Note: two events at AGU13 this morning dovetail in with this essay. The first, a slide from Dr. Judith Lean which says: “There are no operational forecasts of global climate change”.
The second was a tweet by Dr. Gavin Schmidt, attending Lenny Smith’s lecture (which I couldn’t due to needing to file a radio news report from the AGU press room) that said:
Smith: usefulness of climate models for mitigation 'as good as it gets', usefulness for adaptation? Not so much #AGU13
— Gavin Schmidt (@ClimateOfGavin) December 10, 2013
With those events in mind, this essay from Dr. William Gray (of hurricane forecasting fame) is prescient.
Guest essay by Dr. William M. Gray
My 60-year experience in meteorology has led me to develop a profound disrespect for the philosophy and science behind numerical climate modeling. The simulations that have been directed at determining the influence of a doubling of CO2 on Earth’s temperature have been made with flawed and oversimplified internal physical assumptions. These modeling scenarios have shown a near uniformity in CO2 doubling causing a warming of 2-5oC (4-9oF). There is no physical way, however, that an atmospheric doubling of the very small amount of background CO2 gas would ever be able to bring about such large global temperature increases.
It is no surprise that the global temperature in recent decades has not been rising as the climate models have predicted. Reliable long-range climate modeling is not possible and may never be possible. It is in our nation’s best interest that this mode of prophecy be exposed for its inherent futility. Belief in these climate model predictions has had a profound deleterious influence on our country’s (and foreign) governmental policies on the environment and energy.
The still-strong—but false—belief that skillful long-range climate prediction is possible is thus a dangerous idea. The results of the climate models have helped foster the current political clamor for greatly reducing fossil fuel use even though electricity generation costs from wind and solar are typically three to five times higher than generation from fossil fuels. The excuse for this clamor for renewable energy is to a large extent the strongly expressed views of the five Intergovernmental Panel on Climate Change (IPCC) reports, which are based on the large (and unrealistic) catastrophic global warming projections from climate models.
The pervasive influence of these IPCC reports (from 1990 to 2013) derives from the near-universal lack of climate knowledge among the general population. Overly biased and sensational media reports have been able to brainwash a high percentage of the public. A very similar lack of sophisticated climate knowledge exists among our top government officials, environmentalists, and most of the world’s prestigious scientists. Holding a high government position or having excelled in a non-climate scientific specialty does not automatically confer a superior understanding of climate.
Lack of climate understanding, however, has not prevented our government leaders and others from using the public’s fear of detrimental climate change as a political or social tool to further some of their other desired goals. Climate modeling output lends an air of authority that is not warranted by the unrealistic model input physics and the overly simplified and inadequate numerical techniques. (Model grids cannot resolve cumulus convective elements, for example.) It is impossible for climate models to predict the globe’s future climate for at least three basic reasons.
One, decadal and century-scale deep-ocean circulation changes (likely related to long time-scale ocean salinity variations), such as the global Meridional Overturning Circulation (MOC) and Atlantic Thermohaline Circulation (THC), are very difficult to measure and are not yet well-enough understood to be included realistically in the climate models. The last century-and-a-half global warming of ~0.6oC appears to be a result of the general slowdown of the oceans’ MOC over this period. The number of multidecadal up-and-down global mean temperature changes appears also to have been driven by the multidecadal MOC. Models do not yet incorporate this fundamental physical component.
Two, the very large climate modeling overestimates of global warming are primarily a result of the assumed positive water-vapor feedback processes (about 2oC extra global warming with a CO2 doubling in most models). Models assume any upper tropospheric warming also brings about upper tropospheric water-vapor increase as well, because they assume atmospheric relative humidity (RH) remains quasi-constant. But measurements and theoretical considerations of deep cumulonimbus (Cb) convective clouds indicate any increase of CO2 and its associated increase in global rainfall would lead to a reduction of upper tropospheric RH and a consequent enhancement (not curtailment) of Outgoing Longwave Radiation (OLR) to space.
The water-vapor feedback loop, in reality, is weakly negative, not strongly positive as nearly all the model CO2 doubling simulations indicate. The climate models are not able to resolve or correctly parameterize the fundamentally important climate forcing influences of the deep penetrating cumulonimbus (Cb) convection elements. This is a fundamental deficiency.
Three, the CO2 global warming question has so far been treated from a “radiation only” perspective. Disregarding water-vapor feedback changes, it has been assumed a doubling of CO2 will cause a blockage of Outgoing Long-wave Radiation (OLR) of 3.7 Wm-2. To compensate for this blockage without feedback, it has been assumed an enhanced global warming of about 1oC would be required for counterbalance. But global energy budget considerations indicate only about half (0.5oC, not 1oC) of the 3.7 Wm-2 OLR blockage of CO2 should be expected to be expended for temperature compensation. The other half of the compensation for the 3.7 Wm-2 OLR blockage will come from the extra energy that must be utilized for surface evaporation (~1.85 Wm-2) to sustain the needed increase of the global hydrologic cycle by about 2 percent.
Earth experiences a unique climate because of its 70 percent water surface and its continuously functioning hydrologic cycle. The stronger the globe’s hydrologic cycle, the greater the globe’s cooling potential. All the global energy used for surface evaporation and tropospheric condensation warming is lost to space through OLR flux.
Thus, with zero water-vapor feedback we should expect a doubling of CO2 to cause no more than about 0.5oC (not 1oC) of global warming and the rest of the compensation to come from enhanced surface evaporation, atmospheric condensation warming, and enhanced OLR to space. If there is a small negative water-vapor feedback of only -0.1 to -0.3oC (as I believe to be the case), then a doubling of CO2 should be expected to cause a global warming of no more than about 0.2-0.4oC. Such a small temperature change should be of little societal concern during the remainder of this century.
It is the height of foolishness for the United States or any foreign government to base any energy or environmental policy decisions on the results of long-range numerical climate model predictions, or of the recommendations emanating from the biased, politically driven reports of the IPCC.
###
William M. Gray, Ph.D. (gray@atmos.colostate.edu) is professor emeritus of atmospheric science at Colorado State University and head of the Tropical Meteorology Project at CSU’s Department of Atmospheric Sciences.
Konrad says:
December 11, 2013 at 5:24 am
“CO2 global warming question has so far been treated from a “radiation only” perspective”
Dr. Gray is close to “getting it”, but not quite.
The net effect of radiative gases in our atmosphere is cooling at all concentrations above 0.0ppm.
To understand this, you only have to understand 4 simple points –
1. Radiative cooling at altitude is critical to continued strong vertical tropospheric circulation in the Hadley, Ferrel and Polar tropospheric convection cells.
2. The observed lapse rate below the topopause is a result of strong vertical circulation of gases across a gravity induced pressure gradient.
3. Incident LWIR cannot heat nor slow the cooling rate of liquid water that is free to evaporatively cool. (sorry Willis, but empirical experiment proves you wrong)
4. Without radiative cooling at altitude and the resultant strong vertical tropospheric circulation, our atmosphere would trend isothermal, with its temperature driven by surface Tmax, not surface Tav. (sorry Dr. Spencer, but empirical experiment proves you wrong)
That’s it. That’s all you need to know. Adding radiative gases to the atmosphere will not reduce the atmospheres radiative cooling ability. Global warming is a physical impossibility.
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Konrad I believe you have it right … until the last paragraph.
You do appreciate that the black-body temp of the Earth is 255K – yet we live on a planet of ave temp 288K. What causes the 33K temp differential, if not GHG’s?
GHG’s do not reduce the atmosphere’s (absolute cooling) ability but they DO set that cooling to occur at a higher temperature.
Consider that the Earth had no GHG’s or water – then the LR (lapse rate) would be set by turbulent motion moving air down (warming lower down – compression) and air up (cooling aloft – rarefaction). This due various processes including latitudinal temp differential and formation of jet-streams via Coriolis, (dry) convection etc. So a LR is set after time. Now in this (hypothetical) world the atmosphere is transparent to ALL radiation (no heating other than a narrow surface lyr due conduction at the surface). In this case the temperature would be set at the surface at 255K (snowball earth or black-body temp in equilibrium with solar) and the LR would proceed upwards from that.
Now just as the coolest time of day is not at dawn but a little time after because radiation (SW) in, needs to equal radiation (IR) out, before temps can rise, then when GHG’s are added to the atmosphere this absorption/re-emission moves the balance of SW in vs IR out higher up (they absorb IR and so now the surface is not the balance point). Such that on Earth this is at around ~7km. With absorption efficiency proportional to air density, and integrating over the depth of the atmosphere this yields an exponential decrease of temperature with altitude because of the exponential decrease in air density, and a temperature at the top of atmosphere of about 210 K – that, that we see at the Tropopause.
http://acmg.seas.harvard.edu/people/faculty/djj/book/bookchap7.html#13581
Any further addition of GHG’s moves the balance point higher up and resets the LR to that point with a consequent rise in surface temp.
So, in short, GW (via GHG’s) is a physical fact.
I make it about 6.6 w/m2 at the surface. Using a very rough, very simple model we have in “pre-industrial” times
OLR (to space) = Incoming Solar radiation =~ 240 w/m2
Surface energy flux = ~388 w/m2.
Double atmospheric CO2 so that OLR = 236 w/m2 (reduction of 4 w/m2)
Fraction of OLR/Surface = 236/388 = 0.608
Because OLR is less than Incoming Solar then the surface must warm and continue to warm until balance is restored.
New Surface Temp = 240/0.608 = 394.57 w/m2 i.e. an increase of ~6.6 w/m2. This represents a temperature increase of ~1.2 degrees (14.6K -> 15.8K).
John,
This is wrong because most of the GHE is due to water vapor and not CO2. You can’t use a simple ratio off OLR between the surface and TOA to derive a figure of 6.6 watts/m2 surface forcing. The TOA forcing of 3.7 watts/m2 will be the same as that at the surface to first order neglecting any water vapor feedback.
This is where the 1C figure of warming for a doubling of CO2 comes from because the Planck response DS = 4.sigma.T^3.DT works out at 3.5 watts/m2/deg.C.
Dr Gray argues that 1.8 watts / m2 is expended in latent heat of evaporation from oceans. He assumes zero feedback from H2O to derive 0.5C warming. The whole AGW argument boil down to just one thing.
How does the water cycle act to a change in forcing ?
For me the answer is obvious. The presence of 70% ocean cover on Earth must stabilize the climate from any excursions in climate otherwise the oceans would have boiled away billions of years ago as the sun’s radiation has increased by 30% since the oceans formed.
I look forward to your paper explaining, providing evidence for and quantifying the “bypass mechanism”.
I would like to see even one of the “settled science” crowd debate Dr. Gray .
Al Gore isn’t even worth consideration.
It is absolutely incredible that the scientific community sits by while scam artists use them to validate utter nonsense.
Way to go Dr Gray!
Tom J;
Know of a nice 426 Hemi for sale?
>>>>>>>>>>>>>>
Nice? Sacrilegious! There was nothing nice about the 426 Hemi. It is a 30+ year old engine that still strikes fear into the hearts of muscle car owners everywhere. I remember a one page ad in one of the muscle car mags back in the 60’s that had the list of all the performance features of the engine, and at the bottom it said “425 Horse Power”. At the bottom of the page, in print so fine you needed a magnifying glass to read it, it said:
So, you’re wondering, with all that, why only 425 HP? Well, if it was 585 HP, it wouldn’t be street legal.
Dear Tom J (and davidmhoffer),
Thank you, so much. I wish someone as kind and thoughtful as you had not had to go onto disability. I hope the opening of the door to art has proven to be rewarding and gives you much joy. Heh, no, try Craig’s List. 😉
Re: davidmhoffer’s point about horsepower — wow — that was impressive 30 years ago. Pretty amazing. In the 1960’s and early 70’s, Chevy had to be similarly careful with its stated specs for several of its models. Would you believe (yes, I’m sure you would) that there was a tort case in the U.S. where the plaintiff sued because Chevrolet made a car that went so fast he said that it “caused” his injuries. I forget who won. Regardless, I think it influenced the speedometer’s to only go up to 120 (or whatever the max became). A good thing that came out of tort litigation (not all that lawyers do is bad) was the collapsible hood ornaments — the old ones were a cruel beauty.
Okay, I will stop, now. Enjoyed the friendly banter. Science can be fun, but muscle cars rock!
Your WUWT ally,
Janice
TB says:
December 11, 2013 at 3:03 pm
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“You do appreciate that the black-body temp of the Earth is 255K – yet we live on a planet of ave temp 288K. What causes the 33K temp differential, if not GHG’s?”
Right there you have your finger on the central problem of the failed radiative green house hypothesis. Attempting to apply SB equations to determine the “surface” temperature of a moving gas atmosphere with a pressure gradient over a liquid water ocean was a critical mistake. Claiming a black body temperature for such a planet derived through the misapplication of SB equations to moving fluids is a nonsense.
“GHG’s do not reduce the atmosphere’s (absolute cooling) ability but they DO set that cooling to occur at a higher temperature.”
No, that won’t work either. Without the ability to both absorb and emit radiation, our atmosphere would still be heated by surface conduction and the release of latent heat, but it would have no effective means of cooling. Surface conduction is ineffective at cooling a moving gas atmosphere with a pressure gradient. The experiment to demonstrate this is simple. Without radiative gases, our atmosphere can easily heat, but it cannot easily cool.
“Consider that the Earth had no GHG’s or water – then the LR (lapse rate) would be set by turbulent motion moving air down (warming lower down – compression) and air up (cooling aloft – rarefaction).”
The lapse rate is a product of strong vertical convective circulation below the tropopause. This circulation is dependant on radiative cooling allowing subsidence of air masses at altitude. Without radiative gases, tropospheric convective circulation in Hadley, Ferrel and Polar cells would stall and the atmosphere would trend isothermal through gas conduction. Quite simply the speed of tropospheric convective circulation and the resulting lapse rate is dependant on radiative gases.
Global warming believers often cite the 1938 work of G. S. Callendar. What they never mention is the 1938 response of Sir George Simpson –
“………….but he would like to mention a few points which Mr. Callendar might wish to reconsider. In the first place he thought it was not sufficiently realised by non-meteorologists who came for the first time to help the Society in its study, that it was impossible to solve the problem of the temperature distribution in the atmosphere by working out the radiation. The atmosphere was not in a state of radiative equilibrium, and it also received heat by transfer from one part to another. In the second place, one had to remember that the temperature distribution in the atmosphere was determined almost entirely by the movement of the air up and down. This forced the atmosphere into a temperature distribution which was quite out of balance with the radiation. One could not, therefore, calculate the effect of changing any one factor in the atmosphere, and he felt that the actual numerical results which Mr. Callendar had obtained could not be used to give a definite indication of the order of magnitude of the effect.”
Sir George Simpson’s criticism is as valid today as it was in 1938. You should note the similarity to Dr. Gray’s statement – “CO2 global warming question has so far been treated from a “radiation only” perspective”
Neither the anthropogenic global warming hypothesis nor its foundation, the radiative greenhouse hypothesis, are valid. You cannot determine a “black-body” temperature for the planet by applying SB equations to a moving gas atmosphere over a liquid water ocean. You cannot calculate changes in radiative flux into and out of the lower and upper atmosphere without simultaneously calculating the changes in speed of tropospheric convective circulation and thereby the speed of mechanical energy transport from the surface.
There is a slight radiative greenhouse effect on earth, most notable over land at night. However the NET effect of radiative gases in our atmosphere is cooling at all concentrations above 0.0ppm
If the atmosphere couldn’t radiate (via GHGs) it could cool only by evaporative gas escape into space. The equilibrium point of that process is not a survivable one.
@ur momisugly Eric Simpson — fwiw — I read the Forbes article you linked at 9:44pm yesterday. Thank you for sharing that. It nicely covered the basics for non-scientists. The author obviously had done his homework, however…, I would have tightened up the style (he needs to take a lesson on conciseness and more powerful sentence structure from YOU, Mr. Simpson) and used a chart for a big chunk of those CO2-and-temperature-levels-through-the-ages-numbers. Forbes magazine started pushing “green” garbage a few years ago and I stopped reading them. Great to know that, as of May, 2011, at least, they published this!
Hey, Wrecktafire, did you have a chance to look at that thread I linked for you above (yesterday at 10:16pm)? I think you’d thoroughly enjoy reading the comments on it. If my taking liberties with your name offended you, please forgive me. I just wanted you to know someone recognized your wit.
Janice
Wreck;
It doesn’t take billions of times. One or two bad guesses (or biased plugs) can roon the whole demmed thang. And every parameter is a fudge begging to be tweaked.
@Janice: I have not yet read the link–I will put it in my queue. Thanks for the thought!
And I did not interpret your reference to my screen name as a negative thing, not in the least.
-W
Konrad 4:48pm: “There is a slight radiative greenhouse effect on earth..”
Dr. Gray top post: “…a doubling of CO2 should be expected to cause a global (surface) warming of no more than about 0.2-0.4C.”
G.S. Callendar 1938: CO2 Mean Global Surface Delta T 0.16C for 20th century, 0.36C 21st century (Table VI).
Well, well, at least 3 reasoned agreements (rounded) along with many modern atm. thermo. text books. In accord with GHCN thermometer century scale observations (rounded).
For the simple but not easy basic “slight” GHE (Konrad term) physics, see the Callendar 1938 paper and the link by TB 12/11 3:03pm Chapter 7. Recognize the effects of varying measured f term (fraction terrestrial radiation absorption by atm.) in eqn. 7.16 (for those can read math ex Konrad).
Also see GS Callendar 1938 p. 239 reply to Sir George Simpson that Konrad did not clip.
http://onlinelibrary.wiley.com/doi/10.1002/qj.49706427503/pdf
@ur momisugly Wrecktafire — Good! Thanks, so much, for responding. J
Hi, Brian H,
My reference to the billions of times is from the number of cells in the 3-dimensional grid that the modelers use in a GCM, times the number of time-slices used in a model run. If errors are reasonably small and no X factors come in (such as from the sun or a volcano), a model has a decent shot at putting a few accurate years together.
But you are right: the acknowledged poverty of cloud water vapor parts of the models is a stake through the heart of the GCM beast. There is great room for improvement, and I expect that such improvement will take place, if for no other reason that the modellers are getting a terrific spanking by reality. 🙂
John Finn: the paper is in preparation. The Quantification is via the reduction of atmospheric water vapour as pCO2 has increased.
Glad that you picked up on this point because it has been missed by Climate Alchemy. yet ti is obvious to any process engineer with knowledge of control systems.
It’s not wrong. Over- simplified maybe – but not wrong. A surface energy flux of ~390 w/m2 drives a
TOA flux ~240 w/m2 (i.e. equivalent to incoming solar energy). As CO2 accumulates in the upper DRIER and colder atmosphere the average emission altitude is increased. In other words more energy is emitted from a colder region. The rate of emission will, therefore, decrease (S-B Law). Line by line radiative transfer equations (e.g. as used by MODTRAN) show that doubling CO2 reduces the outflow of LWIR by ~3.7 w/m2. To restore the energy balance the surface temperature will need to increase by ~1.2 degrees C (not including feedbacks).
ice ages?
You have evidence for this reduction in atmospheric water vapour?
Do the glacial/interglacial transitions not pose a bit of a stumbling block?
There is ample evidence of the reduction of atmospheric water vapour, e.g. Solomons et al which showed a fall of stratospheric pH2O by 10% since 2000. Also Miskolczi showed 61 years of radiosonde data proving reduction of pH2O.
The glacial/interglacial transitions are from biofeedback via the thermohaline circulation system. Turn it off and the Fe trace element decreases so you have much lower phytoplankton growth, also lower pCO2 (cooler oceans) means terrestrial vegetation collapses too. The mechanism is an increase in cloud albedo – Sagan’s aerosol optical physics is wrong, as is all that part of Climate Alchemy dependent on it!
Trick says:
December 11, 2013 at 9:43 pm
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Oh no Trick, you’ve gone and done it again!
You cite Callendar’s reply to Sir George Simpson in the hope that it supports the case for global warming. It clearly doesn’t.
“..in replying, G. S. Callendar said he realised the extreme complexity of the temperature control at any particular region of the earth’s surface and also that radiative equilibrium was not actually established, but if any substance is added to the atmosphere which delays the transfer of low temperature radiation, without interfering with the arrival or distribution of the heat supply, some rise of temperature appears to be inevitable in those parts which are furthest from outer space.”
Read that again “without interfering with the arrival or distribution of the heat supply”. That is exactly what radiative gases are doing. They play a critical role in strong vertical tropospheric convective circulation. They therefore play a critical role in the primary mechanism of energy transport and distribution within our atmosphere. Sir George Simpson’s criticisms are valid. Callendar did not properly consider atmospheric circulation and certainly didn’t understand the critical role radiative gases play in driving it.
It is also notable that that nowhere in Callendar’s work does he even address the role of radiative gases in cooling the upper atmosphere.
Oh, and TB’s link? The usual static atmosphere two layer radiative model tripe. No modelling of atmospheric circulation responses to increased radiative absorption by the lower atmosphere and increased radiative emission by the upper atmosphere. There is the brief hand waving about GCMs being “three dimensional” but of course that is also tripe. GCMs do not have the vertical resolution to model what Callendar also failed to compute.
The cites both you and TB offered have essentially proved Dr. Gray’s statement – “CO2 global warming question has so far been treated from a “radiation only” perspective” to be correct.
Konrad says:
December 11, 2013 at 4:48 pm
TB says:
December 11, 2013 at 3:03 pm
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>snip>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Konrad the BB temp of the Earth is that reached either without an atmosphere or one that is GHG free. A BB temp has nothing to do with moving gases or oceans – it is a simple property of a BB – the SOLID earth (has to be a BB means having a transparent atmosphere). This gives a temp of –18C. Now suppose this atmosphere is of N2, which does not absorb/emit IR. Sunlight is converted to heat at the planets surface, and to maintain energy balance, radiates back to space. This goes straight through the N2. The surface will warm to just the temp that’s needed, on average, to achieve that outward radiation level (BB temp).
The surface will not be uniform. Some parts will be hotter than others, and this will set up local turbulence/convection. Growing and taking heat from the tropics to colder parts. The N2 will be in motion.
There will be some energy exchange from this convection but on balance, heat flux to the N2 goes nowhere. For N2 cannot emit it to space. It can only conduct it back to the surface (somewhere).
Therefor the BB calculation for a planet with a non-GHG atmosphere is very much valid.
“The lapse rate is a product of strong vertical convective circulation below the tropopause. This circulation is dependent on radiative cooling allowing subsidence of air masses at altitude. Without radiative gases, tropospheric convective circulation in Hadley, Ferrel and Polar cells would stall and the atmosphere would trend isothermal through gas conduction. Quite simply the speed of tropospheric convective circulation and the resulting lapse rate is dependent on radiative gases.”
Konrad. The LR is much more than a product of convective circulation, Convection in temperate/polar zones plays but apart of atmospheric motion. Jet-stream and baroclinically and vortically induced uplift via thermal wind/Coriolis predominate.
And no, the atmosphere would not stall and trend isothermal through conduction. Conduction would take an order of magnitude to work though from the surface to the trop. Air would be in motion way before then. Frictional slowing at the surface and differential “conduction” would cause motion and hence turbulence. This turbulence (obviously) means some vertical motion, which brings in the gas laws and a “heat pump” action would transport heat down and cool the upper layers. Take a balloon from 10000ft down to 1000ft it will compress and warm. Now a similar “balloon” must rise to replace it. This rises and cools. Now remember this is an isotherm atmosphere and so it arrives aloft and cools it’s surrounding just as the descending “balloon” warms” it. Over time a LR forms (not yet the DALR). Remember this is achieved by turbulence NOT convection. Remember also, there will be day/night and great latitudinal differences in surfacing heating to get all this going.
“….The atmosphere was not in a state of radiative equilibrium, and it also received heat by transfer from one part to another. In the second place, one had to remember that the temperature distribution in the atmosphere was determined almost entirely by the movement of the air up and down. This forced the atmosphere into a temperature distribution which was quite out of balance with the radiation. One could not, therefore, calculate the effect of changing any one factor in the atmosphere….”
“You cannot determine a “black-body” temperature for the planet by applying SB equations to a moving gas atmosphere over a liquid water ocean. You cannot calculate changes in radiative flux into and out of the lower and upper atmosphere without simultaneously calculating the changes in speed of tropospheric convective circulation and thereby the speed of mechanical energy transport from the surface.”
We do not determine a black body temp for a planet by applying SB to the atmosphere. It’s mass makes this irrelevant in the first instance (1000th of the mass of the oceans). And oceans radiate as well. We do not need (in this transparent air) to calculate changes in radiative flux. It is zero within it. It is a non BB and therefore irrelevant (in this special case).
All that applies is the BB temp that this planet reaches – on Earth it WOULD be 255K (-18C). Oceans, or in this case ice, do not matter as they radiate also and would eventually come into equilibrium with the average temp of the land-mass. You then have your steady state conditions. Now put a transparent atmosphere on this planet (ignoring the initial LR due to compression). Yes it would be isothermal and then comes the build up of turbulent mixing as described above. The convection will come later in the process when the adiabatic loss of internal energy in the rising and expanding air parcel matches that of the mechanically induced LR and specifically when less. Then “true” convection starts.
Now put GHG’s into this atmosphere and radiative effects come into play. Experiment/theory has shown for ~150 years that GHG’s slow electromagnetic transmission via diffusion/back-scattering/re-emission.
These gases have the effect of raising the radiative surface of the (now) Earth (~7km) and hence the LR starts from there (ave temp globally at 7km matches the BB temp of -18C). The LR remains the same and continues to the surface to reach there at +15C.
“There is a slight radiative greenhouse effect on earth, most notable over land at night. However the NET effect of radiative gases in our atmosphere is cooling at all concentrations above 0.0ppm”
So you are saying that the v high temperature of Venus’s CO2 atmosphere is entirely due to weight of atmosphere?
Konrad, I spent many years of my career on long night-shifts monitoring the weather for road hazards whilst making/delivering Forecasts. Road temperature sensors respond very quickly to cloud cover, even thin Cirrus at a temp of –30C at 30000ft will cause an immediate slowing/reversal of cooling (NOT heating – just a slowing of emission and heating via ground flux –because of re-emission of IR. The GHE from a thin layer of (frozen) water 6 miles up. This is obvious as we can see clouds. GHG’s do the same unseen. They just do, sorry.
John Finn says:
December 12, 2013 at 1:50 am
“As CO2 accumulates in the upper DRIER and colder atmosphere the average emission altitude is increased. In other words more energy is emitted from a colder region. The rate of emission will, therefore, decrease (S-B Law).”
But, consider this:
Satellite measurements of Earth emission data show that the IR photons absorbed by CO2 molecules are not re-emitted before the energy gained is redistributed by collisions with other non-greenhouse gas molecules. We know this because the re-emission of radiation does not occur at a black body temperature of 288K and instead occurs at a black body temperature of about 210 to 220K characteristic of general air temperatures at altitudes from 10.5 km to 22 km.
This part of the atmosphere is called the tropopause, where the temperature does not vary much from an average of 217K. Any change in the effective radiating level in the tropopause will not reduce the heat emitted, and not cause atmospheric warming.
Konrad 2:57am: “(interfering with arrival of heat) is exactly what radiative gases are doing.”
Thanks for good form completing your Callendar 1938 clip. That’s progress. However until you can effectively rebut Fig. 7-11 in the Chapt. 7 link provided by TB 3:03pm, your assertion here is empirically proven incorrect for the sun, earth, atm. thermo. system in the context of Callendar’s reply.
“…nowhere in Callendar’s work does he even address the role of radiative gases in cooling the upper atmosphere.”
Unsupported assertion. Please refer Callendar’s Table V for upper atmosphere consideration and the discussion pp. 229-230. Especially paragraph 4 p. 229. I should not have to spell it out for you since GS Callendar does it well enough even in the light of your Sir George Simpson clip & reply in the 1938 paper.
“..two layer radiative model tripe.”
Progress is achieved by showing exactly where the worthless tripe is found in TB 3:03pm link for Chapt. 7. You won’t be able to do so with sound theory and empirical test – only support you offer so far is your informal assertion of problems in GCMs obvious to all.
@Janice Moore: thanks for the good read. Yes, there were excellent comments (on how the exact same models could produce different results on different computers).
Two things about the article bugged me (I’ll have to post to that thread):
1 It would be nice to know what the mean was, to compare the standard deviation with
2 The table could use more explanation. Without more info, I am wondering if the column headers “initial condition ensemble” and “software system ensemble” were accidentally swapped, based on what is varying in the columns beneath.
Perhaps Mr. Watts can help us out?
Climate models treat the future as an average. However, the future is not an average. Here is an example that shows why:
Say for example you bought 1 lottery ticket each year for $1. The prize was $1 million, and the odds of winning 1 in 5 million.
The climate models would predict that on average each year you would win 20 cents from $1 bet, for a net loss of 80 cents per year. After 10 years you would be down $8.
However, when we actually arrive at the future 10 years from now we will find it is nothing like what the climate models predict. Almost certainly you will be down $10, not the $8 predicted by the climate models. Or with long odds you could be up almost $1 million or more.
However, in no case will you be down the $8 predicted. Yet the IPCC is 95% sure that is the correct answer.