By Christopher Monckton of Brenchley
Responses to my post of December 28 about climate sensitivity have been particularly interesting. This further posting answers some of the feedback.
My earlier posting explained how the textbooks establish that if albedo and insolation were held constant but all greenhouse gases were removed from the air the Earth’s surface temperature would be 255 K. Since today’s temperature is 288 K, the presence as opposed to absence of all the greenhouse gases – including H2O, CO2, CH4, N2O and stratospheric O3 – causes 33 K warming.
Kiehl and Trenberth say that the interval of total forcing from the five main greenhouse gases is 101[86, 125] Watts per square meter. Since just about all temperature feedbacks since the dawn of the Earth have acted by now, the post-feedback or equilibrium system climate sensitivity parameter is 33 K divided by the forcing interval – namely 0.33[0.27, 0.39] Kelvin per Watt per square meter.
Multiplying the system sensitivity parameter interval by any given radiative forcing yields the corresponding equilibrium temperature change. The IPCC takes the forcing from a doubling of CO2 concentration as 3.7 Watts per square meter, so the corresponding warming – the system climate sensitivity – is 1.2[1.0, 1.4] K, or about one-third of the IPCC’s 3.3[2.0, 4.5] K.
I also demonstrated that the officially-estimated 2 Watts per square meter of radiative forcings and consequent manmade temperature changes of 0.4-0.8 K since 1750 indicated a transient industrial-era sensitivity of 1.1[0.7, 1.5] K, very much in line with the independently-determined system sensitivity.
Accordingly. transient and equilibrium sensitivities are so close to one another that temperature feedbacks – additional forcings that arise purely because temperature has changed in response to initial or base forcings – are very likely to be net-zero.
Indeed, with net-zero feedbacks the IPCC’s transient-sensitivity parameter is 0.31 Kelvin per Watt per square meter, close to the 0.33 that I had derived as the system equilibrium or post-feedback parameter.
I concluded that climate sensitivity to the doubling of CO2 concentration expected this century is low enough to be harmless.
One regular troll – one can tell he is a troll by his silly hate-speech about how I “continue to fool yourself and others” – attempted to say that Kiehl and Trenberth’s 86-125 Watts per square meter of total forcing from the presence of the top five greenhouse gases included the feedbacks consequent upon the forcing, asserting, without evidence, that I (and by implication the two authors) was confusing forcings and feedbacks.
No: Kiehl and Trenberth are quite specific in their paper: “We calculate the longwave radiative forcing of a given gas by sequentially removing atmospheric absorbers from the radiation model. We perform these calculations for clear and cloudy sky conditions to illustrate the role of clouds to a given absorber for the total radiative forcing. Table 3 lists the individual contribution of each absorber to the total clear-sky [and cloudy-sky] radiative forcing.” Forcing, not feedback. Indeed, the word “feedback” does not occur even once in Kiehl & Trenberth’s paper.
In particular, the troll thought we were treating the water-vapor feedback as though it were a forcing. We were not, of course, but let us pretend for a moment that we were. If we now add CO2 to the atmospheric mix and disturb what the IPCC assumes to have been a prior climatic equilibrium, then by the Clausius-Clapeyron relation the space occupied by the atmosphere is capable of holding near-exponentially more water vapor as it warms. This – to the extent that it occurred – would indeed be a feedback.
However, as Paltridge et al. (2009) have demonstrated, it is not clear that the water vapor feedback is anything like as strongly positive as the IPCC would like us to believe. Below the mid-troposphere, additional water vapor makes very little difference because its principal absorption bands are largely saturated. Above it, the additional water vapor tends to subside harmlessly to lower altitudes, again making very little difference to temperature. The authors conclude that feedbacks are somewhat net-negative, a conclusion supported by measurements given in papers such as Lindzen & Choi (2009, 2010), Spencer & Braswell (2010, 2011), and Shaviv (2011).
It is also worth recalling that Solomon et al. (2009) say equilibrium will not be reached for up to 3000 years after we perturb the climate. If so, it is only the transient climate change (one-third of the IPCC’s ’quilibrium estimate) that will occur in our lifetime and in that of our grandchildren. Whichever way you stack it, manmade warming in our own era will be small and, therefore, harmless.
A true-believer at the recent Los Alamos quinquennial climate conference at Santa Fe asked me, in a horrified voice, whether I was really willing to allow our grandchildren to pay for the consequences of our folly in emitting so much CO2. Since the warming we shall cause will be small and may well prove to be beneficial, one hopes future generations will be grateful to us.
Besides, as President Klaus of the Czech Republic has wisely pointed out, if we damage our grandchildren’s inheritance by blowing it on useless windmills, mercury-filled light-bulbs, solar panels, and a gallimaufry of suchlike costly, wasteful, environment-destroying fashion statements, our heirs will certainly not thank us.
Mr. Wingo and others wonder whether it is appropriate to assume that the sum of various different fourth powers of temperature over the entire surface of the Earth will be equal to the fourth power of the global temperature as determined by the fundamental equation of radiative transfer. By zonal calculation on several hundred zones of equal height and hence of equal spherical-surface area, making due allowance for the solar azimuth angle applicable to each zone, I have determined that the equation does indeed provide a very-nearly-accurate mean surface temperature, varying from the sum of the zonal means by just 0.5 K in total. In mathematical terms, the Holder inequality is in this instance near-vanishingly small.
Dr. Nikolov, however, considers that the textbooks and the literature are wrong in this respect: but I have deliberately confined my analysis to textbook methods and “mainstream-science” data precisely so as to minimize the scope for any disagreement on the part of those who – until now – have gone along with the IPCC’s assertion that climate sensitivity is high enough to be dangerous. Deploying their own methods and drawing proper conclusions from them is more likely to lead them to rethink their position than attempting to reinvent the wheel.
Mr. Martin asks whether I’d be willing to apply my calculations to Venus. However, I do not share the view of Al Gore, Dr. Nikolov, or Mr. Huffman that Venus is likely to give us the answers we need about climate sensitivity on Earth. A brief critique of Mr. Huffman’s analysis of the Venusian atmospheric soup and its implications for climate sensitivity is at Jo Nova’s ever-fragrant and always-eloquent website.
Brian H asks whether Dr. Nikolov is right in his finding that, for several astronomical bodies [including Venus] all that matters in the determination of surface temperature is the mass of the atmospheric overburden. Since I am not yet content that Dr. Nikolov is right in concluding that the Earth’s characteristic-emission temperature is 100 K less than the 255 K given in the textbooks, I am disinclined to enquire further into his theory until this rather large discrepancy is resolved.
Rosco is surprised by the notion of dividing the incoming solar irradiance by 4 to determine the Wattage per square meter of the Earth’s surface. I have taken this textbook step because the Earth intercepts a disk-sized area of insolation, which must be distributed over the rotating spherical surface, and the ratio of the surface area of a disk to that of a sphere of equal radius is 1:4.
Other commenters have asked whether the fact that the characteristic-emission sphere has a greater surface area than the Earth makes a difference. No, it doesn’t, because the ratio of the surface areas of disk and sphere is 1:4 regardless of the radius and hence surface area of the sphere.
Rosco also cites Kiehl and Trenberth’s notion that the radiation absorbed and emitted at the Earth’s surface is 390 Watts per square meter. The two authors indicate, in effect, that they derived that value by multiplying the fourth power of the Earth’s mean surface temperature of 288 K by the Stefan-Boltzmann constant (0.0000000567 Watts per square meter per Kelvin to the fourth power).
If Kiehl & Trenberth were right to assume that a strict Stefan-Boltzmann relation holds at the surface in this way, then we might legitimately point out that the pre-feedback climate-sensitivity parameter – the first differential of the fundamental equation of radiative transfer at the above values for surface radiative flux and temperature – would be just 288/(390 x 4) = 0.18 Kelvin per Watt per square meter. If so, even if we were to assume the IPCC’s implicit central estimate of strongly net-positive feedbacks at 2.1 Watts per square meter per Kelvin the equilibrium climate sensitivity to a CO2 doubling would be 3.7 x 0.18 / (1 – 2.1 x 0.18) = 1.1 K. And where have we seen that value before?
In all this, of course, I do not warrant any of the IPCC’s or Kiehl and Trenberth’s or the textbooks’ methods or data or results as correct: that would be well above my pay-grade. However, as Mr. Fernley-Jones has correctly noticed, I am quite happy to demonstrate that if their methods and values are correct then climate sensitivity – whichever way one does the calculation – is about one-third of what they would like us to believe it is.
All the contributors – even the trolls – have greatly helped me in clarifying what is in essence a simple but not simpliste argument. To those who have wanted to complicate the argument in various ways, I say that, as the splendid Willis Eschenbach has pointed out before in this column, one should keep firmly in mind the distinction between first-order effects that definitely change the outcome, second-order effects that may or may not change it but won’t change it much, and third-order effects that definitely won’t change it enough to make a difference. One should ruthlessly exclude third-order effects, however superficially interesting.
Given that the IPCC seems to be exaggerating climate sensitivity threefold, only the largest first-order influences are going to make a significant difference to the calculation. And it is the official or textbook treatment of these influences that I have used throughout.
My New Year’s resolution is to write a short book about the climate question, in which the outcome of the discussions here will be presented. The book will say that climate sensitivity is low; that, even if it were as high as the IPCC wants us to think, it would be at least an order of magnitude cheaper to adapt to the consequences of any warming that may occur than to try, Canute-like, to prevent it; that there are multiple lines of evidence for systematic and connected corruption and fraud on the part of the surprisingly small clique of politically-motivated “scientists” who have fabricated and driven the now-failing climate scare; and that too many who ought to know better have looked the other way as their academic, scientific, political, or journalistic colleagues have perpetrated and perpetuated their shoddy frauds, because silence in the face of official mendacity is socially convenient, politically expedient, and, above all, financially profitable.
The final chapter will add that there is a real danger that the UN, using advisors from the European Union, will succeed in exploiting the fraudulent science peddled by the climate/environment axis as a Trojan horse to extinguish democracy in those countries which, unlike the nations of Europe, are still fortunate enough to have it; that the world’s freedom is consequently at immediate and grave risk from the vaunting ambition of a grasping, talent-free, scientifically-illiterate ruling elite of world-government wannabes everywhere; but that – as the recent history of the bureaucratic-centralist and now-failed EU has demonstrated – the power-mad adidacts are doomed, and they will be brought low by the ineluctable futility of their attempts to tinker with the laws of physics and of economics.
The army of light and truth, however few we be, will quietly triumph over the forces of darkness in the end: for, whether they like it or not, the unalterable truth cannot indefinitely be confused, concealed, or contradicted. We did not make the laws of science: therefore, it is beyond our power to repeal them.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Monckton of Brenchley says:
You are still missing the basic point: Anything can be a feedback or a forcing, depending on the context, i.e., the particular “experiment” you are running on the Earth’s climate system. In the context of determining the net radiative contribution of each greenhouse gas to the total greenhouse effect, Kiehl and Trenberth have considered all of the gases to be forcings because they were just trying to answer the question, “What is the total radiative effect of all of the greenhouse gases and what amount is directly attributable to each greenhouse gas?”
However, if we now consider a specific experiment, such as removing all of the non-condensable greenhouse gases from the atmosphere and asks what happens, what will happen in reality is that the resulting temperature drop will cause much of the water vapor to also be removed from the atmosphere. Hence, you do not need to directly reduce the forcing by 86-125 W/m^2 in order to get most of 33 K temperature change. You just need to take out most of the non-condensable greenhouse gases and then this causes the water vapor to come out and you lose most of the radiative effect due to it also.
This is, once again, analogous to the “Bill Gates feedback” that I discussed http://wattsupwiththat.com/2011/12/30/feedback-about-feedbacks-and-suchlike-fooleries/#comment-848211 . If you just look at the amount of money (“forcing”) needed to feed 5 million people, you would conclude that you need $500 million. So, the question becomes, does the public (“CO2”) need to contribute an amount (“forcing”) of $500 million. And, the answer is no: The public only needs to contribute $100 million to cause the feeding of 5 million hungry people to occur (“the temperature to rise by 33K”) because the Bill Gates “feedback” supplies the other $400 million.
You claim that the 86-125 W/m^2 somehow does not include the water vapor feedback but that is nonsense. What Kiehl and Trenberth have provided you with is the total radiative effect of the water vapor that is in the atmosphere. Without doing some serious calculations, you and they have no way of knowing what fraction of that water vapor (and hence of its radiative effect) would be there even if the non-condensable greenhouse gases weren’t present and how much is there only because the non-condensable greenhouse gases have warmed the atmosphere enough for the water vapor to be there.
The mistake you are making here is a mistake that is made by a lot of skeptics. For example, people have often said basically, “How is it possible to even predict that the temperature increases by 3 K when the forcing increases by 4 W/m^2 when the Steffan-Bolltzmann Equation clearly shows that the increase due to such a radiative effect is only about 1.1 K?” And, the answer to this is that, while the original radiative effect of the CO2 is only 4 W/m^2, the total radiative effect of everything that changes, the clouds, the water vapor, the ice albedo, etc., would be close to 12 W/m^2…and hence the temperature rise necessary to balance this would be about 3 K.
Monckton of Brenchley says:
Not according to the scientists who actually study this ( http://www.sciencemag.org/content/306/5697/821.summary ):
“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. ”
Halleluja.
Get some idea as to how all those factors vary and how the system responds in order to work back towards the pressure dominated baseline temperature and then you have some idea as to how the system works.
The secret underlying it all is that the total system energy content varies little if at all unless global atmospheric pressure or solar input changes.
In the meantime one can achieve wide variations in the energy flow from surface to space or across the surface via changes in the REGIONAL surface air pressure distribution which is where climate changes come in.
Sure, no problem. Hopefully I did the algebra all correctly — it’s a pain to do algebra at a keyboard when you can’t run latex on the result to look at it. But then, it is pretty simple algebra. I think that this is one of NZ’s most interesting points — I’m not convinced that “pressure” per se is responsible for heat trapping as there is a bit of question begging in there that confuses cause and effect (as noted in a post a few days ago) but I’m very firmly convinced that neglecting effects on the order of dT/T or (dT/T)^2 in BOTH spatial AND temporal averaging is a capital mistake. I also do think that there is very probably a pressure effect, but I’m guessing that it has more to do with convection rates than with ideal gas laws. In any event, the correct rules should involve temperature dependent bulk moduli, not PV = NkT per se, or if you prefer, Navier-Stokes solutions of chaotic complexity.
What I think that they got right is that there is a strong and largely ignored coupling between contact cooling of the surface via convection (including evaporation and conduction) and radiative cooling and trapping. Convection moves heat up through the bulk of the greenhouse gas column to where it can be efficiently radiated; I suspect that it is favorably driven as long as the surface is differentially warmed and cooled (as it is) to create those colorful, often wet, convection rolls called “the weather”. The weather and the wind are evidence that bulk transport of energy is rather important in the Earth’s dynamic energy balance. Not to mention the fact that northern Europe isn’t one big ice-pack. You’d think that people would learn from the fact that Scandinavia isn’t big ball of ice (but Greenland pretty much is, at about the same latitude). Good old Gulf Stream. Then there is the hypothesis that the Younger Dryas was caused by the interruption of the Gulf Stream when a huge freshwater ice dam broke during the original warming phase of the Holocene.
Here’s another one. I make beer. On part of making beer is boiling the wort for some hours to reduce the fluid volume of the barley-sugar-water to the right specific gravity to ferment to the desired target alcohol level (and do things to proteins and sugars and at the right point to bitter and flavor it with the hops). Big pot, lots of fluid, hot on the bottom, cool on the top (even before the boil). The otherwise reasonably clear liquid is full of little chunkies of coagulated proteins as well, so the liquid has a clearly visible “texture” that lets you see the movement of the fluid.
As any good fluid physicist should understand, the heating on the bottom relative to the top creates instability. Warm water is much less dense than cold water, from 4C right up to 100+ C (beer/syrup boils a bit over 100C). Conduction is slow. Radiation is very slow. Rather than heating the water in a stratified way, bottom to top, as the bottom water heats, it expands and experiences a buoyancy force from the denser cooler water above and around it. It is pushed up. Of course at the top there is nowhere to go (it’s in a pot, bound by gravity) so it just displaces the cooler water there, which sinks, is heated at the bottom, rises to the top, gives off its heat via evaporation and conduction and radiation, cools a bit, sinks, picks up more heat, iterate indefinitely.
But the rising and falling are not uniform. The wort creates convection rolls of warmer lower pressure lower density rising liquid and cooler higher pressure higher density falling liquid, heating at the bottom, transporting the heat to the top, giving it off there, and going back to the bottom for another load all while the liquid itself gradually warms. When the convection is obstructed, one can quickly build up a much higher temperature differential, and it actually takes MUCH longer to reach equilibrium — you can actually boil off all of the liquid on the bottom in local patches and scorch things in contact there because the bottom of the pan isn’t COOLED by the convection rolls.
In a pot, the convection rolls are clearly manifest — usually it goes up on one half of my pot and down on the other, unless I stir it or have it really perfectly aligned on the heat. On the earth, the same process occurs in a very irregularly shaped, heated, and cooled “pot”. Heat is dumped in from the sun, but in a constantly varying pattern as clouds move around reflecting a large fraction of incident energy from some areas and not others. It is differentially absorbed by the ground and the water. Some of that heat is differentially released immediately into the air (which is itself also directly warmed by the light that passes through it). Some causes evaporation of water, cooling the surface of land or water but carrying away absorbed heat into the air. Air, too, rises when warm and falls as it cools and this creates huge masses of air that are just as trapped as the beer in my pot, rising over here, falling over there, and running along the ground or upper troposphere in between in both vertical rolls and in horizontal cycles as well. This air all moves in a rotating frame that causes it to deflect as it moves, creating large scale patterns of circulation around low and high pressure systems. All of this is driven by thermal differentials that move energy around, carrying it from where there is a lot to where there is less as an approximate rule, carrying it from where it is relatively hot (down low) up to where it is relatively cool (above) as an approximate rule.
Radiation is what ultimately removes the energy picked up from the sun, but it is not all radiation from the solid ground that does it, nor is it all, or even mostly, CO_2 in dry air responsible for obstructing that heat transport. This is why, in the desert where the humidity is very low, on a quiet night it can freeze by morning where the temperature rises to close to 100F during the day. Not much of a “greenhouse” effect there, I’d say (and the best possible measure of true greenhouse effect cooling, one that is unfortunately not generally directly studied).
When the heat is transported up by convection, it goes through the greenhouse reflector. The stronger the greenhouse trapping, the greater the thermal pressure differential, the comparatively stronger the convective transport process becomes and the more efficient the cooling becomes. The “stratified” reflective blanket is penetrated by the cooling holes of convective rolls, by the active transport of heat from where it is trapped to where it is not. All of this favors smaller sensitivities.
If there is a real lesson in this, this is it. It is a simple principle of very elementary thermodynamics that all perturbations away from the simple radiative model of cooling obstructed by greenhouse gases will increase the cooling rate compared to the purely radiative baseline. It will do this because the greater temperature differentials are a source of free energy that is begging to do work. The system will nearly invariably self-organize to do work, and in the process reduce the temperature differential between the lower and upper troposphere. This, in turn, will increase the efficiency of the radiative cooling by lifting the heat to be lost up above the greenhouse blanket. I don’t know why this simple argument is ignored so often in climate studies when it is the source of the very instability that produces the convective rolls in my heating beer, the wind in my hair, the rain on my garden, and the seasons. Heat trapping is never improved by a heat-differential instability — that would just make the system even more unstable!
Hence the full expectation that the climate sensitivity and feedback should be expected to be negative and cool the earth compared to what one might expect from “pure” CO_2 greenhouse trapping even before one looks at its details. This is just the “fluctuation/dissipation theorem”, and the climate models that postulate egregiously high climate sensitivity are egregious because they violate it. Given the existence of multiple modes (e.g. radiation and convection) for non-equilibrium energy transport, blocking one will increase the rate of others, not vice versa. Sometimes so well that it is difficult to see any effect of the blockage.
This argument doesn’t really depend much upon water, but the evaporative cycle in general is a perfect example. It cools down low and warms up high, with a very, very few exceptions brought about by peculiar geography (e.g. Santa Ana winds) because in general the warmer moist air rises, gives off its heat, condenses as (cooler) water, and falls. Yes, the clouds and water vapor modulate albedo and greenhouse trapping, but most of this modulation is random compared to improved transport as the temperature differential increases. Again one expects the overall effect of water to be negative to neutral, not positive feedback, because it will in general consume free energy to move water around relative to static stratified models, energy seeking equilibrium with outer space at 3K far overhead, energy that wants to move vertically (on average) from the warm surface to the cold overhead and horizontally from hot places to cooler places.
rgb
Reposted from Ira Glickstein’s thread on N&Z as I think it is pertinant to this thread also:
Folks, as I watch this discussion I keep seeing people get lost in the details. Stand back and look at the big picture.
N&Z have provided a formula that appears to have predictive skill. One CANNOT falsify it by arguing the details! Sure radiative absorption and re-emission happens in a certain way. Sure convection happens in a certain way. Sure lapse rate works in a certain way.
So What?
If there is one thing we’ve learned over the last few years of the climate debate it is (or should be) that our understanding of the mechanisms and how they interact with one another is woefully incomplete. If we were anywhere near to understanding all the pieces of the puzzle and how they fit together, we’d have climate models with predictive skills coming out the yin yang. But the fact is we don’t.
I liken this discussion to being given a pail full of gravel and being asked to determine the weight of the gravel. I could thoroughly mix the gravel, extract a representative sample, weigh each rock, pebble and grain of sand, extrapolate the expected change in distribution of the rocks, pebbles, and sand from top of the bucket to the bottom of the bucket based on known paramaters for the settling of gravel over time, and from there arrive at an estimate of the weight of the gravel in the pail.
Or I could weigh the gravel and the pail, then pour the gravel out, and weigh the pail.
What N&Z are purporting to do is the latter. One cannot falsify their results by arguing about what the proper distribution of grains of sand is or how gravel does or does not settle when poured into a pail. The only way to determine if they are on to something is to weigh the gravel.
What they have said is that for a given TOA radiance, and a given mean surface atmospheric pressure, they can calculate the average surface temperature of a planet. They’ve even published their predictions for no less than EIGHT planetary bodies!
The only question we should be interested in at this point (it seems to me) is this:
Did they get the surface temps of those planetary bodies right or not?
If no, then their formulas are wrong.
If yes, then it seems to me there are only two possibilities.
1. Their formulas are correct, we just don’t know exactly WHY they are correct.
or
2. They successfully predicted the surface temps of 8 celestial bodies by coincidence.
If the latter, that’s one awfull big coincidence!
So, would it not make sense to dispense with the arguments about the life time of a photon in earth atmosphere, how convection changes with pressure, what absorption bands various gases have and just answer the question:
Did they nail the temps of those planetary bodies? Or not?
Robert Brown says:
It is not ignored. A near as I can tell, what you are describing is called the “lapse rate feedback” and it is a negative feedback included in all of the climate models that comes about because, indeed, the higher altitudes of the troposphere are expected to warm a little more than the surface…and, since it is these high altitudes that are mainly important in determining how much temperature rise has to occur to re-establish energy balance, the surface warms less.
[Your description is vague enough that one could also interpret your argument as being that the greenhouse effect is smaller once convection comes into play than before it. That would be a statement that corresponds not so much to the lapse rate feedback but to the fact that the greenhouse effect is indeed of a smaller magnitude in models that include convection than in purely radiative analyses. Again, this is why all quantitative calculations of the effect include the effect of convection…i.e., it is what essentially does not allow the lapse rate to exceed the adiabatic lapse rate.]
However, there are other feedbacks that come into play that are positive. In particular, much of the same physics that controls the lapse rate feedback also controls the water vapor feedback, i.e., the fact that more water vapor in the atmosphere leads to more absorption of terrestrial radiation. Because these two processes are controlled by similar physics, it turns out that the spread amongst the climate models that is seen for the combined effect of these two feedbacks is much smaller than the spread for each individually. (I.e., models with a positive water vapor feedback that is larger in magnitude also tend to have a negative lapse rate feedback that is larger in magnitude, and models with a positive water vapor feedback that is smaller in magnitude also tend to have a negative lapse rate feedback that is smaller in magnitude.)
The fact that the net feedback due to water vapor and lapse rate feedbacks are reasonably well-simulated by the models is confirmed by satellite data for fluctuations that occur (and, for the long term multidecadal trends too, although here the data is a little less trustworthy because of artifacts that can affect these trends). See, for example, http://www.sciencemag.org/content/310/5749/841.abstract
Robert Brown:
many thanks, the article is posted here:
http://tallbloke.wordpress.com/2012/01/02/robert-brown-what-we-dont-know-about-energy-flow/
Feel free to join the Jelbring thread too, that’s where the action is today. Hans Jelbring himself has joined in the discussion.
davidmhoffer says:
Well, given that their formulas are based on a calculated value T_gb that appears to have been calculated incorrectly, their formula is probably not really correct. (See http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-850853 , although the credit should go to cba for arguing that they didn’t even do the math correctly, as I originally thought they had.)
Not when they have six free parameters, it isn’t! They didn’t predict anything. They simply did an empirical fit to some data using lots of free parameters!
Robert Brown,
A breath of fresh air, as a retired chemical engineer I think your big picture sensitivity asessment is a great approach.
(As far as I’m concerned anyone contemplating trying to model or understand the physics of the atmosphere should first be skilled in “Transport Phenomena”. If anyone is interested the seminal text by Bird, Stewart and Lightfoot is the reference text, I understand the first edition is better than the second which contains some errors that escaped proofing. “Transport Phenomena” was not tought until the 3rd year of my 4 year degree programme. A solid grasp of the principles of heat transfer, mass transfer, thermodynamics, physical and reaction chemistry and calculus.)
Old Mike
Joel shore;
Not when they have six free parameters, it isn’t! They didn’t predict anything. They simply did an empirical fit to some data using lots of free parameters!>>>
Equation 8. 2 parameters.
Robert, in addition to Joel’s misapprehensions and inability to see that the major feedbacks are as you said, negative, you have some further crit on Tamino’s blog from the comment linked below going forward to deal with if you feel like enlightening them.
Watch it though, Grant Foster plays dirty with snipping comments.
http://tamino.wordpress.com/2011/12/10/oh-pleeze/#comment-58042
Not according to the scientists who actually study this (
I go with Chris on this. If temperatures were so sensitive to changing conditions we would have either gone into thermal runaway long ago (don’t bring up Venus, it is a red herring), or the Earth would be iced over long ago.
This is where the faint sun paradox comes in. The sun was demonstrably weaker 3 billion years ago with an atmosphere not that different than today, with continents configured wildly different than today and yet temperatures were still temperate. CO2, maybe, but CO2 was 10x what it is today, suggesting yet again that temperature sensitivities are less than what has been advertised.
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.
Excellent post, and thus the underlying basis for my interest in actually going out and doing detailed measurements of the system as it is, not doing more fruitless computer modeling, unless it is to set hypotheses that the experimentalists then go out and get the data for in order to test the hypothesis!
davidmhoffer says:
Try again: Equation (8) has only two parameters but all it relates is T_S and N_TE. Equation (7) relating N_TE to the surface pressure P_S has another 4 parameters. So, to relate the physically-measured quantities of T_S and P_S, you have 6 free parameters.
Dennis Ray Wingo says:
I can’t even follow your logic here. On the one hand, you ask, “How could the climate possibly be so temperate when the sun was that much weaker?” And, then on the other hand, you claim solving this with CO2 only requires very low temperature sensitivities! So, which is it? The fact is that there are huge uncertainties associated with 3 billion years ago, both in terms of temperatures and CO2 levels…but, yes, the best current understanding would be that there are geochemical feedbacks that operate on long time scales and add some stability, namely that cold temperatures tend to lead to a buildup of CO2 (because the processes that remove it from the atmosphere don’t operate when everything is frozen over) and likewise that these processes speed up when it warms. This would explain why the climate system is seen to be quite sensitive to perturbations on shorter timescales but that the climate has nonetheless remained within some quite broad limits (and it is unclear how broad, since there is still a lot of uncertainty about snowball/slushball events) over the long haul.
Joel Shore says:
January 2, 2012 at 2:51 pm
davidmhoffer says:
Equation 8. 2 parameters.
Try again: Equation (8) has only two parameters but all it relates is T_S and N_TE. Equation (7) relating N_TE to the surface pressure P_S has another 4 parameters. So, to relate the physically-measured quantities of T_S and P_S, you have 6 free parameters>>>
8 is derived from 7, not the other way around.
Joel: See Ned Nikolovs reply to Alan McIntire on the other thread. Those parameters are not as free as you would love them to be.
“They simply did an empirical fit to some data using lots of free parameters!”
And found that the curve fitting all the solar system bodies they tested comes out very similar in shape to the Temperature/potential temperature ratio as a function of atmospheric pressure according to the Poisson formula based on the Gas Law.
Heh.
Wriggle wriggle.
tallbloke: I don’t see where you are talking about regarding Nikolov’s reply. And, since they admitted flat-out that the fit the 4 parameters in Eq. (7), I don’t see them not being very free. [It seems that one of the parameters in Eq. (8) is not really free because it represents the 2.7 K background, so they maybe they only have 5 free parameters.]
And, the fact is that it is only vaguely similar in shape to the temperature / potential temperature ratio. Heck, that ratio goes to zero as pressure goes to zero while their ratio goes to 1.
Basically, this is a Rorschach test: Anybody who can ignore the wealth of empirical evidence that shows the surface temperature is elevated by the greenhouse effect, embracing instead a “theory” that doesn’t even satisfy conservation of energy, is simply demonstrating what pathetic extremes people can go to when their ideology drives them to reject science in favor of nonsense! It really exposes how much of the “skeptic” movement is not about science at all…It is about rationalizing what one’s ideology dictates one wants to believe.
Like I said, Young Earth creationists really don’t stack up all that badly against believers in Nikolov’s “theory”.
Robert Brown :
January 2, 2012 at 8:21 am
Dr Brown, I feel I must at least write a temporary comment here at this very moment. Have been digging through your math and it’s implications ever since I read you commenting back in response to my paragraph and have been trying to write a long response back. I see so much underneath you equations.
That is an impressive mathematical breakdown of that so-simple paragraph. Thanks for the jump to the differentials. But you know, I think I understand why it queued you. That really is one of the very main, if not THE main (though incorrect), parameters that the justification of all of this radiative work in climate science seems to stand upon. Seems so un-physical.
When I can gather all of my thoughts and put in proper words (i wish!), I’ll write back here. Got quite a bit to say and hopefully get some assurance someone else sees where I am coming from on this subject.
Will read any responses over at tallbloke’s TalkShop.
davidmhoffer says:
January 2, 2012 at 10:48 am
…
N&Z have provided a formula that appears to have predictive skill. One CANNOT falsify it by arguing the details! Sure radiative absorption and re-emission happens in a certain way. Sure convection happens in a certain way. Sure lapse rate works in a certain way.
So What?
If there is one thing we’ve learned over the last few years of the climate debate it is (or should be) that our understanding of the mechanisms and how they interact with one another is woefully incomplete. …
>>>>>>>>>>>>>>>>>>>>
O’ man o’ man David !! I’ve been waiting for a good year for you to say that. You saw me post on your site that I was going to fight the physics battle, right? Well your statement above hits it right on the head.
I’m not good at getting the concepts through to others, but now, you seem to be seeing it. Just read Dr Brown’s two long comments above, twice, for he has so well explained so many of my point I’ve been making in such a piecemeal manner spread across so many posts and comments. His ability to put it all together in just two comments is phenomenal to me. Now we are getting somewhere, maybe, if these thoughts can stay together and not be torn apart in the natural flow of four posts a day. (I call that flow ‘blog hell’)
Joel Shore says:
January 2, 2012 at 4:34 pm
Basically, this is a Rorschach test: Anybody who can ignore the wealth of empirical evidence that shows the surface temperature is elevated by the greenhouse effect, embracing instead a “theory” that doesn’t even satisfy conservation of energy,
I’ve answered your misconception of what Nikolov and Zeller are saying on the UTC thread here:
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-851393
Like I said, Young Earth creationists really don’t stack up all that badly against believers in Nikolov’s “theory”.
Repeating your stupidity doesn’t make you appear any cleverer.
“Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating.
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-851393
Why so complicated. With higher density at the surface, you will improve convection.
This means the ground will be cooler and the air will be warmer.
Normally in sunlight the ground is much warmer than the air above it.
Normally, if you stop convection- greenhouse or inside a car one gets warmer air.
A greenhouse or inside a car is preventing heat from going into the atmosphere [warming it].
So normally grass, dirt, sand, in sunlight is warmer than the air above it, with more air density the surface will be cooled more [more energy will removed from it].
If the surface was the same temperature as the surface air during sunlight you have very high air temperature. A black roof in summer can be 180 F. If you stop convection it could slightly hotter, maybe 200 F,
If you had better convection it might instead get 170 F and air temperature of 160F- or higher than hotter air temperature record.
“The biggest scorcher ever noted was on September 13, 1922, in El Azizia (also known as Al ‘Aziziyah), Libya, when the mercury hit 136 degrees Fahrenheit. El Azizia is near the Sahara desert …
California’s Death Valley had the second-highest temperature. This desert area hit 134 degrees Fahrenheit in 1913”
If we have less air density, the ground would get slightly warmer- less convection. And one would lower air temperature. Because less energy being transported to the air.
What we talking about is hardly unknown. But it’s natural. Like water vapor, it’s not unknown, it’s simply ignored. And instead we have this obsession with CO2- a minor warming affect [or even possibly a net cooling effect].
The statement that “The point is that as temperatures increase, the rate at which the Earth loses heat goes strictly up, all things being equal.” is where the good Doctor Brown goes GIGO. It is correct that the rate at which the Earth’s SURFACE loses heat goes strictly up, but the surface is NOT where most of the thermal IR is emitted to space.
That is rather high up in the atmosphere, which can be seen by comparing the emission to space with the Planck distribution of thermal emission from the surface (here for example, but there are plenty of accurate measurements and models). The point at which the emission curve matches a blackbody curve tells you what the temperature of the effective altitude at which emission is occurring to space. Raising the greenhouse gas concentration raises the level at which the emission to space occurs to a colder level, and thus one where emission is slower. To make up for that the surface has to warm in order to push more energy through the open window directly into space
Arthur Smith handled the surface temperature distribution issue in some detail. To cut a long story there short, assumption of a uniform surface temperature UNDERESTIMATES the effect of greenhouse gases on surface temperature. To return to the first paragraph, DECREASING the temperature at which the Earth’s atmosphere radiates to space by increasing greenhouse gases, requires that the surface temperature INCREASE in order to restore radiative balance.
tallbloke says:
And I have explained why your “answer” is not an answer here: I’ve answered your misconception of what Nikolov and Zeller are saying on the UTC thread here:
http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-851393
I am not trying to be clever. I am just stating the obvious. Any reasonably-competent physical scientist reading the nonsense being written in support of Nikolov’s theory would conclude the same thing. The problem is that you guys here talk among yourselves and get a false notion that you are actually saying sensible things, as you can dismiss the few of us who are trying to explain why what you are saying is nonsense. (And, to be fair, those few of us include some AGW skeptics like Spencer, Monckton, Ira, and Eschenbach on this particular issue.)
@tallbloke: Sorry…My previous post had the wrong link in it to my response. Here it is: http://wattsupwiththat.com/2011/12/29/unified-theory-of-climate/#comment-851644