content, all change the way temperature is distributed (and hence lost to radiation) and all contribute, I’m quite certain, in nontrivial ways to the average global temperature. When heat is concentrated in the tropics, T_h is higher (and T_c is lower) compared to T and the world cools faster. When heat is distributed (convected) to the poles, T_h is closer to T_c and the world cools overall more slowly, closer to a baseline blackbody. When daytime temperatures are much higher than nighttime tempratures, the world cools relatively quickly; when they are more the same it is closer to baseline black/grey body. When dayside albedo is high less power is absorbed in the first place, and net cooling occurs; when nightside albedo is high there is less night cooling, less temperature differential, and so on.
The point is that this is a complex problem, not a simple one. When anyone claims that it is simple, they are probably trying to sell you something. It isn’t a simple physics problem, and it is nearly certain that we don’t yet know how all of the physics is laid out. The really annoying thing about the entire climate debate is the presumption by everyone that the science is settled. It is not. It is not even close to being settled. We will still be learning important things about the climate a decade from now. Until all of the physics is known, and there are no more watt/m^2 scale surprises, we won’t be able to build an accurate model, and until we can build an accurate model on a geological time scale, we won’t be able to answer the one simple question that must be answered before we can even estimate AGW:
What is the temperature that it would be outside right now, if CO_2 were still at its pre-industrial level?
I don’t think we can begin to answer this question based on what we know right now. We can’t explain why the MWP happened (without CO_2 modulation). We can’t explain why the LIA happened (without CO_2 modulation). We can’t explain all of the other significant climate changes all the way back to the Holocene Optimum (much warmer than today) or the Younger Dryas (much colder than today) even in just the Holocene. We can’t explain why there are ice ages 90,000 years out of every 100,000, why it was much warmer 15 million years ago, why geological time hot and cold periods come along and last for millions to hundreds of millions of years. We don’t know when the Holocene will end, or why it will end when it ends, or how long it will take to go from warm to cold conditions. We are pretty sure the Sun has a lot to do with all of this but we don’t know how, or whether or not it involves more than just the Sun. We cannot predict solar state decades in advance, let alone centuries, and don’t do that well predicting it on a timescale of merely years in advance. We cannot predict when or how strong the decadal oscillations will occur. We don’t know when continental drift will alter e.g. oceanic or atmospheric circulation patterns “enough” for new modes to emerge (modes which could lead to abrupt and violent changes in climate all over the world).
Finally, we don’t know how to build a faithful global climate model, in part because we need answers to many of these questions before we can do so! Until we can, we’re just building nonlinear function fitters that do OK at interpolation, and are lousy at extrapolation.
rgb
Y’see, here in a nutshell is the problem I (and I suspect some others) have with climate models as they stand and the reliance placed upon them. It’s a massive exercise in false confidence and precision.
We don’t know what factors affect our climate. Some modellers have hypothesised that they know the main ones and that, by stripping out the ‘natural’ effects and doing a bit of curve-fitting, think they can get good results. Frankly, they’re kidding themselves and everyone else. As you say later, there’s not really such a thing as natural variability if that is meant to mean true randomness. What we should mean by it is the physical, chemical and biological processes at play that are independent of humanity’s suspected influences. These should have a preHow can we “predict what the underlying warming rates will be when natural variability forcing is removed” when we can’t really say with any confidence that we know the value, sign, or existence of every natural variability forcing? How can the resultant projections be said to reflect anything approaching reality?
Additionally, we don’t know the effects of inter-dependency between all known, suspected and unknown variables and their interrelated feedbacks. Modellers can’t just remove natural variability forcing as though it’s that easily compartmentalised, never mind that easily identifiable. Do we know every way in which the sun affects our climate? Cloudiness (at high/low altitudes, at high/low latitudes), photosynthesis —> evapotranspiration —> atmospheric water vapour levels, ozone formation and destruction, oceanic heat storage and release, jet circulation, differential air pressure at various altitudes, etc, etc? Do we know how CO2 affects everything else? Do we know how everything else affects CO2? And that;s just the start. Do we understand all short, medium and long-term cycles enough to write off the short-term ones as noise and to quantify and strip out the effects of medium and long-term cycles? Do we know that we’ve got the main factors covered, or do we just think that an approximate fit, given a favourable interpretation, over a very short period of time, with frankly unknowable confidence limits and error bars (despite best endeavours) is good enough to pronounce as settled science?
It’ll be great when we’re finally in a position to know, understand and predict our global and regional climate. We’re still a long way off. We may get there in the decades and centuries to come, or we may never get there. If we do, we may still have precious little influence over it. It seems that an unseemly political imperative is driving modellers to prescribe false confidence to their work at far too early a stage in the process.
It is a total waste of time for both sides.
Mann made his stuff up.
Those who say they know other things are just the flip side.
No one knows nor will they/we/others know for a long long time if ever.
Time to be productive on the real problems of man kind.
Much misdirection of time and energy going on with this.
Excellent article.
I have now read and reread this article several times and the discussion from the previous article that I believe was a comment within. Not sure as a lot of info has been absorbed. Mental fusion?
Thank you WUWT for bringing the most intelligent discussions to light.
I will now read the comments above which may cause mental confusion..
Wonderful article, Dr. Brown. You make a good skeptic.
Keith says:
January 8, 2012 at 4:56 pm
Well said.
R. Gates says:
January 7, 2012 at 10:13 am
“Then, perhaps in some skeptics minds, it was just a curious “coincidence” of history that the end of the LIA happen to coincide with the beginning of the industrial revolution, such that the 40% increase in CO2 since 1750 has had no (or very very little effect), and all the warming right up to today has been due to solar and ocean (delay solar) effects?”
The end of the LIA coincided with the beginning of the industrial revolution? Are you suggesting a causal relationship here? (It is so hard not to burst out laughing.) At the end of the LIA, the manmade CO2 molecules that could be found in the atmosphere could be counted on the fingers of one hand. In 1800, you needed both hands and both feet. In 1900, the number of manmade CO2 particles in the atmosphere had to be tiny. The entire carbon belching industrial base of the US could have been contained in the settled areas of Pennsylvania. This whole train of thought is just nutty.
Is it fair to say that the two systems would oscillate within the same parameters but the probability of them being synchronized is nil?
Sadly, no, not over long times. The systems could be as different as a ferromagnet magnetized up and an “identical” ferromagnet magnetized down. Or in the case of the Earth, as different as Glacial Earth and Interglacial Earth. The point is that both of these latter possibilities can be “stable” states for exactly the same insolation, etc, because feedbacks in the global system can themselves reconfigure to make them stable.
If you look at the link to chaos theory I provided, and look at the figure that shows two loopy braids of lines, that provides an heuristic picture of the kind of possibilities available to coupled nonlinear differential systems. At the heart of each loop is something called a “strange attractor”, which is typically a limit point. The x and y axes are coordinates in a generalized (phase) space that represent the state of the system at any given time, x(t),y(t). The lines themselves are the trajectory of the system over time moving under the influence of the underlying dynamics. The point of the figure is that instead of their being a single “orbit” the way the earth orbits a regular attractor like the sun, the system oscillates around one attractor for a time, then the other, then both. Instead of nice closed orbits the orbits themselves are almost never the same.
Two trajectories that are started close to one another will usually start out, for a while, orbiting the attractors the same general way. But over time — often a remarkably short time — the two trajectories will diverge. One will flip over to the other attractor and the other won’t. After a remarkably short time, the two trajectories are almost completely decorrelated in that the knowledge of where one lies (in the general accessible phase space) provides one with no help at all in guessing the location of the other.
It’s only in this final sense that you are correct. Either system has to be found in the space of physically consistent states, states that are accessible via the differential process from the starting points. There is no guarantee that the trajectories will “fill phase space”. So in this sense they are both going to be found within the phase space accessible from the starting points. If those two starting points are close enough, they will probably sample very similar phase spaces, but there is no guarantee that they will be identical — especially if there are (many) more than two attractors, and if some simple parameter. In stat mech, with different assumptions, there is a theorem to that regard, but in the general case of open system dynamics in a chaotic system, IFAIK no.
If you are interested in this sort of thing (which can be fun to play with, actually) you can look up things like the “predator-prey differential equations”, e.g.
http://en.wikipedia.org/wiki/Lotka%E2%80%93Volterra_equation
IIRC this is one of the simplest systems exhibiting an attractor and limit cycle, and illustrates many of the features of more complicated dynamical systems. The attractor/fixed point in this case is the population of e.g. foxes and rabbits that remains in perfect equilibrium from year to year. Note well that this equation is deterministic, but of course a real population — even being modelled — always has random (or at least, “unpredictable”) variations — a certain amount of noise — and is actually discretized and not continuous as one cannot have half a cheetah eating \pi baboons.
A better continuous “kind” of differential equation for describing systems like this with noise is something called a Langevin equation in physics — a system with “fast” microscopic degrees of freedom that one accounts for on average with a stochastic term, and slower degrees of freedom one integrates out like the predator prey equation. In physics it is a special limiting case of something called a generalized Master equation, which is the full integrodifferential description of a many body open quantum system and is really, really difficult. The general approach, however, is not inapplicable here — and is a presumed part of most of the simplified climate models. When you “smooth” the temperature by e.g. doing a running average, you are giving up information (the short time variation) and trying to reduce the complexity of the system by focussing on the slower time scale dynamics.
If the system really is simple — has a single attractor and is in a very regular oscillation around it where the “noise” one is smoothing out really is irrelevant and just adds small variation to a single trajectory — this is probably OK. If the system is multistable and has many locally stable points, or worse if some of the degrees of freedom are things like the Sun whose time evolution is completely outside of “the system” and whose future you cannot predict and whose effect you do not precisely know, so that the attractors themselves can be moving around as the system evolves locally — it is probably not OK.
The symptom of the latter kind of multistable system where it is probably not OK is a series of punctuated equilibria, visible in the smoothed data. The 30 year satellite data and SST data fairly clearly shows this kind of behavior.
One final very important point — systems that oscillate almost always have negative feedback. In fact, that is the fundamental thing that defines an oscillatory system — it has attractors in it. Attractors are themselves stable (equilibrium) points such that if the system is perturbed from them it is pulled back towards equilibrium, not pushed away from it. In the general case of attractors in high dimensional spaces, this leads to the (Poincare) cycles around the attractors visible in the predator-prey equations or the Chaos figure with two strange attractors, except that they can get very, very complicated (and difficult to visualize) in 3+ dimensional spaces (where I’m not talking about physical spaces, note well, but parametric “phase” spaces, state spaces). Within some neighborhood of an attractor there is generally a fair bit of local stability — trajectories in that neighborhood will oscillate tightly around the one attractor and will be relatively unlikely to switch over to other attractors. Hence glacial and interglacial periods tend to last a fairly long time (compared to all of the many shorter timescales available to the system.
Moving a single underlying external parameter — e.g. anthropogenic CO_2 concentration, Solar state, geomagnetic state — can be thought of as moving the fixed points of the multistable system. If we linearize, we can often guess at least the direction of the first order direction of the movement. For example, more CO_2, given the greenhouse effect, should increase heat trapping, hence increase average global temperature. The stable fixed point should thus move a bit up in the warming direction.
Nearly all of the argument “revolves” (in more ways than one:-) around two simple problems, and note that I’m presenting them in a very different way than usual:
a) Is this linear response assumption valid? This is not a trivial question. Increased CO_2 in a multistable system doesn’t just move the local attractor, it moves all the attractors, and not necessarily in simple linear ways in a really complicated system with many negative feedbacks (there by hypothesis all over the place because the system is dominated by attractors). In many systems, there are conservation principles at work (not necessarily known ones) that act as constraints so that moving one attractor up moves another one down or increases the “barrier height” between two attractors and hence deforms all of the limit cycles.
b) Is the response the order of the mean difference between attractors being predominantly sampled within the system already? If it is greater, then it is likely not just to move the current attractor but to kick the system over to a new attractor. And it may not be the attractor you expect, one on the warmer side of the previous one. More warming, as warmists state in more heuristic terms, can make the system oscillate more wildly and hence be both warmer at the warmest part of the oscillation and colder at the coldest part of the oscillation. If the new excursion of the oscillation is great enough, it can kick the system into oscillation around a new attractor altogether on either side of things.
Note that this latter statement is still oversimplified as it makes it sound like there are only two directions, warmer and cooler. But that is not true. There is warmer with morewater vapor in the atmosphere, warmer with less water vapor in the atmosphere, warmer with the sun active, warmer with the sun not active, warmer with sea ice increasing, warmer with sea ice decreasing, warmer with more clouds, warmer with less clouds, and the clouds in question can be day side or night side clouds, arctic or antarctic clouds, in the summer, fall, winter or spring, really month by month if not day by day, with feedbacks everywhere — tweaking any single aspect of this cycle affects all of the rest, and I haven’t even begun to list all of the important dimensions or note that there are really important time scales with nearly periodic oscillation of many of these drivers, or noted that the underlying dynamics takes place on a spinning globe that generates airflow vortices as standard operating procedure that have lifetimes ranging from days to decades.
I have argued in posts above that the punctuated quasi-equilibrium evident in the climate record makes it very likely that the answer to b) is yes. The anthropogenic CO_2 shifts the system by order of or more than the distance between attractors, simply because the system jumped around between attractors even during time periods when there was no anthropogenic CO_2. Furthermore, the excursion of the system as it wandered among the attractors was as great as it is today, and not qualitatively different.
This strongly suggests that while the the linear response assumption made in a) may be valid (per attractor) — or may not, but it will be a huge problem to prove it — the effect is less than the natural excursion, not greater than the natural excursion, and the negative feedback factors that make the multistable attractors (locally) attractive also act as negative feedback on the CO_2 induced shift!
The latter is the fluctuation-dissipation theorem, as I already noted in one thread or another (two tired of writing to go see if it was this one). In an open system in a locally stable phase, the oscillations (fluctuations) couple to the dissipation so that more fluctuation makes more dissipation — negative feedback. If this is not true, the locally stable phase is not stable.
This is a strong argument against catastrophe! The point is that given that CO_2 is making only small, slow, local shifts of the attractors compared to the large shifts of the system between the attractors, if there was a point where the system was likely to fall over to a much warmer stable point — the “catastrophe” threatened by the warmists — it almost certainly would have already done it, as the phase oscillations over the last ten thousand years have on numerous occasions made it as warm as it is right now.
The fact that this has not happened is actually enormously strong evidence against both positive feedback and catastrophe. Yes, anthropogenic CO_2 may have shifted all the attractor temperatures a bit higher, it may have made small rearrangements of the attractors, but there is no evidence that suggests that it is probably going to suddenly create at new attractor far outside of the normal range of variation already visible in the climate record. Is it impossible? Of course not. But it is not probable.
I’ll close with an analogy. When physicists were getting ready to test the first nuclear bomb, there was some concern expressed by the less gifted physicists present that in doing so they might “ignite the Earth’s atmosphere” or somehow turn the Earth into a Sun (note that this was before there was any understanding of fusion — the sun’s energy cycle was still not understood). I’ve read (far more recently) some concern that collisions at the LHC could have the same effect — create a mini-black hole or the like that swallows the Earth.
Both of these are silly fears (although offered up, note well, by real scientists, because they could see that these outcomes were possible, at least in principle) and here’s why.
The temperature and pressure created by the nuclear bomb is not unique! Although it is rare, asteroids fall to the earth, and when they do they create pressures and temperatures much higher than those produced by nuclear bombs. A very modest sized asteroid can release more energy in a few milliseconds than tens of thousands of times the total explosive energy of all of the man-made explosives, including nuclear bombs, on Earth! In a nutshell, if it could happen (with any reasonable probability), it already would have happened.
Ditto the fears associated with the LHC, or other “super” colliders. Sure, it generates collisions on the order of electron-teravolts, but this sort of energy in nuclear collisions is not unique! The Earth is constantly being bombarded by high energy particles given off by extremely energetic events like supernovae that happened long ago and far away. The energies of these cosmic rays are vastly greater than anything we will ever be able to produce in the laboratory until the laboratory in question contains a supernova. The most energetic cosmic ray ever observed (so far) was a (presumably) proton with the kinetic energy of a fastball-pitched baseball, a baseball travelling at some 150 kilometers per hour. Since we’ve seen one of these in a few decades of looking, we have to assume that they happen all the time — literally every second a cosmic ray of this sort of energy is hitting the Earth (BIG target) somewhere. If such a collision could create a black hole that destroyed planets with any significant probability, we would have been toast long, long ago.
Hence it is silly to fear the LHC or nuclear ignition. If either were probable, we wouldn’t be here to build an LHC or nuclear bomb.
It is not quite that silly to fear CAGW. The truth is that we haven’t been around long enough to know enough about the climate system to be able to tell what sorts of feedbacks and factors structure the multistable climate attractors, so one can create a number of doomsday scenarios — warming to a critical point that releases massive amounts of methane that heats things suddenly so that the ocean degasses all of its CO_2 and the ice caps melt and the oceans boil and suddenly there we are, Venus Earth with a mean temperature outside of 200 C. If we can imagine it and write it down, it must be possible, right? Science fiction novels galore explore just that sort of thing. Or movies proposing the opposite — the appearance of attractors that somehow instantly freeze the entire planet and bring about an ice age. Hey! It could happen!
But is it probable?
Here is where the argument above provides us with a great deal of comfort. There is little in the climate record to suggest the existence of another major stable state, another major attractor, well above the current warm phase attractor. Quite the opposite — the record over the last few tens of millions of years suggest that we are in the middle of a prolonged cooling phase of the planet, of the sort that has happened repeatedly over geological time, such that we are in the warm phase major attractor, and that there is literally nothing out there above it to go to. If there were, we would have gone there, instead, as local variations and oscillation around the many> minor warm phase attractors has repeatedly sampled conditions that would have been likely to cause a transition to occur if one was at all likely. At the very least, there would be a trace of it in the thermal record of the last million years or thereabouts, and there isn’t. We’re in one of the longest, warmest interglacials of the last five, although not at the warmest point of the current interglacial (the Holocene). If there were a still warmer attractor out there, the warmest point of the Holocene would have been likely to find it.
Since it manifestly did not, that suggests that the overall feedbacks are safely negative and all of the “catastrophe” hypotheses but one are relatively unlikely.
The one that should be worrisome? Catastrophic Global Cooling. We know that there is a cold phase major attractor some 5-10C cooler than current temperatures. Human civilization arose in the Holocene, and we have not yet advanced to where it can survive a cold phase transition back to glacial conditions, not without the death of 5 billion people and probable near-collapse of civilization. We know that this transition not only can occur, but will occur. We do not know when, why, or how to estimate its general probability. We do know that the LIA — a mere 400-500 years ago — was the coolest period in the entire Holocene post the Younger Dryas excursion; in general the Holocene appears to be cooling from its warmest period, and the twentieth century was a Grand Solar Maximum, the most active sun in 11,000 years, a maximum that is now clearly past.
IMO we are far more likely to be hanging out over an instability in which a complete transition to cold phase becomes uncomfortably likely than we are to be near a transition to a superwarm phase that there is no evidence of in the climate record. The probability is higher for two reasons. One is that unlike the superwarm phase, we know that the cold phase actually exists, and is a lot more stable than the warm phase. The “size” of the quasistable Poincare cycle oscillations around the cold phase major attractor is much larger than that around the warm phase attractors, and brief periods of warming often get squashed before turning into actual interglacials — that’s how stable they are.
The other is that we spend 90% of the time in glacial phase, only 10% in interglacial, and the Holocene is already one of the longer interglacials! There is dynamics on long timescales that we do not understand at work here. We have only the foggiest idea of what causes the (essentially chaotic) transition from warm phase to cold phase or vice versa — very crude ideas involving combinations of Milankovich cycles, the tipping of the ecliptic, the precession of the poles, orbital resonances, and stuff like that, but there is clearly a strong feedback within the climate cycle that enables cold phase “tipping”, probably related to albedo.
It could be something as simple as a quiet sun; the LIA-Maunder minimum suggests that we should actively fear a quiet sun, because something in the nonlinear differential system seems to favor colder attractors (still in the warm phase major attractor) during Maunder-type minima. One has to imagine that conversion to glaciation phase is more likely at the bottom of e.g. the LIA than at any other time, and the Holocene is probably living on borrowed time at this point, where a prolonged LIA-like interval could tip it over.
To be honest, even a LIA would be a disaster far greater than most of the warmist catastrophic imaginings. The population of the world is enormous compared to what it was in the last ice age, and a huge fraction of it lives and grows food on temperate zone land. Early frost and late spring could both reduce the available land and halve the number of crops grown on the land that survives, even before full blown glaciation. Cold (warm) phases are often associated with temperature/tropic droughts, as well, at least in parts of the world. IMO, the “rapid” onset of a LIA could kill a billion people as crops in Siberia and China and Canada and the northern US fail, and could easily destabilize the world’s tenuous political situation to where global war again becomes likely to add to our woes.
We may ultimately discover that AGW was our salvation — the CO_2 released by our jump to civilization may ameliorate or postpone the next LIA, it may block cold-phase excursion that could begin the next REAL ice age for decades or even a century. In the meantime, perhaps we can get our act together and figure out how to live together in a civilized world, not a few civilized countries where people are well off and all the rest where they are poor and more or less enslaved by a handful of tyrants or religious oligarchs.
Note well, this latter bit is itself “speculative fiction” — I don’t fully understand climate cycles either (it’s a hard problem). But at least there I can provide evidence for a lurking catastrophe in the actual climate record, so it is a lot less “fiction” than CAGW.
rgb
@ur momisugly Dr. Robert Brown
Thank you for sharing you thoughts with us. I do not see anything that you have written that I would not agree with. This has been a very thought provoking session.
Serious consideration should be given to organizing the leading article along with your additional comments for a publication. It should also include the comment you post concerning the atmosphere on another thread around Christmas here on WUWT. I looked for it but was not able to locate it.
That publication should be required reading for all levels of education before graduation and certainly any politician prior to voting for / against any legislation of funding for such research related to climate issues.
Very good information here that should be widely distributed.
rb;
You repeat, with emphasis, that question a few times. But it’s not going to have the impact you think, because in “common parlance” probable means >50%. It doesn’t have the technical qualifiers you “probably” automatically assume. It means “likely”, “most likely”, or even “highly likely”.
You mean, I hope, “Is the probability enough to care about?” or SLT.
And you run head-on into the “Precautionary Principle” nonsense. And all the “Phony Phat-Tail” pseudo-statistics. With a background of delusional downsides to warming, from extreme weather (which actually reduces as you evenly spread tropical warmth across the latitudes) to desertification of the entire temperate zone (which is in fact characteristic of cooling periods — see Greening of the Sahel, Roman Warm Period agriculture in North Africa, etc.)
So I suggest a change or refinement of that vocabulary when you’re not addressing specialists or students.
Here, you truly reveal yourself as a damfool. That will occur at about 30,000 – 50,000 ppm, — about 2 orders of magnitude higher than present, IOW — assuming that it is displacing O2 as it gets up to that 3% to 5% level. And even then, “death” is not likely. Exhaled breath is far higher than that.
Blech.
None of the models offered to date to clarify this puzzle, is not true and appropriate.
Earth in its orbit around the Sun , where there is very low temperatures, can’t heat Sun’s heat either any local sources of heat for billions of years.There must be some other more powerful and permanent source of heat.
What it could be inside the constelation of the solar system? The logical answer is that it must be a game of electro-magnetic fields which operate between the earth’s womb (and other celestial bodies with multiple discontinuies in the mass) ,can be maintained that does not harden like Moon(with a minimum of discontinuity or without).
We all know the working principle of electro-arc furnaces, where iron ore is melted.Agains, do the same electro-magnetic fields promoter complement each other depending on the mutual position of the Earth and Sun.
This is the most basic ideas for a solution for this problem and consideration should be taken into account and everything related to the database in these areas.
Sorry for my bad English.