By Christopher Monckton of Brenchly
Joe Born (March 12) raises some questions about our paper Why models run hot: results from an irreducibly simple climate model, published in January in the Science Bulletin of the Chinese Academy of Sciences.
To get a copy of our paper, go to scibull.com and click on “Most Read Articles”. By an order of magnitude, our paper is the all-time no. 1 in the journal’s 60-year archive for downloads either of the abstract or of the full text.
Mr Born says that he is not sure he should take on trust our assertion that the Planck or instantaneous climate-sensitivity parameter is about 0.31 Kelvin per Watt per square meter; that we “obscure” the influences on the fraction of equilibrium temperature response attained in a given year; that we have used that fraction “improperly”; that we have incorrectly assumed a steep initial increase in temperature response; that we have relied on a model generated by a step-function representing the effects of a sudden pulse in CO2 concentration rather than one in which concentration increases by little and little; that it is “not clear” how we have determined that the 0.6 K committed but unrealized global warming predicted by the IPCC was not likely to occur; that our model should have taken more explicit account of the fact that different feedbacks operate over different timescales; that we were wrong to state that in an electronic circuit the output voltage transits from the positive to the negative rail at loop gains >1; and that our discussion of electronic circuitry was “unnecessary”.
Phew! I shall answer each of these points briefly.
First, however, Mr Born’s essay is predicated on a fundamental assumption that is flat wrong. He says that increasing CO2 concentration raises the optical density of the atmosphere, in turn raising the effective altitude [so far so good],
“and, lapse rate being what it is, reduces the effective temperature from which the Earth radiates into space, so less heat escapes, and the Earth warms”.
No. The characteristic-emission layer – the “altitude” from which the Earth appears to radiate spaceward, and at which, uniquely in the climate system, the fundamental equation of radiative transfer applies – is the locus of all points at or above the Earth’s surface at which incoming and outgoing radiation are equal. In general, the mean altitude of the locus of these balance-points rises as a greenhouse gas is added to the atmosphere. Thus far, Mr Born is correct.
His fundamental error lies in his assertion that the increase in the Earth’s characteristic-emission altitude reduces the effective temperature at that altitude, “so less heat escapes, and the Earth warms”.
The truth, which follows from the definition of the characteristic-emission layer and from the fundamental equation of radiative transfer that applies uniquely at that layer, is that the Earth’s effective radiating temperature is unaffected by a mere change in the mean altitude of that layer. It is not, as Mr Born says it is, “reduced” as the altitude increases.
The radiative-transfer identity, first derived empirically by the Slovene mathematician Stefan and demonstrated theoretically five years later by his Austrian pupil Ludwig Boltzmann, equates the flux density at the characteristic-emission layer with the product of three parameters: the emissivity of that layer; the Stefan-Boltzmann constant; and the fourth power of temperature.
Now, the flux density is constant, provided that total solar irradiance is constant (which, averaged over the 11-year cycle, it broadly is), and provided that the Earth’s albedo does not change much (it doesn’t). Emissivity is as near constant at unity as makes no difference; and the Stefan-Boltzmann constant is – er – constant. It necessarily follows that the temperature of the emission layer is constant unless any of the other three terms in the equation changes – and none of them changes much, if at all, merely in response to an increase in the mean altitude of the characteristic-emission layer.
Precisely because the effective radiating temperature at the characteristic-emission layer is near-constant under an increase in the mean altitude of the characteristic-emission layer, and precisely because the lapse rate of atmospheric temperature with altitude is very nearly constant under that increase, it is the surface temperature, not the effective radiating temperature at the characteristic-emission altitude, that rises in response to that increase in altitude.
Many of the subsequent errors in Mr Born’s understanding appear to flow from this one.
So to the individual points he makes.
First, the value of the Planck parameter. We stated in our paper that we had accepted the IPCC’s stated value. We might also have explained that we did not take it on trust. Indeed, the first of many fundamental errors in the climate modelers’ methodology that I identified, back in 2006, was the mismatch between the official value 0.31 K W–1 m2 and the Earth’s surface value 0.18 K W–1 m2 that was implicit in Kevin Trenberth’s 1997 paper on the Earth’s radiation budget.
As our paper explains, to a first approximation the Planck parameter is simply the first differential of the fundamental equation of radiative transfer – i.e., 0.27 K W–1 m2. However, allowance for the Hölder inequality obliges us to integrate the differentials latitude by latitude, based on variations in both radiation and temperature. That brings the value up by about one-sixth, to 0.31 K W–1 m2.
To verify that the modelers had done this calculation correctly, I asked John Christy for 30 years’-worth of satellite mid-troposphere temperature anomaly data in latitudinal steps of 2.5 degrees and spent a weekend doing the zenith angles, frustal geometry and integration myself. My value for the Planck parameter agreed with that of the IPCC to three decimal places. And, precisely because all of the parameters in the fundamental equation of radiative transfer are as near constant as makes no difference, the Planck parameter is not going to change all that much in our lifetime.
Next, Mr Born says we “obscure” the influences on the fraction equilibrium temperature response attained a given number of years after a radiative perturbation. Far from it. We begin by making an elementary point somehow not stated by Mr Born: that if there be any feedbacks (whether net-positive or net-negative) operating on the climate object, then the instantaneous and equilibrium temperature responses to a given radiative perturbation will not be identical, and there will be some pathway, over time to equilibrium, by which the temperature response will increase (with net-positive feedbacks) or decrease (with net-negative feedbacks) compared with the instantaneous response.
We continue by explaining the IPCC’s values – in its 2007 and 2013 reports – for the principal temperature feedbacks. We further explain that the response to feedbacks over time is not linear, but (assuming the IPCC’s strongly net-positive feedbacks) follows a curve in which, typically, half the approach to equilibrium occurs in the first 100 years, and the remainder occurs over the next 3000 years (see e.g. Solomon et al., 2009). We also provide a simple table of values over time that are unlikely to introduce too much error. The table was derived from a graph in Gerard Roe’s magisterial paper of 2009 on feedbacks and the climate. Far from obscuring anything, we had made everything explicit.
Mr Born goes on to say we had used the fraction of equilibrium temperature response “improperly”. However, it is trivial that in all runs of our model that concerned equilibrium sensitivity (and most of them did) that fraction is simply unity. In those runs that concerned instantaneous sensitivity (some did), that fraction is simply the ratio of the Planck to the equilibrium sensitivity parameter. In those runs that concerned transient sensitivity, we were dealing with sub-centennial timescales, so that up to half of the equilibrium response should have been evident. All of this is uncontroversial, mainstream climate science. Admittedly, it is very badly explained in the IPCC’s documents: but not the least value of our paper has been in explaining simple concepts such as this one.
Next Mr Born says we have incorrectly assumed a steep initial increase in temperature response (one can see this steep initial response quite clearly in Roe’s graph). Mr Born may or may not be right that there should not be a steep initial increase; but, like it or not, that is the assumption the IPCC and others make. We provided worked examples in the paper to show this. In short, Mr Born’s quarrel on this point is not with us but with the IPCC.
Furthermore, once we had calibrated the model using the IPCC’s assumptions and had obtained much the same sensitivities as it had published, we then adopted assumptions that seemed to us to be less inappropriate, and ran the model to reach our own estimates of climate sensitivity: around 1 K per Co2 doubling.
One of those assumptions, attested to by a growing body of papers in the literature, some dozen of which we cited, is that temperature feedbacks are probably net-negative. Here, for instance, is a graph from Lindzen & Choi (2009), showing the predictions of 11 models compared with measurements from the ERBE and CERES satellites:
Given the probability that temperature feedbacks are net-negative, we ourselves had not assumed a strong initial temperature increase: for that assumption, made by the IPCC, depends crucially on strongly net-positive feedbacks, some of which – such as water vapor – are supposed to be quick-acting. However, the ISCCP data appear to suggest no increase in column water vapor in recent decades, and even something of a decrease at the crucial mid-troposphere altitude:
Mr Born complains that in determining the fraction of equilibrium temperature response at any given year we relied on a model generated by a step-function representing the effects of a sudden pulse in CO2 concentration rather than one in which concentration increases by little and little. So we did: however, as the paper explains, we tested the model to ensure that the results it generated over, say, 100 years were much the same as those of the IPCC. It generated broadly similar results.
As it happens, I had first come across the problem of stimuli occurring not instantaneously but over a term of years when studying the epidemiology of HIV transmission. My then model, adopted by some hospitals in the national health service, overcame the problem by the use of matrix addition, but sensitivity tests showed that assuming a single stimulus all at once produced very little difference compared with the time-smeared stimulus, merely displacing the response by a few years. Similar considerations apply to the climate.
Besides, our model is just that – a model. If Mr Born does not like our values for the fraction of equilibrium temperature response attained after a given period, he is of course free to choose his own values by whatever more complex method he may prefer. But, unless he chooses values that depart a long way from mainstream climate science, the final sensitivities he determines with our simple model will not be vastly different from our own estimates.
Next, Mr Born says it is “not clear” how we have determined that the 0.6 K committed but unrealized global warming predicted by the IPCC was not likely to occur. On the contrary, it is explicitly stated. We assumed ad argumentum that all warming since 1850 was anthropogenic, ran our model and found that the variance between its predicted warming to 2014 and the observed outturn was nil, implying – as explicitly stated in the paper, that there is no committed but unrealized global warming in the pipeline. See table 4 of our paper.
Interestingly, the official answer of the “hokey team” to our point is that we should have assumed that more than all the warming since 1850 was manmade. On that point, we disagree. For They cannot at once argue that the hefty increase in solar activity between the Maunder Minimum 0f 1645-1715 and the near-Grand Maximum of 1925-1995 had no influence on global temperature, but that the decline in solar activity since its peak in 1960 is so great that it would have caused significant cooling in the absence of anthropogenic forcings over the period.
Mr Born also complains that our model should have taken more explicit account of the fact that different feedbacks operate over different timescales. Well, our transience fraction may be tuned at will to take account of that fact. And we even presented a table of values of that fraction over time to take account of a mainstream, conventional distribution of temperature feedbacks and their influences over time. If Mr Born disagrees with Dr Roe’s curve, he is of course entirely free to substitute his own. We presented not tablets of stone but a model.
Next, Mr Born devotes much ink but not much light to his assertion that we were wrong to state that in an electronic circuit the output voltage transits from the positive to the negative rail at loop gains >1. We consulted the reviewed literature; a process engineer with three doctorates, who also consulted the literature; a doctor of climatology specializing in feedback analysis as applied to the Earth’s climate; and a Professor ditto (the last two being among the top six worldwide in this highly specialist field). I also discussed the question of the response-versus-loop-gain curve with a group of IPCC lead authors at a talk I gave at the University of Tasmania three years ago.
Not one of these eminent advisers agrees with Mr Born. That, on its own, does not mean he is wrong: but it does mean that the point we raise is at least respectable.
The Bode feedback-amplification equation is entirely clear: at loop gains >1 the equation mandates that the temperature response becomes negative. In an electronic circuit one can of course – as Mr Born does at rather tedious length – find ways of making the circuit oscillate even in the absence of loop gains >1, and one can find ways of making it not oscillate even at loop gains >1.
However, the equation actually used in the climate models (including ours) is, like it or not, the Bode system-gain equation. Mr Born carefully plots only that part of the graph of the equation below a loop gain of 1:
However, our paper plots the graph both sides of a loop gain of unity. A loop gain of 1 is equivalent to the feedback sum of 3.2 Watts per square meter per Kelvin in Mr Born’s graph, for in the climate the loop gain is the product of the feedback sum and the Planck parameter, and the Planck parameter is the reciprocal of 3.2.
On reading Mr Born’s piece one would think the point we had raised was both trivial and inappropriate. However, the specialists whom we consulted, and the equation itself, suggest that our point is both non-trivial and substantial.
Indeed, the Professor, until I debated the issue with him before a learned society somewhere in Europe a couple of years back, was a true-believer in the profitably catastrophist viewpoint. When I displayed the full plot of the Bode equation he went white.
He wrote to me afterwards, sending me a paper in which he had himself urged caution in the use of Bode in climate modeling. A few weeks ago he got in touch again to say he has thought about the matter ever since and has now concluded – damn you, Monckton – that I am right, and that in consequence climate sensitivity cannot be more than 1 K and may be less.
He has submitted a paper for peer review. If that paper is published, and if it proves correct, the science will indeed be settled – but in a direction entirely uncongenial to the profiteers of doom.
One of the IPCC lead authors in Tasmania interrupted my talk when I showed the full Bode graph and said: “Have you published this?” No, I replied. “But you must,” he said. “This changes everything!” Yes, I said, I rather think it does.
If the Bode equation is inappropriate for loop gains >1, then it may also be inappropriate for loop gains <1. It may – at least in its unmodified form – be the wrong equation altogether. And without it one cannot get away with claiming the absurdly high and unphysical sensitivities the IPCC profits by asking us to believe in.
At minimum, tough asymptotic bounds to constrain the behavior of the equation at the singularity should be imposed. That, at any rate, is what the very small variability of global temperature over the past 810,000 years would suggest: and, on that point, Mr Born surely agrees with us.
The hokey team have responded to this point by saying that the paleoclimate record (showing temperature varying by only 3.5 K either side of the long-run mean over the past 810,000 years) demonstrates high net-positive feedback in response to very small forcings over the period.
Accordingly, I consulted an eminent geologist who said the positive and negative forcings over so long a timescale were very substantial. So I consulted another geologist. He said the same.
Mr Born’s final point is that our discussion of electronic circuitry was “unnecessary”. Not so. The models use an equation taken from electronic circuitry, where it represents a real event, the phase-transition of the voltage from the positive to the negative rail at a loop gain of unity, and misapply it to the climate, which is an object in a class to which that equation does not apply, especially at the very high loop gains implicit in the IPCC’s estimates of climate sensitivity.
There are two principal reasons why the Bode equation – unless it is modified in some fashion analogous to Mr Born’s modification of a circuit to prevent its output from behaving as it would otherwise do – does not apply to the climate.
First, as temperature feedbacks and hence loop gain increase, there comes no moment at which the effect of the feedbacks is to reverse the output and push temperatures down, though that is what the Bode equation in the form in which it is applied to the climate models mandates.
Secondly, in an electronic circuit the output [voltage] is a bare output: it does not act to equilibrate the circuit following the perturbation amplified by the feedback. In the climate, however, an increase in surface temperature is precisely the mechanism by which the object self-equilibrates, and the Bode equation simply does not model this situation.
For these reasons, we considered it important to raise an early red flag about the applicability of the Bode equation. We are not the first to have done so, but as far as we know our brief treatment of the problem is more explicit than anything that has been published before in the reviewed literature.
I have a further paper on the Bode question in the works that has passed review by an eminent expert in the field (I don’t know who, but the journal is in awe of him). The paper will be published in the next few months.
At no point did that reviewer (or any reviewer) question the validity of the point we raised. On the contrary, he said that the paper was a good definition of a real problem. The paper describes the problem in some detail and raises questions designed to lead to a solution.
Readers who have struggled through to this point may now like to read our paper in Science Bulletin for themselves. There is, perhaps, not a lot wrong with it after all.
I get so tired of cryptic sarcastic responses from certain “authoritarian” people.
If the earths atmosphere wasn’t self-correcting, the planet would have burned out long ago, or have been completely frozen, take your pick.
We are still here after billions of years of change.
Unless Al Gore runs for president in 2016. Heard that today on the Michael Medveyd show, people 3 cars away on the highway doing 60 MPH could hear me screaming!
And that’s exactly why CAGW theory is a crock, for if – put simply – the theory of a modest rise in temperature automatically leading to a series of further large increases was true, we would not be here to discuss it. The Earth has its own imperfect thermostat and we have little idea how it really works.
One thing which always puzzles me is this: if temperature rises, then obviously there should be more water vapour in the atmosphere, but why does the IPCC state that this would mean less clouds?
In response to Mr Miller, actually we have a very good idea of the processes by which the Earth’s thermostasis is mantained within an interval little greater than that programmed into a domestic thermostat. The atmosphere, after all, is sandwiched between two near-infinite heat-sinks: the oceans and outer space. The heat capacity of the oceans is so large that even the billions of “Hiroshima bombs” of energy that the climate-extremists talk of do not much alter ocean temperature. Then there are the processes of evaporation and convection that take heat away from the surface. And so on.
All these processes and properties of the climate ensure that, under modern conditions, the Earth’s thermostat is near-perfect. For the past 810,000 years, global mean surface temperature as reconstructed on the basis of ice-core samples has varied by little more than 3 Kelvin either side of the long-run mean, and that is not much more than 1% in absolute terms.
Mr. Monckton, thank you for willingness to actually respond to so many questions and critiques.
Regarding this portion of Mr. Millers question, I would appreciate your response, or any response from anyone who knows.
“One thing which always puzzles me is this: if temperature rises, then obviously there should be more water vapour in the atmosphere, but why does the IPCC state that this would mean less clouds?
Where do the IPCC say this would mean less(sic) clouds?
Lord Monckton wrote:
And isn’t that remarkably beautiful! Siddhartha, after spending a lifetime torturing himself looking for Nirvana finally came to the realization that one does not need to fast, or do yoga, or mediate, or whatever, to reach Nirvana. We are already here! There is nothing to do but see it in front of us: we need fresh water, and rain miraculously falls from the sky; we need coffee in the morning, and the most incredible network of people and technology all conspire, as if by magic, to fill our cup; we need a narrow temperature range to flourish, and as if adjusted by the hand of some great benevolent being, our thermostat stays set at nice and comfy.
This is it. This is your life. This is Nirvana.
Incidentally, that San Francisco is surrounded by a near-infinite heat sink explains its remarkably even temperature year-round.
Cheers Lord Monckton. You’re the Buddha of the Brenchley.
One more comment:
Heard a radio ad today about the “warm winter” we had in the US Pacific NW, and therefore the coming summer was going to be a scorcher.
Their solution??? Install residential AC to combat global warming!!!😱😱😱
Yes, let’s use more energy to keep ourselves cooler.
And this from a company who regularly promotes energy conservation in commercial buildings to “prevent” global warming.
My head hurts…
“Their solution??? Install residential AC to combat global warming!!!😱😱😱”
Sounds like somebody wants more CO2 “credits” or an increase solar/wind electric generating rates.
http://www.scibull.com:8080/EN/article/showBrowseTopList.do
Unfortunately, there is likely to be something of a delay before I can respond completely. In fact, I can’t get to the most-central issue right now. But let me make a down payment before I turn in.
block; there is necessarily a lag—of what magnitude I’ll admit I don’t know—between the optical-density stimulus and the temperature response, even before any knock-on effects.
Lord Monckton says that “Mr Born’s essay is predicated on a fundamental assumption that is flat wrong. . . . His fundamental error lies in his assertion that the increase in the Earth’s characteristic-emission altitude reduces the effective temperature at that altitude, ‘so less heat escapes, and the Earth warms’.” Lord Monckton’s characterization is that “the Earth’s effective radiating temperature is unaffected by a mere change in the mean altitude of that layer.”
I say potato, he says potahto.
My understanding is that the earth warms—the surface temperature increases—to raise the temperature of the new, higher emission altitude to what the previous, lower emission altitude’s temperature was. If carbon-dioxide concentration suddenly exhibited an increase, the effective radiation altitude would suddenly increase, but the surface’s heat capacity would prevent its temperature from responding instantaneously. So initially the effective emission altitude would be cooler than the previous emission altitude was, and the surface temperature would need to increase so that a constant lapse rate would cause the new effective emission altitude’s temperature to rise in tandem with the surface and thereby redress the erstwhile radiation imbalance. When it has done so, then, yes, the Earth’s effective radiating temperature is ultimately unaffected by the change.
The surface temperature rises fast, but that rise is not instantaneous. And it rises because less heat was escaping. Why was less escaping? Because, until the surface could warm, the effective radiation temperature was lower at the higher altitude. That’s why I employed my Fig.3’s
Now, it is entirely possible—indeed, likely—that my understanding of how forcing results from CO2-concentration increase is in some respects faulty. But Lord Monckton has not made a very compelling case for that proposition. More important, though, he has not identified how the transience-fraction issues to which my post was directed depend on the radiation-altitude issue; he does not explain how “Many of the subsequent errors in Mr Born’s understanding appear to flow from this one.” The issues I raised have nothing to do with how the forcing arose; they deal with the model’s treatment of the response to that forcing.
So in my view the radiation-altitude issue is really a bit of a red herring. As is Lord Monckton’s statement that “Mr Born says that he is not sure he should take on trust our assertion that the Planck or instantaneous climate-sensitivity parameter is about 0.31 Kelvin per Watt per square meter.” Actually, I wasn’t aware I’d made an issue of that; as far as I recall, I merely admitted that I had accepted it blindly when Bill Illis questioned my having done so. What does it matter whether I accepted it on faith? I didn’t criticize the paper because of the value the authors adopted for that parameter.
I need to put off the more-substantive issues for a bit, but before I go, I’ll mention two very specific issues that anyone can check for himself.
In Monckton et al.’s §7 they refer to their Table 4, which compares their model output with the observed temperature increase, and they conclude from it that
Now, Table 4 compares the temperature increase they refer to as “
(Model)” with the observed value they called “
(Obs.) HadCRUT4,” showing that the central value of the former equaled sole value of the latter, namely, 0.8 K. The 
subscript might suggest that those values are temperature results of doubling CO2, but the §7 text identifies the latter value as the advance in temperature between January 1850 and April 2014, while Table 4 shows how Monckton et al. arrived at the former, modeled value: the formula 
, where that 
value corresponds to the measured CO2 increase for that time interval. The resultant computation was 
, the value in their table. Since the 
value used in that computation is the ratio of the time-
temperature change to the equilibrium value, it is hard not to infer from their model that there’s (1 – 0.6) * 0.8 K / 0.6 = 0.5 K left in the pipleline.
values for f < 0 are questionable if you plot the implied step response by running the following R code:
So how did they conclude that committed but unrealized warming was non-existent?
One last observation for now. You’ll find that the Table 2
r_tbl2 = rbind(rep(1, 12),
c(0.65, 0.70, 0.74, 0.77, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.85),
c(0.55, 0.63, 0.65, 0.68, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.75, 0.76),
c(0.40, 0.49, 0.53, 0.56, 0.57, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.64),
c(0.15, 0.19, 0.22, 0.23, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.30, 0.30));
r_tbl2_padded = cbind(rep(0, 5), r_tbl2)
f_tbl2 = c(0, 0.5, 1.3, 2.1, 2.9);
t_tbl2 = (0:12) * 25;
L_0 = 0.3125
L_inf = L_0 / (1 - L_0 * f_tbl2);
u_tbl2 = L_inf * r_tbl2_padded;
plot(NA, xlim = c(0, 300), ylim = range(0, u_tbl2), xlab = "Time in Years", ylab = "Step Response");
for(i in 1:length(f_tbl2)){
lines(t_tbl2, u_tbl2[i, ], col = i);
}
legend("bottomright", legend = paste("f =", f_tbl2), lty = 1, col = 1:5, bty = "n");
Doesn’t it seem odd that the f = 0 curve intersects the f = 0.5 and f = 1.3 curves?
Joe Born,
Yup.
They didn’t.
Mr Born May find it profitable to study the altitudinal profile of temperature change. He will discover that the temperature at the characteristic emission layer does not change, precisely as the fundamental equation of radiative transfer dictates. His posting incorrectly said it would change.
He has also not appreciated that the IPCCs definition of committed but unrealised warming is warming that should have happened by now, not at equilibrium.
As to the values of the transience fraction over time, Mr Born is free to adopt any values he wishes.
Christopher Monckton,
As your colleague Dr. Briggs would be the first to tell you, varying a parameter does not change reality. You have made claims about reality based on an rₜ value of 0.6 in your own model, and published results in peer-reviewed literature which are apparently inconsistent. Your calculations and communicated conclusions are at issue here, not IPCC definitions.
Asked and answered, twice. The definition of “committed but unrealized warming” that the IPCC has in mind is not the warming to equilibrium that has not yet occurred as a result of our past sins of emission, but the warming that it considers ought to have occurred to date.
Of course varying the value of a parameter will alter the output of our model, or of any model. That is precisely my point. If Mr Born does not like the values we have derived from Dr Roe’s paper of 2009, as we carefully explained them in the text of the paper, he is free – as any user of a model is – to adopt his own preferred values.
Our choice of values – if you or Mr Born do not like it – does not invalidate the model. Don’t whine. Just choose your own values and make your own determination of climate sensitivity. But our best estimate is that it will be around 1 K at equilibrium – and, at equilibrium, there is no argument about the value of the transience fraction. It is by definition unity. Let us not, therefore, quibble about how many angels live and move and have their being on the head of a pin.
Christopher Monckton,
Finally. Mr Born has already computed the same answer I have: Since the rₜ=0.6 value used in that computation [Table 4] is the ratio of the time-t temperature change to the equilibrium value, it is hard not to infer from their model that there’s (1 – 0.6) * 0.8 K / 0.6 = 0.5 K left in the pipleline.
And then he asks the same question I have been: So how did they conclude that committed but unrealized warming was non-existent?
Anyone with basic algebra and the barest understanding of the meaning of equilibrium can see the clear implication of your model output using parameters derived from Table 4:
1) 0.8 K + 0.5 K = 1.3 K
2) 0.5 K ≠ 0.0 K
The only possible, and therefore only proper, conclusion is that the system is NOT at equilibrium and 0.5 K additional warming is “in the pipeline” even if all net forcing change went to zero from now until equilibrium has been realized. Yet we read at the bottom right of p. 130 in MSLB (2015):
8.4 How much post-1850 global warming was anthropogenic?
Assuming 285 ppmv CO₂ in 1850 and 400 ppmv in 2014, and applying the observationally derived values of fₜ, holding rₜ at unity, and taking qₜ⁻¹ = 2.29/1.813 = 1.263 to allow for the greater fraction of past warming attributable to CH₄, the simple model determines the approximate fraction of the 0.8 K observed global warming since 1850 that was anthropogenic as 78% [62%, 104%].
If it is assumed that gₜ < +0.1, warming is already at equilibrium, since rₜ → 1 for the implicit values fₜ ≤ 0.3 W m⁻² K⁻¹, on this scenario there is probably no committed but unrealized global warming. If AR4 is correct in its estimate that 0.6 K warming is in the pipeline, then < 0.2 K anthropogenic warming has occurred since 1850, indicating that warming realized since then is substantially natural.
Again, I refer you to your own paper, Table 4, and note that rₜ is NOT set to unity, but 0.6. The conclusions of your text above do not follow from that premise. At best there is some unresolved ambiguity in your argument which you’ve yet to articulate or I’ve yet to comprehend. In the middle, we have an honest, but serious, error which was missed by peer-review and could (should) be rectified by publishing a correction. At worst, you are saying two different things as if they were one and hoping nobody will notice.
The more you appeal to non-relevant IPCC definitions by way of defense of this paper, the more it looks like the latter, worst case, is the operative one.
Granted, but this is another irrelevancy. As I have previously stipulated, I am not quibbling here about what I think the “true” value of rₜ should be. The issue at hand is that MSLB (2015) is ambiguous as to whether the system is at equilibrium or not. You would do well to address that issue directly, without further diversions, as the balance of your main conclusions flow from it.
Do the math. After 2.3 W/m2 of forcing, IPCC would expect 2 K of warming at equilibrium, of which just 0.9 K has occurred to date. That leaves 1.1 K to come, of which IPCC reckons about half, or 0.6 K, should have occurred by now. It is that 0.6 K that is committed but not yet realized.
I confess to having been unaware of that, to me, at least, incomprehensible definition of committed but unrealized warming. It “should have” happened by now? I struggle to put a meaning to that expression. Do you have a link to that definition?
See my comment about the math. IPCC would expect 1.1 K warming from now to equilibrium on the basis of our past sins of emission, but it would expect only 0.6 K of that to have occurred by now.
Joe and Christopher,
You both seem to agree that the higher effective emissions location will be the same temperature as before and you both assume that as a consequence the surface temperature must rise in order to support the increased length of lapse rate slope at the new height and temperature.
That differs from AGW theory which says that the new effective emissions height is at a lower temperature and so less energy flows to space and the surface tempetrature must rise.
However, Christopher has pointed out just how stable the surface temperature has been despite vast changes over vast time scales apart from during ice age / interglacial epochs which appear to be driven substantially by variations in the distribution and amount of insolation via the Milankovitch cycles.
The reason for that stability is that you are all wrong about the surface temperature and the effective emissions height needing to rise.
I explained why above but no one has picked up on the point.
The reason is the behaviour of gases when they move up or down within a gravitational field.
Unlike solids and liquids the molecules of gases move apart when lifted upward within a gravitational field because there is then less weight bearing down from above to force them closer together.
As they move apart during upward movement their kinetic energy changes to potential energy and they cool as per the Gas Laws.
As they move closer together during downward movement their potential energy changes to kinetic energy and they warm as per the Gas Laws.
It is that process which creates the lapse rate slope and convection up and down would still be present even without GHGs because of uneven surface heating causing density differentials in the horizontal plane. The atmosphere could never become isothermal as proposed by many.
In the absence of radiative gases all radiation to space must be from the surface and so all potential energy created from kinetic energy during uplift must be returned to the surface as kinetic energy during descent before it can be radiated to space. In that case the amount of kinetic energy removed from the surface during uplift is exactly the same as the kinetic energy returned to the surface duriong descent.
In the presence of radiative gases it becomes possible for radiation to escape to space from within the atmosphere which short circuits the convective process.
However, if that happens then a differential develops between kinetic energy removed from the surface on ascent and kinetic energy returned to the surface on descent.
It is that reduction of kinetic energy returning to the surface on the descent which offsets the potential surface warming effect of radiative gases so the surface temperature and the effective radiating height both remain the same.
That is how one must reconcile the Gas Laws with the radiative theory of atmospheric gasers whilst accounting for the remarkable thermal stability of planets with atmospheres.
Mr Wilde is not correct to say that my understanding of the unchanging temperature of the characteristic-emission layer is not standard theory. In the head posting I have carefully explained that the near-constant temperature of the characteristic-emission layer is a direct consequence of the fundamental equation of radiative transfer, which is not up for repeal anytime soon, being one of the few results in climatology that has not only been derived empirically but also demonstrated theoretically.
It is trivial that, all other things being equal, a higher altitude within the troposphere will be cooler than a lower altitude. However, a radiative perturbation means there is a warming of the entire atmosphere, so that the new altitude at which emission is “seen” by satellites to occur becomes warmer than that altitude was before. But it is at the same temperature as the lower altitude at which emissions were previously “seen” was before the perturbation.
Lord Monckton clarifies his position relative to the standard theory so perhaps I misunderstood the standard theory. I am sure someone has explained that theory as the higher level being cooler and thus emitting less energy to space but perhaps they were wrong.
As I said previously I agree that if GHGs have a net warming effect then all else being equal the effective emission height would be higher but at the same temperature as the previous lower emission height.
However, one still needs to address my fundamental point that in reality all else is not equal and the effective emission height and surface temperature need not change at all because in the presence of radiative gases radiating direct to space from within the atmosphere less kinetic energy can be returned to the surface in convective descent that was taken up from the surface in convective ascent.
That reduced energy returning to the surface offsets the potential surface warming effect of GHGs so that no change in surface temperature or effective emission height is required.
“As I said previously I agree that if GHGs have a net warming effect then all else being equal the effective emission height would be higher but at the same temperature as the previous lower emission height.”
Stephen:
I take the theory to be that the path-length of terrestrial IR to space is increased, as in more CO2 molecules and with the column lengthened vertically – therefore at a lower temp at the top. GHG’s have raided the Earth’s BB temp by 33C with -18C now around 7km up. Without them it would be -18C on the deck. That process proceeds in parallel. Unfortunately.
@KevinK March 16, 2015 at 5:10 pm
I see the sun as the ‘power source’ for our climate.
I see external influences as the signal. (Set Point, if you wish) These influences could include cosmic particles (creating clouds etc).
I see a multitude of feedback loops: air holds varying amounts of water depending upon temperature.
Clouds form (become visible H2O) with only small changes in temperature.
Wind is created due to small changes in temperature.
I see the differential between land and sea heating causing wind (the midday sea breeze).
There is a host of interactions caused by the variations in air temperature and its impact on its water holding ability.
The amount of water evaporated from the oceans and land, then dropped as rain is huge, a lot of ‘work’ is going on in our climate system.
Do you still persist in the view that none of the above could be analogous to a variable amount of ‘damping’ causing the ‘Measured Value’ (MV) to remain close to a long term value?
Steven;
“Do you still persist in the view that none of the above could be analogous to a variable amount of ‘damping’ causing the ‘Measured Value’ (MV) to remain close to a long term value?”
Yes, a variable amount of damping that causes the “MV” to remain close to a long term value (as determined by the massive thermal capacity of the Oceans) is probably the correct long term value.
As an engineer the first thing I look at when “figuring out” the room temperature inside my house is THE FURNACE. It is providing all of the thermal energy inside my house, the tee tiny little bit of “back-radiation” (not an additional energy source) from the ceiling has no effect on the “room temperature”….
The only “furnace” determining the temperatures inside my house is the furnace, outside of my house it is the SUN (big yellow ball that rises and falls every day).
Cheers, KevinK
Christopher Monckton, if you have a chance could you respond to my question in this post here…
http://wattsupwiththat.com/2015/03/16/where-the-complex-climate-models-go-wrong/#comment-1885248
======================================================
BTW, thirty years ago who could of guessed that such scientific discourse and debate could be carried out in such a public accessible and open manner. It is remarkable. I wish all lobby efforts were legally and severely restricted to such open scrutiny.
Using MODTRAN and doubling the amount of CO2 from 400 to 800 ppm produces an increase of IR radiation reaching the surface by about 2-3 Wm-2. Putting this into Stephan Boltzmans equation and solving for T gives and increase of about 0.1 to 0.2 K.
As there is no evidence for positive feedback in the historical record then what’s the problem.
The problem would be that Modtran does not give the amount of IR reaching the surface.
In the non-feedback case doubling CO2 will give a surface temperature increase of about 1.2 degrees Celsius . As you say, that in itself is not a problem.
MikeB “The problem would be that Modtran does not give the amount of IR reaching the surface.”
Then why if the model is given the following inputs:
CO2 = 400ppm
Locality = Mid Latitude Summer
Altitude = 0 , looking UP
No Clouds or rain
does it give as MODEL OUTPUT
Downward IR Heat Flux = 310.106 W/m2
Changing CO2 to 400ppm yields
Downward IR Heat Flux 312.21 W/m2
Looking up from the ground a doubling of CO2 from 400ppm to 800ppm changes the Downward IR Heat Flux from 310.106 W/m2 to 312.21 W/m2
(Locality set to mid latitude summer)
See MODTRAN http://climatemodels.uchicago.edu/modtran/modtran.html
Yes, sorry. I always do it looking down to see the reduction in outgoing LWIR.
Willis Eschenbach had a posting on this very subject some time ago.
http://wattsupwiththat.com/2014/04/12/a-modtran-mystery/
In particular see the comment by Pekka Pirilä
Up welling, down welling, SWIR, LWIR, S-B constant, pages full of calculus are well & good between us girls, but it all leaves the public and the media cold, thinking only “climate $cienti$t experts” understand it.
We need something simple, easy to understand to lay before the public and media that illustrates how powerful the water cycle is and how insignificant in comparison is CO2.
Drawing on my own experience (don’t we all) for every kWh (3,412 Btu) that leaves a typical Rankine cycle steam power plant as electricity, 50/35 or 143% that much energy passes through that cooling tower handled by the evaporation of water. Try doing the same with air.
Because of real or politically imagined shortages of water, air cooled condensers have become a popular option to the wet tower. Contrast the size of the equipment and energy required to handle the same heat load using air (CO2).
We have to find the wooden stake or silver bullet that puts an end to this nonsense.
Come back to reality Nick. Try to think of something relevant.
If one looks at all of the data objectively the solar/climate connection is very evident.
Let me touch on isolated issues as time permits.
value into their Table 2—Monckton et al.’s used Table 2 improperly.
values. For the 75-year ramp used in transient-climate-response discussions, for example, the response is between 68% and 78%—or even 84% if you accept that table’s first-row values—of the step-response value.
For now, let’s consider the following: “Next Mr Born says we have incorrectly assumed a steep initial increase in temperature response.” That’s misleading; I objected to the response not because of what it was but because of the way it was arrived at. As we shall see, though, Lord Monckton actually did get around to giving a straight answer to my real objection. So let’s recall what that objection was.
The values in Gerard Roe’s paper for time t were based on the stimulus’s having assumed its current (in that case, 4 W/m^2) value t years before. But Monckton et al compared the resultant output with that of a system whose stimulus rose gradually. Note the distinction between stimulus and response. I wasn’t objecting because Roe’s response rose gradually, I was objecting to the fact that apples were being compared with oranges. Essentially, this is what Monckton et al. were saying: Since the response of the model Roe relied on had a given value y at a time t years after its stimulus assumed a certain value x, we’re going to take y as our model’s output whenever the current stimulus is x after having increased for t years.
In any but the most trivial of systems, the current output depends not merely on the current stimulus value but also (and, typically, principally) on its history. Now, if the radiative forcing had been a step function, then taking the Roe value for t years after the step occurred would have been proper. For any other stimulus, though, that approach is improper. For any other stimulus, you have to convolve that stimulus’s rate of change with the step response; you can’t just pick a step-response value. So, even if we assume that Roe’s model was correct, and even if we assume that Monckton et al. correctly copied the corresponding
But then Lord Monckton actually gave the authors’ rationale for the approach they took. He had inferred from his epidemiological work that assuming a stimulus step rather than the actual, gradual stimulus change makes little difference. He said of that experience that “assuming a single stimulus all at once produced very little difference compared with the time-smeared stimulus, merely displacing the response by a few years. Similar considerations apply to the climate.”
Of course using the step response for just any stimulus does not in general produce acceptable results, but it is at least plausible that in the case of the climate’s response to a ramp stimulus Lord Monckton’s rationale holds up. So I thank Lord Monckton for addressing an issue I actually raised.
Moreover, his answer is reasonably consistent with his Table 2
Unfortunately, such calculations are so sensitive that such a difference can be significant. Since the fifth row’s ramp response at 75 year equals the fourth row’s step response for that time, for example, one could infer an equilibrium response that’s over three times too high by failing to take the type of stimulus into account. Still, that sensitivity is a problem that afflicts such determinations generally; it is not a particular shortcoming of Monckton et al.’s model.
Data does not lie.
It certainly can!
That’s an interesting chart. Where can I read about it?
You have thousands of years based on proxies, tree ring, ice cores, sediments, Ouija boards, who knows what with an uncertainty of maybe +/- 25% and spliced onto the end is a hockey stick of a hundred years of various instrument data, surface, sea, troposphere? complete with UHI, TOB, and outright fraud! Yeah, data can lie like rug!
Science by Murphy’s Law. Or in other words, why bother doing it at all.
In that there is no empirical evidence ever presented that proves atmospheric CO2 up to 400 ppm has any measurable effect on near surface air temperatures ….. then why do so many learned individuals continue to infer or suggest that ….. “increases in CO2 caused/causes increases in near surface temperatures”?
Do said learned individuals require the aforesaid “unknown CO2 fudge-factor” simply to bolster theirs or other’s claims about near surface air temperatures?
One of the points I am trying to bring out is the following:
The problem with so many in climate science is that the scientist(which is a stretch) in this field try to prove their points as to what may or may not effect the climate with specific items, as if they are in ISOLATION, rather then in the context of the entire climatic picture.
Again a given force and magnitude changes of that force which may impact the climate has to be taken into consideration with the entire spectrum of items that are exerting an influence on the climate at that given time ,along with the state of the climate at that given time in order to get a sense of what impact that specific force may or may not exert on the climate.
This is why it is so hard to prove and show a simple cause and effect relationship between the climate and items exerting a force upon the climate even though it does exist.
Along those lines many data sources show convincingly that the temperature response from the Holocene Optimum to Present Day has been governed by Milankovitch Cycles which have been in an ever so slight cooling pattern post 8000 BC – present with solar variability superimposed upon this pattern which can explain the warmer periods in global temperatures within this very slow gradual cooling trend. Those warmer periods being the Minoan ,Roman ,Medieval, and recent Modern Warm Period.
To refine the global temperature record further data on the PDO,AMO ,ENSO and VOLCANIC ACTIVITY ,have to be further superimposed upon the data provided by Solar Variability, and Milankovitch Cycles.
This data when evaluated against the existing global temperature record (especially post Holocene Optimum – Present Day) gives the best explanation for the existing global temperature record.
Some will argue that this is not so, and they are in denial and want the data to conform to the way they think rather then trying to conform the way they think to what the data shows.
AGW enthusiast are the perfect example of this, who ignore the data which does not correlate with their absurd theory. If this were not so they would have abandoned this theory a long time ago.
What a pleasure to read Lord Monckton! I love his style, and I am so glad that he has brought some sense to the silliness of AGW. Seems they got lost in their equations, but they didn’t include all the relevant factors.
+1
That chart can be found on the web-site talkblokestalkshop.
In addition to the argument I just presented ,data further shows that CO2 concentrations are in response to the climate, forestation and biological processes and this is why CO2 always follows the temperature and never leads it.
AGW theory does not conform to what the data is presenting.
Here is the data ,now you need to reconcile your theory with the data.
http://www.c3headlines.com/are-todays-temperatures-unusual/
On the page linked by Salvatore, there is a graph of long term global temperature that appears to show the equivalent of a +/- rail, with a bias toward the positive, similar to what one would find in a dual power supply electronic circuit. Is there a min/max temperature rail, or is that an artifact caused by a measurement limitation? Hopefully the image will display.
http://c3headlines.typepad.com/.a/6a010536b58035970c01b7c6dadeb8970b-450wi
Christopher Monckton – Thank you for bringing us this most excellent debate and your vigorous defense of your paper. You are an shining example of a true skeptical observer.
Leif lsvalgaard – You are a much respected scientist and we are lucky to have you participate on this blog. You keep us well grounded here. However, over the last couple years you seem to harden into a more dogmatic scientist, incapable of giving credit, where some credit is deserved. The fat lady has not sung her song on climate change nor has Sol revealed all of her secrets yet. Allow some room (respect) for other peoples work and especially their data. It will make you an even greater scientist. EOS (end of sermon) GK
I would love to give more credit where it is due. Who do you think deserves more credit?
“You are a much respected scientist and we are lucky to have you participate on this blog. You keep us well grounded here. However, over the last couple years you seem to harden…”
I’ve wanted to comment on this for quite some time, as I’ve watched the change over the years.
I’m often disappointed in how Dr. Svalgaard is treated by many commenting. He has shown a willingness to engage and his input is much too valuable for him to be treated poorly. As a long time reader, my two cents is that he has been attacked so often and that has brought out “tone”.
We could argue which came first, but at this point it is irrelevant. Dr. Svalgaard’s contribution is huge and it seems to me he’s earned being treated respectfully by everyone.
Another installment.
’s but a reader is justified in wondering how the authors got theirs.
The problem I have with using the Roe plot is that Monckton et al. don’t tell how they got from the plot to their table. How, for instance, did they identify the point in that plot’s blue area that represents feedback of 2.1 W/m^2/K at 75 years? Also, did the source of that model establish how well it matched the climate system, or was he just taking arbitrary values (as I did in my post) to illustrate a point? I still don’t know the answer. Yes, I get it that we can roll our own
As to the circuit, Lord Monckton mentions many eminent but unnamed luminaries who say I’m wrong. Well, I gave actual specifics of how a circuit works. I left no ambiguity. I presented a clear target. If they can identify any point at which I erred, I’m happy to hear it. But vague statements about my providing a “modification of a circuit to prevent its output from behaving as it would otherwise do” don’t cut it.
Note that Lord Monckton does not identify what that modification is or how it prevents what the circuit would otherwise do. The only departure of that circuit from straight positive feedback is that the amplifier has a limit—as they all do. Without that limit, the output would have kept growing positively without bound—and without the “transit to the negative rail.” If I am wrong about that behavior, it should be a simple matter for Lord Monckton’s vaunted experts to point it out.
Look, I may be just a retired lawyer, but I, too, have dealt with experts. In fact, I fixed radar sets myself during the Vietnam War; I heard of Bode when Lord Monckton was still an adolescent, and I know how tricky it is to characterize the math properly. I have no doubt that there’s some way the g>1 regime can be characterized as reversing voltage; in the AC analysis, there’s certainly a phase change at g=1.
But I showed that Lord Monckton’s “transit to the negative rail” is an inapposite description of circuit behavior, at least in the context of establishing that math that works for circuit feedback doesn’t work for the climate. Again, my description left little to the imagination; if there was something incorrect about the behavior I described, it should be a simple matter for Lord Monckton’s brain trust to identify it.
The Bode relation shows a singularity at loop gain 1 that is not applicable to the climate. Furthermore, Bode does not model dynamical systems whose output is the agent of their self – equilibration.
Monckton of Brenchley, a very misleading statement – temperature has varied by little more than 3 Kelvin either side of the long-run mean, and that is not much more than 1% in absolute terms.
Data has shown it has been more like 5 Kelvin ,but that aside what is much more meaningful is that although the climate in absolute terms of temperature variation is relatively stable the climate is unstable when it comes to being in a glacial state versus an inter-glacial state. In addition the places where the earth changes from inter-glacial to glacial conditions experience a temperature change far greater then 5k. The 5k change or 3k change in temperature you suggest only valid due to the fact the global temperatures in the tropical areas of the globe show very little temperature change during glacial versus inter- glacial global conditions.
Let us begin by agreeing the facts. After halving the Antarctic temperature changes indicated by the ice cores to allow for polar amplification in the usual fashion, the variations in global temperature either side of the 810,000-year mean are about 3.5 K, or little more than 1% in absolute terms. These small variations are sufficient to cause ice ages at the lower bound and interglacial warm periods toward the upper bound: but, as should surely be obvious, adding CO2 to the atmosphere does not menace us with an ice age: it merely serves to prolong the interglacial.
The paleoclimate record tells us that at present we are about 4.5 K above the glacial minimum temperature, and 2.5 K below the peak mean global temperature achieved during the previous interglacial about 100,000 years ago. That is quite a comfortable place to be. In the unlikely event that global temperature rose by a further 2 K, we should still be below the previous interglacial.
But the central point is that, given the very large forcings first one way and then the other caused by the Milankovich/Croll cycles, the eruption of supervolcanoes, etc. the final variance in temperature has been altogether too small for us to be able to posit the existence of strongly net-positive temperature feedbacks in today’s conditions.
Take away the over-positivity of the IPCC’s feedback sum (and it has taken a major step towards our position in its 2013 report), and then take away the unsatisfactory Bode system-gain equation (or modify it to remove its defects), and climate sensitivity falls to not more than a third to a half of what the IPCC predicts. And that means we have no climate crisis.
As a nominally-educated layman (just a simple Bachelor of Science), I wonder, isn’t the entire issue of a single forcing a bit of a red-herring? My impression is that the skeptic camp is under a bit of pressure to – not just discredit – but provide a counter-argument to the concept that C02 (and particularly that sticky HUMAN C02) is the main driver. In as complex a system as climate – which involves everything from greenhouse gases, to solar energy (which itself is subject to orbital variance), tides, tectonic activity, and any number of other factors, it seems unlikely that any one aspect is, by itself, a driver or predictor of future climates – certainly nothing within the capacity to predictably regulate.
…In as complex a system as climate – which involves everything from greenhouse gases, to solar energy (which itself is subject to orbital variance), tides, tectonic activity, and any number of other factors, it seems unlikely that any one aspect is, by itself, a driver or predictor of future climates – certainly nothing within the capacity to predictably regulate….
More likely, any of the above, considered on their own, COULD be drivers, but the result of the complex interactions (which we can neither predict nor regulate) is likely to be as near zero as makes no difference – since we see from history that the climate is a fairly stable phenomenon…
However, I don’t think the complex climate models have gone wrong. The activists needed heat prediction – the models provided it – the grants kept coming in. As Willis often says: “What’s not to like?”…
My thanks to all here for a most informative and thought-provoking thread, conducted for the most part in the greatest good humour by Lord Monckton and also by some of his critics. Thanks also that the usual football crowd have stayed away, perhaps recognising the high standard of the debate.
Some of you may not know that Christopher Monckton is not himself a science major, but has taken much time and trouble to study (and, prima facie, master) the necessary disciplines in order to be a part of these massively important investigations. Some will count that against him, but I think we all – alarmists and sceptics alike- owe him a considerable debt. Even if he is not right.
It is rather unfortunate for us that Lord Monckton is – solely by virtue of the welcome longevity of his father -not enfranchised to speak and vote in the UK House of Lords. That time-honoured institution is sorely lacking in free thinkers of his calibre; increasingly so now that it is moving inexorably towards an appointed/elected assembly which will be merely an echo-chamber for the petty politicos of the Commons.
Keep at it, Christopher
Mothcatcher is very kind. I shall do my best to keep at it, as he suggests. Our paper provides some good reasons why the models are exaggerating climate sensitivity. So far, there has been no really strong scientific challenge to our analysis. We are looking forward to seeing whether any of the usual suspects submits a paper to the Science Bulletin in attempted refutation of what we have said. And we have asked the editors to extend the usual academic courtesy to us, if that should happen, and allow us to reply to any attempted rebuttal in the same issue of the journal.
I have now learned that my more detailed paper on the problems presented by the incautious application of the Bode system-gain equation in the models will appear next month,
I am happy to see this point discussed as it struck me as an odd statement, as I noted in a comment on Mr Born’s article:
Mr Born:
>>“and, lapse rate being what it is, reduces the effective temperature from which the Earth radiates into space, so less heat escapes, and the Earth warms”.
I objected to that statement about less heat escaping.
Lord M:
>”No. The characteristic-emission layer – the “altitude” from which the Earth appears to radiate spaceward, and at which, uniquely in the climate system, the fundamental equation of radiative transfer applies – is the locus of all points at or above the Earth’s surface at which incoming and outgoing radiation are equal. In general, the mean altitude of the locus of these balance-points rises as a greenhouse gas is added to the atmosphere. Thus far, Mr Born is correct.”
That provides a good definition and I also agree.
Lord M.
>”His fundamental error lies in his assertion that the increase in the Earth’s characteristic-emission altitude reduces the effective temperature at that altitude, “so less heat escapes, and the Earth warms”.
Agreed, about the part that says it loses less heat and is thus responsible for the increase in the surface temperature.
Lord M.
>”The truth, which follows from the definition of the characteristic-emission layer and from the fundamental equation of radiative transfer that applies uniquely at that layer, is that the Earth’s effective radiating temperature is unaffected by a mere change in the mean altitude of that layer.”
I do not agree that the mere change in mean altitude does not affect the radiating temperature. The need for an increase in altitude was, remember, caused by an increase in the number of radiating molecules of GHG’s. This change has not been considered in the analysis. Doubling the amount of CO2 makes for a more radiative atmosphere.
It is true that increasing the temperature of the atmosphere means the altitude of characteristic-emissions layer will rise but neither Mr Born’s nor Lord M’s description is correct with respect to the temperature of that theoretical radiating layer.
I hope I have read and understood this correctly. Mr Born’s position is that the altitude increase will cause an adiabatic temperature drop and less total heat will be lost into space ‘at a lower temperature’. The ‘less heat’ thing we already addressed. It is not less heat. Mr Born is confusing heat energy with temperature. OK, we are over it.
There are two ways to increase temperature of the system: put in more heat, or insulate the Earth with GHG’s. Putting in more heat means more heat has to be lost. More GHG’s requires an increase in the temperature at which the increased number of GHG molecules radiate, or an increase in the radiating surface (which an altitude change accomplishes to a slight extent).
Do you see where I am going with this? The input about output heat are assumed to be constant with chemical conversion on the ground (plants) being the only subtraction and we are talking about an increase in GHG’s only. If there are more GHG molecules, there are more radiators at altitude, just as everywhere else. Increasing the surface temperature by increasing GHG concentrations raises the effective altitude from which that heat must be radiated – that is agreed. However the average temperature of those radiating molecules is not as high as it used to be because now there are more of them radiating at that altitude. The albedo has changed.
It is the same as darkening a pot. If heat input to a pot is constant and low, the temperature of the pot surface will stabilise at some temperature. Increasing the heat transfer efficiency to the pot will raise the temperature of the radiating surface until it is in balance again, at a higher temperature. But if the pot was darkened it will radiate more effectively and the temperature of the surface will drop, whether the heat coming in was increased, constant or decreased. If it was in equilibrium, and the pot surface colour changes (akin to changing the GHG concentration) the temperature will change.
Adding GHG’s to the atmosphere raises the surface temperature. It also raises the effective radiating altitude, but simultaneously, the equation that ‘sets the temperature’ allows that the effective radiating temperature will drop because the atmosphere has become more efficient at radiating heat.
Conclusion: An increase in GHG’s will raise the effective altitude of radiation into space, provided that the increased efficiency of radiation caused by that increase in GHG concentration is not larger than the need to increase the altitude (which holds open the possibility that the altitude might decrease).
A linear increase in GHG concentration causes a non-linear change in the altitude from which the heat will radiate. Because an increase in altitude will decrease the temperature at which the radiation takes place, the temperature cannot drop and still maintain the same total energy loss unless there is an increase in the number of ‘forward radiating’ molecules, which by definition, there is. That, I believe, is where both authors erred.
Double the GHG concentration, double the radiating capacity at any given temperature. As it is not necessary to double the amount of heat lost, only to maintain the rate, the radiating temperature will definitely be lower than it was and further, the effective altitude will definitely be higher (because that is where it is colder). These conditions will prevail if the cause of the altitude increase was an increase in GHG concentration. In the end the total energy lost will be equal to the input, as before, sent out at a lower temperature by a greater number of radiating molecules.
Crispin in Waterloo,
Almost. This is an equilibrium problem as you correctly identify. The theory to invoke is that the effective radiation altitude is a response of the system attempting to reach equilibrium, not the cause of it being out of equilibrium to begin with. Radiative transfer codes don’t rely on it as a parameter, but it is something that emerges from them. Even so, my understanding is that it’s generally considered a curiosity value. Nobody writing serious literature is attempting to pin it down because it’s not directly observable and doesn’t have any use further down the line for other calculations. I think ScienceOfDoom argues these points rather well …
http://scienceofdoom.com/2013/01/08/visualizing-atmospheric-radiation-part-three-average-height-of-emission/
… which rather obviously influences my understanding of the concept. It checks out with everything I’ve read in literature, so I trust it. YMMV.
Brandon I am not sure you got the point of that paragraph compared with the conclusion. If an especially effective GHG was introduced to the atmosphere, it ‘might’ radiate so effectively at a lower temperature that the effective altitude actually dropped with an increase in the GHG concentration, and with a rise in surface temperature. I am just describing the possibility, not that I have a working example.
“The theory to invoke is that the effective radiation altitude is a response of the system attempting to reach equilibrium, not the cause of it being out of equilibrium to begin with. ”
I didn’t suggest that it was. The ’cause’ of the surface temp rise is an increase in GHG’s. Whether there are thunderstorms bring that heat up to altitude or not, or it is a peaceful planet below, makes difference to the effective altitude of radiative cooling. But we can’t have a claim for needing an increase in altitude because of the higher temperature at the surface without also including in the mental model an increase in the ability of that same atmosphere to radiate more effectively at a lower temperature because of the increase in the GHG concentration.
In brief, it will stabilise at an altitude and temperature lower than ‘one might expect’.
Suppose the concentration rose so high that the effective radiating altitude was below the average cloud height? Would Guam tip over?
Crispin in Waterloo,
You’re right, I don’t get the point because to me it makes no physical sense. By Kirchoff, an effective emitter is an equally effective absorber. Emissivity/absorptivity is wavelength sensitive, which is why doing any serious radiative transfer work requires (spectral) line-by-line codes to get reasonably accurate answers. Your instinct that an effective emitter will tend to cool things is correct, but only in part — it’s only going to be able to do that when more than half of its radiating energy is free to escape the system entirely. That’s not true at the surface.
Yes I know. I should have made it more clear that my comment there was directed at the many others here who have described the effect in those terms. The cause of the warming due to GHGs at the surface is because increasing those gasses increases the optical thickness of the atmosphere in wavelengths the planet is “trying to use” to shed absorbed solar energy. The 15 micron band is particularly important because not only is that in the fat part of the S-B curve for the surface, it’s the sweet-spot for CO2 absorptivity/emissivity as well:
http://acd.ucar.edu/textbook/ch15/fig3.jpg
That’s a really elegant plot in a lot of ways, not least because taking the shot over the Sahara minimizes the “interference” from water vapor and better isolates CO2’s role. Note that the S-B predicted temperature in the atmospheric “window” portion of the plot is 320 K, implying a surface temperature of 47°C. However, in the 15 micron CO2 band, the predicted S-B temperature is only 220 K, so …
http://mintaka.sdsu.edu/GF/explain/thermal/figs/stdatm.gif
… a rough guess is that those photons were emitted at an average altitude somewhere around 10 km.
Absolutely yes, it does make a difference. I believe that’s one reason why literature doesn’t attempt to put a value on it. It would be fiendishly difficult to figure out from observation, and not much use.
I don’t like that rebuttal to the claim any more than the claim itself. The atmosphere is an infinite number of layers of gas encompassing an essentially solid sphere. The only hard boundary is the surface. The whole reason for the Beer-Lambert law is that the attenuation of light through a fluid is a completely different process from sensible heat diffusing through a solid material to a well-defined surface and thence radiating away.
You MUST keep in mind that good emitters at a given wavelength area ALSO good ABSORBERS at the same wavelength.
Which brings us to …
If one is thinking of this only in terms of radiative cooling and surface area, none of this is going to work like ‘one might expect’.
No, but I’m going to go tip back a beer because I’m temporarily weary of trying to explain energy balance and equilibrium problems to folk who only look at one half of the relevant fluxes. If we must use the surface area argument — and I’d really rather we didn’t since it’s not the most relevant physics — ponder the notion that the inner portion of that surface is radiating back down at the same time.
It is always wise to start with the appropriate equation. The equation that governs the relation between temperature and radiation at the characteristic emission layer is the fundamental equation of radiative transfer. Under the assumptions that total incoming solar irradiance is constant over time, that albedo does not change, that emissivity is constant at close to unity, it necessarily and ineluctably follows that the temperature of the characteristic-emission layer is constant.
Lord M
Well I can’t fault this as a whole: “Under the assumptions that total incoming solar irradiance is constant over time, that albedo does not change, that emissivity is constant at close to unity, it necessarily and ineluctably follows that the temperature of the characteristic-emission layer is constant.”
But the albedo of the atmosphere does change because the concentration of radiating gases has changed. That is my point. Your sentence is correct, but doesn’t apply to an altered system but has one assumption too many.
Here is my version:
Under the assumptions that total incoming solar irradiance is constant over time, that the albedo of the atmosphere changes with the concentration of CO2, that emissivity of the surface is constant at close to unity, it necessarily and ineluctably follows that the temperature of the characteristic-emission layer will drop, otherwise it would over-cool the atmosphere, completely undoing the GH effect.
Either the emitting layer is cooler, or CO2 has no net effect on temperature. One of the two.
Coming at it from the other side, if the ‘exit temperature’ were constant, and knowing that the emissivity and irradiance are also constant, it would follow that there had been no change in the concentration of radiating gases. We are running this thought experiment because the concentration has changed, therefore the absorption and radiation is more effective, both up and down, ergo the albedo has changed. Not the albedo of the surface, the albedo of the effective radiating layer of the atmosphere. The surface remains at unity.
If I printed small black dots on the outside surface of a polished silver pot, it would settle on a temperature for any given constant input of heat. If I (only) print more dots on the surface, the surface temperature will drop if the input of heat remains constant because I have changed the albedo. CO2 molecules are like radiating black dots.
An irreducibly simple climate model must consider the change in atmospheric albedo because the GH effect is directly caused by a change in the albedo of the atmosphere catching IR more efficiently on the way up. It is the atmosphere that is radiating into space, not the surface. Increasing the concentration of CO2 increases the outward radiating efficiency, same as with the silver pot.
The only reason why one hypothesizes about an ‘effective radiating level’ (ERL) being all of a sudden too cool and hence being out of balance with the incoming from the Sun, leading to warming below, is that one tends to postulate an instantaneous doubling of atmospheric CO2 concentration in the various climate sensitivity scenarios. In reality, Monckton is right; such a cooling of the ERL would never actually measurably occur, because the rise in CO2 is far too slow and gradual and the system would thus have no problem adjusting practically in phase.
Kristian
“The only reason why one hypothesizes about an ‘effective radiating level’ (ERL) being all of a sudden too cool and hence being out of balance with the incoming from the Sun, leading to warming below, is that one tends to postulate an instantaneous doubling of atmospheric CO2 concentration in the various climate sensitivity scenarios. ”
That is simply not going to happen – it was poorly thought out guess. It is not the reason why ‘it warms below’. Far from it.
Whether or not the increase were sudden or slow, the fact is that adding CO2 to the water vapour and other CO2 is going to increase the effectiveness of the radiating medium – the air. That means to be in balance, the emitting layer will be cooler than it was before the CO2 was added. This is straightforward and can be determined from the concentration and radiating characteristics of water vapour and CO2 (as the most important direct transmitters of heat into space). As soon as the calculation is done for two different gas mixes, the characteristic radiating temperature is known, and the answers are not the same. Higher CO2 means it radiates more ‘efficiently’ and can leak the heat, so to speak, at a lower temperature, which implies that it will be at a higher altitude, or if at the same altitude, it is cooler (cooled by radiation).
For a postulated doubling of CO2, the effect should easily be measured. Suppose the effective elevation is 16 km. What is the temperature? Double the efficiency of the CO2 portion of the atmosphere (by increasing its concentration). Three things could happen:
The air dries out (which has been measured and is happening)
The temperature drops (ditto)
The altitude of the effective elevation rises (don’t know).
Other things being equal, only CO2 rising, the average temperature of the emitting layer will drop. Maybe a combination. If the temperature remains the same, then the water vapour concentration must drop to compensate for it or the altitude must drop. For constant T, the equation requires one or both. It has to balance.
“and provided that the Earth’s albedo does not change much (it doesn’t).”
Is this really established? Phillip Goode, etal. from Big Bear Solar Observatory are claiming that changes in albedo that have been measured at Big Bear over the last decades translate to a six watts per square meter variation.
Variations in cloud cover do indeed cause changes in albedo, but these changes tend to cancel over time, roughly in phase with the ocean oscillations,
Yes, this is my understanding, they cancel over time – meaning times greater than a year (like the oceans). Also, I believe, after glancing at the Big Bear graphs, meaning times greater than a decade. This “cancel over time” notion brings to mind the lesson of the playa lakes: Great Salt Lake, Lago Enriquillo, Devils Lake of North Dakota, and Laguna Epecuen. That is to say, that appropriate averages in the context of climate can mean averages over a time far greater than a year because even though Devils Lake in North Dakota has an average annual rainfall of twenty inches doesn’t mean that over the decades the lake level won’t vary by as much as fifty feet. Hence, if climate models take albedo or conversely emmisivity as a factor ( or parameter, I’m not sure which term is more appropriate), then they are taking on something with a good amount of uncertainty – over time.