Feedback about feedbacks and suchlike fooleries

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.