From Dr Roy Spencer’s Global Warming Blog
by Roy W. Spencer, Ph. D.
There was a recent weeks-long exchange of emails between many climate people — professional and amateur — regarding the idea that air pressure (in combination with absorbed solar energy) is what causes temperature. There were insults launched at those who refused to believe what a certain physics-trained person says should be a revolution in our understanding of planetary temperatures. That person even managed to get a paper published in a journal that (in my opinion) used reviewers who were in over their heads on the subject.
The whole ordeal makes me think of the Dunning-Kruger Effect, which is the tendency for people who start to understand a complex subject to overestimate their level of understanding. This then leads to a point of peak overconfidence (climbing “Mount Stupid”), which then gradually relaxes as more is learned and the person increasingly realizes that the subject is more complicated and nuanced than they originally thought.
I claim that the person in question who thinks [pressure + absorbed solar energy = temperature] is still stuck on Mount Stupid.
The reason I bring this up again (I’ve preached on it before) is that many have been misled into believing the “theory”. As a result, I have spent many years responding to questions from the public (including science-savvy citizens) regarding the issue. Many have been convinced by the “theory”, and have joined the proponent of the theory on Mount Stupid.
After lurking in the weeks-long email discussion, I finally responded with the following summary of the issue. I have removed the person’s name to protect the not-so-innocent.
SUBJECT: Where <NAME REDACTED> Is Right… and Where <PRONOUN REDACTED> Is Wrong
All:
After working in meteorology and then climate during my 40+ year career, I think I can offer some insight into the issues being discussed in these emails. Like <NAME REDACTED>, I have always been skeptical of what I have been told until I could fully understand an issue for myself.
I’m sure the following explanations will be of help to many of you. (I suspect <NAME REDACTED> is too invested in theories to change <PRONOUN REDACTED> mind.) Many of the concepts are not trivial, and I will admit it wasn’t until many years after all of my education (PhD Meteorology) that I finally understood a few of them, because they were not taught in school. Dick Lindzen helped me in this in the early climate research years.
Most of what follows is fundamental atmospheric thermodynamics, and I question whether <NAME REDACTED> really did take a university-level Atmospheric Thermodynamics course. If he did, I’d like to know where.
And if <PRONOUN REDACTED> shows me <PRONOUN REDACTED> grades, I’ll show <PRONOUN REDACTED> mine.
A THOUGHT EXPERIMENT
Imagine you could suddenly dump an extra 1 atmosphere of air on top of the existing atmosphere, what would happen to air temperature in the 1 ATM below? Just as <NAME REDACTED> would predict, the temperature of the original atmosphere below would increase greatly through adiabatic compression.
But what would happen NEXT?….
The high [hot] atmospheric temperatures in the lower atmosphere would then be far out of energy balance compared to what existed before. The result would be cooling of all of that air that was heated through adiabatic (or nearly so) compression (work done on the lower atmosphere) until a new state of energy equilibrium was reached. The energy loss would be through infrared radiation of the hotter air.
In fact is it always ENERGY BALANCE that determines temperature, through the 1st Law of Thermodynamics. A change in temperature is proportional to the rate of energy input minus the energy output (which includes any work done in the process).
In contrast, the Ideal Gas Law (PV=nRT) cannot tell you what the temperature “should be”. It only says how the variables P, V, and T are interrelated during the process of re-equilibration and in the final equilibrium state. What <NAME REDACTED> misses in <PRONOUN REDACTED> theory is the “n” part of the equation (the number of moles, or mass… which is in the density form of the equation, P = rho RT). In my hypothetical 2-atmosphere thought experiment, as the lower atmosphere cools to reach a new state of energy equilibrium with the solar input, the decreasing temperature causes an increase in the air density (“shrinkage”), and the pressure remains the same… even while the temperature is changing.
Specifically, following the 1st Law, the internal temperature of a volume of atmosphere exposed to an energy INPUT will increase until the temperature-dependent energy OUTPUT processes equal the rate of energy gain. This is true of every physical system… the atmosphere, a pot of water on the stove, a car’s engine, the human body, the interior of the sun, etc. That energy equilibrium is what determines the final temperature. (In the real atmosphere, there are constant energy imbalances and thus changes in temperature; Trenberth’s global-average energy balance diagram is only useful to gain a conceptual understanding of the relative role of the major energy flows in the global-average climate system.)
THE IDEAL GAS LAW
Again, the Ideal Gas Law equation (PV=nRT) cannot tell you what the temperature of a gas should be, only energy flows in and out can do that. The gas law just tells you how the P, n, and T are interrelated for a given volume (V) of air. Yes, <NAME REDACTED>, on short time scales, ascending air cools and descending air warms, but if all of that motion was to stop, energy flow processes would then determine what the final temperature would be… not what the air pressure is.
For a given surface air pressure, a huge range of temperatures is possible, and that huge range is all due to energy flow processes. Again, if the near-surface air temperature over the whole planet is much higher than local energy flow processes can support, the temperature falls, and the air’s volume shrinks (or density, rho, increases, according to the equivalent Ideal Gas Law equation, P=rhoRT). The surface air pressure remains the same because the total mass of the atmosphere is unchanged.
SO WHY MIGHT THERE BE A CLOSE RELATIONSHIP BETWEEN DIFFERENT PLANET’S LOWER ATMOSPHERIC TEMPERATURE AND PRESSURE?
I haven’t studied the atmospheres of other planets, because I don’t care. Even if those other planets did not exist, they are not necessary for understanding our own atmosphere. But if indeed <NAME REDACTED> is correct about a close statistical relationship between different planets’ surface air pressure and temperature, after adjusting for solar input, then I suspect it’s because the more atmosphere there is, the more greenhouse gases there are.
On the subject of GHGs, I’ve forgotten… does <NAME REDACTED> believe that air absorbs and emits IR energy? Because the greenhouse effect is a necessary consequence of that absorption/emission. Energetically, the GHE is a radiative insulator. It’s analogous to adding insulation to a heated building’s walls in winter. For a given energy input into the building, the air temperature inside will rise, and the outside of the walls will experience a temperature fall. This is exactly what the GHE does to the atmospheric temperature profile (in an energetic sense.. clearly involving radiation rather than conduction as a heat transfer mechanism).
If <NAME REDACTED> doesn’t believe air absorbs IR energy, how does <PRONOUN REDACTED> explain all of the thousands of spectroscopic measurements of CO2, water vapor, and methane as a function of temperature and pressure? And if <PRONOUN REDACTED> does believe the atmosphere absorbs and emits IR energy, then <PRONOUN REDACTED> must also believe in a greenhouse effect, because it is a necessary consequence…. the greenhouse effect in planetary atmospheres always causes warming of the lower atmosphere and cooling of the upper atmosphere.
(BTW, it is a common misconception that air which absorbs IR energy immediately loses that energy through emission of IR. Not true. Look up the “kinetic theory of gases” and related concepts. When CO2 or H2O vapor molecules absorb IR photons they extremely rapidly lose their extra energy to other air molecules through collisions. This happens much faster [by a factor of ~50,000] than the time it takes to re-emit energy through IR photons. This is how IR absorption immediately leads to “thermalization” [a term I hate].
Furthermore, it is crucial to understand that since IR absorption is largely independent of temperature, but IR loss is VERY dependent upon temperature, almost all air in the atmosphere is in a continual state of IR energy imbalance. Much of that imbalance is what [is balanced by] convective overturning.
WHAT IS THE ROLE OF THE ADIABATIC LAPSE RATE?
The adiabatic lapse rate in the troposphere (9.8 deg C per km without moisture condensation) is the RESULT OF convective overturning. If condensation of moisture is involved in updrafts, then the lapse rate is lower. Like the Ideal Gas Law, it doesn’t tell you what the temperature “should” be. It just tells you how the temperature of an air parcel changes during ascent or descent, if there is no energy gain or loss (“a-diabatic”). [But there are energy gains and losses occurring everywhere, all the time, and those determine what the absolute temperature will be — not pressure.]
HOW DOES THE GREENHOUSE EFFECT PLAY INTO THE LAPSE RATE?
This is a very interesting subject. It is something that even many atmospheric scientists and climate researchers don’t really understand. The combination of solar heating of the surface and IR absorption and emission by the surface and atmosphere ALONE, WITHOUT ANY CONVECTIVE OVERTURNING would result in an extremely steep tropospheric lapse rate, with very high surface temperatures and exceedingly cold upper tropospheric temperatures. This was first demonstrated by Manabe & Strickler (1964), and it’s called the “pure radiative equilibrium” case. It is sort of what makes the term “greenhouse effect” technically correct; like a real greenhouse inhibiting convective heat loss [because it has a roof], the greenhouse effect is, by definition, what happens WITHOUT the resulting convective overturning.
But in the real world, convective overturning is the RESPONSE to this GHE destabilization! So, that 33 deg. GHE warming people talk about? That’s not the GHE. It’s the GHE + CONVECTION. Without convection, that 33 deg. C figure would be more like 65 or 75 deg. C. Which then leads to another fascinating question…
WHAT WOULD HAPPEN IF THE ATMOSPHERE DID NOT ABSORB AND EMIT IR ENERGY?
Imagine a cold planetary atmosphere with no energy input. Then, turn on the sun. Solar heating of the surface would warm the atmosphere through convective overturning. But the [deep] atmosphere would have no way to shed that energy to cool in the presence of all of that energy input. The temperature of the [deep] atmosphere would then continue to rise until it had the same temperature as the surface, through its entire depth. Long before that process finished convective overturning would have stopped, because the atmosphere would be too stable to support convection. The atmosphere would eventually become isothermal (or nearly so, since there might be some planetary scale overturning between the tropics and the poles, due to their different rates of solar input), with the same temperature as the surface. Interestingly, as a result all weather activity would cease. All clouds would probably disappear, resulting in higher temperatures. Any [remaining] circulation systems would have a planetary scale, because the horizontal scale of those systems are related to the lapse rate (through the “Rossby radius of deformation”), which is also why the stratosphere only has planetary-scale circulations.
-Roy
Temperature is the kinetic energy of stuff.
PV=nRT is state equation that describes their relation ship.
Q=UA(Th-Tc) is a process equation that explains why surface is hotter than ToA.
Same KE process as the insulated walls of a house.
Correction: Temperature is an average measure of kinetic energy.
To move fluid through an hydraulic resistance requires a pressure difference.
To move current through an electrical resistance requires a voltage difference.
To move heat (energy in motion) through a thermal resistance requires a temperature difference.
Physics be physics.
The temperature gradient thru insulated stuff = lapse rate.
Our atmosphere’s lapse rate is caused by convection. Dr. Spencer did not get into that aspect but water vapor is lighter than air, so it is not really possible for a water planet to have an isothermal lapse rate and zero convection ….when the atmospheric components other than water vapor have nearly ideal gas behavior and MW greater than water.
BB requires ALL energy entering and leaving do so by radiation.
With kinetic processes present the surface cannot radiate at 396 W/m^2.
Earth is cooler with the atmosphere/water vapor/30% albedo not warmer. Near Earth outer space is 394 K, 121 C, 250 F. 288 K w – 255 K w/o = 33 C cooler -18 C Earth is just flat wrong. Dividing 1,368 by 4 to average 342 over Spherical ToA is wrong.
Ubiquitous GHE heat balance graphics don’t balance and violate LoT. Refer to TFK_bams09.
Solar balance 1: 160 in = 17 + 80 + 63 out. Balance complete.
Calculated balance 2: 396 S-B BB at 16 C / 333 “back” radiation cold to warm w/o work violates Lot 2. 63 LWIR net duplicates balance 1 violating GAAP.
Kinetic heat transfer processes of contiguous atmospheric molecules render surface BB impossible. By definition all energy entering and leaving a BB must do so by radiation. Entering: 30% albedo = not BB. OLR: 17sensible & 80 latent = not BB. TFK_bams09: 97 out of 160 leave by kinetic processes, 63 by LWIR = not BB. As demonstrated by experiment, the gold standard of classical science.
For the experimental write up see:
https://principia-scientific.org/debunking-the-greenhouse-gas-theory-with-a-boiling-water-pot/
Search: Bruges group “boiling water pot” Schroeder
RGHE theory is as much a failure as caloric, phlogiston, luminiferous ether, spontaneous generation and several others.
When GHE fails the entire CAGW house of cards implodes like the Titan submersible.
Nicholas…your weekly nonsense where you fail to understand 396-333 of electromagntic flux IS the 63 watts of heat radiation and the 63 watts that LEAVES the surface….ENTERS the air above…it’s called “conservation of energy”…GAAP is for tax lawyers. And 63+80+17=160 the sunlight absorbed, also conservation of energy…..Please quit reposting your incompetent cherry-picked interpretation of the energy budget.
Have not drawn much fire on the following WUWT post. Guess that’s because it does not need a PhD (Knows everything about everything and wrong about none of it.) to obfuscate w esoteric handwavium. Any unwashed prole who can balance a checkbook can spot the egregious errors.
The GHE debate is not just about the alarmist’s hocus pocus thermodynamic handwavium, but simple bookkeeping, i.e. 63 + 63 = 63.
TFK_bams09 and all of its clones don’t just violate LoT (160 in & 396 out LoT1 & 333 “back” from cold to warm wo work LoT 2) but basic GAAP.
The same 63 W/m^2 LWIR appears twice, once from the real solar balance: 160 – 80 – 17 = 1st 63 & again from the calc’d/“measured”/imaginary surface BB 396 – 333 “back” = 2nd 63.
The second appears in the calcs, (356-333=23+40) the first does not. What happened? Is the real 63s absence error or deceit??
Only one of these loops is needed to balance OLR at ToA so that means the other is “extra” (violates LoT1) free floating, unaccounted for, looking for a home and apparently dropped down someone’s boot top.
Only one of these balance loops belongs on the graphic.
I suggest keeping the real one.
The imaginary one can join RCP 8.5 in the trash bin of failed science.
Incoming positive, outgoing negative
TFK_bams09
+160 surface – 80 latent – 17 sensible – 1st 63 but AWOL – 396 BB + 333 back – 2nd 63 LWIR = – 63 AWOL
Solar 1st 63 goes missing
Does not balance.
Both 63s reach OLR
+160 surface – 80 latent – 17 sensible – 1st 63 LWIR – 396 BB + 333 back – 2nd 63 LWIR = – 126
Does not balance.
1st 63 to OLR, 2nd 63 goes nowhere.
+160 surface – 80 latent – 17 sensible – 1st 63 LWIR – 396 BB + 333 back + 2nd 63 LWIR = 0
Balances.
1st 63 reaches OLR at ToA.
80/17/63 really from sun
2nd 63 must return to surface.
396/333/63 imaginary
Personally, I’ve always thought the concept of phlogiston deserved more attention. Just like the aether, we can’t sense it, we can’t measure it, but it served for quite awhile as the equivalent of a ‘thought experiment’ with no possibility of falsification.
The theory that pressure causes temperature deserves the same respect. Or lack thereof.
At least the phenomenological phlogiston theory didn’t impose any political restrictions (to my knowledge) on the peasantry of the 18th century. In fact, it seems rather harmless today compared to the restrictions the Left has in mind for us enlightened moderns pursuant to the belief that the phenomenological physics of radiative transfer theory ‘explains’ how the bulk of the energy leaving the Earth’s surface is transported through the troposphere.
Really liked your addition to the newly revived Phlogiston Theory. “Phenomenological” is hereby added to the title: Phenomenological Phlogiston Theory.
Since we can’t compete with ‘antidisestablishmentantarianism’ as the longest word in the dictionary, maybe we can go for the longest title? For starters, how about “Phenomenological Phantasmagorical Phlogiston Theory.”
Hocus pocus handwavium.
‘WHAT WOULD HAPPEN IF THE ATMOSPHERE DID NOT ABSORB AND EMIT IR ENERGY?’
…doesn’t seem consistent with this:
‘But the [deep] atmosphere would have no way to shed that energy to cool in the presence of all of that energy input.’
…i.e., why wouldn’t the thermal radiation emitted by the Earth’s surface pass directly to space (and not collect $200) through what would effectively be a wide open atmospheric window?
Isn’t the point that the conductive transfer of energy to the atmosphere at the surface would not be emitted by IR and thus the temperature would not reduce with altitude?
It would, reread what Roy wrote
I did. There’s no mention of the surface radiating directly to space in the text below his question re. conditions in an atmosphere lacking IR active gas species.
Note, I have no doubt that such an atmosphere would effectively become isothermal due to the absence of convection, but it would certainly be much less hospitable (colder) than the one we have today.
I would think that in such a scenario, the entire atmosphere, top to bottom, would end up the same temperature as the Earth’s surface. The earth heats the atmosphere by contact, but the atmosphere can’t transfer that energy to space.
Indeed, albeit with complications due to Earth’s diurnal cycle. My only point was that there was no mention that any thermal radiation from the Earth’s surface would directly escape to space.
“I would think”
No you wouldn’t. Can you tell us what the Second Law of Thermodynamics says, Professor?
So more greenhouse gases “trap” more heat, but no greenhouse gases “traps” more/all heat? The logic seems twisted…
“Long before that process finished convective overturning would have stopped, because the atmosphere would be too stable to support convection. The atmosphere would eventually become isothermal (or nearly so,”
What’s the rationale behind this statement? This thought experiment recognizes molecular heat transfer but that the resultant convection from an initial (presumably) cold atmosphere encountering a warmed surface would eventually stop when the entire atmosphere matched the surface temperature, which must have cooled as it transfered heat to the adjacent atmosphere. This sounds so different from an actual planet, such as Earth, as to be pointless.
Does Dr. Spencer think it is relevant to the so-called GHE? The function of a real greenhouse is to inhibit advection and involves little if any convection (other than inside the greenhouse). It does that by enclosing a space, something that no gas mixture can simulate. Be wary of tossing around the Dunning-Kruger term.
In summer the air gets hot because there is much sunshine. In winter the air gets cold because there is less sunshine, but in summer and winter air pressure is about the same. Thus it is concluded air has little effect on air temperature.
The air pressure in the tropics is the same as the air pressure at the poles.
Tilted axis creates a 700 W/m^2 swing in ISR from summer to winter.
What makes that air out of a compressor hot?
That 250 hp motor.
Interesting – you deny that compressing air heats it!
A new level of strange.
Air released from a compressed state is cold because of it losing internal energy via expansion. The air that the compressor has, well, compressed, is hot because of increase in internal energy by dint of the molecules being closer together and hence having more collisions (work done).
Compressed air when left will cool as with any atmosphere subject to compression, as it is a “one time” event and the air is not being continuously being uncompressed then compressed again (continual work). If that were not the case then we would have free energy!
The atmosphere around a planet inevitably develops convective overturning which creates a constant process of decompression within rising columns and compression within falling columns. Thus continual work.
The concept of an isothermal atmosphere around a planet with uneven surface heating is a fantasy never observed in reality with or without radiative characteristics in the atmosphere.
If one then introduces radiative characteristics to a non radiative atmosphere what happens is that uneven radiation between parcels of air disturbs the lapse rate set by gravity and density so as to immediately change the speed of convective overturning.
That change in speed alters the rate at which KE returns to the surface beneath descending columns so that the rate of radiative emission from surface to space changes to neutralise any potential change in surface temperature.
From our emissions of CO2 the change in speed of convective overturning would be imperceptible and would manifest itslf in a miniscule change in the size and or position of the convective Hadley, Ferrel or Polar atmospheric cells.
I wonder whether we will soon see a rush of downticks to reduce the effect of my comments.
That has happened in the past.
Up/down ticks??
Suspected this process.
Happens regularly.
If an AGW sceptic appears to be making progress then a number of alarmists pile on with downticks.
Incoming sunlight generates water vapor which is lighter than air and will still generate convection, cloud, and rainfall on this theoretical almost-Earth mostly water-covered planet that has no “greenhouse gases” and is thus trying to be isothermal….but can’t…but i’m giving you the upvote anyway…
Incoming sunlight generates surface heat.
Surface heat produces latent effects.
We have 100hp of compressors at one of my facilities. The outlet pipe is 2” however the old system used to have an 1 1/2” pipe so there was a reducer about 20’ away from the compressors. When we were in operation the pipe temperature after the cooler was near ambient temperature, the temperature at the reducer was about 60 degrees higher.
That, however, seems an effect of the flowing non-ideal gas.
For the other topic:
Any scuba diver knows that if you open up an air tank at ambient temperature, the dreaming air at the outlet is cold.
A two-stage compressor has a heat exchanger between the stages to remove compression heat.
A car’s turbo has an intercooler.
WW II aircraft had intercoolers on superchargers to reach 35,000 feet.
Compressing air creates heat.
Not a secret.
But it takes work.
Some of the work produces heat, some of it produces pressure.
This is incorrect. If you believe the kinetic theory of gases, the individual molecules involved do not “lose” energy, they continue moving at the same speed. What does change? That kinetic energy is now applied to a larger volume thereby reducing the pressure. So how do pressure and volume change in relation to each other when unconstrained?
First, one must understand that all the gas laws are state equations. That means they only describe what occurs in a system at equilibrium. They are really only useful to evaluate what occurs when one variable changes.
Look at Boyles Law: P1V1=P2V2. The way this is evaluated is to make P1V1 = k and determine what P2 is when changing to V2. Yet if V2 is unconstrained, what does P2 end up being?
Example 1.
Let P1 = 64 psi and V1 = 1 cu ft. k = 64. So set P2V2 = 64 and assume P2 = 32 psi. What is V2? V2 = 64/32 = 2 cu ft.
Example 2
Let P1 = 64 psi and V1 = 1 cu ft. Again, k = 64. So set P2V2 = 64 but let V2 = 100 cu ft. What is P2? P2 = 64/100 = 0.64 psi.
Now let’s look at the combined gas law P1V1/T1 = P2V2/T2. Again, set P1V1/T1 equal to a constant. What combination of variables of P2, V2, and T2 will equal that constant. I’ll guarantee it is a large number of combinations.
The upshot? You need to explain how energy is lost via expansion. Just don’t make an assertion without proof. Remember, the law of conservation of energy means energy can’t be destroyed, it must go somewhere. Where does it go?
As Dr. Spencer points out, atmospheric conditions are complicated. There are many forces involved. Trying to simplify the conditions to one simple statement is not scientific. Adiabatic expansion does not have to be isothermal. Why? Does work enter into it? How about lower number of molecules per unit of volume causing a decreasing pressure and the corresponding temperature? Take a look at the combined gas law I show above.
As usual, you see what you want to see. He said nothing of the sort.
Simple consideration of how much force was exerted on a piston rod during the expansion from high pressure V1 to lower pressure but higher volume P2, plus entropy, allows solutions to these equations including final temperatures…for the last 150 years…and since yesterday’s first year engineering thermo class…
No, I do not. Air compressors heat the crap out the air.
The compressor heats the air that is in the tank. When it is released from the tank, it cools.
The tank loses heat to the surroundings before it is released.
Dr. Spencer, are you trying to say that if the Earth’s atmosphere was twice or thrice the density it is today, all with the same percentages of nitrogen, oxygen, argon, CO2, water vapor and so forth and with the same sun and distance of the Earth from it, our surface temperature would be the same? I had always thought that the temperature of the “air” on Venus was very high for two reasons, it is closer to the sun and its atmosphere is many times more dense that of Earth. No?
Venus is hot because its atmosphere is 96.5% CO2 and although closer to the Sun has an albedo of 0.75 (Earth = 0.3).
It’s surface pressure is not the source of it’s surface temp. because of the reasons Dr Spencer states – the GHE.
Mars has an atmosphere that is 95.32% CO2 and it’s cold there.
cp
My Sybil Dunning-Kruger for today.
The more “matter” an electromagnetic wave has to pass,
the “slower” it moves(the transfer, the speed stays the same).
That’s why caves have identical temperatures during summer and winter.
That’s why venus is superhot everywhere during night and day.
No to little atmosphere = the temperature changges quickly, as there is barely any resistance to the incoming rays.
No more zigzagging around.
What is Mars’ 14-16 um band radiance?
‘What is Mars’ 14-16 um band radiance?’
Better yet, what does atmospheric ‘radiance’ have to do with electromagnetic energy transport through the Earth’s troposphere?
“The RTE [radiative transfer equation] was introduced 125 years ago by Eugene von Lommel, while the heuristic concept of radiance was definitively formulated in 1906 by Max Planck. Subsequently, they were supplemented by the seemingly obvious concept of a directional radiometer [DR}. Since then, measurements with WCRs [well-collimated radiometers] and calculations based on the RTE have been at the very heart of the disciplines of atmospheric radiation, remote sensing, astrophysics, heat energy transfer, and biomedical optics.
Yet from the fundamental-physics perspective, both the discipline of DR and the RTT [radiative transfer theory] have been based on phenomenological notions many of which turned out to be profound misconceptions. It has been demonstrated that contrary to the widespread belief, a WCR does not, in general, measure the flow of electro-magnetic energy along its axis, while the radiance cannot be interpreted as quantifying the amounts of electro-magnetic energy transported simultaneously in various directions.”
https://pubs.aip.org/aip/acp/article/1531/1/11/922276/125-years-of-radiative-transfer-Enduring-triumphs
Because there is F all atmosphere.
Like gas molecules to collide with each other.
Surface pressure is around 6mb or 0.6% of Earth’s.
It also receives less solar SW fluctuating between 36% to 52% of Earth’s values.
That’s why it’s CO2 atmosphere does not exhibit a GHE.
Mars .006 bars, Venus 92 Bars, a factor of 15,000 more CO2 for photons to attempt to pass through…
Distance matters.
Maybe you should look at the ideal gas laws. GHE has little to do with temps on VENUS.
I and science disagree with you.
The ideal gas laws have nothing to do with it ….
“AI Overview
No, the ideal gas laws do not contradict the greenhouse effect. They describe different physical properties of the atmosphere and actually work in harmony to explain how Earth’s climate operates. [1, 2, 3]
How They Work Together
“
It dictates that an atmospheric column’s temperature generally decreases with altitude because the pressure drops as you rise. [1, 2, 3, 4, 5]
As I said before, PV=nRT is a state equation. In this example, pressure is not the only variable that changes. “n” changes because “V” changes. It is impossible to predict the change in all the other variables while the change is occurring. Only after equilibrium is reached can one use the ideal gas law to obtain the value of an unmeasured variable, and that is assuming you can measure all the others.
Your references say the same thing. To calculate the value of a variable, one must know the other values in the functional relationship. Just saying one changes redundant. All the others do also, except for the constant.
The ideal gas law doesn’t apply on Venus, the lower atmosphere is super critical CO2, the Van der Waals Equation of State is what applies there.
Atmospheric pressure is around 94 x that of Earth at the surface of Venus, and the temperature where the altitude = 1 Bar the temperature is close to that of Earth’s surface. The high albedo of Venus, due to highly reflective sulfuric acid clouds, means that only around 6% of solar energy reaches the surface, so very little IR to ‘back-radiate’. If Venus were at the same distance from the Sun as Earth, the temperature at the 1 Bar altitude would be cooler than Earth’s surface.
“Atmospheric pressure is around 94 x that of Earth at the surface of Venus, and the temperature where the altitude = 1 Bar the temperature is close to that of Earth’s surface.”
You beat me to it.
Yes, same pressure = same temperature.
The surface temperature ofan atmosphere is set at the effective level of LWIR emission to space takes place and the higher it is the greater said lapse rate can increase the atmosphere’s temperature on descent to the surface.
“altitude = 1 Bar the temperature is close to that of Earth’s surface.””
Actually not:
“AI Overview
In Venus’ atmosphere, at the altitude where the air pressure is exactly 1Bar – 50 to 53 kilometers above the surface, the temperature hovers around 75C.
The atmospheric lapse rate on Venus—the rate at which temperature decreases with altitude—is approximately 7.5 to 7.7 K/km”
SO:
51.5 x 7.6 =391 K
And +75K
=466K
Venus’ 14-16 um band radiance is about 120 W.m-2.sr-1. As a point of comparison Earth emits about 12 W.m-2.sr-1 in this band.
“AI Overview:
Venus’ extreme surface temperature—averaging around 467°C (872°F)—is caused by a runaway greenhouse effect. This is driven by an incredibly thick, carbon-dioxide-rich atmosphere that traps incoming solar heat and prevents it from escaping back into space. [1, 2, 3]
The main drivers of this intense heat include:
“
A few pertinent facts about Venus:
Atmospheric pressure is 95 times that of Earth
Has a retrograde rotation
It takes longer to rotate once on its axis than it does to orbit the sun
It has a high albedo as shown by its appearance as the brightest object in the sky
I speculate that if instead of Carbon Dioxide the atmosphere was made up of Nitrogen or Oxygen or Fluorine the surface temperature would still be significantly higher than that on Earth.
Mar’s atmosphere is also nearly 100% CO2, yet it is not a hot place. (There is more CO2 in Mar’s atmosphere than there is in the Earth’s.)
Because there is F all atmosphere.
Like gas molecules to collide with each other.
Surface pressure is around 6mb or 0.6% of Earth’s.
It also receives less solar SW fluctuating between 36% to 52% of Earth’s values.
That’s why it’s CO2 atmosphere does not exhibit a GHE.
Mars has significantly less 14-16 um radiation and a thin atmosphere. As a result its GHE is small.
Steven Goddard agrees … https://wattsupwiththat.com/2010/05/08/venus-envy/
Mark Twain observed, “The trouble with most of us is that we know too much that ain’t so.”
Adding to the “Δ33C without an atmosphere” (see other article) that completely ain’t so is the example of Venus.
Venus, we are told, has an atmosphere that is almost pure carbon dioxide and an extremely high surface temperature, 750 K, and this is allegedly due to the radiative greenhouse effect, RGHE. But the only apparent defense is, “Well, WHAT else could it BE?!” (besides/also molten core volcanism)
Well, what follows is the else it could be: (Q = U * A * ΔT) aka a contiguous participating media.
Venus is 70% of the Earth’s distance to the sun, its average solar constant/irradiance is about twice as intense as that of earth, 2,602 W/m^2 as opposed to 1,361 W/m^2.
But the albedo of Venus is 0.77 compared to 0.31 for the Earth – or – Venus 601.5 W/m^2 net ASR (absorbed solar radiation) compared to Earth 943.9 W/m^2 net ASR.
The Venusian atmosphere is 250 km thick as opposed to Earth’s at 100 km. Picture how hot you would get stacking 1.5 more blankets on your bed. RGHE’s got jack to do with it, it’s all Q = U * A * ΔT.
The thermal conductivity of carbon dioxide is about half that of air, 0.0146 W/m-K as opposed to 0.0240 W/m-K so it takes twice the ΔT/m to move the same kJ from surface to ToA.
Put the higher irradiance & albedo (lower Q = lower ΔT), thickness (greater thickness increases ΔT) and conductivity (lower conductivity raises ΔT) all together: 601.5/943.9 * 250/100 * 0.0240/0.0146 = 2.61.
So, Q = U * A * ΔT suggests that the Venusian ΔT would be 2.61 times greater than that of Earth. If the surface of the Earth is 15C/288K and ToA is effectively 0K then Earth ΔT = 288C. Venus ΔT would be 2.61 * 288 C = 748.8 K surface temperature.
All explained, no need for any S-B BB LWIR RGHE hocus pocus.
Simplest explanation for the observation.
(NASA planetary data sheet, engr tool box, first principles & math)
Yet when you compare Venus vs. Earth temperatures at the same density, the only thing required to differentiate the temperatures is the distance from the Sun.
All that CO2 makes Venus no hotter when you control for atmospheric density.
https://theendofthemystery.blogspot.com/2010/11/venus-no-greenhouse-effect.html?m=1
WUWT?
If energy counts the movement of particles
and Venus has more particles that can move
then Venus can have more energy.
but energy is not temperature.
Tony Heller agrees … https://wattsupwiththat.com/2010/05/08/venus-envy/
Venus has no water.
I suspect that pressure is the root cause here. However, not atmospheric but intracranial.
Re:
How is evaporation from the ocean affected when air pressure rises?
Will evaporation from the ocean decrease or increase?
Are there several self-correcting mechanisms that regulate temperature?
Rising temperature – increasing air pressure – decreasing evaporation.
Falling temperature – decreasing air pressure – increasing evaporation.
Increasing solar radiation – increasing evaporation.
Decreasing solar radiation – decreasing evaporation.
“Are there several self-correcting mechanisms that regulate temperature?”
Those that have attempted to climb Everest say it’s impossible to get a decent cup of tea or coffee at base camp, because water boils at 80ºC at that altitude. Even if you bring boiling water in a thermos flask from sea level, it cools the instant you take the cap off.
I would suspect that since increasing pressure means that there are more molecules per unit volume of air, that would imply that greater air pressure would mean the atmosphere could hold more water.
Rising temperature means more evaporation, not less.
I agreed with the Gas Law PVT relationship, as presented. However, I had a problem with the GHE addendum.
During a molecular collision, vibrational energy is transferred to kinetic energy.I have a problem with that. How does a photon jump from a molecule to then transfer its energy to movement in another molecule?
Another comment
If a molecule gains a photon, its mass will change (E=MC^2), its velocity will change (be slower -lower temperature).
Molecules that collide can still go through inelastc collisions without having to transfer energy of photons.
After saying all this, can someone explain to me why CO2 and chlorine tanks(both GHEs), don’t overheat in a storage facility
Heat in the atmosphere is transferred via three mechanisms:
Radiation, convection and conduction.
IR light is an electromagnetic wave with wavelengths ranging from about 780 nanometers (nm) to 1 millimeter (mm).
And as such cannot be BB.
“How does a photon jump from a molecule to then transfer its energy to movement in another molecule?”
A “photon” is nothing more than a quanta of energy. An inelastic collision conserves momentum although the kinetic energy content can change (mv1 + mv2) = (m1+m2)v_final. Kinetic energy can be transformed into heat, sound, deformation, etc. Energy *can* be transferred between the colliding objects, it’s a vector result, and it doesn’t *have* to be a photon amount of energy. The loss of kinetic energy can result in changes in vibration/rotation modes, in molecular structure, even a change in temperature without a “photon” quanta of energy being involved. Both objects can incur a loss of kinetic energy through it being converted to a different form (heat, sound, deformation, etc).
‘A “photon” is nothing more than a quanta of energy.’
That’s right. It’s amazing how effective the alarmists have been with their CAGW narrative that ‘photons’ are particles bouncing up and down through the troposphere, and that throughout this process, these particles are conserved rather than energy itself.
“Quantum” please! “Quanta” is the plural.
Since different amounts of energy are defined for individual “photons” based on the frequency associated with the photon, the term “quanta” is probably correct. Photon1 can have a different energy level than Photon2, thus two “quanta” of energy packets exist.
In fact, photons don’t actually exist inside a molecule, quantized energy states do. Collisions can result in the emission of photons in the form of an EM wave, or they can result in a change of the internal motions of the molecule, or they can result in a heat energy change of the molecule, or they can result in an exchange of kinetic energy.
No fair, you’ve been reading again.
I’m not even convinced that most CAGW supporters even understand the inverse square law. Photon density is proportional to 1/r^2. Photon density determines the flux crossing any point in space per unit time. If the surface of the earth emits 100 photons/ m^2-sec then at a height of 10 meters the density becomes 100/10^2 or 1 photons/m^2-sec.
What doesn’t change is the photon density per sterradian. W/(m^2)(sr) This is called the “radiance”. (the steradian is the solid angle extending from a point. the area subtended by a steradian expands with distance thus offsetting the 1/r^2 factor)
The radiance from the earth to space is a continuous, constantly-changing variable based on energy input and energy output from each and every point on the earth. All kinds of things affect the radiance from any point including cloud cover, surface composition, and atmospheric composition. Atmospheric composition causes path loss from things like scattering, absorption, etc and is different and varying all over the globe.
We simply do not have a sufficient measuring system (e.g. CERES) to capture all of this information with a small measurement uncertainty interval. The measurement uncertainty interval is *NOT* based on the number of samples but on the accuracy of the data and the capability to capture the variability of the phenomena around the globe over time.
Converting radiance measurements to “flux” ADDS even more measurement uncertainty. And then trying to develop some kind of “flux balance” for the globe from this is even worse.
I would love to see a Joules-in vs Joules-out radiative balance calculation over a year, a decade, a century, and millennium along with an objective measurement uncertainty budget.
Bingo!
“Photon density is proportional to 1/r^2. Photon density determines the flux crossing any point in space per unit time. If the surface of the earth emits 100 photons/ m^2-sec then at a height of 10 meters the density becomes 100/10^2 or 1 photons/m^2-sec.”
Nonsense! The Earth’s radius is ~6,400km so the ratio would be 6400/6400.001, a minuscule reduction.
The radius of the radiation sphere starts at the point of radiation and NOT at the center of the earth!
The center of the earth as the point where GRAVITY originates is useful but only an abstraction.
Radio and TV stations don’t calculate their EM antenna field strengths based upon the distance from the center of the earth. They use the point of emission.
An EM wave emitted by a CO2 molecule starts at the location of the molecule, not the center of the earth.
You said: “If the surface of the earth emits 100 photons/ m^2-sec then at a height of 10 meters the density becomes 100/10^2 or 1 photons/m^2-sec.”
Then you qualified it by saying: “The radius of the radiation sphere starts at the point of radiation and NOT at the center of the earth!”
Your post to which I was responding didn’t say that the radiation was from a single point on the Earth’s surface.
“An EM wave emitted by a CO2 molecule starts at the location of the molecule, not the center of the earth.”
Not relevant, the excited CO2 molecule would emit a single photon in a random direction, the energy of that photon will not change with distance from the source!
First, a molecule does not emit a photon particle that goes off in a given direction. A molecule emits an EM wave with the energy of a photon.
The energy in the EM wave is spread over ever-expanding spheres. This reduces the energy at any given radius from the point of origin. As the radius doubles, the energy is reduced by 1/r².
“First, a molecule does not emit a photon particle that goes off in a given direction. A molecule emits an EM wave with the energy of a photon.
The energy in the EM wave is spread over ever-expanding spheres.”
No it does not, it’s clear you don’t know anything about the subject! I suggest you read a freshman Physical chemistry text.
From
29.3: Photon Energies and the Electromagnetic Spectrum – Physics LibreTexts
Hmmm! Frequency. Wavelength. What do these terms have to do with? Oh, right, EM waves.
“Your post to which I was responding didn’t say that the radiation was from a single point on the Earth’s surface.”
ROFL!!! So you assumed the radiation was from the center of the earth?
“Not relevant, the excited CO2 molecule would emit a single photon in a random direction, the energy of that photon will not change with distance from the source!”
The emission of the excited CO2 molecule is an EM wave, not a bullet. A photon is just a quanta of energy. How much energy is in the emitted EM wave? (Hint: joules vs joules/sec-m^2)
““Your post to which I was responding didn’t say that the radiation was from a single point on the Earth’s surface.”
ROFL!!! So you assumed the radiation was from the center of the earth?”
No I assumed it was from the surface of a sphere!
“The emission of the excited CO2 molecule is an EM wave, not a bullet. A photon is just a quanta of energy. How much energy is in the emitted EM wave? (Hint: joules vs joules/sec-m^2)”
No the emission from an excited CO2 molecule is a single photon with the energy equal to the difference between the excited energy level and the ground state (~1.33×10^-23 kJ/photon).
If it originated from the surface, then how did the radius of the earth enter into the calculation?
The energy contained in the EM wave that carries the energy of the photon is E=hf=hc/λ, f=frequency and λ=wavelength. Those are both characteristics of an EM wave.
Yeah. I’m aware of that. My question was about the AGW ‘consensus’, that on collision, the vibrational energy is transferred to the molecule, thereby causing it to move faster (get hotter).
The ejected/transferred photon energy must be the same as that absorbed. You can’t have a partial vibrational state (you can’t be partially pregnant). This photon energy (wavelength) that is normally invisible to the other molecule can suddenly interact with that photon.
That is the part that I want explained.
“The ejected/transferred photon energy must be the same as that absorbed. “
Why?
The emitted radiation from a black body doesn’t have to have the same photon energy as the absorbed energy it receives. What gets emitted is based on the temperature of the black body and the temperature of a black body doesn’t have to match the temperature of the absorbed radiation.
Your statement requires two objects in temperature equilibrium. There is no physical requirement that an equilibrium state always exists between two objects.
Kinetic energy transferred to molecule1 from molecule2 does *NOT* have to be quantized. If the kinetic energy received by molecule1 exceeds the energy needed to change the vibrational mode to the next qantized state the excess kinetic energy can affect other characteristics of the molecule such as translational speed, rotational speed, etc.
If the molecule emits radiation due to a quantized vibrational level decrease then it emits a photon of that energy change. But the energy the molecule emits does not have to be the same as the amount of kinetic energy absorbed due to a collision.
A gas is not a blackbody.
“A gas is not a blackbody.”
So what? That makes your statement “The ejected/transferred photon energy must be the same as that absorbed.“ even more non-physical for a gas.
If a volume of gas doesn’t have to emit at the same temperature as absorbed energy quanta then a single molecule of that gas doesn’t have to either.
It’s a rotational/vibrational state where the separation of the rotational energy levels is much smaller than that of the vibrational levels, each vibrational level has an associated set of rotational energy levels close to it. Typically absorption of IR radiation by a CO2 molecule in the atmosphere excites the bending mode of the molecule, a collision with a N2 molecule can deactivate the bending motion and transfer that energy to the kinetic energy of the N2 molecule while the vibrational energy of the CO2 molecule returns to its ground state.
Think of it like a pendulum, collision of the pendulum ball with another object can stop the pendulum swinging and increase the kinetic energy of the other object.
I’m not trying to be picky. I have read elsewhere that it is the rotational energy that is transferred, but you mention that the CO2 molecule returns to ground state. It (the energy) can’t just disappear. Is the vibrational energy emitted and the rotational energy ‘transferred’?
The vibrational (bending mode) and rotational energy can both be transferred via collisions, a much more rapid process near the Earth’s surface than re-emission. Typically an excited CO2 molecule is in the first vibrational state with minor associated rotational states.
Who said that the transfer of energy from one molecule to another can only be done via photons?
Does the energy of the photon transform to mass, or to a different form of energy? My understanding is that the photon increases the rotational energy of the molecule that captures it.
You seen to think that all the energy that goes into a tank of CO2, stays there forever, constantly getting hotter. You are ignoring the effects of thermal conduction.
I said the tank doesn’t get hot.
Because they usually have refrigerant cooling systems mounted on them.
Of course. Silly me.
Actually, it is not pressure plus absorbed solar energy that creates the enhanced surface temperature above that expected from the S-B equation.
One has to add convective overturning of the atmosphere.
I have tried to explain that previously to Roy and others who countered by saying that there can be no such overturning in a transparent atmosphere free of radiative characteristics.
That is their blind spot.
Convective overturning will occur even in a fully transparent non radiative atmosphere because of uneven surface heating in the horizontal plane around the planet.
Once convection begins there will be a delay in the loss of energy to space due to the time taken for KE (heat) to convert to PE (which is not heat and cannot radiate) in the rising columns and PE back to KE in the descending columns.
That delay causes a build of of total energy (KE plus PE) within the system and thus a rise in surface temperature.
Radiative characteristics in the atmosphere not required.
When criticising a proposition any critics should take care to first get the proposition right and in this case they do not.
The mass of the atmosphere increases as air pressure increases.
An increase in atmospheric mass can hold more thermal energy.
More atmospheric mass reduces temperature variations between day and night, creating a more stable and moderate climate.
More mass leads to more KE plus PE which leads to a longer delay in emission of solar energy to space thus a higher surface temperature.
Despite the harsh conditions on the surface of Venus and the composition of the atmosphere, at around 50 km to 65 km above the surface of the planet, where the atmospheric pressure is close to Earth’s surface pressure, temperatures are also close to those of the Earth’s surface.
Is it the combination of air pressure and atmospheric density that creates the Earth’s temperature?
A given atmospheric density absorbs a certain amount of thermal radiation that creates the Earth’s temperature.
If the atmospheric density decreases, the temperature decreases.
If the atmospheric density increases, the temperature increases.
If the atmospheric density decreases, the amount of solar radiation that reaches the Earth’s surface increases.
If the atmospheric density increases, the amount of solar radiation that reaches the Earth’s surface decreases.
Is ocean temperature affected by atmospheric density?
Yes, it looks like temperature is related to atmospheric pressure.
Venus is a good example.
Mark Twain observed, “The trouble with most of us is that we know too much that ain’t so.”
Adding to the “Δ33C without an atmosphere” (see other article) that completely ain’t so is the example of Venus.
Venus, we are told, has an atmosphere that is almost pure carbon dioxide and an extremely high surface temperature, 750 K, and this is allegedly due to the radiative greenhouse effect, RGHE. But the only apparent defense is, “Well, WHAT else could it BE?!” (besides/also molten core volcanism)
Well, what follows is the else it could be: (Q = U * A * ΔT) aka a contiguous participating media.
Venus is 70% of the Earth’s distance to the sun, its average solar constant/irradiance is about twice as intense as that of earth, 2,602 W/m^2 as opposed to 1,361 W/m^2.
But the albedo of Venus is 0.77 compared to 0.31 for the Earth – or – Venus 601.5 W/m^2 net ASR (absorbed solar radiation) compared to Earth 943.9 W/m^2 net ASR.
The Venusian atmosphere is 250 km thick as opposed to Earth’s at 100 km. Picture how hot you would get stacking 1.5 more blankets on your bed. RGHE’s got jack to do with it, it’s all Q = U * A * ΔT.
The thermal conductivity of carbon dioxide is about half that of air, 0.0146 W/m-K as opposed to 0.0240 W/m-K so it takes twice the ΔT/m to move the same kJ from surface to ToA.
Put the higher irradiance & albedo (lower Q = lower ΔT), thickness (greater thickness increases ΔT) and conductivity (lower conductivity raises ΔT) all together: 601.5/943.9 * 250/100 * 0.0240/0.0146 = 2.61.
So, Q = U * A * ΔT suggests that the Venusian ΔT would be 2.61 times greater than that of Earth. If the surface of the Earth is 15C/288K and ToA is effectively 0K then Earth ΔT = 288C. Venus ΔT would be 2.61 * 288 C = 748.8 K surface temperature.
All explained, no need for any S-B BB LWIR RGHE hocus pocus.
Simplest explanation for the observation.
(NASA planetary data sheet, engr tool box, first principles & math)
Agree.
The reason Venus pressure is so high is because of the temperature. The temperature as you say, at 50km height is the same as earth. At this height the planet has sulphuric acid clouds which circle the planet, which reflect and also absorb the suns radiation (2,660 W/m2). This heating of the clouds (approx. 500 W/m2) produce the super rotational winds which circle the planet (100m/s). When these winds reach the night side, these winds have dropped down to 30km. This downwelling of the winds (atmosphere) at an adiabatic lapse rate of 10.8 C/km gives you the temperature on the surface of 465c. The temperature of Venus has nothing to do with a runaway greenhouse effect, it is the work done by gravity on the atmosphere. All this data can be found by looking at there data on Japanese probe Akatsuki.
“where the atmospheric pressure is close to Earth’s surface pressure, temperatures are also close to those of the Earth’s surface.”
Not exactly, at 50km where the pressure is about 1atm the temperature is about 75ºC!
He forgot the adjustment for the distance from the Sun.
When adjusted for the distance from the Sun.
This I have a problem with. If you mean the mass contained within a given volume at the surface of the earth, I would agree that compression increases the amount of gas in a given volume. However, pressure does not by itself add atmosphere molecules to the total mass.
Evaporation adds molecules to the atmosphere.
Volcanoes release gases into the atmosphere.
Burning coal adds molecules to the atmosphere.
Through decomposition and the nitrogen cycle, fungi and bacteria break down dead organic matter and release nitrogen back into the ecosystem as ammonia or atmospheric nitrogen.
Would you consider that there are more molecules per cubic meter at sea level than at 1000 meters above?
“That delay causes a build of of total energy (KE plus PE) within the system and thus a rise in surface temperature.”
Earth is a heat sink, be it ocean or land. That introduces another avenue of delay in heat transfer. It also modulates the effect of rising/falling atmosphere columns.
It’s far more complicated than a simple radiative in/out balance.
“The atmosphere would eventually become isothermal (or nearly so, since there might be some planetary scale overturning between the tropics and the poles, due to their different rates of solar input), with the same temperature as the surface.”
This is nonsense.
Due to the spherical/ uneven geometry of a planet the amount of solar energy hitting any given location at any given moment is never the same, Add a spin, rough surfaces with mountains and valleys and movement around the energy source and that compounds the phenomenon of uneven surface heating. It is not just an issue of tropics and poles but between every point on the surface all around from moment to moment all the time.
An unevenly heated surface will create parcels of air of different densities adjacent to each other at the surface and the less dense parcels will rise.
After a while a permanent pattern around the planet will arise such as on Earth with the distribution of our Hadley, Ferrel and Polar cells.
That is going to happen even if there are no radiative materials in the atmosphere at all.
It is not necessary for energy loss to space from within the atmosphere to occur for stability to be maintained.
Such radiative materials will cause local disturbances in the lapse rate which automatically affects convection speeds by changing the relative densities of adjacent parcels of air all around the planet.
The net outcome is to change the speed at which KE is returned to the surface by downward convection for radiation to space.
It is that change in speed in returning KE to the surface that neutralises the potential thermal effect from radiative materials so as to maintain the presence of the atmosphere indefinitely.
An isothermal atmosphere in the absence of radiative characteristics is an impossibility.
Do you have a counter argument, Roy? Would love to see it.
There’s no appreciable spin on Venus, its rotational period (day) is 243 earth days and its year is 224 earth days.
Margot et al (2021) state “Venus is tilted by 2.6392 ± 0.0008 degrees (1σ) with respect to its orbital plane. The spin axis precesses at a rate of 44.58 ±3.3 arcseconds per year (1σ), which gives a normalized moment of inertia of 0.337 ±0.024 and yields a rough estimate of the size of the core. The average sidereal day on Venus in the 2006–2020 interval is 243.0226 ± 0.0013 Earth days (1σ). The spin period of the solid planet exhibits variations of 61 ppm (∼20 minutes) with a possible diurnal or semidiurnal forcing. The length-of-day variations imply that changes in atmospheric angular momentum of at least∼4% are transferred to the solid planet.”
Margot, JL., Campbell, D.B., Giorgini, J.D. et al. Spin state and moment of inertia of Venus. Nat Astron 5, 676–683 (2021)
According to Sanchez-Lavega et al 2017, the Venusian atmosphere rotates some 60-80 times faster than the planetary body.
Sánchez-Lavega, A., Lebonnois, S., Imamura, T. et al. The Atmospheric Dynamics of Venus. Space Sci Rev 212, 1541–1616 (2017)
The Venusian atmosphere consists of 96.5% carbon dioxide and 3.5% Nitrogen. At ground level the pressure is sufficient to turn the atmosphere into a supercritical fluid consisting primarily of supercritical Carbon Dioxide with some supercritical Nitrogen.
Venus has no intrinsic magnetic field like the Earth, but does possess an induced field caused by interaction between the solar wind and the atmosphere.
The presence of spin is not an essential feature. It is just another factor that prevents surface heating from being evenly distributed.
Hope you don’t mind me asking, but are you a Co-author of this paper? The Venusian Insolation Atmospheric Topside Thermal Heating
Yes
Wilde: The theory of yours and Mulholland have many similarities, but also some differences, to the N&Z theory that Spencer is discussing here. What will yoy say is the main differences and similarities compared to N&Z?
Pravda Pundit,
Stephen Wilde and I (Philip Mulholland) have developed a dynamic, circulation-focused framework that emphasises atmospheric mass movement, adiabatic processes, and the redistribution of heat via convection and winds. This work highlights how the atmosphere acts like a heat engine, with descending air returning kinetic energy to the surface and how changes in lapse rate or circulation speed can neutralise potential warming from radiative gases.
Main similarities with N&Z (Nikolov & Zeller):
Both reject the idea that the atmosphere would become isothermal in the absence of radiative gases.Both stress the critical role of atmospheric pressure/mass and adiabatic compression/expansion in setting the temperature profile.Both argue that the standard greenhouse gas narrative overstates the direct radiative role of trace gases and understates mechanical/thermodynamic processes.Key differences:
N&Z focus primarily on an empirical pressure-temperature relationship across planets, proposing that surface temperature is largely a function of total atmospheric mass, solar input, and pressure (with the greenhouse effect being a minor or mischaracterised factor).Wilde/Mulholland place stronger emphasis on ongoing dynamic processes — uneven solar heating, horizontal density gradients, permanent circulation cells (Hadley, Ferrel, Polar), and the speed of convective overturning. We see the atmosphere as an active heat redistribution system rather than a static pressure-determined one. This approach is more process-oriented and less reliant on a single empirical formula.Building on the framework of Stephen’s prior studies, my own current work on the Dew-Point Anchor Hypothesis (DPAH) shares some common ground with both. It treats the lifting condensation level (LCL) of the dominant condensing volatile (water on Earth, sulfuric acid on Venus) as a primary thermodynamic anchor. This provides a physically observable boundary condition that helps constrain the vertical structure and preferred equilibrium states, while still respecting energy balance and dynamic circulation.
For the Venus application (relevant to the isothermal discussion), see my latest Zenodo deposit: Dew-Point Anchor Hypothesis (DPAH) Markovian Stochastic Modelling of the Venus Atmosphere: Inverse Paradigm Anchored at Sulfuric Acid LCL Cloud Deck
This work explores how anchoring at the cloud deck (rather than the surface) produces realistic vertical profiles and super-rotation without requiring an isothermal outcome.
Happy to discuss further — these debates are healthy and help clarify the real physics.
Stephen Wilde makes a very good point here. The idea that a planetary atmosphere without radiative gases would inevitably become isothermal ignores the fundamental reality of uneven solar heating on a rotating, spherical planet with varied terrain. Horizontal temperature (and thus density) gradients will always drive circulation — Hadley/Ferrel/Polar cells on Earth, or super-rotating flows on Venus — regardless of whether the atmosphere can radiate IR. Convection and advection are inevitable consequences of geometry and rotation.
Dr. Spencer’s thought experiment is useful for illustrating energy balance principles, but real planetary atmospheres are far more dynamic. The persistence of strong circulation and non-isothermal profiles even in highly opaque atmospheres like Venus supports the view that dynamic processes anchored by condensation levels play a central role.
I’ve been developing a complementary framework called the Dew-Point Anchor Hypothesis (DPAH). On Venus, it applies an inverse approach: treating the sulfuric acid lifting condensation level (LCL) cloud deck as the primary thermodynamic anchor, rather than starting from surface temperature. This produces stable vertical structure and circulation patterns consistent with observations.
My most recent open-access deposit explores this specifically:
Dew-Point Anchor Hypothesis (DPAH) Markovian Stochastic Modelling of the Venus Atmosphere: Inverse Paradigm Anchored at Sulfuric Acid LCL Cloud Deck
It suggests that the dominant condensing volatile (sulfuric acid) serves as the key boundary condition governing the atmospheric column — similar in spirit to how Stephen’s ideas emphasize dynamic heat redistribution over purely radiative assumptions.
Would be interested in thoughts from Stephen Wilde, Roy Spencer, or others on how these anchoring concepts might reconcile or extend the discussion.
H2O effects the lapse rate…. There are nice formulas for doing the calculation.
CO2 does not. !
If anyone thinks it does, please produce the lapse rate formula based on CO2 concentration.
“Because the greenhouse effect is a necessary consequence of that absorption/emission. Energetically, the GHE is a radiative insulator. It’s analogous to adding insulation to a heated building’s walls in winter.”
I disagree with the author in the use of a passive insulating layer analogy. This is most unfortunate in the long-running promotion of the poorly named “greenhouse effect” as a talking point within the “climate” debates. The strength of the emission of longwave energy to space is a product of dynamic operation as the atmosphere performs powerfully as the compressible working fluid of its own circulation. The most obvious factor is the active formation and dissipation of clouds, related to weather systems, in which rising air or descending air dominates.
So let’s please retire the use of a static (passive) “insulator” concept to explain the suppression of longwave energy to space. The overall result comes from an integration over time and location of highly variable values.
From last Sunday’s “open thread” for more elaboration on this point:
https://wattsupwiththat.com/2026/05/24/open-thread-191/#comment-4198292
Thank you for listening.
“The overall result comes from an integration over time and location of highly variable values.”
100%!
You simply cannot decouple the heat sink that land and ocean present for heat loss/gain from radiative heat loss/gain. Both are time functions and the relationship is highly variable. Integration has to be done over at least centuries if not longer.
‘I disagree with the author in the use of a passive insulating layer analogy.’
As we all should.
To accept this fundamental tenet of ‘lukewarmerism’ is to accept without question the AGW narrative that any and all human emissions of CO2 will inevitably result in raising Earth’s average surface temperature. Fortunately, we know from extensive studies of carbonate and ice cores that past variations in atmospheric CO2 concentration, that dwarf anything we could effect from burning fossil fuels, have had no impact on temperature.
Hence, the only logical conclusion that can be drawn from these studies is that there is a significant problem with the conjecture that the phenomenological physics of radiant transfer theory realistically explains how the bulk of the energy emitted by the Earth’s surface is transported through the troposphere.
The earth is a house covered in open windows (i.e. radiative loss vs conductivie loss). Adding insulation in the walls of the house won’t change the temperature inside the house much if at all. The temperature is going to be set by how fast the furnace can input heat into the house vs how much heat goes out the windows.
“Fortunately, we know from extensive studies of carbonate and ice cores that past variations in atmospheric CO2 concentration, that dwarf anything we could effect from burning fossil fuels, have had no impact on temperature.”
What about that, Roy? If CO2 raises the Earth’s temperature enough to notice, then why is it that much larger concentrations of CO2 (7000ppm versus 430ppm today) in the past did not cause a noticeable rise in Earth’s temperatures?
There does not seem to be a connection between increased CO2 and increased temperatures. Nothing we can measure, at any rate.
This is a discrepancy that has not been explained.
And there are further discrepancies.
Like CENTURIES of REVERSE CORRELATION at every inflection point, and the fact that temperatures begin to RISE when CO2 is (a) FALLING and (b) near its LOW point, and temperatures begin to FALL when CO2 is (a) RISING and (b) near its HIGH point.
All of which suggests atmospheric CO2 is a non-factor in “driving” climate change.
Yes I still await a meaningful response to how the Earth experienced GLACIATION with ten times today’s atmospheric CO2.
CO2 is a non-factor.
A GHE in Phoenix is quite different than a GHE in Nome.
“But in the real world, convective overturning is the RESPONSE to this GHE destabilization! So, that 33 deg. GHE warming people talk about? That’s not the GHE. It’s the GHE + CONVECTION.”
It’s GHE + Convection + CONDUCTION.
The earth, both land and ocean, present as heat sinks whose mode of heat transport is conductive. The operation of those heat sinks is intimately coupled with atmospheric convection and with radiative flux from the earth’s surface through the atmosphere.
RGHE theory says “288 K (15 C) w – 255 K (-18 C) w/o = a 33 C colder ice ball Earth.” 255 K assumes w/o case keeps 30% albedo, an assumption akin to criminal fraud. Nobody agrees 288 K is GMST plus it was 15 C in 1896. 288 K is a physical surface measurement. 255 K is a S-B equilibrium calculation at ToA.
That “not-so-innocent” redacted fellow is Ned Nikolov.
Having noticed the inverse correlation between altitude and air temperatures, and not believing in the so-called “greenhouse effect,” Ned concluded that atmospheric pressure determines surface temperatures. Consequently, he believes that, over glaciation cycles, about 1/3 of the Earth’s atmosphere must have alternately vanished and reappeared.
I’m not kidding, that’s really what he contends.
I was one of the participants in that email conversation with Ned & Roy. Several of us tried patiently to explain to Ned the problems with his hypothesis, to no avail.
Instead, he prevailed on Roger T. to post his nonsense on Roger’s blog, here:
https://tallbloke.wordpress.com/2026/05/23/discussion-between-roy-spencer-and-ned-nikolov-about-the-n-z-climate-concept/
I’ve tried twice over the last week to comment there, but Roger seems to be blocking comments critical of Ned’s hypothesis. I’m mildly disappointed that Roger T. published such silliness, but I’m extremely disappointed that he’s apparently censoring the comments to prevent rebuttal of of it. Aside from a quibble over the hypothetical adiabatic lapse rate on an imaginary Earth with no GHGs, Ned is wrong about almost everything.
A few years ago, Roger understood that Ned’s hypothesis is impossible. Roger wrote to Ned:
Roger was right, but now he seems to have forgotten what he then understood.
The following is a slightly edited version of the first of the two comments which I attempted to post on Roger’s blog, a week ago:
——– BEGIN UNAPPROVED COMMENT ——–
When I first read of Nikolov & Zeller’s machinations to get their paper published—spelling their names backward to dodge a blacklist—I was inclined to be sympathetic. But it turns out that their work is just really bad.
Ned Nikolov says (and Karl Zeller presumably agrees) that, repeatedly over the last 780K years, roughly 1/3 of the Earth’s atmosphere somehow vanished and then reappeared, then vanished and then reappeared, repeatedly over glaciation cycles. That’s physically impossible, but Ned insists that it must have happened, because he’s sure that temperatures are controlled by air pressure.
Here’re a couple of other rebuttals of that nonsense:
● https://www.drroyspencer.com/2018/12/giving-credit-to-willis-eschenbach/
● https://www.quora.com/Did-Nikolov-and-Zeller-prove-that-atmospheres-warm-planets-only-through-pressure-and-not-as-a-result-of-greenhouse-gases/answer/Bob-Wentworth
This is Ned’s graph, captured as a screenshot from one of his videos (here), except that I added the pink annotations, and pruned the lefthand part:
When I challenged Ned over the impossibility of the Earth repeatedly losing and then recovering 1/3 of its atmosphere over the last 780K years, without even affecting the N2:O2:Ar ratio, he defended his claim with hand-waving. He wrote (here’s a screenshot):
In reply, I pointed out that at the current rate of atmosphere loss it would take eleven times the age of the universe for 33% of the Earth’s atmosphere to be lost to space (screenshot).
Ned ignored that.
I tried again, saying (screenshot):
Ned replied (screenshot):
In other words, Ned just doesn’t care that what he believes is impossible.
——– END UNAPPROVED COMMENT ——–
I warned Willie Soon about this Nikolov three years ago. Willie and CERES have been dragged down by Nikolov and Scaffeta and it pains me. Willie’s a good guy and been dragged down by these people.
Willie should have known better. It’s unfortunate.
There is no oxygen in the atmosphere at the time of the snowball earth period.
That Nikolov graph went back only 780,000 years (and the part I showed only goes back 500K years). During all of that period, O2 levels were nearly identical to now.
If you go back billions of years (or even hundreds of millions of years), conditions were, indeed, quite different. What’s your point, Victor?
Nitrogen and oxygen decrease during ice ages.
https://www.science.org/doi/10.1126/sciadv.abj9341
The point is that 1/3rd of the atmosphere presumably disappeared, their discussions take the current composition of the atmosphere as a given. Back during the Ice Ball Earth episode (episodes?), presumably the ratio at that time would have disappeared.
By molar fraction, the Earth’s dry atmosphere is currently about 21% O2.
By molar fraction, 800K years ago the Earth’s dry atmosphere was about 21% O2.
The differences which that paper discusses are tiny: something like 21.1% vs. 20.95% of the atmosphere, over 800K years.
In contrast, Ned claims that the atmosphere increased in total mass by about 50% over only about 10K years.
So 130,000 ppm?! Didn’t think it was ever more than 7,000 ppm.
Still no “runaway greenhouse effect” though! And we’re supposed to shake in our boots over ~420 ppm?! 🤣
If 1/3rd of the atmosphere were to disappear, that would mean that the partial pressure of O2 in the atmosphere would also decrease by 33%. That would have a huge impact on anything that needs O2 in order to survive, it would also make life impossible in many mountains.
Ditto for CO2 and plants.
All true.
I’m really all for de-bunking junk science. Now, if we can only get our climate scientists to stop conflating the thermal radiative properties of condensed matter with those of GHGs in order to model atmospheric ‘slabs’ as a series of black body radiators. Doing so would not only advance the science beyond the phenomenological physics of applying radiant transfer theory to explain energy transport through the troposphere, but would also eliminate one of the bigger ‘hooks’ the Left relies upon to overthrow (classical) liberalism, i.e., the demonization of fossil fuel use.
Please would someone explain what this paper is suggesting as I am unable to fully or even partially understand it!
https://arxiv.org/pdf/1806.06835
Sun heats the surface.
Surface heats the air.
In a closed system when T increases P must increase.
T causes P.
Agreed, and vice-versa in a closed system. It is by this principle that diesel engines work. But our atmosphere is open to space, so an increase in T will cause E (expansion). Expansion of the atmosphere on a planetary scale will be imperceptible, but will have a compensatory cooling effect.
The earth isn’t a closed system, the atmosphere can expand into space, keeping pressure the same.
Except that the Earth’s atmosphere IS NOT in a “closed system”.
It is not contained in a box an is free to expand upwards when heated.
Is this relevant https://www.space.com/space-exploration/satellites/solar-activity-space-junk-crash-earth-faster ?This states “After linking the space-junk trajectories to the long-term solar data, the researchers found that increased solar activity boosted atmospheric density around the space junk. This created more drag, which slowed the debris pieces’ orbit and sped up their descent.“
The paper itself can be found here.
https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2026.1797886/full
Back in 1979, when Skylab came back to Earth (sorry about that Australia.) I read several articles about how it was coming down sooner than expected because NASA had not anticipated how much a solar maximum could heat and expand the upper atmosphere. NASA was planning a rescue mission to boost Skylab to a higher orbit, but it wasn’t ready in time.
Fondly recalling the John Belushi skit on the SkyLab “landing.” 🤣😂
Dr. Spencer,
I have a problem with your description of an insulator. An insulator on the warm side will warm to the temperature of the room, surface, etc. It cools to the cold temperature on the cold side. The inside of the insulator is akin to a resistance against heat flow and warms just like a resistor in an electrical circuit does.
The question becomes can an insulator become warmer than the hot side and thereby increase the temperature of the warm side? Most engineers have been trained to say that can’t happen. Heat flow basically is determined by Th-Tc. When the two are in equilibrium, Th = Tc, there is no longer any flow of heat occurring. Tc cannot exceed Th unless external energy is added. Tc becoming hotter than Th via accumulating heat is impossible. That would be reversing entropy without additional work.
How then does the GHG insulator lose heat. Two ways, via radiation and conduction to non-radiating molecules, i.e., a heat sink. Can the heat sink exceed the temperature of the GHG layer? Again, not possible. Is heat stored for later release, sure.
Lastly, energy in equals energy out is way too simple. It ignores the fact that there is an intermediate step involved, the surface, both oceans and land. Oceans can store heat for months, years, even centuries. Some of the that energy will not be seen at TOA in our lifetimes. Land probably doesn’t have the long term storage but it does store heat over spring and summer through diffusion and releases that heat in fall and winter. This tends to lower the average energy out versus energy in. As you should know by now, arithmetic averaging is one of my pet peeves. It is why I learned calculus up to vector calculus so time varying phenomena could be accurately addressed.
When more insulation is applied, the outside will initially fall in temperature as the heat flow through the wall is reduced.
As the temperature inside the room increases, the rate of energy moving through the wall increases until the flow is large enough to balance the heat being added to the room.
Once the heat flow returns to the pre-insulation increase levels, the temperature of the outside of the will also return t pre-insulation increase levels.
The earth isn’t a closed house with a furnace inside and the only heat loss is conductive loss through the walls. It’s a house covered in open windows (radiative heat loss). Adding insulation to the walls won’t change the temperature in the house very much. The furnace will still be fighting the heat loss through the open windows as the main factor determining the temperature inside the house.
Not a valid analogy, because in the atmosphere, heat that is trying to escape through a wall can’t slide over an leave through a window.
Photons do not have the ability to change their wavelength.
No, convection goes through the wall, radiation is like inside air escaping through a hole in the wall.
Insulation in the wall will impact heat convection through the wall but won’t affect the flow of the inside air out the hole.
Heat trying to leave via convection through the wall can certainty escape through the hole that is a window. Heat isn’t a solid the size of the house wall.
Convection and radiation are two different paths. It’s no different than hooking a wire to a resistor and then to the battery and hooking a wire to the battery without a resistor. The resistor in the one wire (the wall) won’t affect the current flowing in the wire without the resistor (the window).
It’s why, when IR imaging a house, you get a different reading from the wall of the house than you do from a leaky window. If the heat can’t escape through the leaky window then window companies like Pella would see a big drop in their business.
Changing the transmission characteristics of the windows will alter the temperature inside, which is what CO2 does to the atmosphere.
“Changing the transmission characteristics of the windows”
And what does this have to do with the earth/atmosphere/space thermodynamic system as far as GHE impact is concerned? Adding insulation to the walls is *NOT* changing the windows in any way.
Worse – this “house” not only has open windows, but has no furnace or boiler warming it from the inside, but only the Sun warming it from outside.
NOW think of how meaningless “adding insulation” to the walls is!
“Heat flow basically is determined by Th-Tc.”
This is correct. And note that there is no need for any “gross heat” or “net heat” in this description. So I assume we won’t hear you mumbling any of that nonsense any more. Right, Jim?
“When Th = Tc, there is no longer any flow of heat occurring.”
Correct. Including “gross” heat. Right, Jim?
The vertical circulation of the atmosphere due to water evaporation and condensation functions as a solar powered heat pump in phase with the day night cycle.
Even in a perfectly dry atmosphere, there will still be vertical circulation, caused by the temperature difference between the surface and the interface to space.. The presence of liquid water on the surface greatly enhances this circulation.
GRAVITY causes Pressure ( mass * temperature ) .
And the adiabatic exchange of Gravitational potential an thermal kinetic+radiant energy , keeping total energy density constant , as required by conservation of energy , causes the temperature gradient , aka lapse .
It’s the same energy it takes to lift a rocket to orbit .
The gradient extends to the cores of planets .
Convection is the effort of heated areas to try to realign with the adiabatic gradient .
Like pressure it is an effect , not a prime cause .
See also https://cosy.com/y23/Sat.Feb,20230204.html discussing Robert Holmes work .
But , I have yet to see a computation of the radiative equilibrium temperature of the planet from the ~ 278.7+-2.3 gray body temperature around our orbit , and even a single
lumped Schwarzschildcolor spectrum of the planet , https://cosy.com/y26/NL202603.html#278.7+-2.3 . And until one can present a calculation of the equilibrium temperature of that envelope , quantitative understanding of the gradient within , which must match that envelope , is not possible .The idea that gravity causes temperature is itself a violation of conservation of energy.
Where does the energy needed to maintain temperature come from. Gravity is not energy.
Are you seriously trying to claim that the reason why the Earth’s core is hot is because of gravity?
If so, please explain why Mars’ core cooled off. Did gravity around Mars decrease?
“The idea that gravity causes temperature is itself a violation of conservation of energy.”
No one said that “gravity causes temperature”. The actual argument is that gravity creates a PE gradient. At equilibrium, with non-zero energy present in the system, this must be opposed by some other gradient – for example, a KE one. I.e. temperature.
Now what does the Second Law of Thermodynamics tell us, Professor?
Imagine you used solar energy to run an enormous planetary scale heat pump with the low pressure cold coils at altitude and the high pressure warm coils at sea level. This would create an atmospheric lapse rate where the upper atmosphere was cold and the surface was hot.
It isnt pressure that does the warming. It is the circulation of the working fluid against a pressure gradient that pumps heat from cold to hot. Ammonia refrigeration and mechanical heat pumps all use evaporation and condensation to pump heat against a gradient, as does the earth’s atmosphere.
“ALONE, WITHOUT ANY CONVECTIVE OVERTURNING would result in an extremely steep tropospheric lapse rate”
When convection breaks down, like with high latitude winter, lapse rate and GHE shrink.
On the other hand, continuing to believe in things after they have been disproven, is stupid.
What do you call your continued belief in an “exception” to the Second Law of Thermodynamics, Professor? Would you call that “stupid” too?