While CO2 warming effects have raised earth’s temperature to present levels, CO2’s absorbed wavelengths are saturated. More CO2 will have reduced warming effects going forward. On the other hand, more CO2 increases collisions with O2 and N2 allowing those air molecules to release heat absorbed from conduction with the ground to be radiated back to space.
Those cooling effects offset warming, reduce dangerous inversion layer heating, and maintain a balanced climate.
Jim Steele is Director emeritus of San Francisco State University’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and proud member of CO2 Coalition
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Jim:
I may be misinterpreting your argument but are you saying that because “CO2 is saturated for dominant wavelengths”.
Then the GHE is not going to give continued increases in forcing of equivalence for each doubling of concentration.
Is this your stance?
Yes indeed. And due to that saturation, climate models are all over the place regards “climate sensitivity.
That saturation effect has been reported by many expert atmospheric scientists like Wijngaarden & Happer published in Dependence of Earth’s Thermal Radiation on Five Most Abundant Greenhouse Gases (2020)
But also as seen in the following quote from an article on the main alarmist Michael Mann’s website in 2009 discussing saturation:
“We see that for the pre-industrial CO2 concentration, it is only the wavelength range between about 13.5 and 17 microns (millionths of a meter) that can be considered to be saturated. Within this range, it is indeed true that adding more CO2 would not significantly increase the amount of absorption”.
To clarify, in part due to questionable equation and in part due to increasing saturation, a doubling from 10 to 20 ppm would calculate to add the same warming as doubling 400 to 800 ppm
Yes, that is the meaning of logarithmic in the sense of the equation ….
5.35 ln(C/Co)
and so doubling from 400 to 800 would cause another 3.7 W/m^2 of forcing.
Do you agree?
Seems not as you say “questionable equation”
Wijngaarden & Happer published in Dependence of Earth’s Thermal Radiation on Five Most Abundant Greenhouse Gases (2020).
Reproduced numbers in the same ball-park as other 1D modelling (without feedbacks) – so why is it so important?
The emission side of the effect that lies above the Effective emission level is the driving half.
That is that as concentrations increase then so that level rises and emission takes place a lower temperature and hence via SB, weaker.
Do you agree?
To be more specific regards W & H 2020
Nick Stokes from …..
”We could emit as much CO2 as we like; with no effect.”
The paper says nothing like that. It goes through the old argument between Arrhenius and Angstrom; the Arrhenius argument prevailed, and this paper does not contradict it. The key outcome is probably Table 5, where they compare their CO2 sensitivities with those calculated 50 or so years ago by Manabe, and by Hunt and by Kluft (recent). The fixed relative humidity numbers are 2.9(2.2), 2.2, 2.7, 2.3. The last number is theirs, and is completely in line with the earlier results, and certainly does not say that CO2 could be added with no effect. It says the CS would be 2.3C per doubling.
The forcing increments due to GHG increase are shown in Table 3. They explicitly say, correctly,
“The forcing increments in Table 3 are comparable to those calculated by others.”
and
“The “saturation” is what it is. The GHE still works. And, I repeat, their calculated CS is 2.3C/doubling. Right in the IPCC range. They have basically repeated the old calculation of Manabe with updated radiative properties, and got a very similar result.’”
Again why is the W& H 2020 paper so often featured here given that they say “The forcing increments in Table 3 are comparable to those calculated by others.” ?
“so why is it so important?”
Perhaps it is important in that it reinforces those earlier works, many of which concluded that such warming is not dangerous. Doubling the current concentration is probably a far fetched goal. Then, net feedbacks are probably negative, meaning that 2.3C is unattainable.
Consider the destructive results of much higher past concentrations, as indicated by the best available evidence.
Did you consider the flaring of the wings of absorption bands due to pressure and collision broadening? Did you consider that most of the energy CO2 emits that does eventually escape to space does so at higher altitudes and that by adding more CO2 you effectively push the escape height higher and higher where the atmosphere is colder where less heat can escape. Thus the issue with the saturation argument is two fold. First, the effect isn’t actually saturated yet. Second, even when it does saturate (that is a long ways off) adding more CO2 will still create a positive energy perturbation on the planet.
Err…”pressure and collision broadening” should have been “pressure/collision and doppler broadening”.
What I said just above …. But left the other absorption bands pressure broadening for later.
I suggest you go back and watch the whole video before rant.
First it was never stated that the saturation of 13.5 to 7 micron wavelengths was the entire story. Indeed there is also pressure broadening. But those are secondary. What was argued the primary absorption bands are saturated and that primary effect is no longer in play.
Second, it has been published in 2021 that about 90% of the downward infrared to thee surface emanates from atmospheric layers 1600 meters and below. Above that altitude the greenhouse gas cooling effects dominate. More CO2 at higher altitudes will increase cooling, not warmin, as you falsely claim
CO2 at a higher altitude is colder. CO2 emits in proportion to its temperature. Less CO2 means the escape height is lower and warmer so there is more radiance in W/m2.sr. More CO2 means the escape height is higher and colder so there is less radiance in W/m2.sr. It is important to understand that we’re talking about the altitude at which the cross sectional density of CO2 is low enough that UWIR actually does have a free escape.
And as I mentioned above if more CO2 cooled the troposphere then we should be observing a cooling troposphere simultaneous with a warming stratosphere. We observe the exact opposite effect though. That observation is inconsistent with the hypothesis that more CO2 is a cooling agent.
Your description seems to anticipate that lower CO2 traps heat until it can be radiated directly to space. I would postulate something more like diffusion taking place where the concentration of lower CO2 would result in a higher diffusion rate to space. A gradient if you will. I don’t think a queue of CO2 molecules waiting for a chance to radiate to space is a correct one.
The bogus argument to dismiss saturation effects, is another perfect example of how trolls cherry pick the warming dynamic and ignore the cooling dynamics to push catastrophic climate change.
The thermodynamics remain the same even with added CO2. If CO2 at a higher colder altitude emits heat to space more slowly, it will also emit heat back towards earth more slowly.
The net movement of heat from the surface back to space remains. Warmer layers always emit more radiation upwards than colder layers above emit back radiation towards the surface.
Thermodynamics 101:
God, people that come up with this stuff are dumb.
Folks, there are 2 prime movers of Earth climate.
#1: THE SUN. This one should be obvious.
#2: THE TEMPERATURE OF OUTER SPACE IN THIS REGION OF THE GALAXY.
That’s right, folks. Space is “warmer” in some areas, and “cooler” in others. This all depends on our galactic orbital position. Temperatures in our galaxy vary, mainly due to galactic cannibalizations. If you go to the southern hemisphere, you can see the small and large Magellanic clouds. These “clouds” are 2 small galaxies the Milky Way has cannibalized in the last few hundred million years or so.
Where 2 galaxies collide, there is a warming of space in that region caused by the gravitational sheer forces. This means that as we orbit the milky way, we will pass through different regions of space that are warmer and cooler.
Here’s the rub. The “warmer zones” of the galaxy are the more hazardous zones. It’s where we get more extra-galactic objects entering our space. Think, Ouamuamua.
The small impacts we suffer come from within our solar system. The BIG impacts, come from WITHOUT. The evidence of extra galactic impacts in our solar system are many…
Earth’s plate tectonics.
Mariner trench on Mars.
The unique orbital tilt of Uranus (a close flyby)
The great red spot on Jupiter is likely caused by a hot planetary core fragment floating on a sea of metallic hydrogen which collided with Jupiter long ago.
The asteroid belt.
All of these are direct signs of HUGE, FAST IMPACTS. And the only place you generate those kinds of relative velocities are from extra-solar objects.
So sorry, all you “global warming” non-scientific types. The temperature of the Earth is determined by the Sun and by the temperature of outer space, and that’s ALL.
Coincidentally, how THICK a planet’s atmosphere is is dependent on how much water vapor it contains. Earth is losing her oceans to space over time (as Mars did) and hence her atmosphere will eventually thin, the planet will continue to cool and desertify (as it has been doing for a LONG time now) and we’ll eventually look JUST like Mars.
And eventually, Venus will cool to a point where its atmosphere will precipitate the liquid water out, and this precipitous thinning of the atmosphere will take Venus from being uninhabitable to being habitable in literally a few hundred years, maybe even LESS. But once it hits that very special point where the atmosphere can begin to give up its moisture to oceans, the atmosphere will begin to thin VERY QUICKLY and Venus will cool VERY QUICKLY. Despite the high levels of CO2, lol.
Jim
Here is a model diagram that preserves the two distinct and separate environments of day and night.
The Atmospheric Reservoir Energy Recycling Process
What’s your point???
We both are saying there is a good radiative balance
With the sun shining on a single illuminated hemisphere the average beam intensity is powerful enough the melt ice on the surface of the lit globe.
Again whats your point regards the cooling role of greenhouse gases???
Greenhouse gasses and a greenhouse are as similar as apples and oranges. Greenhouses control convection or they would not work. CO2 and other such gases have no such ability.
The GREENHOUSE EFFECT is an unproven theory saturated with anecdotal correlations.
Thanks Jim.
As I understand it’s well established even by the climate mainstream that, above the tropopause, CO2 cools the atmosphere by ejecting more IR photons to space, thus a cooling stratosphere is part of the story.
This can occur in limited regions.
The issue is relative location of the emission height for IR to space compared to the height of the tropopause. When emission height moves into the stratosphere, where lapse flattens and sometimes reverses, the IR emission rate can increase with height. That sometimes occurs in cold polar regions (where IR emission rate is low).
I posted a link to this video on my Facebook page plus Will Happer’s description, and I am now blocked. The fascist left knows no shame
Hmmm, Now I am back on FB
here is screenshot
Now Im blocked again
Facebook is anti-American. Anti-freedom.
I think Facebook is in for some changes in the near future. As soon as Republicans take control of Congress.
Jim,
When you say “CO2 wavelengths are saturated” you should define exactly what you mean.
“Saturation is not what many think.”
The usual official climate science usage is that AT CURRENT ATMOSPHERIC CO2 CONCENTRATION, the CO2 greenhouse effect has produced about all the warming it is capable of. However, add more CO2 to the atmosphere, as currently is occurring, and CO2 is quite capable of producing more warming.
Some think of CO2 saturation as the logarithmic-like decrease in the power forcing factor that produces warming as CO2 increases. That largely occurs because, as CO2 increases an increasing amount of warming occurs from the quantum IR lines located on either side of the main, central 15 micron CO2 line representing the fundamental C-O vibration frequency. Because the IR photon absorption cross section decreases as one moves away from 15 microns, the power forcing decreases as atmospheric CO2 concentration increases. This means at 100 ppm CO2 the warming effect per molecule is larger than at 200 ppm, which is also larger than at 400 ppm, etc. However, the power forcing effect is approximately constant each time CO2 is doubled — about 3 watts.
The amount of greenhouse warming depends on the rate new CO2 is added to the atmosphere, and that addition rate currently is rather large.
Let me fix a few things …
“On the other hand, more CO2 increases collisions with O2 and N2, allowing those air molecules to release heat absorbed from conduction with the ground to be radiated back to space.”
The heat ‘radiated to space’ comes from high in the atmosphere. The more CO2, the higher that final radiating layer is. Because of the lapse rate in the atmosphere, the higher the radiating layer, the cooler it is and the LESS radiation emitted to space.
More CO2 = LESS cooling, not MORE cooling.
Also, very little energy is transferred by conduction. Much more is by radiation and evaporation.
You fixed nothing, but did many other effects.
The point is that the “saturation” you mention does indeed apply low in the atmosphere, but ‘fades’ away higher up. The more CO2, the higher you have to go before the saturation’ fades’. That means the radiation that escapes to space necessarily comes from higher — and cooler — regions. That means LESS radiation to space. That means more energy staying. That means a warmer earth.
That is not the impression I got from what you have been saying.
The bogus argument to dismiss saturation effects, is another perfect example of how trolls cherry pick the warming dynamic and ignore the cooling dynamics to push catastrophic climate change.
The thermodynamics remain the same even with added CO2. If CO2 at a higher colder altitude emits heat to space more slowly, it will also eemit heat back towards earth more slowly.
The net movement of heat from the surface back to space remains. Warmer layers always emit more radiation upwards than colder layers above emit back radiation towards the surface.
The bogus argument to dismiss saturation effects, is another perfect example of how trolls cherry pick the warming dynamic and ignore the cooling dynamics to push catastrophic climate change.
The thermodynamics remain the same even with added CO2. If CO2 at a higher colder altitude emits heat to space more slowly, it will also eemit heat back towards earth more slowly.
The net movement of heat from the surface back to space remains. Warmer layers always emit more radiation upwards than colder layers above emit back radiation towards the surface.
Are you guys ever going to learn?
Every time this Anthony Banton guy and bdgwx show up they intentionally ignore the point of the original post and drag the conversation further and further into the pedantic weeds over everything BUT the original article.
They are more technically competent and smarter trolls than griff or Loydo, but they’re trolls just the same.
Engaging their off topic pedantry accomplishes exactly what they want; the important point of the article subsumed under hundreds of tangential jabbering comments about what they want to talk about rather than what the article is. And they usually pick the silliest or weakest response to run off into left field with, until you can’t even see where you started.
Indeed that seems to be their mission, to intentionally ignore the point of the original post and drag the conversation further and further into the pedantic weeds over everything BUT the original article. A common troll tactic
Jim:
That’s because a (the main) supporting arguments in your post are specious.
The main absorption bands for CO2 many be saturated … but there others that come into play and the GHE functions by emission of LWIR to space above the effective emission layer which at ~8km has plenty of space to rise to lower temperatures and thus emit more weakly.
The W&H 2020 paper says nothing new, and indeed the GHE will continue to cause warming at the decreasing log rate that is predicted and hitherto observed.
Also N2 and O2 emit to space.
They cool as all atoms do via EM radiation, that it is not at the peak band of terrestrial temperature emission does not preclude that basic physics.
Quoting…
“drag the conversation further and further into the pedantic weeds over everything BUT the original article.”
Is nowhere near the truth.
It seems that you are not prepared for some challenging arguments and rebuttals (as you would have had should this have been submitted as a paper to a journal )… not very scientific of you IMHO.
Don’t get on your high-horse and have a hissy-fit just because some knowledgeable people have dared to challenge your assertions (NOT diverted from them!) – rathe than have the usual hugs ‘n’ kisses that are expected and the norm here
“They are more technically competent and smarter trolls than griff or Loydo, but they’re trolls just the same.”
A “Troll” is not someone who merely disagrees with an argument. Otherwise an “argument of “position could never be challenged without rancour.
If I were to come her and …
“…. deliberately tries to offend, cause trouble or directly attack people by posting derogatory comments on Facebook … , on forums and other social media,……. Not every argument can be considered as trolling; a difference of opinion can lead to healthy discussion which can be invaluable on forums.”
https://www.endsleigh.co.uk/blog/post/what-is-internet-trolling/
I do know this place is for, err “sceptics” who only want their cognitive dissonance confirmed – as the nature of the presentation of articles here encourages.
I do nothing more than state (with links) what the consensus science says. Of course denizens don’t like it and I wont change minds … but at least they are exposed to it and see the counter to the often “fake facts” reported here.
It seems like you and the troll factory go on a full fledge attack any science that challenges your theoretical group think to er protect your cognitive dissonance and the political power fear mongering gives you
“It seems like you and the troll factory go on a full fledge attack any science that challenges your theoretical group”
Jim:
It’s not “personal group think” at all.
And I am responding to your intransigence and now ad hom (I am NOT a “Troll”)- just because I am asking knowledgeable questions of you.
Given that there are contrarians in any walk of life (often ideologically motivated) there are some in (on the fringes of usually) that dont like what the the science says, and come across all “sciencey” – and that you are without answering my questions respectfully (even at all).
That you don’t like it does not make my posting of consensus science/meteorology “personal” – all links/references have come from consensus science sources.
It is up to you to provide to burden of proof otherwise.
The world is not upside down quite yet despite the bizarre madness of the likes of the QAnon conspiracy nutters.
Refusing to address my enquiries and calling me a “Troll” is not what I would expect of someone of your credentials.
Then again, what you say here, I would not expect of someone with your credentials.
First, if I’ve offended you or anyone else on here I am sorry. That is never my intention. My main intent in this particular blog post is making sure people understand that CO2’s net effect in the troposphere and below is warming; not cooling. Secondarily it is that CO2’s absorption isn’t actually saturated due to the broadening of the spectral lines and that even if it were saturated it would still have a net warming effect in the troposphere due to the increased emission height where it is cooler and thus decreases radiant intensity. Don’t hear what I’m not saying. I’m not saying CO2’s radiative force is linear. It’s not. It is logarithmic. But let’s not pretend like this is some bombshell epiphany that scientists don’t know about. Afterall, this logarithmic relationship was first discovered in the late 1800’s and then further refined with the development of radiative transfer schemes in the middle of the 20th century.
The bogus argument to dismiss saturation effects, is another perfect example of how trolls cherry pick the warming dynamic and ignore the cooling dynamics to push catastrophic climate change.
The thermodynamics remain the same even with added CO2. If CO2 at a higher colder altitude emits heat to space more slowly, it will also eemit heat back towards earth more slowly.
The net movement of heat from the surface back to space remains. Warmer layers always emit more radiation upwards than colder layers above emit back radiation towards the surface.
“it will also emit heat back towards earth more slowly.”
No
We have established that we are above the effective emission layer and so the majority of LWIR exits to space, and as CO2 increases the EEL becomes progressively colder/weaker at it.
The surface DeltaT is maintained by the Trop below the EEL and by convection.
GMST rising as -g/cp LR from that layer to the surface.
GHE theory 101.
“we have established” LOL
You are making empty claims
“The net movement of heat from the surface back to space remains. Warmer layers always emit more radiation upwards than colder layers above emit back radiation towards the surface.”
Of course it does and they do.
But the GHE adds another ~ 150 W/m^2 from those “colder layers” down to the surface before those W/m^2 exit to space via LWIR emission from GHGs in the Trop above the EEL. And that amount will increase by 3.7 W/m^2 for every doubling of CO2 concentration (neglecting feedbacks of final ECS).
I fully agree. People who grow agitated when challenged and accuse the challenger of not being serious often do not view their own reasoning and thoughts with critical eyes.
To say that CO2 is “saturated” means that at the current CO2 concentrations, implies it is producing all the warming it is capable of. However, even that amount could modestly change if atmospheric conditions change appropriately.
There is NO saturation against additional warming if CO2 increases.
The degree of warming depends on the proportional amount CO2 increases and not on the numerical amount CO2 increases. Thus, if CO2 doubles from almost any concentration level, forcing will increase by about 3 watts/cm^2. However, if CO2 is increased by say 5 ppm at a total concentration of 400 ppm, the forcing will only be half as great compared to the forcing when increasing CO2 by 5 ppm at a total CO2 concentration of 200 ppm. This is the so-called logarithmic curve of decreasing warming. Forcing is simply proportional to the proportional CO2 increase; nothing magical.
Hmm now I am blocked from Twitter
Hmmm and then when I post about it, I am no longer blocked
Now Im blocked again
I’ve been thinking about the comments that CO2, being a greenhouse gas, can help cool the planet because O2 and N2 cannot radiate energy to outer space while CO2 and other greenhouse gases can. I believe a thorough analysis will show that this is basically an untrue statement. If there were no greenhouse gases in the atmosphere, and since diatomic molecules are transparent to the incoming solar radiation, the only way the O2 and N2 could be heated is by sensible heat from contact with the ground and water which is heated by incoming solar radiation, and by the latent heat of vaporization surrendered by water which condenses in the atmosphere. I have not attempted to calculate the amount of heating of the atmosphere which would occur by these processes, but I assume someone has, or perhaps someone knows and can report how much heat is transferred by these two processes. What has been widely reported and is generally accepted is that the temperature of the atmosphere would be about 0 deg F if there were no greenhouse gases. If there were no sun, we can assume the temperature of the earth would be the same as its surroundings, and would be well below 0 deg F, so the amount of heat transferred from the ground and water to the air must be substantial. But, since we do have greenhouse gases, we know that they also provide additional heat to atmospheric O2 and N2. As the greenhouse gases are warmed by radiation, they pass on some of that energy to the non greenhouse gases, and they warm up, which accounts for the atmosphere being about 60 deg F rather than 0 deg F. So, the net effect of greenhouse gases is not to help cool the earth, but to warm it up. It makes no sense to think of greenhouse gases as providing cooling, even though they are causing energy to be transferred away from the atmosphere by radiation. If the greenhouse gases were not present, the atmosphere would cool off.
You make the same mistake as others have by failing to address the main point, or to just ignore it. Indeed greenhouse gas and non-greenhouse gas collisions can both warm and cool. No one argues against that. But you ignore the added energy acquired by collisions with the surface, conduction, that give rise to the sensible heating that escapes from the surface, which amounts to about one/seventh of the total surface heat budget. Without greenhouse gases O2 and N2 can not shed that heat, so the net change is greenhouse gases cool the atmosphere. And without greenhouse gases O2 and N2, cannot transfer the gained daytime heat back to the surface because at night when the surface cools an inversion layer forms
I did mention that the air gains sensible heat from the ground and oceans, but what an atmosphere with only diatomic molecules will not do is impede the heat loss by radiation to outer space. Do you disagree that without greenhouses gases the earth would be much cooler than it actually is? If so, is there a calculation to show that it would be warmer?
, a doubling from 10 to 20 ppm would calculate to add the same warming as doubling 400 to 800 ppm
=====
What is never considered in the calculation of ECS is the first increase in CO2 from 0ppm.
Starting from 0ppm, you have an infinite number of doublings to reach 10ppm or any other value, which reduces the ECS to zero at the limit.
This of course explains why no one has been able to nail down a value for ECS after many decades of trying. ECS is an iterative formula specifying the value of each iteration without having defined the zero condition.
As such, ECS has no solution because the zero condition, the initial doubling from zero is not defined.
When CO2 is very low, the IR emission height to space is much lower in the atmosphere, the IR emission rate is higher, and warming from CO2 is relatively small.
Across the broad 15 micron CO2 band, say 13-17 microns, most of the IR emitted when CO2 is below 100 ppm moves directly to space without absorption and with no warming effects.
For those who like to speak of “CO2 saturation”, is CO2 saturated under these conditions, when only a narrow part of the CO2 IR band participates??
If the ECS from 1 to 2ppm is the same as the ECS from 400 to 800ppm then the Ecs from 0.01 to 0.02ppm must also be the same.
And the Ecs from 0.001 to 0.002ppm, and from 0.0001 to 0.0002ppm, and from 0.00001 to 0.00002ppm on to infinity.
In other words, there have already been any infinite number of doublings in the amount of CO2 in the atmosphere.
As such, any value for ECS greater than zero will result in an infinite surface temperature. And a negative value for ECS will result in a temperature of absolute zero.
As such, the only possible value for ECS is zero.
The math behind this is solid. I’ll write it up and submit time permitting.
They’re not the same. Also, if you don’t mind let me provide a couple of important tips before doing your calculation. Make sure you factor in the Komabayashi–Ingersoll and Simpson–Nakajima limits for the upper bound and the blackbody temperature in the no-GHG case with 1360 W/m2 of TSI for the lower bound. If your calculation yields < 255K as a lower bound or > 350K for an upper bound then you’ve probably neglected an important concept.
then you’ve probably neglected an important concept.
=======!=
My point was that the definition of ECS leads to nonsense because of Zeno’s paradox.
The definition itself is the problem because it leads to negative infinity. There is an error in my calculation on the positive side because CO2 cannot exceed 100%
If you’re getting negative infinity then you’ve almost certainly made an assumption you shouldn’t have. Determining CO2’s temperature response effect is a ridiculously complicated matter.
They’re not the same.
=========
Please explain why. The definition of ECS is quite simple. The temperature change from a doubling of CO2. It doesnt specify the domain. So it must be constant for any doubling..
It’s not quite that simple. ECS includes feedbacks. There is the slow-feedback ECS and the fast-feedback ECS. The SB ECS can take tens of thousands of years to fully play out while the FB ECS is limited to about 150 years (give or take) which excludes long duration processes like some components of the carbon cycle and ice sheet melting.
Anyway, these feedbacks play out differently depending on how the current state. So 2xCO2 in one era might exhibit 6.0C of warming while in another it might only be 1.5C even though the RF is 3.7 W/m2 in both cases. The sensitivity to the temperature is response can vary between 0.5 and 2.0 C per W/m2. It’s also not even static. In other words, it may start on the low end but then as warming progresses and initiates tipping points it may begin to rise. But then there will a point where it begins to dip again as those tipping points eventually self limit and clamp out.
The ice sheets are a good example of this. At some point enough warming will have occurred to tip the melting over the edge of recovery resulting in increased sensitivities as albedo begins to decline. But once all of the ice melts the effect ceases and the albedo stabilizes cause the sensitivity to decline as well.
The point is that not all doublings are the same even if the RF is the same between the two. And that brings up the next caveat. The RF isn’t exactly the same for each doubling. Myhre 1998 provides a simple estimation of the RF via 5.35*ln(C/Ci) where C is the current concentration and Ci in the initial concentration. And although not spelled out in that particular publication it is believed this simple relationship only holds for a narrow range of concentrations say from 10 to 10000 ppm.
It is also important to note that the cumulative forcing effect of CO2 at 300 ppm is about 30 W/m2 (Schmidt 2010). This implies the Myhre 1998 relationship could hold all the way down to 1 ppm. But it’ll breakdown very fast below that and personally I wouldn’t use it for anything below 10 ppm. You’ll have to use more complex and numerically intensive radiative transfer schemes to provide an estimate with a broader range of inputs.
Komabayashi–Ingersoll
=========
From what I can see this limit is based on the positive feedback water 1D model.
Rather than limit temperature it says that you will get runaway warming with increased CO2 above a certain limit.
This looks to be early work back in the day when people believed Venus surface temperatures were due to runaway warming due to CO2.
In plain language the radiation limits represent the maximum output a planet can sustain. If the input exceeds the output then a runaway will occur. For Earth the KI and SN limits are 320 W/m2 and 300 W/m2 respectively. The SN limit is a bit lower so that would be most applicable for Earth. And since Earth only takes in 240 W/m2 of input there is a 60 W/m2 gap preventing the runaway.
Also note that CO2 does not change this limit as it increases. This effectively clamps the temperature rise to that which only CO2’s direct radiative force (and tandem feedbacks) can supply on their own. Thus there is a finite limit to the amount of warming that can occur limited by the carbon stock available which is likely to be less 10,000 ppm.
But even if we manufactured CO2 like there’s no tomorrow and managed to exceed 10,000 ppm the warming would still be clamped due to the logarithmic relationship with the resultant forcing. Even at ridiculous concentration radiative modeling shows that the temperature will begin clamping near 340K.
Venus has no such clamps because its KI limit is below its solar input thus paying the way for a runaway GHE.
Let’s look at the hatchet job that someone, not necessarily author Jim Steele, did on the Kiehl & Trenberth-type power flux flow and “balance” diagram presented at the top of the above article as background for the clickable YouTube video:
— incoming and outgoing power fluxes presented to 0.1 W/m^2 precision (seriously???)
— power flux for incoming solar TOA asserted to be at ±0.1 W/m^2 accuracy, when it is known that over the course of one solar cycle (one ~11-year period), the Sun’s emitted energy varies on average at about 0.1 percent, or ±0.17 W/m^2
— Reflected solar from atmosphere, clouds and Earth’s surface is stated to be 100.0±2 W/m^2, yielding a calculated total albedo of (100.0±2)/(340.2±0.1) = 0.288–0.300, despite Earth’s average albedo being measured and publicized as varying across a much smaller range of 0.299–0.301 from March, 2000, through December, 2011 (see https://earthobservatory.nasa.gov/images/84499/measuring-earths-albedo )
— “All sky atmospheric window” flux (i.e., radiation from ground directly to space) is stated to be 20±4 W/m^2. “Clear sky emission” is stated to be 266.4±3.3 W/m^2. Combining these, one obtains a possible total radiated emissions range of 279.1–293.7 W/m^2. In comparison, subtracting total reflected solar (100.0±2) from total incoming solar (340.2±0.1 W/m^2) one calculates a net absorbed radiation flux range of 238.1–242.3 W/m^2, so clearly there is a mathematical error here since the worst-case range mismatch (high-end to high-end) is 51.4 W/m^2 whereas the diagram states the TOA imbalance as being only 0.6±0.4 W/m^2.
— Alternatively, if one combines that stated “all sky atmospheric window” flux of 20±4 W/m^2 with the stated “outgoing longwave radiation” flux of 239.7±3.3 W/m^2, which accounts for cloud effects, one calculates a total emissions range of 252.4–267.0 W/m^2, which is a different range than calculated in the preceding paragraph and which also departs from the incoming solar minus albedo range by as much as 24.7 W/m^2 whereas the diagram states the TOA imbalance as being only 0.6±0.4 W/m^2.
— Just a simple look at the stated variabilities for “reflected solar” (±2 W/m^2), or “all sky atmospheric window” (±4 W/m^2), or “clear sky emission” (±3.3 W/m^2), or “outgoing longwave radiation” (±3.3 W/m^2) is sufficient to falsify the stated “Top of Atmosphere imbalance” could have the stated variability of ±0.4 W/m^2 . . . no detailed error analysis is required.
Clearly, the presented K&T-type diagram at the top of the above article is FUBAR.
So where is the evidence for the photon?
……just curious…..did anyone play with CO2 back when it was the #1 coolant for the world ??
Putting a chunk of dry ice in a bucket of water was tons of fun :)……anyone remember that cloud that came rolling out…….and went down to the lowest level possible ……
just curious.
Noticed right away . . . and quickly concluded that the reason the CO2-induced clouds “went down to the lowest level possible” was because the visible condensation of water droplets comprising the clouds showed the ensemble (H2O condensation droplets plus CO2 vapor) was much cooler, and therefore more dense, than the surrounding air that had not been cooled by the dry ice (having a temperature of about minus 109 °F).
P.S. Also, I never wondered why the “clouds” disappeared so quickly.
Once again, the lie that never dies is peddled as common knowledge.
The lie is that the T^4 Stefan-Boltzmann Law can be inverted so that surface photons returned to the Earth’s surface can reraise its temperature. The truth is that the temperature of the surface causes radiation that follows the S-B Law, but not vice-versa.In the case of the Earth’s surface, the only heating is caused by solar radiation at 0.4-0.8 microns, raising the temperature to the range of -50C to +50C, with a wavelength range of 8-13 microns. Returning the longer wavelength radiation doesn’t make the tail wag the dog and reheat the surface to the same temperature that the Sun did.
This lie is based on the bigger lie that all photons of any wavelength have the same power to raise the temperature of an absorbing material based on raw energy (Joules) alone. The truth is that a rod of temperature T cools by emitting radiation controlled by Planck’s Radiation Law, whose power curve has a peak power wavelength dependent solely on T, independent of the material, meaning that its radiation can’t raise the temperature of an absorbing material higher than T, regardless of the material. Thus, CO2’s 15 micron radiation absorption/emission wavelength has a Planck radiation temperature of -80C, colder than dry ice, hence its radiation is indistinguishable from an iron rod cooled to -80C, which can’t melt an ice cube, much less cause global warming. The U.N. IPCC lie machine tries to twist the science like a pretzel with ridiculous arguments about energy balance at the top of the atmosphere, claiming that the surface will magically increase its temperature to maintain the balance without any feedback signal or any increased radiation energy input at any temperature. It’s fantasy and magic, not science. The IPCC just wishes that atmospheric CO2 can cause global warming, and jumps to save us from our anxieties by demanding trillions, with no money-back guarantee, intending the money to be used for redistribution of wealth using climate as a punch line. Since it’s currently picking up steam daily, the hardened global Marxists at the top of the IPCC must be laughing all the way to the bank.
https://www.quora.com/Without-greenhouse-gases-in-the-atmosphere-would-Earth-be-able-to-dissipate-enough-heath-to-stay-cool/answer/TL-Winslow