Guest Post by Ira Glickstein
The Unified Theory of Climate post is exciting and could shake the world of Climate Science to its roots. I would love it if the conventional understanding of the Atmospheric “Greenhouse” Effect (GHE) presented by the Official Climate Team could be overturned, and that would be the case if the theory of Ned Nikolov and Karl Zeller, both PhDs, turns out to be scientifically correct.
Sadly, it seems to me they have made some basic mistakes that, among other faults, confuse cause and effect. I appreciate that WUWT is open to new ideas, and I support the decision to publish this theory, along with both positive and negative comments by readers.
Correlation does not prove causation. For example, the more policemen directing traffic, the worse the jam is. Yes, when the police and tow trucks first respond to an accident they may slow the traffic down a bit until the disabled automobiles are removed. However, there is no doubt the original cause of the jam was the accident, and the reason police presence is generally proportional to the severity of the jam level is that more or fewer are ordered to respond. Thus, Accident >>CAUSES>> Traffic Jam >>CAUSES>> Police is the correct interpretation.
Al Gore made a similar error when, in his infamous movie An Inconvenient Truth, he made a big deal about the undoubted corrrelation in the Ice Core record between CO2 levels and Temperature without mentioning the equally apparent fact that Temperatures increase and decrease hundreds of years before CO2 levels follow suit.
While it is true that rising CO2 levels do have a positive feedback that contributes to slightly increased Temperatures, the primary direction of causation is Temperature >>CAUSES>> CO2. The proof is in the fact that, in each Glacial cycle, Temperatures begin their rapid decline precisely when CO2 levels are at their highest, and rapid Temperature increase is initiated exactly when CO2 levels are their lowest. Thus, Something Else >>CAUSES>> Temperature>>CAUSES>> CO2. Further proof may be had by placing an open can of carbonated beverage in the refigerator and another on the table, and noting that the “fizz” (CO2) outgasses more rapidly from the can at room temperature.
Moving on to Nikolov, the claim appears to be that the pressure of the Atmosphere is the main cause of temperature changes on Earth. The basic claim is PRESSURE >>CAUSES>>TEMPERATURE.
PV = nRT
Given a gas in a container, the above formula allows us to calculate the effect of changes to the following variables: Pressure (P), Volume (V), Temperature (T, in Kelvins), and Number of molecules (n). (R is a constant.)
The figure shows two cases involving a sealed, non-insulated container, with a Volume, V, of air:
(A) Store that container of air in the ambient cool Temperature Tr of a refrigerator. Then, increase the Number n of molecules in the container by pumping in more air. the Pressure (P) within the container will increase. Due to the work done to compress the air in the fixed volume container, the Temperature within the container will also increase from (Tr) to some higher value. But, please note, when we stop increasing n, both P and T in the container will stabilize. Then, as the container, warmed by the work we did compressing the air, radiates, conducts, and convects that heat to the cool interior of the refrigerator, the Temperature slowly decreases back to the original Tr.
(B) We take a similar container from the cool refrigerator at Temperature Tr and place it on a kitchen chair, where the ambient Temperature Tk is higher. The container is warmed by radiation, conduction and convection and the Temperature rises asymptotically towards Tk. The Pressure P rises slowly and stabilizes at some higher level. Please note the pressure remains high forever so long as the temperature remains elevated.
In case (A) Pressure >>CAUSES A TEMPORARY>> increase in Temperature.
In case (B) Temperature >>CAUSES A PERMANENT>> increase in Pressure.
I do not believe any reader will disagree with this highly simplified thought experiment. Of course, the Nikolov theory is far more complex, but, I believe it amounts to confusing the cause, namely radiation from the Sun and Downwelling Long-Wave Infrared (LW DWIR) from the so-called “Greenhouse” gases (GHG) in the Atmosphere with the effect, Atmospheric pressure.
Some Red Flags in the Unified Theory
1) According to Nikolov, our Atmosphere
“… boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K!”
If, as Nikolov claims, the Atmosphere boosts the surface temperature by 133K, then, absent the Atmosphere the Earth would be 288K – 133K = 155K. This is contradicted by the fact that the Moon, which has no Atmosphere and is at the same distance from the Sun as our Earth, has an average temperature of about 250K. Yes, the albedo of the Moon is 0.12 and that of the Earth is 0.3, but that difference would make the Moon only about 8K cooler than an Atmosphere-free Earth, not 95K cooler! Impossible!
2) In the following quote from Nikolov, NTE is “Atmospheric Near-Surface Thermal Enhancement” and SPGB is a “Standard Planetary Gray Body”
NTE should not be confused with an actual energy, however, since it only defines the relative (fractional) increase of a planet’s surface temperature above that of a SPGB. Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating. [Emphasis added]
This, it seems to me, is an admission that the source of energy for their “Atmospheric Near-Surface Thermal Enhancement” process comes from the Sun, and, therefore, their “Enhancement” is as they admit, not “actual energy”. I would add the energy that would otherwise be lost to space (DW LWIR) to the energy from the Sun, eliminating any need for the “Thermal Enhancement” provided by Atmospheric pressure.
3) As we know when investigating financial misconduct, follow the money. Well, in Climate Science we follow the Energy. We know from actual measurements (see my Visualizing the “Greenhouse” Effect – Emission-Spectra) the radiative energy and spectra of Upwelling Long-Wave Infrared (UW LWIR), from the Surface to the so-called “greenhouse” gases (GHG) in the Atmosphere, and the Downwelling (DW LWIR) from those gases back to the Surface.
The only heed Nikolov seems to give to GHG and those measured radiative energies is that they are insufficient to raise the temperature of the Surface by 133K.
… our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible.
Of course not! Which is why the conventional explanation of the GHE is that the GHE raises the temperature by only about 33K (or perhaps a bit less -or more- but only a bit and definitely not 100K!).
4) Nikolov notes that, based on “interplanetary data in Table 1” (Mercury, Venus, Earth, Moon, Mars, Europe, Titan, Triton):
… we discovered that NTE was strongly related to total surface pressure through a nearly perfect regression fit…
Of course, one would expect planets and moons in our Solar system to have some similarities.
“… the atmosphere does not act as a ‘blanket’ reducing the surface infrared cooling to space as maintained by the current GH theory, but is in and of itself a source of extra energy through pressure. This makes the GH effect a thermodynamic phenomenon, not a radiative one as presently assumed!
I just cannot square this assertion with the clear measurements of UW and DW LWIR, and the fact that the wavelengths involved are exactly those of water vapor, carbon dioxide, and other GHGs.
Equation (7) allows us to derive a simple yet robust formula for predicting a planet’s mean surface temperature as a function of only two variables – TOA solar irradiance and mean atmospheric surface pressure,…”
Yes, TOA solar irradiance would be expected to be important in predicting mean surface temperature, but mean atmospheric surface pressure, it seems to me, would more likely be a result than a cause of temperature. But, I could be wrong.
Conclusion
I, as much as anyone else here at WUWT, would love to see the Official Climate Team put in its proper place. I think climate (CO2) sensitivity is less than the IPCC 2ºC to 4.5ºC, and most likely below 1ºC. The Nikolov Unified Climate Theory goes in the direction of reducing climate sensitivity, apparently even making it negative, but, much as I would like to accept it, I remain unconvinced. Nevertheless, I congratulate Nikolov and Zeller for having the courage and tenacity to put this theory forward. Perhaps it will trigger some other alternative theory that will be more successful.
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UPDATE: This thread is closed – see the newest one “A matter of some Gravity” where the discussion continues.
davidmhoffer says:
Look, everyone knows that the real world is complicated, but are you trying to make the claim that because of these complications, we can’t even measure the total amount of energy absorbed by the Earth + atmosphere system well enough to distinguish between 240 W/m^2 and 390 W/m^2 as the average intensity when we take this total energy and divide by surface area and time? Trenberth is frustrated because we don’t can’t directly measure these numbers down to the fraction of a W/m^2 necessary to directly determine the current energy imbalance due to greenhouse gas accumulations…but even if the number is off by 10 W/m^2, it isn’t going to make a very big difference for what we are discussing here.
No…Willis is not assuming any temperature distribution. He is simply noting the fact that there is no conceivable temperature distribution that gives an average temperature higher than 255 K for a blackbody emitting 240 W/m^2. This is based on a rigorous mathematical theorem that states that the maximum possible average temperature you can have if you are emitting a certain amount of power is the one associated with a uniform distribution.
HE IS NOT ASSUMING A UNIFORM TEMPERATURE DISTRIBUTION…HE IS USING THIS DISTRIBUTION ONLY TO DETERMINE AN MATHEMATICALLY- RIGOROUS UPPER BOUND ON WHAT THE AVERAGE TEMPERATURE COULD POSSIBLY BE. (By the way, as it turns out, the earth’s current temperature distribution is such that assuming it to be uniform is a pretty good approximation for determining the average temperature…but that is besides the point.)
No…It is not utterly ridiculous. It is impossible for it not cool to an average temperature of 255 K or less. You seem to think that something that is MATHEMATICALLY IMPOSSIBLE will happen. A blackbody surface constrained to emit 240 W/m^2 on average is constrained to be at no greater average temperature than 255 K. There is no way that moving heat to change the temperature distribution can get you around that fact because there is no temperature distribution that results in emission of 240 W/m^2 and has an average temperature higher than 255 K.
“It can all be made very simple as follows:
i) The Greenhouse Effect however caused results from a slowing down in the transmission of solar energy into the Earth system, through the system and out again to space.”
Agreed.
Greenhouse Effect is lousy word/term. But that is term used and what you said does define it, and that is how it’s defined by people who believe in AGW.
“i) Due to that slowing down more energy accumulates within the system which heats up.”
One could also say sunlight is converted into different kinds of energy- such heat. Sunlight makes molecules move and vibrant in various ways.
“iii) The process is exactly the same whether the slowdown is caused by gravity or by GHGs. One cannot argue that one is a breach of the Laws of Thermodynamics and the other not. Either both are or neither are.”
Also heat capacity and chemical processes. Coal is made from energy of sunlight. Oxygen is chemical energy- as such it is enormous amount of stored sunlight energy. Both oxygen and hydrocarbons are stored on earth for million and with oxygen billions of years.
The vast storage of oxygen and hydrocarbons is why humans have abundant cheap energy.
But the chemical storage of energy is rather minor in terms of other stored energy. Oceans store far more energy. Water vapor could be said to have a shorter duration and has massive amounts of energy, in terms we use as energy sources- not more than oxygen is probably but equal or more than current hydrocarbons available- is somewhere around the ballpark.
Methane in oceans etc is not available at our current technology and/or economics but is equal or more that current hydrocarbon use.
What is mostly mentioned in this post is regarding the stored energy in the atmospheric gases.
This by “proponents” seems somewhat “under estimated” or under appreciated.
It shown quite easily:
Molecules of atmospheric gas has a velocity of 500 meters per second. 500 m/s is 1116 mph.
Now the earth atmosphere has mass of 5.1 x 10^18 kg. Which is 5,100,000,000,000,000,000 kg
or 5,100,000,000,000,000 tonnes which are going 1116 mph.
It is true the ocean utter dwarfs this amount energy- but it’s not what any human could call
“not much”. It’s simple physics: Kinetic Energy equal 1/2 the Mass times velocity squared.
Or 2.55 x 10^18 times 500 squared. 2.55 x 10^18 times 250,000 is the amount joules of energy
stored. Or if expressed as energy used: 2.55 x 10^18 times 250,000 is how many watts.
“iv) The gravitational effect involves every atom and molecule in the system including Oxygen and Nitrogen. It is too powerful for the non radiative processes such as conduction, convection and evaporation to negate it so radiative processes have to finish the job.”
Yes, radiative process are also involved. It never been very clear how much this is, a few watts per square meter for CO2. This would be a lot. I seen claims of it being more and being less.
I am not a professional climate, and easy to find the amount energy stored in atmosphere in terms of it’s KE- and I can say how much is fairly accurately. It’s not off by more 50%. And there is no doubt about it.
“v) Thus the gravitational effect sets up the baseline lapse rate which is set as an inviolable minimum.”
Right as said above. And it’s a huge elephant in the room- not mentioned. More than not mentioned- it’s denied by claiming earth would well below freezing without greenhouse gases.
That is their first premise. Or opening sales pitch.
“vi) The GHGs add another influence on top of the gravitational effect but it is the same effect in principle. However it is limited to the atmosphere and involves only a miniscule fraction of total mass.”
It does seem to limit it’s affect.
“vii) The thermal effect of those GHGs is to add energy to the atmosphere alone and it does seek to increase the lapse rate over and above that set by gravity and pressure.”
Yes how or to what Greenhouses gas affect lapse rate could be important in some regards- but these affects and magnitude not clear to me at this point. They are clear enough that they aren’t going to have huge global effects- there no hope of CAGW.
But CAGW isn’t even a serious fantasy to anyone who is familiar with science [and is not religious type fanatic or caught up in this kind of frenzy- which can responsible for overwhelming reason, which btw something most humans don’t like to consider as common.]
“viii) Due to the GHG effect being limited to the air and being proportionately tiny compared to the gravitational effect the non radiative processes have little difficulty dealing with it and the vertical temperature profile of the atmosphere changes to on average and overall restore the baseline lapse rate set by gravity.”
Yes.
“ix) Thus the radiative component of the greenhouse effect caused by GHGs is neutralised .”
I wouldn’t go that far.
Also I wouldn’t say that CO2 couldn’t have other affects, which are not even addressed
at this point. Again, not CAGW, but rather other affects. I am thinking for example, of maybe something to do with cloud formation??
“x) The climate consequence is a shift in the surface pressure distribution which has to occur in order to accommodate the change in the vertical temperature profile of the atmosphere but it is miniscule compared to natural variations caused by sun and oceans.”
Yes
Bart says:
(1) No, the radiative intensity emitted by the surface can always be written as sigma*epsilon*T^4 where the “average emissivity” epsilon is a number between 0 and 1. (I use the term “average emissivity here to distinguish it from the emissivity at a certain wavelength, although to my knowledge most people would just call it the emissivity.) Admittedly, in the general case, this “average emissivity” can have some temperature dependence (which comes from the fact that the emissivity itself is a function of wavelength), but it will still always be between 0 and 1.
(2) For terrestrial surfaces at terrestrial temperatures, the “average emissivity” is in fact very close to 1. This is stuff that is well-studied because of the importance of remote sensing in our modern world. See here: http://www.icess.ucsb.edu/modis/EMIS/html/em.html For example, here is a plot of the emissivity vs wavelength for sea water: http://www.icess.ucsb.edu/modis/EMIS/images/seawat10.gif
(3) Conduction and convection are not relevant in determining what a surface emits radiatively. If you want to contradict at least a century of physics, please provide a citation showing otherwise.
All,
I meant to add that if you don’t quite get what I said, then read what Bart said. In fact, ignore what I said and read what Bart said twice.
“I meant to add that if you don’t quite get what I said, then read what Bart said. In fact, ignore what I said and read what Bart said twice.”
I assume you meant:
http://wattsupwiththat.com/2011/12/29/unified-climate-theory-may-confuse-cause-and-effect/#comment-856534
Or that doesn’t work, quoting it:
“Here is the Planck distribution for blackbody energy states. Here is how it is integrated to produce the Stefan-Boltzmann law.”
The second link [second Here] doesn’t work for me.
Remainder of the post:
“The Planck distribution IS NOT INHERENT in every material body. It is a VERY SPECIAL energy distribution. There is no basis whatsoever, and given potent effects of conduction and especially convection from it, every reason to doubt, that the Earth’s surface supports a distribution of energy states which is ANYTHING LIKE a Planck distribution.
This is not hard, guys, if you take the time to learn your tools and what they do, and what they do not do.”
I said ( http://wattsupwiththat.com/2011/12/29/unified-climate-theory-may-confuse-cause-and-effect/#comment-856648 ):
I wrote that wrong, of course. If delta_f is the frequency hift and f is the frequency, then delta_f / f = 6.9 x 10^(-10). The frequency shift is hence 1 part in 1.4 x 10^9 or less than 1 part in one billion.
Joel Shore says:
January 7, 2012 at 10:13 am
“(1) No, the radiative intensity emitted by the surface can always be written as sigma*epsilon*T^4 where the “average emissivity” epsilon is a number between 0 and 1.”
Sure, it can always be written like that. Whether it has precise predictive power or not is quite another matter.
SB is intended for a surface which is in radiative equilibrium. The surface of the Earth is not in radiative equilibrium. Your plot for seawater shows quite clearly that the spectrum deviates significantly from that of a blackbody. And, they do not show that the modeshape scales conformally as T^4. I bet you it does not.
“(3) Conduction and convection are not relevant in determining what a surface emits radiatively.”
The energy distribution is very relevant. Conduction and convection influence the energy distribution. Stop playing dumb.
“If you want to contradict at least a century of physics, please provide a citation showing otherwise.”
Translation: you’ve run out of arguments.
Willis Eschenbach says:
January 7, 2012 at 12:20 am
“My question is, what is the mechanism proposed by Nikolov that can raise a blackbody planet’s temperature above the directly calculated S-B temperature value, the “blackbody temperature” corresponding to the radiation it is receiving?”
Firstly, let us take it as established that the planet’s surface does not behave as a blackbody. A blackbody exchanges energy through radiation only.
Now, let us be precise and speak not of temperature, but of energy. The energy retained at the surface is a result of balancing the energy flux. Energy comes in, and energy escapes. If it fails to escape, the energy content rises, which then increases the rate at which it escapes. When the rate of escape equals the rate of influx, you reach a steady state.
Energy cannot be created nor destroyed. But, energy flux does not have to balance at every point in time, just over the long term before everything is baked to a crisp or frozen solid. So, energy can be accumulated or retained until balance is established.
So, the question boils down to, what mechanism allows for greater retention of energy without GHGs? And, an answer could be, the thermal mass of the atmosphere, and the process of convection. How does the atmosphere then expel energy so that balance is achieved? Two possible mechanisms have been suggested by other commenters of which I have taken note: exchange with the surface for re-radiation, and collisions of energetic particles in the atmosphere which result in non-spontaneous emission of radiation. For the first, balance is achieved when the atmosphere is exchanging heat with the surface at net-zero rate. For the second, well, this acts just like the hypothesized GHG mechanism and needs no further comment. Other possibilities I have noted: phase transitions and ionized airglow. And, then there are unknown unknowns.
Is this enough without GHGs to account for a significant part of the warming? That, I do not know, which is why I am agnostic on the question for now. But, we cannot say with surety that a particular hypothesis is true solely on the basis of whether we can think of another mechanism or not. That kind of muddled thinking is what brought us the AGW fiasco in the first place. You have to prove that your favored mechanism is right. I have not yet seen evidence which leads me to conclude the GHG hypothesis is necessarily correct. Consistency is NOT proof.
Let me clarify this:
There is no doubt that GHGs will absorb outward radiation. There is no doubt that they will re-radiate a portion of that back to the Earth. There is not doubt that, that must cause some warming. I do not doubt that emission spectra of the Earth show gaps in critical GHG bands.
I am not convinced by pressure-temperature relationships that non-GHG warming necessarily occurs on a significant level, any more than I am convinced of it by the fact that planets move in elliptical orbits about a central massive star. I.e., it is not particularly relevant to the question: pressure and temperature are known to be related.
My remaining questions are:
1) are those gaps solely the result of interception of radiation by GHGs, or do those gaps already exist in significant form in the surface radiation profile? How do atmospheric conductance and convection alter the distribution of energy states at the surface of the Earth?
2) How much warming results from GHG reflectance and, if potentially significant, could that potential be offset by reactive changes (feedback) to the system such that its net effect is small?
“…or do those gaps already exist in significant form in the surface radiation profile?”
Something which points in this direction are the results reported here. Between 1970 and 1997, CO2 concentration in the atmosphere rose from about 325 to about 365 ppmv. If we assume temperature of radiation in the CO2 bands should have risen at least proportional to the 1/4th power, it should have gone from about 290K to 300K. But, there was little, if any, change at all.
Joel, what is the emissivty of a CO2 H2O mixture at 288 K at 1 ATM?
Bart says:
January 7, 2012 at 11:50 am
Bart,
Thanks for what I think is a very fair restatement of N & Z’s (hypo)thesis, caveats and all. The only thing I would add is that they started by redefining what the gray body temperature of a planetary sphere would be without an atmosphere. I’ve seen quite a few comments by even those that think N & Z is total bunk that there may be something there. So there’s two things going on, separate but related. Assuming their GB temperature calculation is correct, which hasn’t been accepted but hasn’t been disproved either, some way needs to be found to explain the extra 89 (122-33) K difference between what GHGs supposedly account for and what we actually see.
I’m totally out of my depth here, which should be obvious, but I’m really enjoying this thread. For what it’s worth, my intuition says there’s something to what N & Z are saying. Admittedly, that’s the same intuition that has nearly got me killed more than once, but still…
mkelly,
You would have to specify the nature of the mixture, and the depth of the gas before emissivity could be determined. There are a variety of references that might help yo find the number if you are willing to do the legwork.
“Assuming their GB temperature calculation is correct, which hasn’t been accepted but hasn’t been disproved either, some way needs to be found to explain the extra 89 (122-33) K difference between what GHGs supposedly account for and what we actually see.”
Not sure, but it maybe be a body which has very little heat capacity.
The moon even after it’s nite has fair amount of heat capacity.
If you started with a cold moon- say 20 K at surface and basically 20 K 100 meter below surface and then began heating it with sunlight it would much cooler than it is.
You still get about 123 C in daylight but it cool quicker and would drop lower than 100 K at nite- say around 30 K. So simply half of 70 K is minus 35 K.
Next regions other than tropics, won’t warm as quickly, you may have near present temperatures
in near equator regions but without heat capacity in higher latitudes- one less solar energy per square and takes longer to get to warmer- so that might account for say – 10 K.
If start cold and have atmosphere, it’s even colder- equator temperatures probably would reach 123 C. And if you faster rotation, again the average temperature will be lower.
Given enough time- say 1000 years one would have a warmer planet.
So all these factors could add up to 89 or more K.
“it’s even colder- equator temperatures probably would reach 123”
i meant would NOT reach 123 C, depends on how much atmosphere.
Think how energy would be lost with earth type atmosphere with convection.
You have hard time frying eggs on sidewalk- you need 70 C, and probably
lose 10 C or more from conduction, to get to 100 C- you would lose more
than 20 C from- therefore instead 123, it’s highest temperature is 100 C or less.
Iceman, thanks for your kind words. Nearly a year ago I posted a graph here at WUWT of US Temperatures vs CO2 levels, showing a lack of correlation in the 1930’s and 1970’s. See Forget CO2, US Debt Causes Warming! Total US Debt (public and private) as a percentage of US Gross Domestic Product (GDP) correlates with NASA GISS US Annual Mean Temperature Anomaly better than CO2 levels! So, if we want to reduce warming, cut the debt! My “theory” seems better than the Universal Theory right now :^)
Bart @ur momisugly January 7, 11:46 am
Bart, you commented in part to Joel Shore:
IMO, that is a very important observation. As you say, the emissivity from sea water as referenced by Joel, (assuming it is not unduly influenced by GHG’s), is far from Planckian. You may remember my guest post concerning a “paradox with the Trenberth cartoon”:
http://wattsupwiththat.com/2011/10/26/does-the-trenberth-et-al-%e2%80%9cearth%e2%80%99s-energy-budget-diagram%e2%80%9d-contain-a-paradox/
In the addendum, I had thought that the various plots of radiation observed from space, (or modelled), were complicated by emissions coming from various sources and altitudes and whatnot, but it seems, not that simple. Interesting that Trenberth assigned an emissivity of 1, when clearly over 70% of the surface is considerably less than that, if Joel’s reference is correct.
JAE
I recall that you expressed some doubts on an earlier thread as to whether the ocean could be treated as a black body. You may find my exchange with Bart; see my post just above, interesting.
Bart says:
January 7, 2012 at 12:06 pm
1) are those gaps solely the result of interception of radiation by GHGs, or do those gaps already exist in significant form in the surface radiation profile? How do atmospheric conductance and convection alter the distribution of energy states at the surface of the Earth?
The gaps are solely the result of GHG absorption, check out MODTRAN to see, for example.
Conduction and convection changes the temperature of the surface and therefore the total emission, read any undergraduate text on heat transfer.
gbaikie says:
January 7, 2012 at 2:41 pm
“Assuming their GB temperature calculation is correct, which hasn’t been accepted but hasn’t been disproved either, some way needs to be found to explain the extra 89 (122-33) K difference between what GHGs supposedly account for and what we actually see.”
It certainly isn’t correct, it’s based on the erroneous model that the darkside of the planet is at absolute zero which leads to about 100K error for the earth.
Bart says:
Bob Fernley-Jones says:
Good God, folks, please learn how to read a graph! The entire y axis of that graph is from 0.96 to 0.995! Over that entire wavelength range shown (which corresponds to a factor of 4 in peak absolute temperature of the peak emission), the value of emissivity is 0.98 +/- 0.01 where 0.01 is my generous estimate of the standard deviation. Furthermore, the Planckian curve is going to integrate over that distribution…So, the resulting variation in the power with temperature is probably going to get further reduced. Then you have the fact that the temperature is proportional to the fourth root of power, which means if the emissivity causes the power to vary by 1%, that translates into a quarter percent in absolute temperature.
You guys are picking nits here!
What energy distribution?
No…It means that you actually have to take some responsibility to justify your arguments, especially when those arguments don’t agree with standard physics.
Bob & Bart,
Are you looking at the same diagram I am for emissivity of water? http://www.icess.ucsb.edu/modis/EMIS/images/seawat10.gif
The graph shows the emissivity as 0.98 +/- 0.01 over the entire range of wavelengths of interest. I would not consider 0.98 to be “considerably less than” 1.00.
Furthermore, I disagree with “SB is intended for a surface which is in radiative equilibrium.” SB gives the power emitted as a function of the temperature of the object, whether or not it is in equilibrium with other objects around.
markx says:
January 7, 2012 at 6:54 am
World 1 – grey featureless, no atmosphere; under a constant radiative energy source.
Or consider 3 worlds the first with an atmosphere one tenth of Earth’s pressure mostly N2 with a low concentration of CO2, this will have a weak GH warming.
The second with ten times the pressure (~Earth’s) but the same number density of CO2 as the first, this will have a stronger GH warming due to pressure broadening o f the CO2 spectral lines.
Finally the third has a further factor of ten pressure increase but otherwise the same, this will have an even stronger GH warming for the same reason. See the respective spectra here:
http://i302.photobucket.com/albums/nn107/Sprintstar400/CO2101copy.jpg
Bob Fernley-Jones says:
January 7, 2012 at 3:17 pm
Bart @ur momisugly January 7, 11:46 am
Bart, you commented in part to Joel Shore:
…SB is intended for a surface which is in radiative equilibrium. The surface of the Earth is not in radiative equilibrium. Your plot for seawater shows quite clearly that the spectrum deviates significantly from that of a blackbody. And, they do not show that the modeshape scales conformally as T^4. I bet you it does not…
IMO, that is a very important observation. As you say, the emissivity from sea water as referenced by Joel, (assuming it is not unduly influenced by GHG’s), is far from Planckian.
Far from! It’s close to a perfect Black body in the wavelength range shown in that graph.
You may remember my guest post concerning a “paradox with the Trenberth cartoon”:
http://wattsupwiththat.com/2011/10/26/does-the-trenberth-et-al-%e2%80%9cearth%e2%80%99s-energy-budget-diagram%e2%80%9d-contain-a-paradox/
In the addendum, I had thought that the various plots of radiation observed from space, (or modelled), were complicated by emissions coming from various sources and altitudes and whatnot, but it seems, not that simple. Interesting that Trenberth assigned an emissivity of 1, when clearly over 70% of the surface is considerably less than that, if Joel’s reference is correct.
Since when has varying between 0.96 and 0.99 with an average of ~0.98 been ‘considerably less than’ 1.0?
“You may remember my guest post concerning a “paradox with the Trenberth cartoon” ” I do, and I had problems with your problems even then. You never commented on how Trenberth had 199 W.m^-2 radiating to space and 333 W.m^-2 radiating back to the surface. The gaseous radiators with which I am familiar are reasonably symmetrical – i.e. they emit equally in all directions. I suppose there could be some handwaving about changes in density with atmosphere, or changes in water vapour with altitude, to try to explain the discrepancy – but as far as I am concerned it is THE major discrepancy in the whole Trenberth story.
Tim Folkerts says:
You would also have to specify the wavelength or wavelength range that you want to average over. Unlike solids and liquid, gas spectral absorption / emission is extremely squirrelly. Bart is freaking out because over the wavelength range from 3.5 to 14 microns, the emissivity of sea water can vary by 0.98 +/- 0.01 (where the +/- is a generous estimate of the 1-sigma standard deviation). For gases, the absorption can vary by many orders of magnitude over miniscule wavelength ranges! That’s why exact calculations of radiative transfer in the atmosphere involve using line-by-line radiation codes.