Keeping a cool head amid warming hysteria. By CARDINAL GEORGE PELL [Southern hemisphere COOLING]

Thank you for the responses. This will take some reading/digesting.

I clearly don't know a great deal about atmospheric dynamics and I'll have to refresh - I took three undergrad courses in AD 20 years ago.

I also worked all night so in my addled state it sounds to me like you are saying that a paper on the DOE site (and the science, as you present it) means that CO2 is only a small part of the cause of extreme temperatures on Venus. The paper even claims this was already the scientific consensus in the reference it cites from 1984.

In my sweep I can't find any scientific sources that agree with your conclusion except that one paper. If they correctly quoted their source at the time then their source has been revised and in any case it does not appear to be te consensus. You would also think that such an earth shaking conclusion by the DOE would have been followed up on...

I appreciate you investing all this effort in me and will follow up when I've had some sleep.

In my sweep I can't find any scientific sources that agree with your conclusion except that one paper.

You apparently are not looking at the volumes of peer-reviewed studies associated with the Pioneer & Venera venus flyby and landing projects, as well as the multitude of limb microwave studies that all confirm precisely what I have been saying.

The lack of water vapor on Venus precludes the kind of "greenhouse" that is evoked by the popularization of the concept.

I have found literally dozens of such studies all citing nil water vapor and high level clouds as the dominant factor in the Venus temperature environment.

Even basic themodynamics makes the case clear. We have the knowm logarithmic relationship for CO2 forcing which hold for high concentrations of CO2 and any gas at high concentrations that make very clear that CO2 can only contribute to a limited extent absorbing incident IR.

A sobering fact about CO2 and any other molecule for that matter is that the ultimate limit is established by it's IR spectrographic absorption which when at maximum concentrations approaches the exponential limiting form, R(1-e^(-kC)) as available IR photons are overwhelmed in relation to the number of CO2 molecules. In otherwords, a CO2 atmosphere cannot absorb more IR radiation than is present as represented by the equilibrium blackbody temperature conditions. You can't get energy for nowhere.

If CO2 forcing were near linear as a climate driver, the upper maximum envelope of earth's surface temperatures would have a curve similar to the CO2 the concentration curve over geological time.

The measurable limit in climate sensitivity to increasing CO2 is clearly represented in the average surface temperature of the earth in the following graphical presentation of the earth's geological history providing a clear demonstration of the limits of CO2 as a driver of global temperature as well as its lack of correlation to the large swings in earth's temperatures:

Global Surface Temperature and Atmospheric CO2 over Geologic Time

Late Carboniferous to Early Permian time (315 mya -- 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ).

Temperature after C.R. Scotese
CO2 after R.A. Berner, 1994

There has historically been much more CO2 in our atmosphere than exists today. For example, during the Jurassic Period (200 mya), average CO2 concentrations were about 900 ppm or about 2.5 times higher than today. The highest concentrations of CO2 during all of the Paleozoic Era occurred during the Ordovician Period, exceeding 6000 ppm -- more than 16 times higher than today.

The Carboniferous Period and the Ordovician Period were the only geological periods during the Paleozoic Era when global temperatures were as low as they are today.

To the consternation of global warming proponents, the Late Ordovician Period was also an Ice Age, with CO2 concentrations nearly 15 times higher than today-- 5500 ppm. According to greenhouse theory, Earth should have been exceedingly hot. Instead, global temperatures were no warmer than today. Clearly, other factors besides atmospheric carbon influence earth temperatures and global warming.

Using the above chart and knowing the logarithmic relationship of direct radiative forcing we can test what the forcing for CO2 is at the extremes represented above in geological history must be.

To due so, I took the above chart and did a bit of digitizing and overlaid a linear response line across the envelope of temperatures depicted in the geological history:

A 0.24^oC change in Earth's surface temperature per CO₂ doubling is depicted in the resulting graphic:

The upper horizontal redline represents a temperature of 22.8^oC at the chart Cambrian CO₂ peak of 7000ppm.

The second and descending redline is a rough approximation of the average peak temperatures connecting similar conditions of albedo and other climate factors, the downtrending redline terminates at approximately 21.6^oC, with roughly deep ice age conditions of ~200 ppmv CO₂ concentration from ice core studies yielding for ~5 doublings of CO2 concentration.

Given ~5 doublings of CO2 in the above graphic, and using DF = 5.35 ln(C/C₀) wm^-2 [Myhre et al. 1998, Geophys.Res.Lett., 25:2715-2718].

We get ~8.6 w/m² change in radiative flux due to the change in CO2 concentrations above.

Applying Boltzman once again, using initial 22.8^oC (i.e. 295.8K @ T_o) we get

F_o = 1*5.67*10^-8(295.8^oK)⁴ = 434.09 w/m²

Subtracting 8.6 w/m² for cooling due to decreasing CO2 we get

434.1-8.6 = 425.5 w/m²

Calculating a final CO2 delta T as

T = (E/s)^0.25 = (425.5/5.67*10^-8)^0.25= 294.32K

computing the difference we get (295.8-294.32) = 1.48 K (i.e 1.48^oC)

Which conforms very closely with the 22.8-21.6 = 1.2^oC change in max temperatures of the graphic, confirming of what we can determine from first principles in regards surface heating affects,

In regards

http://www.eia.doe.gov/cneaf/alternate/page/environment/chap2.html

Scientists used to believe that Venus fell victim to the greenhouse effect because 96 percent of its atmosphere is carbon dioxide, with nitrogen accounting for almost all the remainder [26]. It is now generally agreed within the planetary atmospheres community that carbon dioxide alone would lead to an average temperature of less than 25oC. The primary reason that Venus is warmer than this is the presence of sulfuric acid cloud cover over the entire planet, extending from about 50 kilometers to 70 kilometers from the surface.

Venus blackbody temperature is 231.7K [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html ]

By the Boltzman black body relation:

Blackbody flux (E₂₃₁) without atmosphere & clouds effects = 5.67*10^-8(231.7^oK)⁴ = 163.41 w/m²

Venus: Surface pressure = 92 bars, @231.7K, CO2 concentration = 0.962;
Earth Surface pressure = 1 bar, @231.7K, @ CO2 concentration = 380ppmv, Tropopause IR flux = 139.79 w/m2
according to 1976 standard atmosphere MODTRAN Radiation Calc (with 0 GHGs other than CO2)
@ CO2 concentration = 380ppmv & 231K temperature condition, = 139.79 w/m²
@ CO2 concentration = 000ppmv & 231K temperature condition, = 152.23 w/m²
Yielding a total absorption of (152.23-139.79) = 12.44 w/m² flux absorbed by 380 ppmv CO2 @ 231.7K temp.
The total concentration of CO2 on Venus with respect to 380ppmv level found on Earth is

92*0.962/(1*0.000380) = 230,373.68 times earth CO2.

Therefore Venus total CO2 IR flux absorption @ Venus 231K blackbody condition with 92 bar 0.962 CO2 is

(5.35*ln(230,376.68) + 12.44) = 78.5 w/m².

The resulting Venus temperature due to CO2 absorption alone @ Venus blackbody conditions becomes:

[(163.41 + 78.5)/(5.67*10^-8)]^0.25 = 255.57K

Thus the maximum change in temperature on Venus for its current level of CO2 & pressure is

(255.57-231.7) = 23.87K (i.e. 23.9^oC)

Which I would say demonstrates the EIA statement:

http://www.eia.doe.gov/cneaf/alternate/page/environment/chap2.html

Scientists used to believe that Venus fell victim to the greenhouse effect because 96 percent of its atmosphere is carbon dioxide, with nitrogen accounting for almost all the remainder [26]. It is now generally agreed within the planetary atmospheres community that carbon dioxide alone would lead to an average temperature of less than 25^oC. The primary reason that Venus is warmer than this is the presence of sulfuric acid cloud cover over the entire planet, extending from about 50 kilometers to 70 kilometers from the surface.

Very well.

First its great you able to reverse engineer their math.

And I'm nowhere near ready for a full response. I'm a bit awed at the work you put into this and I don't want a hasty response.

But couple of questions, if you don't mind.

1. I didn't see any glaring errors in your Venus absorbtion caluculation of ~80w/m^2.. Have you seen the Pioneer Venus probe data that showed about 200 w/m^2 was getting through the cloud shroud with about 20 w/m^2 getting to the surface? That would seem to imply we are missing 100 w/m^2 somewhere.

2. Have you seen either the ~80w/m^2 absorption number or the 25 degree contribution to warming from CO2 anywhere reputable other than that 1994 paper or its 2002 electronic version?

1. I didn't see any glaring errors in your Venus absorbtion caluculation of ~80w/m^2.. Have you seen the Pioneer Venus probe data that showed about 200 w/m^2 was getting through the cloud shroud with about 20 w/m^2 getting to the surface? That would seem to imply we are missing 100 w/m^2 somewhere.

Have you seen the Pioneer Venus probe data that showed about 200 w/m^2 was getting through the cloud shroud with about 20 w/m^2 getting to the surface?

No my calculation are essential taking the NASA data on albedo and blackbody temp as stated in http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html, for Venus.

The blackbody temp is a function of bond albedo 75% of incident solar flux at Venus orbit reflected before it can get into the atmosphere or the surface to be absorbed and re-emitted as IR to be trapped or absorbed by whatever.

What I have done is calculate a theoretical blackbody calc for change in temperature of a psuedo-mirror above Venus, that reflects solar only at 75%, and transmits 100% venus blackbody IR so we remove the effect of the sulfuric acid cloud layer on surface temperature, but do reduce the solar flux to that which is implied by the listed albedo. The idea being, to isolate that effect that due to a CO2 atmosphere absent all other factors.

The CO2 abosorption is set by the spectrographic absorption qualities of CO2, by the MODTRAN & the Myhre relationship as the MODTRAN program isn't designed to handle 92 bar 96% CO2 atmosphere so I had to make use of both to get where we wanted to be.

What was calculated is a purely theorectical number based on the listed blackbody temp as starting point and a 96.2% CO2, 92 bar atmosphere to establish what the contribution of CO2 to the Venus temperature must be.

An alternative route would be to assume a pure blackbody at 231.7K with a 100% IR absorbing gas in the atmosphere.

The calculation would that be for an absorption of all 163.41 w/m2 instead of the 80 we established for CO2, for which we must compensate by raising temperature to a full:

(163.41*2)/(5.67*10^-8)]^0.25 = 275.53K

With a delta T of (275.53-231.7) = 43.3^oC, still a very long way from the conditions actually found at the surface.

Either way, it becomes clear that the conditions on Venus are not due to IR absorption of the atmosphere alone, however efficient it might be at such.

Rather the temperature conditions on Venus surface must be explained in some other mechanism such as cloud scattering and reflection of IR back to the surface in much the same way that a one way mirror would work which brings us back to the applicablility of the conjecture in comment #31, of R. T. Pierrehumbert and C. Erlick (1998):

AMS Online Journals - On the Scattering Greenhouse Effect of CO2 Ice Clouds
Consider an atmosphere-clad planet with net albedo a₀ in the solar spectrum. If it is illuminated by a solar flux, S₀, and radiates infrared to space at a rate, I₀, it is in equilibrium when (1 - a₀)S₀ = I₀. Now introduce a high CO₂ ice cloud with albedo a_c in the visible and a^'_c in the infrared, but that absorbs neither solar nor infrared radiation. This perturbs both the solar and infrared terms in the radiation budget, as shown in Fig. 1 . Let the cloud be high enough that it is above virtually all of the infrared-radiating mass of the atmosphere and suppose that the subcloud atmosphere–surface system is a perfect infrared absorber. Taking into account the effects of multiple scattering between the high cloud and the subcloud regions, the cloud changes the planetary solar albedo to

a = a_c + a₀ [(1 - a_c)²/(1 - a_ca₀)]. (1)

If I₁ is the upward infrared flux from the subcloud atmosphere, the flux escaping to space is (1 - a^'_c)I₁. To restore equilibrium with the insolation S₀, the temperature must change so as to make I₁ = [(1 - a)/(1 - a^'_c)]S₀.
The I₁ required to balance the absorbed solar radiation becomes infinite if a^'_c ® 1 with a < 1, in which case the planetary temperature also becomes infinite. In this limit, the cloud acts like a one-way mirror that lets solar radiation in but does not let any planetary radiation out. This state of affairs would violate the second law of thermodynamics, as the planetary temperature would exceed the solar blackbody temperature. In fact, the temperature limits itself because, once the surface warms to solar temperatures, it radiates at solar wavelengths and the albedo for solar and planetary radiation becomes identical. This limit nevertheless shows the potency of the cloud-mirror effect. In contrast, the conventional greenhouse effect for a single-layer IR-absorbing cloud could increase the unperturbed temperature by no more than a factor of 2^1/4. Unlike the conventional greenhouse effect, the scattering greenhouse effect blocks IR emission to space without the clouds having to absorb any IR themselves. The clouds therefore do not have to heat up in response to the absorbed radiation, which removes a limit to warming inherent in the conventional single-layer case.

2. Have you seen either the ~80w/m^2 absorption number or the 25 degree contribution to warming from CO2 anywhere reputable other than that 1994 paper or its 2002 electronic version?

No, and why would it matter?

The radiative absorption characteristics of CO2 are well known, the blackbody calcs are standard thermodynamics and as we have applied it assumes the maximum efficiency possible for an asbsorption situation. The results are what they are and one is required to look beyond the capacity of CO2 to absorb IR radiation to explain why Venus' surface is as hot as it is.

Just as one must look beyond CO2 alone as to explain all that happens in earth's atmosphere as regards climate here.

P.S.

2. Have you seen either the ~80w/m^2 absorption number or the 25 degree contribution to warming from CO2 anywhere reputable other than that 1994 paper or its 2002 electronic version?

Remember this one from comment #36?

All that is lack is specific numbers, the requirement that more than IR absorption by CO2 being operative and required is clearly and unequivocally stated.

THE VENUSIAN ENVIRONMENT

3.2 Energy Balance

At a distance of 108.2 million km, Venus is closer to the Sun than the Earth by a factor of about Ö2, and so has about twice the incidence of solar energy. It is also much hotter at the surface, nearly 2 times more than the terrestrial mean of about 300 K. These facts are not simple to reconcile, however, because the ubiquitous and highly reflective cloud cover on Venus reflects 76% of the incoming solar flux and this results in a smaller net solar constant for Venus than for Earth. The high surface temperature must, therefore, be due to ‘greenhouse’ warming produced by the thick, cloudy atmosphere, possibly augmented by a contribution from the internal heat of the planet.
It is not simple to prove that the observed atmospheric conditions can in fact generate such a large ‘greenhouse’ effect. The problem is that the massive amounts of carbon dioxide are very effective at blocking the emission of thermal infrared radiation, but only at those wavelengths where the gas has absorption bands, which are far from covering the entire spectrum. Moderate amounts of water vapour are also required, and even then considerable spectral gaps or ‘windows’ remain. These could be blocked by the clouds, since liquid or solid absorbers present some opacity at every wavelength, the details depending on composition and particle size. The problem for early theorists was that using clouds to ‘close’ the greenhouse also tended to block the incoming sunlight, so that the calculated equilibrium temperature of the surface remained well below that observed.
This problem began to be resolved when it was realised that the clouds are made of sulphuric acid droplets, at least in the higher, most easily measured layers. These have the property of being highly absorbing at thermal infrared wavelengths, while being nearly conservative scatterers in the visible and near infrared. Thus, the clouds tend to diffuse downwards those of the incoming solar photon that they do not reflect to space, while blocking thermal emission from the lower atmosphere and surface. This explains the result, surprising at the time, that the Venera landers in the 1970s were able to photograph the surface in natural light. It also means that radiative transfer models, involving weak as well as strong bands of CO2 and H2O, plus those of the minor constituents CO, HCl and SO2, can account for the high surface temperatures by careful incorporation of the scattering and absorbing properties of the clouds.
The total solar energy diffusing through the cloud cover on Venus corresponds to about 17 watts per cm2 of surface insolation on the average, about 12% of the total absorbed by the planet and the atmosphere. The high opacity of the gaseous atmosphere and cloud at longer wavelengths requires the surface to reach temperatures high enough to melt zinc before the upwelling flux is intense enough, and at shorter wavelengths, so that equilibrium is attained. An airless body with the same albedo and at the same distance from the Sun as Venus would reach equilibrium for a mean surface temperature of only about 230 K. This 500K greenhouse enhancement of the surface temperature compares with only about 30K on Earth and 10K on Mars.

>>Just as one must look beyond CO2 alone as to explain all that happens in earth's atmosphere as regards climate here.<<

I'll come back to the rest but I hope you don't think we have a disagreement on this point.

>>Just as one must look beyond CO2 alone as to explain all that happens in earth's atmosphere as regards climate here.<<
I'll come back to the rest but I hope you don't think we have a disagreement on this point.

I'd hope not :O)

Bringing us back to earth, and why Venus is not a very useful analog for earth climate effects even on the subject of clouds.

As can be seen here, cloud altitude as well as composition have a great deal to do with their effect with regard heating and cooling the surface, in fact is at the the core of the problems in predicting what we can expect of the evolution of earth's climate.

Cloud-Radiative Forcing and Climate: Results from the Earth Radiation Budget Experiment
Science 6 January 1989:
Vol. 243. no. 4887, pp. 57 - 63
V. RAMANATHAN ¹, R. D. CESS ², E. F. HARRISON ³, P. MINNIS ³, B. R. BARKSTROM ³, E. AHMAD ⁴, and D. HARTMANN ⁵
¹ Professor in the Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637.
² Professor at the Institute for Atmospheric Sciences, State University of New York at Stony Brook, Stony Brook, NY 11794.
³ Atmospheric Sciences Division, NASA Langley Research Center, Hampton, VA 23665.
⁴ Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637.
⁵ Professor in the Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195.
The study of climate and climate change is hindered by a lackof information on the effect of clouds on the radiation balanceof the earth, referred to as the cloud-radiative forcing. Quantitativeestimates of the global distributions of cloud-radiative forcinghave been obtained from the spaceborne Earth Radiation BudgetExperiment (ERBE) launched in 1984. For the April 1985 period,the global shortwave cloud forcing [-44.5 watts per squaremeter (W/m²)] due to the enhancement of planetary albedo,exceeded in magnitude the longwave cloud forcing (31.3 W/m²)resulting from the greenhouse effect of clouds. Thus, cloudshad a net cooling effect on the earth. This cooling effect islarge over the mid-and high-latitude oceans, with values reaching-100 W/m². The monthly averaged longwave cloud forcing reachedmaximum values of 50 to 100 W/m² over the convectively disturbedregions of the tropics. However, this heating effect is nearlycanceled by a correspondingly large negative shortwave cloudforcing, which indicates the delicately balanced state of thetropics. The size of the observed net cloud forcing is aboutfour times as large as the expected value of radiative forcingfrom a doubling of CO₂. The shortwave and longwave componentsof cloud forcing are about ten times as large as those for aCO₂ doubling. Hence, small changes in the cloud-radiative forcingfields can play a significant role as a climate feedback mechanism.For example, during past glaciations a migration toward theequator of the field of strong, negative cloud-radiative forcing,in response to a similar migration of cooler waters, could havesignificantly amplified oceanic cooling and continental glaciation.

Anybody ever explain why the temp went down during WWII? I mean, the nuclear tests, bombing of Dresden, Hiroshima, Berlin, London, Nagasaki, ...

Looks like a lot of CO2 to me...

Meanwhile Science marches on ;O)

Palaeoenvironmental evidence for solar forcing of Holocene climate linkages to solar science -- Chambers et al. 23 (2) 181 -- Progress in Physical Geography

A good one, and accessible for free, at least for the next 4 days. Sage has a trial subscription going, just as well take advantage and grab whatever you might have an interest in while the door is open !!!!

Anybody ever explain why the temp went down during WWII?

Couldn't possibly have anything to do with solar activity could it?

Personally, I have begun to wonder if MSM prognostications of climate change could be more attributable to reflections of sunspots off the full moon.

LOLOL. Yep, moonbats, all of them.

The largest iceberg ever spotted was sighted by the USS Glacier on November 12, 1956. It measured 208 miles long by 60 miles wide—the size of Belgium.
In winter, the sea ice around Antarctica grows at the rate of 40,000 square miles a day. It effectively doubles the size of the continent, from seven million square miles to 13 million square miles.
The polar ice cap around the South Pole advances about 33 feet annually.