This is a comment by Dr. Robert Brown on the What we don’t know about Earth’s energy flow post. I thought it was so insightful on the topic of climate stability being “pushed” by CO2 forcing that I’ve elevated it to a separate post. – Anthony
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.
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dmh;
A good diagnosis of why that (and other) posts taste slippery-slimy. Disingenuous is the polite term.
R. Gates says:
January 10, 2012 at 6:34 am
growing for a few weeks per year.”
This single statement pretty much summarizes the rest of your shallow and uninformed comments. To lump the entire field of paleoclimate study under the category of “tree records”, especially when I was referring to the mid-Pliocene, indicates a level of ignorance only perhaps exceeded by your fixated vitriol.
———————
Except that davidmhoffer didn’t “lump the entire field of paleoclimate study under the category of ‘tree records'”. He talked about the data specifically. You should know this as the first sentence of the section you quoted said,
“The paleoclimate data has been thoroughly discredited by the leading paleoclimatologists themselves.”
So, the question is are you being intentionally disingenuous or are you unknowingly obtuse. The latter is kind of redundant, but you seem to have no problem with redundancy.
@ur momisugly Brian H: Wryley doesn’t give a rats about DNA. He/she is just taking a shot at the Wal-Mart clientele. Possibly the sophomoric context of the remark failed to alert you to its intention.
By the way, did you know you can ascertain the state of the economy by the ratio of Bimmers to Junkers in a Wal-Mart parking lot?
Paul Vaughan says:
January 9, 2012 at 8:39 pm
Paging Tomas Milanovic … Here hear!!!
For those wishing to know more about the science behind Dr. Browns excellent post, try to get your hands on a book by James Gleick – CHAOS, making of a new science, which is a good beginners guide, without too much maths.
Some good stuff from Thomas Milanovic here if you want to understand the depth of the problems that are encountered by those trying to understand complex dynamic non-linear systems, like weather/climate…
http://judithcurry.com/2011/02/10/spatio-temporal-chaos/
http://judithcurry.com/2011/03/05/chaos-ergodicity-and-attractors/
Some good comments on both threads also well worth reading.
John Marshall says:
January 10, 2012 at 5:55 am >>>>>>>>>>
The exception that proves the rule. The F-16 is also dynamically unstable and flyable only because the computer dampens the positive feed back. Extreme performance is achieved by the computer ‘allowing’ critical instability in the desired direction.
All general aviation aircraft are required by FAA regulation to be dynamically stable to obtain certification.
Reading this article is like consuming a German-sized tankard of cold Bavarian beer after a walk across the Sahara desert – in terms of thirst for scientific insight into what is really behind historically observed (and soon-to-be-observed) climate shifts and the complex and dynamic climate system itself.
Thank-you Dr Brown for this truly refreshing reality check.
The understanding of the climate an a nonlinear / nonequilibrium system with emergent pattern and attractors, is as fundamental an advance in climate science as the insight by Galileo and Copernicus of the earth and other planets as orbiting the sun, rather than the earth-centric epicycle paradigm. CO2-centered (anthropogenic) climate science is directly analagous to the earth-centered epicycle cosmology. This is a sneak preview of a scientific revolution that is still decades away from taking hold in the scientific and public mainstream. Enjoy!
BTW a paired butterfly-wing attractor is not necessarily a Lorenz, it could also be a torn Roessler attractor.
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.
Negative feedback, otherwise referred to as friction, dissipation or damping, is indeed a key ingredient of non-equilibrium pattern systems. One very nice experimental demonstration of this is the oxidation of CO catalysed on a platinum substrate, described by Matthas Bertram and others, in which nonequilibrium complex patterns are established on the Pt surface, but the introduction of positive feedback into the system (by adjustment of gas pressures) opposes the complex patterns and imposes a monotonic regular oscillation. Thus negative feedback (damping) promotes emergent pattern – characterised by attractors – while positive feedback kills off such pattern and imposes regular oscillation.
Thus I see the climatic record with its apparent mix of suggestive regular oscillations with randomnness and variable oscillations as the effects of competing negative and positive feedbacks on a nonlinear-chaotic oscillatory system, with periodic forcing from Milankovich cycles in the long term and other possibly solar cycles in the shorter term.
Another way of describing a system with multiple attractors is as a limit cycle. While a complex multidimensional system is potentially free to adopt an infinite number of states, instead it is attracted to a limited number of states, the limit cycle. In this regard it is very interesting to note Bob Tisdale’s recent demonstration that the sea surface temperatures of the world’s oceans excluding the East Pacific (where the ENSO cycle occurs) only rise (or fall) at ENSO events, and SSTs remain static in between such events.
http://bobtisdale.wordpress.com/2011/12/27/on-the-ipccs-undue-confidence-in-coupled-ocean-atmosphere-climate-models-a-summary-of-recent-posts/
The ENSO has been shown by Bob to be apparently the principle driver of global climatic trends, with the recent temperature rise of the last few decades being in fact 2 or 3 step rises in global SST occuring at La Nina events. Could such periods of apparent stasis represent mini-attractors, and the system as a whole resemble a limit cycle?
Another related observation that was posted last January was the apparent resemblance of the ENSO pattern of oscillating East Pacific SSTs with a spatially distributed Belousov-Zhabotinsky reactor – the classic model of a nonlinear oscillator from inorganic chemistry:
http://wattsupwiththat.com/2011/01/25/is-the-enso-a-nonlinear-oscillator-of-the-belousov-zhabotinsky-reaction-type/
A very interesting article. My only comment is that there is in fact no warming effect from carbon dioxide because it has been proved by Professors Claes Johnson (1) and Nasif Nahle (2) that backradiation cannot warm the surface.
I frankly doubt the proof. First of all, backradiation does not “warm the surface”, sure, but it damn sure can slow its daytime cooling and increase the retention of heat. Go out and buy a “space blanket” — one of those ultrathin reflective pieces of plastic — and wrap your hand in it. Second, the physical mechanism is well understood, makes sense, and is consistent with laboratory experiments.
If you want more proof, note the correlation between nighttime temperature and clouds. I mean this one is simple — you can do it yourself almost any winter night that start out cloudy but is due to clear or vice versa. The temperature is extremely uniform as long as there are clouds overhead backscattering heat and hence slowing radiative cooling, but as soon as the clouds depart it cools, even if there is almost no wind (so it isn’t just that the air coming in is cooler). Finally, note the diurnal temperature differential for hot deserts as a function of local humidity. When it is dry, it is as large as 45C. When the air is relatively humid, it is much smaller.
I will state up front that I personally think it is borderline silly to assert that there is no greenhouse effect. This isn’t even new physics, it is “ancient” physics, and nothing learned in radiation physics that I know of has contradicted the basic theory, although sure there are still arguments over the details and sizes and feedbacks and so on. It is easy to understand, based on physics one can easily measure, and almost certainly a significant factor that contributes to the overall climate of the Earth. All of the serious discussion isn’t “is there a greenhouse effect at all” but about the details, in particular how greenhouse trapping of heat due to CO_2 in general and anthropogenic CO_2 in particular creates a mean rate differential between heating (from a hot source with spectral peak in the visible part of the spectrum, where the atmosphere is transparent) to cooling (from a cold source, radiating with a spectral peak in the IR, where the atmosphere is not particularly transparent). The latter doesn’t “warm” anything — it just cools more slowly than the same warm surface would in a vacuum because the emitted radiation bounces around a lot longer before making it it out at the top of the atmosphere.
The major argument involves the feedbacks and the details of the dynamics. If there is no feedback at all, a doubling of atmospheric CO_2 would lead to a probable increase in mean temperature of the Earth of roughly 1C, not really a problem. If there is net-negative feedback (which I offer a possibly “new” argument for above, although in the world it probably isn’t unique) it will probably be less than 1C. If there is net-positive feedback, it will probably be greater.
The long-term climate record (e.g. the Vostok ice core temperature estimates from the last 500K years) shows no signs of a second, locally stable (still) warmer phase in the general thermal bistability evident. It is usually either cold (glacial stable), warm (interglacial stable), or unstable and fluctuating briefly up (or down) a la Younger Dryas. The warm phase temperature and range of fluctuation is remarkably consistent across interglacials, as is the cold phase temperature, although you can see longer term variation in a longer term paleoclimate proxy record (to the extent that you can trust it).
I cannot emphasize enough the importance of fluctuation-dissipation in analyzing the likelihood of “catastrophe”, BTW. Although it is an open system, and we’re talking about a first order transition between major stable phases, the onset of catastrophe is marked by certain changes. In particular, the lifetime of fluctuations increases. Fluctuations are the key to understanding feedback, as negative feedback is responsible for damping fluctuations. Roy Spencer, in his book, does a beautiful if still somewhat incomplete job of arguing for negative feedback by looking directly at temperature fluctuations. As a system approaches a critical point, where it is likely to make a transition to a different state, one expects fluctuations to become more violent and to last longer. The susceptibility of the system should increase, classically to a divergence at a critical temperature but at the very least towards a strong nonlinear peak. Major changes should occur in things like patterns of circulation as the system flips around more rapidly.
There is basically no evidence that any such thing is occurring in the recent climate record, certainly nothing that cannot easily be interpreted as being well within the range of normal climate fluctuations empirically observed across the Holocene. There has clearly been warming since the LIA. It is reasonable to conclude that some of that warming has been due to anthropogenic changes including CO_2, land use changes, irrigation, blowing black soot around, air pollution, and so on. It’s really OK even for a skeptic to include CO_2 in the list, also — it is silly not to as noted above.
It is, however, almost impossible to determine how much of the warming is due to CO_2 compared to everything else. It could be as little as 0.3C. The problem is that the late 20th century, when the greatest “warming” occurred, was an 11,000 year Grand Solar Maximum, an oft-ignored fact that confounds efforts to “pin” the warming all on CO_2. The assumption “all things being equal” is simply not true for the 20th century — it wasn’t a normal century as far as the Sun was concerned, any more than the 17th century Grand Minimum was. Is it a coincidence that one was the LIA and the other was roughly as warm as the MWP? Perhaps, but one is certainly justified in doubting it! We also have enormous problems with the proxy-extrapolated climate record, variability in actual thermometer-based records, non-uniformity in measurement sites, sparsity of records — even in the scientific era we have lousy, noisy, sparse, data with big error bars that oversamples the hell out of the Northern Hemisphere and urban sites and leaves whole chunks of the world more or less unmeasured, where even where it was measured it was measured with relatively poor and inaccurate instruments. It is IMO impossible to correct this data for systematic bias without introducing systematic bias — the best that can be said is that it is noisy and unreliable and leave it at that.
In fifty or sixty more years, we’ll have a long enough satellite baseline — and I’m sure much improved physics and models — that perhaps we can start to separate out signal, noise, and the effect of all sorts of nonlinear responses in the chaotic climate system. Perhaps we will have a better handle on the sun as well, or we may even discover new physics that is contributing. In the meantime, anthropogenic CO_2 might drive the average temperature a whole degree warmer over the next century — an event that may well be lost in the “noise” of natural variability of the dynamical system itself in response to other drivers and dynamical history — but since non-carbon energy sources are destined to become economically favorable compared to carbon-based ones long before that, there are any number of “catastrophes” we should be worrying about instead.
Like limiting the world’s population of 7 billion and counting. Like decreasing the range between the haves and the have-nots, lifting up the world to civilization. Like working to eliminate religious oligarchy and promote freedom around the world. Like working to understand the world and our universe, because our knowledge gives us power over our environment and control over our own destiny while ignorance never can or will. Like creating great art. Like making the world a place of relative safety. Like being good stewards of our environment, something that sadly, no tragically, has been actually reduced as a distraction with all of the attention concentrated on CO_2.
Like working for World Peace…
Screw CAGW. There is no good reason to expect catastrophe. There is little reason to think that CO_2 won’t start to abate before it doubles anyway before the end of the century. But even if it were dead on true, it might be the lesser of evils compared to carbon taxes and all of the power (political power, not the other kind) games it fuels, all of the distraction from the really serious issues it represents.
Just imagine a world where we had spent billions of dollars not controlling carbon over the last decade, but on building schools, on eliminating pollution, on improving communications, on democracy building, on ending conflicts. Now the billions threaten to swell to tens, to hundreds of billions. We could eliminate global poverty for half of that., with World Peace right around the corner.
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What it takes to “flip” the system back to the other attractor, I believe, is a solar grand minimum where we have finally get a summer with nearly a full Arctic ice pack and not enough insolation when we come out of that grand minimum to melt it again in the face of the now-increased albedo.
I agree, crosspatch. Although there are probably other factors as well. Recall that the YD is supposedly due to the deflection of the oceanic conveyor belt so that the Gulf Stream circulated well south of where it goes now, supposedly caused by a lake of freshwater that diluted the Arctic “suddenly” as a major ice dam melted and drained, well, “Canada”. Even a relatively small change in the salinity of the system is subject to nonlinear/catastrophic sudden variations that could flip a little switch and make another small change that makes another small change, and suddenly you have a fresher arctic (easier to freeze) blocking the warm current that might melt it, and as you say, a feedback loop towards the cold cycle again.
There was a post last week about how parts of the arctic are “suddenly” freshening, due to increased freshwater runoff from streams and rivers out of Russia. This brings up fascinating possibilities — lower solar activity causes higher GCR rates which increases cloud formation which increases albedo near the equator (cooling) and increases rainfall in Siberia — if the various oscillations are phased just right at the time — which freshens the arctic which increases sea ice and blocks the Gulf Stream, which drops the temperature in Europe and the Northeast US and Canada (and Greenland and Iceland) “suddenly” by 2-3C which really increases sea ice and starts glaciation — more precip, colder temperatures, less heat in the tropics… etc.
The point is that the climate system, because it is chaotic, can become extremely sensitive to small systematic changes in things like circulation patterns or cloud formation (less so to uniform changes in temperature). The same forces that are causing it to stay in the current cycles carry it close to the boundaries of other attractors in the multistable space, and some variables may be important control variables that push the system closer to those boundaries. It’s the magnitude of the oscillations that is worrisome, not the mean behavior, and to understand them one needs data, more and better than we currently have.
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“I kept getting “But you’re not a climate scientist” rebuttals.”
Yeah, funny how that argument comes out or not depending on which side of the issue you argue.
Me, I’m just a “denier”.
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Except that davidmhoffer didn’t “lump the entire field of paleoclimate study under the category of ‘tree records’”. He talked about the data specifically. You should know this as the first sentence of the section you quoted said,
“The paleoclimate data has been thoroughly discredited by the leading paleoclimatologists themselves.”
______
My point exactly, as if the “paleoclimate data” was a homogenous thing, that with a single wave of the hand, could be dismissed by the “leading paleoclimatologists”–even if Mr. Hoffer were not simply engaging in weak-minded hyperbole. The study of paleoclimate data is a broad and complex field with many sub-specialties, both in content and historic period of interest, such that no “leading paleoclimatologist” in any one specialty would ever have sufficient knowledge or understanding to credibly dismiss all paleoclimate data–even if they were so inclined, which of course, in reality, they are not. Rather, Mr. Hoffer is once more grasping at straws in his never ending vitriol-powered fantasies. It would be humorous, and is humorous on one level, but certainly quite pathetic on another.
“We know that there is a cold phase major attractor some 5-10C cooler than current temperatures.”
Yes, we do;
http://motls.blogspot.com/2010/07/in-defense-of-milankovitch-by-gerard.html
Thank you Dr Brown for a very lucid discussion of why things are improbable because they haven’t happened yet! That might seem a bit trite to some, but I work in a field of risk analysis where I have to address this issue a lot of the time. We can calculate probabilistic risks only when the hazard has actually occurred; we can examine hypothetical risks based on known mechanisms to create some hazard and address the individual parts of the mechanism for their probabilities (hoping to provide some level of probability); but speculative risks with no known mechanism to cause any hazard are completely beyond the bounds of analysis.
Otherwise known as using Bayes’ Theorem to analyze joint and conditional probabilities. Yes, the proper analysis of climate would be a Bayesian analysis. Sadly, I doubt that most climate researchers have a clue about Bayes theorem. Mann certainly doesn’t.
The assumption that things are unlikely because they haven’t happened yet is predicated on “ergodicity”, the idea that in our abstract state space the natural excursion of the variables has already carried the system into all “accessible” regions and sampled them a fair bit, so that if catastrophe lurks, it must be in the relatively small unsampled part of the volume. Plus a bunch of e.g. smoothness assumptions and the like.
This can always be countered in climate science by the “scenario” method favored by warmists. In the “methane catastrophe” scenario, warming passes a critical point and the ocean bottom degasses massive amounts of methane, turning Earth into a sweatbox “overnight”. In my recently posted “freshwater catastrophe” (not due to me, I’ve read about this elsewhere) a freshening arctic blocks oceanic heat convection and puts Europe and the Arctic into an icebox, also “overnight”. What are the odds of either one? Empirically, slender indeed. People don’t appreciate it, but the Earth spent close to a thousand years of the Holocene with warmer average temperatures than we have right now (Holocene Optimum), doubtless with the temperature within that period fluctuating up and down to much hotter for a year or two and much cooler for a year or two in response to e.g. ENSO (or possibly, completely different global circulation patterns that dominated that epoch). If “methane catastrophe” or polar bear extinction were particularly likely, they probably would have happened then. Similarly, the LIA did not turn into the next real ice age. The Earth’s climate is in fact proven empirically (probably) stable for at least one more additional degree absolute and at least down to 2-3 almost completely missing solar cycles.
But do we hear this sort of analysis in climate research? On the contrary — we have MBH and the hockey stick “denying” that there is any significant climate variability at all that nasty old humans didn’t create, starting in the mid-nineteenth century.
The key to CAGW all along has been the elimination of the natural climate variability from the climate record. With it there, Bayes (also known as “using common sense”, by the way, quite literally) instantly rejects probable catastrophe. With it gone, then the last 150 years are extraordinary, unheard of, remarkable, and can have only one cause, anthropogenic CO_2, because otherwise the Earth’s climate is stable.
Horse. Shit.
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R. Gates;
This single statement pretty much summarizes the rest of your shallow and uninformed comments. To lump the entire field of paleoclimate study under the category of “tree records”, especially when I was referring to the mid-Pliocene, indicates a level of ignorance only perhaps exceeded by your fixated vitriol. >>>>
It would perhaps be helpful then for you to stipulate as to which paleoclimate data you consider credible. A simple handwave and an “oh, I wasn’t talking about tree rings” is sadly deficient in establishing that there exists any paleoclimate data that has any credibility. Please advise.
R. Gates;
Really, get over yourself Mr. Hoffer.>>>
I see I have touched a nerve.
Given the extent of our relationship that we have established over time in this forum, I’d suggest that there is no reason for honorifics. You may call me David or Dave, I’m good with both and quite happy to be on a first name basis with you. What’s your first name? Your REAL first name?
READERS:
For those wishing to be better informed as to the methods by which whateverhisrealfirstnameis Gates is using to hijack threads, misdirect and obfuscate, may I draw your attention to the highly controversial (and in my opinion, dangerous) field of pscyhology known as NLP or Neuro Linguistic Programming. While I can’t say for certain that whateverhisrealfirstnameis Gates is using NLP at all, and if he is, which specific branch of NLP he subscribes to, I’d suggest beginning the the book “Sleight of Mouth” by Robert Dilts.
The description of “Sleight of Mouth” is summarized in many ways as it has many practitioners. I consider it dangerous because in the hands of a trained and ruthless individual, you can convince otherwise intelligent people that the earth is flat and they should give you money for having explained it to them. For a pretty good summary of the major strategies which seem very evident (to me at least) in R. Gates writing, I suggest:
http://www.renewal.ca/nlp21.htm
and scroll down to the section titled “Sleight of Mouth Patterns” to see what I mean.
dmh
But that is only if CO2 actually has a significant warming effect. If 20th century warming was actually caused by the 80 year grand maximum of solar activity that began in the early 1920′s, that would leave little warming to attribute to CO2, and little chance that this slight warming effect will make the difference on whether our climate falls into the cold attractor.
Damn skippy. Not just an 80-year long Grand Maximum (I like to capitalize it to emphasize the point:-) but the strongest one in 11,000 years! You have to go back to the beginning of the Holocene to find a time when the Sun was as active as it was in the 20th century for an extended period of time. Again, I don’t know how to embed figures, but if the moderators would stick figure 17 from section 4 of:
http://solarphysics.livingreviews.org/Articles/lrsp-2008-3/
this paper in here, it would be greatly appreciated (and emphasize the point). BTW, the first red bump is associated with the end of the previous ice age (and almost immediate beginning of the Younger Dryas catastrophe; the second red bump is around the time of the end of the Younger Dryas, and the red patch in the middle has, AFAIK, nothing special about it, it wasn’t synchronous with the Holocene Optimum when global temperatures were between 1 and 2 C warmer than they are right now!
What, the baby seals and polar bears didn’t die over the thousands of years in the Holocene when it was warmer than the present? How is that even possible? I’m such a bad, bad denier…
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Robert Brown says:
January 10, 2012 at 11:17 am
“I frankly doubt the proof. First of all, backradiation does not “warm the surface”, sure, but it damn sure can slow its daytime cooling and increase the retention of heat. Go out and buy a “space blanket” — one of those ultrathin reflective pieces of plastic — and wrap your hand in it. Second, the physical mechanism is well understood, makes sense, and is consistent with laboratory experiments…
…Just imagine a world where we had spent billions of dollars not controlling carbon over the last decade, but on building schools, on eliminating pollution, on improving communications, on democracy building, on ending conflicts. Now the billions threaten to swell to tens, to hundreds of billions. We could eliminate global poverty for half of that., with World Peace right around the corner.”
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Another fantastic post!!! Bravo!!!!!
We can show, with decent evidence, we are at or near a normal inter-glacial peak. The record shows in repeated cases, at pretty clear intervals, what transpires next is a sharp drop towards and in to the predominant glacial state
We’re actually well down from the current (Holocene) interglacial peak, where global temperatures were some 1-2C warmer than they are today. The world has been cooling at an accelerating rate for the last 2000 years, where the stretch from 1000-2000 CE was one of the coldest thousand year stretches of the last 11,000, including the 20th century warming. If we warm as much as 1.5 C more, we will only be reaching (once again) the climate wherein men invented civilization, say the global climate when the Greek and Indian and early Chinese civilizations were all flourishing some 2500 years ago. Historically, warm is good, cold is bad, for humans at least.
Alas, I don’t think one can assume that CO_2 forcing is sufficient to propel us to a new interglacial optimum. There’s that pesky grand maximum in solar activity in the 20th century confounding things, together with what appears to be at least a temperature stabilization now that the maximum is over. The interesting question is, will the temperature significantly decrease like it did from 1945-1965 over the next cycle or two? That would effectively categorically disprove the CAGW hypothesis, positively confirm negative feedback, prove that the state of the sun does have a major effect on climate outside of mere variation of power output. Similarly, if it pauses and then continues rising, it will suggest that the feedback may be net positive. From the slope we will eventually be able to put limits on the feedback that positively exclude both catastrophe and anything to even slightly worry about — I don’t think we’re there on the latter, although I think we are on the former (catastrophe is most unlikely).
rgb
Great post!
This, and your two replies above (@ur momisugly 11.17 and 11.33 am), as well as your previous ones show that you are a great communicator of subjects not easily grasped by those who haven’t studied physics at graduate level.
They also show that it is far better, and invigorating for scientific debate, to point out what is not known. Above all, they show how glorious proper science is.
Wouldn’t it have been wonderful if all the billions, spent on making poor old CO2 the villain in a political drama, had been spent on doing proper climate research instead.
With so much unknown in that field, so much still to discover, it is a pity that the present practitioners of climate science, as represented by The Team, have stymied research of the unknowns. It could have become a great subject to study …
And the same happened during the 8.2ky event when the last of the glacial ice cap apparently gave way and opened what is now Hudson Bay and the larger glacial lake behind it to the Arctic ocean. There were probably several of these events but we had strong enough insolation to maintain an ice free arctic ocean in Summer. That would have been at about the peak of summer insolation.
There are *many* feedbacks that come into play. For example, as the sea levels drop, many shallowly submerged volcanoes in places such as the Red Sea, the Azores, and the Canary Islands (among other places) begin to erupt into the atmosphere instead of seeing their eruptive material dissipate relatively unnoticed into the sea. Also, as ice builds up and sea levels change, there could be some changes in Earth’s rotational mechanics. The length of day would shorten slightly as water is moved from the equator to the North polar region. Looking at a polar view map of ice extent at the LGM, it appears that the rotational pole of Earth might have migrated a bit toward Ellesmere Island in response to mass redistribution.
One paper I found interesting recently is this one that shows absolutely stunning changes in temperature on a decadal scale during the last glacial period:
http://www.clim-past.net/7/1247/2011/cp-7-1247-2011.pdf
Looking at Figure 2 on the 6th page of the PDF, we see several very rapid increases in temperatures followed by gradual cooling. There are also a smaller number of very rapid cooling events, too. In this case, speleothem records from caves in the Alps are compared to Greenland ice core data where it can be seen that most of these rapid changes in temperature are not regional events to Greenland. In fact, we often see the warming starting earlier in the Alps providing a “precursor” signal to what will happen in Greenland relatively shortly after. But the important thing is that we see these rapid “kicks” both positive and negative. Where we happen to be in the insolation cycle probably determines if one of these “kicks” flips us to the opposite stable state. As the interglacial state seems to depend on above average summer insolation of the NH, it seems reasonable that it would be the shortest lived state. Southern Hemisphere insolation doesn’t appear to play much of a role as Antarctica seems to remain glaciated at all times regardless of the state of the system.
Ah now comes Global Cooling (TM).
Hansen just gets richer.
Paint your new white rooftop black. Pfft! We will adapt to whatever nature throws at us. If a population decrease is needed, we will do it slowly through the economics of child rearing etc… GM crops will be cold tollerant and will grow in lower lattitudes. Africa will be the next superpower. We’ll eat the pleantifull bread made in India from African wheat. Technology will prevail, fear is not going to help anyone.
“Like limiting the world’s population of 7 billion and counting. Like decreasing the range between the haves and the have-nots, lifting up the world to civilization…. Like being good stewards of our environment, something that sadly, no tragically, has been actually reduced as a distraction with all of the attention concentrated on CO_2.”>>>>>>>>>>>>>>>>>>>>>>
The only acceptable way to limit the population is to enable the population to self limit. This is achievable by raising living standards throughout the world. Demographics show that fertility rates go down as living standards and longevity go up. Assured reproductive success allows people the luxury of lower birth rates. Negative feedback. This is facilitated by affordable and available energy. The sad irony of the CO2 debate is that carbon is the currency of the biosphere’s economy, the money supply if you will. Even with the advent of nuclear energy (fission and fusion) the use of hydrocarbon energy will still be a desirable thing if for no other reason than it’s fertilizer effect. Get it out of the mattress and into circulation where it can do work For us. The imperative is that we use it wisely. I am afraid that far too many people are blissfully unaware of how their lifestyle is only obtained and maintained through the use and availability of cheap energy. Go Polywell.
ferd berple says:
January 9, 2012 at 8:28 pm
Edit wikipedia to fix the problem. The reference is “cliamte” so it is inaccurate for someone to use “weather” in the sentence.
No way. It was so back in 2008:
http://web.archive.org/web/20080228114204/http://en.wikipedia.org/wiki/Chaos_theory
But they don’t want any chaos related to climate any more. They would rather elimante the reference.
I recommend the Book, ICE – A chilling scientific forecast of a new Ice Age by Fred Hoyle – published already 1981. The real long geological perspectives adressed.
crosspatch quotes:
January 9, 2012 at 5:31 pm
“I kept getting “But you’re not a climate scientist” rebuttals.”
And we should come back with “No climate scientist is a physicist because none of them propose physical hypotheses; rather, every one of them is nothing but a minor league or homegrown statistician.”
Robert of Ottawa says:
January 9, 2012 at 6:37 pm
‘Thing to remember is: Chaos theory applies to quantized phase space; not real space.
…
Chaos theory is a theory that explains why “We don’t know eff!”’
Excellent point that deserves serious attention from everyone. If there is ever to be a climate science that can explain and predict climate phenomena then its principles will require application in the real world. The Devil is in the details and climate science, so-called, studiously avoids them.
I recommend the Book, ICE – A chilling scientific forecast of a new Ice Age by Fred Hoyle – published already 1981. The real geological perspectives adressed.
Back from the mid-60’s through the mid-70’s, the hot topic was whether the dip from 1945 on presaged the advent of the next ice age. All of the current alarmism was the vogue then as well, but it was alarmism regarding cooling, because the local climate cycle had cooled from 1945 on, and there were some fairly bitter and prolonged winters with lots of snow in there. I used to trick or treat in the snow in Skaneateles, NY, in the stretch 1967-1970 — the snow would fall in mid-October and stay on the ground until March. I remember sitting in school in May watching the snow come down outside. In the late 50’s, my mother said she saw snowfall every month of the year while living in Skaneateles.
Fred Hoyle is a very interesting guy. He lost the great Big Bang vs Stead State Universe debate when the 3K microwave background was discovered, the “smoking gun” of the Big Bang. He used to write SF novels in addition to doing some pretty serious physics. And yeah, he was a professional iconoclast. I’m guessing he wrote most of the book before 1981 and then stubbornly went ahead and published it even though the world had arguably turned the corner away from cooling at that point (while not yet starting in with the current warming hysteria).
The warming hysteria isn’t new either. Back in the 1920’s the arctic largely melted, and newspapers were full of alarmism and concern that seals and polar bears and so on were endangered. That was (IIRC) the first point where the idea of a CO_2 catastrophe was first introduced. Good ideas are always ready to be reused, right?
It is just too damned hard to say that we don’t know why the arctic warmed in the 20’s, and we don’t know why it warmed again in the 80s and 90s. It’s correlated (some) with solar state, but that doesn’t seem like a sufficient explanation. CO_2 isn’t even close to a sufficient explanation, especially for the dip in the 1945-1965 era. We don’t really know why the average temperature varies at all. We cannot explain, individually or in concert, the variations in global temperature visible in the many proxy records — stalactites or ice cores. Again there are correlations, but no single factor is sufficient, not even Holy CO_2.
I really don’t find this all that surprising. The Earth is a rather complex system. Arguably the most complex system that we have ever studied, given that everything we know and everything we study is in some sense about the Earth, from basic physics and cosmology right through evolutionary biology. Learning about it is the only really worthwhile human pastime, aside from mastering World of Warcraft and creating art. Everything else is just fulfilling biological imperatives, and we can only do that efficiently to the extent that we understand everything about the world that we live in, at least everything that we can.
Who knows, in another few centuries, we might even get there! Or at least, get closer…
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