A controversial look at Blackbody radiation and Earth minus GHG's

Absorptions bands in the Earth's atmosphere cr...

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Guest Post by Reed Coray

On Dec. 6, 2011 12:12 am Lord Monckton posted a comment on a thread entitled Monckton on sensitivity training at Durban that appeared on this blog on Dec. 5, 2011. In that comment he wrote:

“First, it is not difficult to calculate that the Earth’s characteristic-emission temperature is 255 K. That is the temperature that would obtain at the surface in the absence of any greenhouse gases in the atmosphere. Since today’s surface temperature is 288 K, the presence as opposed to absence of all the greenhouse gases causes a warming of 33 K”.

Since I’m not sure what the definition of the “Earth’s characteristic-emission temperature” is, I can’t disagree with his claim that its value is 255 K. However, I can and do disagree with his claim that 255 K is “the temperature that would obtain at the surface in the absence of any greenhouse gases in the atmosphere”.

When computing the Earth’s surface temperature difference in “the presence as opposed to the absence of all greenhouse gases”, (i) two temperatures (A and B) must be measured/estimated and (ii) the difference in those temperatures computed. The first temperature, A, is the temperature of the Earth’s surface in the presence of an atmosphere that contains both greenhouse gases and non-greenhouse gases. The second temperature, B, is the temperature of the Earth’s surface in the presence of an atmosphere that contains non-greenhouse gases only–i.e., an atmosphere that contains non-greenhouse gases but is devoid of greenhouse gases.

For temperature A almost everyone uses a “measured average” of temperatures over the surface of the Earth. Although issues may exist regarding the algorithm used to compute a “measured average” Earth surface temperature, for the purposes of this discussion I’ll ignore all such issues and accept the value of 288 K as the value of temperature A (the temperature of the Earth’s surface in the presence of an atmosphere that contains both greenhouse gases and non-greenhouse gases).

Thus, we are left with coming up with a way to measure/estimate temperature B (the temperature of the Earth’s surface in the presence of an atmosphere that contains non-greenhouse gases only). We can’t directly measure B because we can’t remove greenhouse gases from the Earth’s atmosphere. This means we must use an algorithm (a model) to estimate B. I believe the algorithm most commonly used to compute the 255 K temperature estimate of B does NOT correspond to a model of “the temperature of the Earth’s surface in the presence of an atmosphere that contains non-greenhouse gases only”. As will be evident by my description (see below) of the commonly used algorithm, if anything that algorithm is more representative of a model of “the temperature of the Earth’s surface in the presence of an atmosphere that contains both greenhouse gases and non-greenhouse gases” than it is representative of a model of “the temperature of the Earth’s surface in the presence of an atmosphere that contains non-greenhouse gases only.”

If I am correct, then the use of 255 K in the computation of the Earth surface temperature difference with and without greenhouse gases is invalid.

Although there are many algorithms that can potentially lead to a 255 K temperature estimate of B, I now present the algorithm that I believe is most commonly used, and discuss why that algorithm does NOT represent “the temperature of the Earth’s surface in the presence of an atmosphere that is devoid of greenhouse gases”. I believe the algorithm described below represents the fundamental equation of radiative transfer for the Earth/Sun system assuming (a) an Earth absorption albedo of 0.3, and (b) an Earth emissivity of 1.

(1) The “effective temperature” of the Sun [i.e., the temperature of a sun-size spherical blackbody for which the radiated electromagnetic power (a) is representative of the total solar radiated power, and (b) has a power spectral density similar to the solar power spectral density] is approximately 5,778 K.

(2) For a spherical blackbody of radius 6.96×10^8 meters (the approximate radius of the sun) at a uniform surface temperature of 5,778 K, (a) the total radiated power is approximately 3.85×10^26 Watts, and (b) the radiated power density at a distance of 1.5×10^11 meters from the center of the blackbody (the approximate distance between the center of the Sun and the center of the Earth) is approximately 1,367 Watts per square meter.

(3) If the center of a sphere of radius 6.44×10^6 meters (the approximate radius of the Earth) is placed at a distance of 1.5×10^11 meters from the center of the Sun, to a good approximation the “effective absorbing area” of that sphere for blackbody radiation from the Sun is 1.3×10^14 square meters; and hence the solar power incident on the effective absorbing area of the sphere of radius 6.44×10^6 meters is approximately 1.78×10^17 Watts (1.3×10^14 square meters x 1,367 Watts per square meter).

(4) If the sphere of radius 6.44×10^6 meters absorbs electromagnetic energy with an “effective absorption albedo” of 0.3, then the solar power absorbed by the sphere is 1.25×10^17 Watts [1.78×10^17 Watts x (1 – 0.3)].

(5) A spherical blackbody (i.e., a spherical body whose surface radiates like a surface having an emissivity of 1) of radius 6.44×10^6 meters and at a temperature 254.87 K (hereafter rounded to 255 K) will radiate energy at the approximate rate of 1.25×10^17 Watts.

(6) If independent of the direction of energy incident on a sphere, the surface temperature of the sphere at any instant in time is everywhere the same, then the sphere possesses the property of perfect-thermal-conduction. Thus, for (a) an inert (no internal thermal energy source) perfect-thermal-conduction spherical body of radius 6.44×10^6 meters and uniform surface temperature 255 K whose center is placed at a distance of 1.5×10^11 meters from the center of an active (internal thermal energy source) spherical blackbody of radius 6.96×10^8 meters and uniform surface temperature 5,778 K, and (b) the inert perfect-thermal-conduction spherical body (i) absorbs electromagnetic energy with an effective absorption albedo of 0.3, and (ii) radiates electromagnetic energy with an emissivity of 1 then the perfect-thermal-conduction inert spherical body at temperature 255 K will be in radiation rate equilibrium with the active spherical blackbody at temperature 5,778 K.  If the phrase “inert perfect-thermal-conduction spherical body of radius 6.44×10^6 meters” is replaced with the word “Earth,” and the phrase ” active spherical blackbody of radius 6.96×10^8 meters and uniform surface temperature 5,778 K” is replaced with the word “Sun”, it can be concluded that: If (a) an “Earth” at temperature 255 K is placed at a distance of 1.5×10^11 meters from the “Sun” and (b) the “Earth” (i) absorbs electromagnetic energy with an effective absorption albedo of 0.3, and (ii) radiates energy with an emissivity of 1, then the “Earth” will be in radiation rate equilibrium with the “Sun.” For the above conditions, the temperature of the “Earth” in radiation rate equilibrium with the “Sun” will be 255 K.

This completes the algorithm that I believe is commonly used to arrive at an “Earth’s characteristic-emission temperature” of 255 K, and hence is used to compute the 33 K temperature difference.

Even ignoring the facts that (1) it is incorrect to use the “average surface temperature” when computing radiation energy loss from a surface, and (2) in the presence of an atmosphere, (a) the blackbody radiation formula may not apply, and (b) blackbody radiation from the surface of the Earth is not the only mechanism for Earth energy loss to space (the atmosphere even without greenhouse gases will be heated by conduction from the Earth surface and both conduction and convection will cause that thermal energy to be distributed throughout the atmosphere, and the heated atmosphere will also radiate energy to space), the problem with using the 255 K temperature computed above to determine the difference between the Earth’s temperature with and without greenhouse gases is that the effective Earth absorption albedo of 0.3 used to generate the 255 K temperature is in part (mainly?) due to clouds in the atmosphere, and atmospheric clouds are created from water vapor, which is a greenhouse gas.

Thus an effective absorption albedo of 0.3 is based on the presence of a greenhouse gas–water vapor. It is illogical to compute a difference between two temperatures both of whose values are based on the presence of greenhouse gases and then claim that temperature difference represents the temperature difference with and without greenhouse gases. Without water vapor, there won’t be any clouds as we know them. Without clouds, the effective absorption albedo of the Earth will likely not be 0.3, and hence without the greenhouse gas water vapor, the Earth’s surface temperature in the absence of greenhouse gases is likely to be something other than 255 K. Thus, the 255 K “Earth characteristic-emission temperature” as computed using the algorithm above is NOT relevant to a discussion of the Earth surface temperature difference for an atmosphere that does and an atmosphere that does not contain greenhouse gases.  Only if 0.3 is the effective absorption albedo of the Earth in the presence of an atmosphere devoid of all greenhouse gases is it fair to claim the presence of greenhouse gases increases the temperature of the Earth by 33 K.

Because clouds reflect a significant amount of incoming solar power, without water vapor I believe the effective absorption albedo of the Earth will be less than 0.3. If true, then more of the Sun’s energy will be absorbed by an Earth whose atmosphere is devoid of greenhouse gases than by an Earth whose atmosphere contains clouds formed from the greenhouse gas water vapor. This implies a higher Earth surface temperature in the absence of water vapor than the “Earth’s characteristic-emission temperature of 255 K”.

For an effective absorption albedo of 0, the temperature of the Earth in radiation rate equilibrium with the Sun will be approximately 278.64 K (hereafter rounded to 279 K). If this value is used as the Earth temperature in the presence of an atmosphere devoid of greenhouse gases, then it can be argued that the presence of greenhouse gases introduces a warming of approximately 9 K (288 Kelvin minus 279 K).

In summation, using the simplified arguments that I believe are also used to arrive at the 33 K temperature difference (i.e., assumed perfect-thermal-conduction Earth, blackbody Earth emission, greybody Earth absorption with an effective absorption albedo between 0 and 0.3, and ignoring atmospheric radiation to space for an Earth atmosphere devoid of greenhouse gases), I conclude the presence of greenhouse gases in the Earth’s atmosphere increases the Earth’s temperature by somewhere between 9 K and 33 K. Thus, I believe the claim that the presence of atmospheric greenhouse gases increases the temperature of the Earth by 33 K is based on an argument that has little relevance to the Earth’s temperature in the presence of an atmosphere devoid of greenhouse gases; and hence at best is misleading and at worst incorrect.

Note: Upon first publication – the guest author Reed Coray was accidentally and unintentionally omitted.

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Bryan

Yes your analysis is correct.
The albedo of the Earth surface is likely to be even less than the 0.12 value for the Moon.
Reason, the 70% of Earth surface covered by water.
Without the greenhouse gases the extra radiation reaching the surface will largely be short wave infra red(slightly longer than visible red down to 5um).
For this EM region the albedo must be getting near zero.

D. Cohen

“…the sphere possesses the property of perfect-thermal-conduction….”
This assumption of perfect thermal conduction for the earth without greenhouse gasses is at least as bad as the albedo assumption. I just looked up the average surface temperature of the moon. Without any atmosphere at all the average lunar surface temperature found after a 2 minute search of the web (so take this value for what it’s worth) is -9 degrees Fahrenheit. The moon is about the same distance from the sun as the earth, so this value could be regarded as a ballpark estimate for what you want to know.

Speed

The original post is here …
http://wattsupwiththat.com/2011/12/05/monckton-on-sensitivity-training-at-durban/
Monckton’s comment is here …
http://www.scienceandpublicpolicy.org/
Who wrote this post?

Lars P.

There are many omission in the +33°K warming calculation.
The direct warming of the atmosphere from direct sunlight is ignored as well as the ocean warming from direct sunrise and the way how the seas get their average temperature, through enthalpy & radiation.
The snowball earth theory without CO2 makes no sense as it ignores the 1365 W/m2 direct solar radiation on a spherical surface in rotation not 1/4 of it on a hypothetical flat world.
Greenhouse is only a fraction of the 33° and no earth energy budget ignoring the oceans has any scientific value.
It is used as it is a useful tool for the CAGW scare.

richard verney

There are strong arguments to suggest that the atmosphere if anything cools us rather than heats us. Certainly, if we did not have an atmosphere day time temperatures would be a lot hotter than we experience. Night time temperatures may be cooler but the extent to which this would be the case depends upon the heat capacity of the liquid storage reservoirs which cover approximately 3/4 of the surface area of the planet..
The average temperatrure of the globe may be out by several degrees, We do not accurately know its albedo nor its emissivity (which are not constants) and the oceans (which themselves are in effect a greenhouse gas albeit in liquid form) is a vast heat storage reservoir. The earth is not a blackbody and I consider that these fundamental problems make the entire BB assessment unreliable.
Further, I consider that it is misconceived to view the earth’s surface temperature as measured today as the base against which the comparison should be made. We are in the midle of an interglacial period and the earth’s surface is untypical warm. The oceans have an average temperature of about 4 degC and this low temperature will come back to bite. Some weighting should be given to take account that over geological time the average surface temperature of the earth is far less than we are privileged to enjoy today.
What if your calculation (or the accepted BB calculation) was performed 20,000 years ago? Many of the fundamentals would be the same and yet in this scenario, the cAGW crowd would have one believe that GHGs were raising the temperature by only about 23K (not 33K).
In posing that question I am aware that ice extent will have changed the albedo, but may be it was less cloudy elsewhere which would tend to offset the change in albedo made by ice.
I would not be surprised if in the real world GHGs add only a few degrees. It is the presence of water and its properties that keep us warm.

From the last few sentences one has therefore to conclude that the climate sensitivity to an additional greenhouse gas must be less than “previously thought”. Or in other words, CO2 adds only 9 K instead of 33 K. Am I right?

John Brookes

OK, that seems like a pretty silly argument. Take a look at Mars. I think Mars would be pretty close to earth without ghgs. No oceans, no vegetation, no ice no animals, just lots of red dirt. But Mars does not have an albedo of 0, it has an albedo of 0.25 – not too disimilar to that of Earth, and certainly a value which will get you closer to 255K than 279K.
As for the assumption of a perfectly thermally conducting Earth, if you abandon this, you will lower the average temperature. Because of the T^4 dependancy of outgoing radiation, having one part of earth at (say) 245 and another of equal area at 265 will result in more outgoing radiation than having it all at 255. Therefore to achieve the same amount of outgoing radiation, the average temperature needs to be lower than 255.
Anyway, well done for writing this, but make a bit more effort to think things through.

Stephen Wilde

This is yet another example of a set of calculations that simply ignores the role of sunlight into the oceans
Since most of the Greenhouse Gases are in fact water vapour the whole exercise is meaningless unless one removes the oceans and all surface water too.
Some warming proponents have suggested that without non condensing GHGs (all those other than water but especially CO2) then in that situation all the water on Earth would freeze. That is their way of attributing ultimate importance to the non condensing GHGs.
However I don’t see that as likely. Sunlight would still penetrate the oceans and water would still evaporate. The water cycle might be slower but it would still be present would it not ?
To my mind this issue goes to the heart of AGW theory which assumes that the Earth is about 33C warmer than it ‘should’ be as a result of GHGs.
What I would like to know is how they feel able to exclude the oceans in setting that temperature. The liquid in the oceans is a vastly more effective system for slowing down the exit of solar energy from the Earth system than are all the GHGs present in the air even including water vapour.
As far as I know Arrhenius et al only considered the atmosphere. They did not consider the role of the oceans so in order to maintain AGW theory it is essential to propose that it is only the non condensing GHGs that keep the oceans liquid.
But that is not the case. It is solar shortwave penetrating the ocean surface that keeps the oceans liquid, creating water vapour in the process and thus making the Earth’s atmosphere warmer than it otherwise would have been.
That solar shortwave into the oceans and the retention of much of that energy for a lengthy period of time is the primary mechanism for slowing down the loss of that energy back to space. Vastly greater than the slowing down caused by GHGs.
It is the atmospheric pressure that dictates the baseline energy content that the oceans can achieve because that pressure determines the energy cost of evaporation by fixing the energy value of the latent heat of evaporation. Namely the difference between the amount of energy required to break the bonds between water molecules relative to the energy required by the breaking process. At current atmospheric pressure the latter is about 5 times the former which is why evaporation is a very powerful net cooling process.
GHGs do NOT affect that baseline energy content for the oceans because they do not significantly affect atmospheric pressure and therefore they can only affect the rate of energy flow from surface to space. Therefore GHGs can only result in a faster water cycle and NOT a change to the baseline energy content for the system as a whole.
The rate of energy flow from surface to space at any given moment is reflected in the relative sizes, intensities and latitudinal positions of the permanent climate zones. It is the shifting of those zones that we perceive as climate change and NOT any significant change in total system energy content.

steveta_uk

Surely if you want to determine the effects of the sun on a body at the distance of the earth with no atmosphere, just look to the moon.

Richard M

I’ve mentioned before that I thought this computation was missing from the literature. I believe you’ve made a great start. However, there is more to the question than just albedo.
The surface of a bare Earth would still have some albedo, but even more important, an atmosphere of O2 and N2 would still absorb and radiate some energy. There would also be some conduction from the surface and 100% of the surface area would be land. Since this kind of atmosphere would NOT radiate very effectively due to its low emissivity, it’s important to determine how much heat would get trapped and what the equilibrium temperature would be.

Alan Statham

This is painful to read. You seem ignorant of many things. You even start by saying you don’t know what is meant by a characteristic emission temperature. I mean, that’s not particularly clear language but anyone with a basic physics education knows what is meant by that. You wrongly claim that you can’t use an average temperature to calculate radiation losses. And you have used nearly 2000 words simply to say that you don’t agree with the albedo commonly used in this simplified calculation.
The calculation neglects the greenhouse effect; it doesn’t neglect the reflective properties of the atmosphere. This is because we wish to estimate the magnitude of the greenhouse effect, so we only take that out.

And not forgetting that our EARTH HAS NO LID.
Then, the question arises: Where is heat saved?
Alternatives:

1) Atmosphere: Air: Volumetric heat capacity: 0.00192 joules /cu-cm.
2) Oceans: Water: Volumetric heat capacity:4.186 joules/cu-cm, i.e., 3227 times than that of Air.

3) Soil: Ground: volumetric heat capacity: About 2.0 joules /cu-cm.
Green House Effect = Confined Heat Effect

No confinement = No effect.

Remember: How soon atmosphere cools down during an eclipse.

richard verney

Stephen Wilde says:
December 26, 2011 at 4:23 am
//////////////////////////////////////
I am with you on much of what you have said.
On several occassions I have had arguments with Willis regarding the oceans freezing. He considers that without GHGs the oceans would freeze. I say to him, he is basing that claim on average conditions and one needs to look not at the average condition but rather to look at the considtions prevailing over the tropics. In the tropics, there is enough sloar energy to ensure that the oceans do not freeze at the tropics. The heat in the tropical ocean is then circulated poleward. May be the circulation pattern and extent would be different to that observed today but the material point is that the tropical ocean would not freeze and some of its heat would be distributed elsewhere.
The key to Earth’s climate is the oceans, the properties of water and the water cycle.

davidmhoffer

Stephen Wilde nails it when he says:
“Since most of the Greenhouse Gases are in fact water vapour the whole exercise is meaningless unless one removes the oceans and all surface water too.”
Further, I don’t think the 255K number is supposed to represent the surface temperature of the earth without greenhouse gases. It is supposed to represent the temperature of the earth without the greenhouse EFFECT. If that is the case, then the logic presented to arrive at 255K seems quite reasonable.
(I’d rather eat bark than admit that the IPCC et al got anything right, but in this case, I think they did)

BenAW

Try this for simplicity:
incoming total radiation 1364 W/m^2 on a disk with a radius the same as earth.
Since a sphere has a four times larger area than a disk divide by 4.
30% albedo: 0,7 x 1364 / 4 = 239 W/m^2 average incoming radiation.
Stefan Boltzmann (SB) then gives the infamous 255K
More realistic seems to divide the incoming radiation over half the sphere, as on the real earth.
The fourth power in SB then has an interesting effect:
0,7 x 1364 / 2 = 477 W/m^2
SB now gives 303K !!!!
So half the earth receives on average enough energie to reach 303K (30 C)
Since the average temp is lower 288K ? (15 C), this surplus is stored and released at the nightside of the earth. Seems very plausible that this results in an average temp of 288K.
No greenhouse effect needed.

Sionn5

One must also understand that there is in inherent temperature due to gravity. Gravity pulls a non greenhouse atmosphere down and this produces a pressure. The ideal gas law can be used to approximate this inherent temperature. This effect occurs on any gravitating body with any type atmosphere and is already neglected in the calculations.

davidmhoffer

who is the author of this? the article only says “news staff” and it isn’t signed either?

It surprises me when people believe 5x10ee18kg of cold, rarefied atmosphere can heat 1350x10ee18kg of water. You can heat a material with a large thermal mass (like water) with a material with a small thermal mass (like a gas), but never if the gas is colder than the liquid. This is an intelligence test.
Imagine a gallon of water on a table in front of you. There are lots of methods that can be used to increase its temperature by 10% (33C). However, which of these methods are at work in the atmosphere?

A thought experiment. If the earth had an albedo of 0 and you could put whatever imaginary layer you wanted around it (with physical properties, i.e. you can’t use one-way glass that doesn’t exist in the real world). What is the maximum temperature?
Could you get the earth to have a higher temperature than a theoretical perfect black-body? If so, does that seem logical?

steveta_uk

John Brookes (December 26, 2011 at 4:18 am)
(245+265) / 2 = 255
sqrt( sqrt( ((245^4)+(265^4)) / 2 ) ) = 255.5864
Not what I was expecting.

wayne

Not only is the Earth not a black body but since oceans cover about 7/10th of the surface, a much smaller area than half of a sphere centered directly under the sun can even have the effect of absorption of incoming radiation as clearly shown in this simple experiment in relation to the specific critical angle:

I can find no reference of this in “climate science” and would appreciate any links someone might have, where this is taken into account or, whether this is calculated within the albedo ~0.30 figure used within such calculations used in this post.

PeterF

“… and the heated atmosphere will also radiate energy to space)”
No, it won’t. When you start with the assumption that there are no greenhouse gases in the atmosphere, then the remaining gases (oxygen and nitrogen in this case) will neither absorb nor radiate in the relevant micrometer range, and hence can’t radiate energy to space. They are not a blackbody.
I am puzzled as to what exactly will happen in such an atmosphere: we will get an adiabatic temperature profile, we will get convection and redistribution of heat through circulation (“wind”), but all heat removal from earth must come from radiative emission from the earth itself, not from its atmosphere. The albedo will be determined solely from the earth’s surface, i.e. its various soils, as the atmosphere will not be radiating.
At the end, this heat redistribution on the globe will possibly result in a justification of the assumption of a single, global temperature which determines the radiative heat loss of the earth.
Or not?

richard verney

steveta_uk says:
December 26, 2011 at 4:24 am
Surely if you want to determine the effects of the sun on a body at the distance of the earth with no atmosphere, just look to the moon.
///////////////////////////////////////////////////////////////////////////////////
Two problems. First, the length of the lunar day. Eg., what would be the average temperature of the moon if a lunar day was only one hour rather than about 27;5 days? This becomes very important when considering the second problem. Second, the moon is a rocky world without the heat storage reservoirs found on Earth (ie., it does not have the equivalent thermal ocean reservoirs).
On Earth, the oceans absorb solar irradiance during the day and then slowly release this at night. The Earth’s rotation of 24 hours playing an important role in this. There is long enough daylight for the oceans to respond to the warmth of the sun, but not too much darkness to permit them to fully convcet/conduct and radiate away the heat so absorbed. If the Earth rotated on its axis once every 100 years, the conditions on Earth would be radically different even though we would still be receiving the same amount of solar energy input.
The Earth is a water world and cannot be likened to a rocky world. As far as I understand matters BB calculations do not work properly for the moon nor for any of the planets in the solar system and the Earth (due to its watery nature) is far more complicated.
I consider the entire rational behind the BB calculations for the Earth to be misconceived . .

Richard M

I think were on the right track here. First, we need to consider the Earth with no oceans and an atmosphere just like the current one without GHGs. Then, we need to add back in the oceans but still keep the GHGs out of the atmosphere. Yes, I realize this is unphysical, but I think in doing those calculations we could learn a lot.
I think it’s very possible the first situation would have a surface temperature greater than what we currently have and what it would be in the second situation. I suspect, as others have indicated, that water cools the planet.

Dave Springer

“If I am correct, then the use of 255 K in the computation of the Earth surface temperature difference with and without greenhouse gases is invalid.”
Yes of course it is. It’s the earth without an atmosphere or ocean and an albedo of zero. The average temperature of the moon is 250K. It has an albedo of 0.15.
Ask the fraudsters sometime to take the ocean out of their climate models and see what happens. The global ocean is where most of the greenhouse effect happens. Water is quite transparent to visible light and quite opaque to infrared. It’s more opaque than water vapor and far more opaque than CO2. Transparency to visible light and opacity to infrared are the properties which distinguish greenhouse gases from non-greenhouse gases. Since gases are technically fluids and liquid water has the requisite properties for greenhouse warming one can then quickly realize that greenhouse heating of the ocean is what does most of the surface warming above blackbody temperature. Sunlight penetrates the ocean to some 100 meters where it absorbed along the way by impurities. All the energy in the sunlight is transferred to the water at the speed of light. However because water is opaque at all far infrared frequencies, unlike CO2 which is opaque only in narrow bands, none of that energy absorbed at depth can escape radiatively – it must be mechanically transported to the surface. That delay in transport, whether it’s water or CO2 doing the delaying, is what causes the so-called greenhouse effect. The ocean, you see, has many times the mass of the atmosphere and thus many times the greenhouse effect. Adding insult to injury the ocean doesn’t absorb any significant energy from downwelling infrared from greenhouse gases because the LWIR energy is completely absorbed in a skin layer just a few micrometers deep which doesn’t mix downwards but rather evaporates and carries the LWIR energy immediately away as latent heat of vaporization.

coldlynx

The classic mistake or “trick” is to calculate the outgoing radiation from earth surface.
As if GHG and cloud does not exist.
Do the math from middle of atmosphere: 50% of atmosphere weight is 500 Mb equal to 5500 meter altitude. Lapse rate for humid atmosphere are about 6 C/1000 meter or for 5500m …… “Ta da”……..33 C colder than on earth surface. Such a coincidence. Not.
The atmospheric window is just that, a small wavelength window where just some radiation escape from earth surface direct to space. Most of outgoing radiation are radiated from the atmosphere.
For an average temperature are an average altitude and by that an average radiation balance just making sense.
By the way, change in UV radiation from the sun alter atmosphere height, that is changing the 500mb altitude, which will change the average surface temperature.

Dave Springer

“the effective Earth absorption albedo of 0.3 used to generate the 255 K temperature is in part (mainly?) due to clouds in the atmosphere, and atmospheric clouds are created from water vapor, which is a greenhouse gas.”
A sticky wicket indeed. The earth and moon are made of the same stuff. The moon has an albedo of ~0.15 which is what the earth would be without an atmosphere. The ocean has an albedo of ~0.00 which makes it a lot darker than the moon. But the ocean can’t exist without an atmosphere to keep it from boiling away. And you can’t have a liquid ocean and an atmosphere without clouds. Clouds have an albedo of ~0.80 and then the combination of all these things gives the planet an albedo in the range of ~0.35 which varies interannually by an unknowm but presumably small amount in the range of +-0.03.
No one knows exactly what the earth’s average albedo really is. Climate models use values which differ by as much as 0.07 from one to another. Speaking in W/m^2 that 0.07 uncertainty is 7% of some 200 Watts per square meter or about 14 W/m2. The net effect of all anthropogenic forcings is claimed to be around 2.5W/m2 so in essence this means that uncertainty in natural albedo forcing is about 6 times greater than anthropogenic forcing. In other words, the models are operating in the dark (so to speak) with uncertainties far greater than the anthropogenic factor they are trying to calculate. Albedo in the climate models is a proverbial fudge factor that is adjusted by the model maker to whatever value gives the best result in conjuction with all the other assumptions and variables. If these models weren’t being considered with more credibility than instruments (if observations disagree with models it is presumed the observations must be wrong!) this would be material for late night talk show comedy skits.

Leonard Weinstein

The writeup is wrong on the two major points. PeterF made the first one, that if there is no greenhouse effect, the atmosphere will not radiate much to space (there would be a small amount from aerosols and very weak diatomic gas effects, but not significant). The second point is the albedo effect. Oceans and clouds have effects, but if no greenhouse effect were present, the clouds (and water vapor) would not be present. The albedo would then be due to ground level absorption. It does not matter if there are oceans or not if the assumption of equivalent albedo is assumed to be the same, as long as no clouds or water vapor is present. The only effect of oceans is storage and distribution, and long term averages would be the same as if no oceans were present. Lord Monckton is correct as far as his statements are made. Get over it.

What about a “leaking condenser”,where the atmosphere, being the dielectric, short circuits during lightning storms (and also during tornadoes, etc.)?

Dave Springer

This implies a higher Earth surface temperature in the absence of water vapor than the “Earth’s characteristic-emission temperature of 255 K”.
“For an effective absorption albedo of 0, the temperature of the Earth in radiation rate equilibrium with the Sun will be approximately 278.64 K (hereafter rounded to 279 K). If this value is used as the Earth temperature in the presence of an atmosphere devoid of greenhouse gases, then it can be argued that the presence of greenhouse gases introduces a warming of approximately 9 K (288 Kelvin minus 279 K).”
Bingo. The ocean has an albedo of effectively 0 and it covers 70% of the surface. The rocks have an effective albedo of 0.15, same as the moon, which is (believe it or not) about the same as weathered asphalt. The moon is a much darker color than one might guess by looking at it because it is contrasted against the inky blackness of space. If it had the albedo of a cloud or snow it would be blinding to look at it.
Anyhow, the albedo of the earth sans greenhouse gases would be around 0.05 instead of .035 which would make it quite a bit warmer than 255K on average.
Technically however, clouds aren’t greenhouse gases. They are composed of liquid water droplets. Water is highly reflective at high angles of incidence so unlike the surface of the ocean with presents a low angle of incidence to sunlight except near the poles and near sundown &* sunset when it doesn’t really matter because solar power is very weak then anyhow, clouds are liquid water in a highly reflective configuration.
It’s tough to imagine how clouds would form without atmospheric water vapor but to be fair one must point out that clouds aren’t composed of water vapor.

Don’t we already have a close by object with no atmosphere? What’s the surface temp on the moon? Can that not be used an an example?

“The Earth is a water world and cannot be likened to a rocky world. As far as I understand matters BB calculations do not work properly for the moon nor for any of the planets in the solar system and the Earth (due to its watery nature) is far more complicated.”
That makes sense. Then it begs the question, that as the earth rotates and continents interupt the water absorbtion, then less heat is captured. Correct? Then that begs the question, was then the differences in climate (ie no winters prior to this ice age) caused by the configuration of the continents? Less exposed land the warmer the planet became? Shallow seas means more life (our oil today), which changes the climate as well.
I don’t think the climate modelers are even close to how the planet works.

Dave Springer

Complicating all this even more is rotation rate. The *measured* average temperature of the moon’s surface is 250K. Its albedo is much lower than the earth’s so by that empirical yardstick the earth should be colder than the moon. However, the blackbody calculation for the earth presumes that it is rotating fast enough for day/night temperature difference to be erased. But it does rotate and does have a diurnal temperature difference. Sans atmosphere the difference would be nearly as great as on the moon (which is a couple of hundred degrees K). Because heat is lost faster when temperature is higher this makes the real-life rotating body colder than the blackbody calculation would produce. Thus we have the circumstance where the earth’s moon with an albedo of 0.15 and a 28 day rotation period has a measured average temperature of 250K and a theoretical earth at albedo 0.30 spinning infinitely fast would be 5K warmer even though the theoretical earth absorbs 15% less energy.
There are so many confounding factors that the 33K figure bandied about for an earth without greenhouse gases is completely untrustworthy and without merit. I use that figure solely for the sake of argument because it isn’t necessary to dispute it in order to show the hideous flaws in computer climate models.
But this is still a great OP as it does point out a very flawed assumption bandied about by CAGW fraudsters as some kind of basic fact that is beyond dispute. Little of what they claim is beyond dispute.

DirkH

PeterF says:
December 26, 2011 at 5:26 am
““… and the heated atmosphere will also radiate energy to space)”
No, it won’t. When you start with the assumption that there are no greenhouse gases in the atmosphere, then the remaining gases (oxygen and nitrogen in this case) will neither absorb nor radiate in the relevant micrometer range, and hence can’t radiate energy to space. They are not a blackbody.”
So O2 and N2 will keep their energy forever even if in the vacuum of space, as they can’t radiate anything? I don’t think that’s how it works. Would be an interesting energy storage if it worked.
http://www.americanthinker.com/2010/02/the_hidden_flaw_in_greenhouse.html
Now, of course O2 and N2 don’t have the absorption/emission bands in the LWIR range that CO2 or H2O have but that surely doesn’t stop them from having SOME emissivity.
Is there a substance with zero emissivity? Only at 0 K.
“real substances have an emissivity between zero and one (0 <ε< 1)."
http://www.learnthermo.com/T1-tutorial/ch04/lesson-B/pg22.php

Thermo

Infrared radiation can’t heat gases (atmosphere), so where is warming effect?

Luther Wu

jrwakefield says:
December 26, 2011 at 6:57 am
Don’t we already have a close by object with no atmosphere? What’s the surface temp on the moon? Can that not be used an an example?
__________________________
250K degrees.

Thierry

Everything concerning the fictitious 33°C greenhouse gases effect has been definitively explained and rebutted by Gerlich & Tscheuschner (2009) in “Falsi fication Of The Atmospheric CO2 Greenhouse E ffects Within The Frame Of Physics” (http://arxiv.org/abs/0707.1161)
This value comes from a wrong use of the Stefan-Boltzmann law (flux imposing local temperature, which is wrong) involving an over simplified planet model (no atmosphere, infinite conductivity, no rotation). The real temperature would be -129°C.
Therefore, this -18°C has no meaning at all.
I do not understand why there is still a debate here.

Dave Springer

Leonard Weinstein says:
December 26, 2011 at 6:32 am
“The writeup is wrong on the two major points. PeterF made the first one, that if there is no greenhouse effect, the atmosphere will not radiate much to space (there would be a small amount from aerosols and very weak diatomic gas effects, but not significant). The second point is the albedo effect. Oceans and clouds have effects, but if no greenhouse effect were present, the clouds (and water vapor) would not be present. The albedo would then be due to ground level absorption. It does not matter if there are oceans or not if the assumption of equivalent albedo is assumed to be the same, as long as no clouds or water vapor is present. The only effect of oceans is storage and distribution, and long term averages would be the same as if no oceans were present. Lord Monckton is correct as far as his statements are made. Get over it.”
No, you’re wrong. The ocean has an effective albedo near zero and it radiates very little. Look up any ocean heat budget study in the literature and you will discover that the ocean loses most of its heat by evaporation not radiation. Land surfaces radiate. Water evaporates. Write that down. Land has an albedo of 0.15. Water has an albedo of 0.00. Write that down too. The go figure out your errors. Monckton is full of crap which is no surprise. He’s a legend in his own mind and has a goodly number of shallow-thinking sycophants such as yourself who worship him simply because he’s on the same side of the debate as you are.

This subject has been pretty well beaten to death by “Science of Doom”. Leonard Weinstein and DeWitt Payne were two of the folks who made the most sense there.

wayne

PeterF says:
December 26, 2011 at 5:26 am
“… and the heated atmosphere will also radiate energy to space)”
No, it won’t. When you start with the assumption that there are no greenhouse gases in the atmosphere, then the remaining gases (oxygen and nitrogen in this case) will neither absorb nor radiate in the relevant micrometer range, and hence can’t radiate energy to space. They are not a blackbody.
>>>
Sorry PeterF but your statement is not strictly correct. Have you never seen the oxygen radiation in lower frequency spectra? You are saying there are no vibrational lines in oxygen and nitrogen in mid-IR but all matter above zero Kelvin, even gases, though weakly, and primarily at microwave frequencies, do radiate electromagnetic wave energy away due to electron accelerations in the gas molecules interactions with each other.
However, a lone isolated molecule of oxygen or nitrogen in the void of space will do exactly as you said, never radiate at all, zero.
One paper I read about a year ago, listed on HITRAN site of I believe nitrogen-argon interaction continuum at about wavenumber 400/cm and lower.
If you have problems with this, give me a link to a radiometry scientific paper proving this otherwise.

davidmhoffer

PeterF says:
December 26, 2011 at 5:26 am
“… and the heated atmosphere will also radiate energy to space)”
No, it won’t. When you start with the assumption that there are no greenhouse gases in the atmosphere, then the remaining gases (oxygen and nitrogen in this case) will neither absorb nor radiate in the relevant micrometer range, and hence can’t radiate energy to space.>>>
Yes it will. The absorptive/radiative spectrum for Oxygen and NO2 is right in the graphic in the article. It may not be as pronounced as water vapour and CO2, but it isn’t zero either. Further, the atmosphere contains plenty of dust which will absorb and radiate depending on the composition of the dust, but more than likely in a very broad spectrum.

Joel Shore

To the author of this post: It is strange that with all that Monckton got wrong in that post (as was well-explained by some of us in the comments therein) you have chosen to attack the one thing that he got right. As davidmhoffer points out, the calculation of the 255 K number is for an atmosphere without a greenhouse effect, not an atmosphere without greenhouse gases. So, the correct calculation to do is to keep the Earth system albedo constant … Or, in other words, to ask, “Given that the Earth system (earth + atmosphere) absorbs 240 W/m^2, how warm could its surface possibly be if there were not a greenhouse effect?” And, the answer is that it could only be about 255 K at most.
BenAW: Your notions don’t even obey energy conservation. You are running yourself in circles getting confused about averages. I suggest you work in terms of total power in and out and then you will hopefully understand why your argument is nonsense.

Dave Springer

Richard M says:
December 26, 2011 at 5:52 am
” think were on the right track here. First, we need to consider the Earth with no oceans and an atmosphere just like the current one without GHGs. Then, we need to add back in the oceans but still keep the GHGs out of the atmosphere. Yes, I realize this is unphysical, but I think in doing those calculations we could learn a lot.”
What you get is a snowball earth. We already have something very similar to that condition to look at in the geologic column. The vast majority of the atmospheric greenhouse effect is from water vapor. On a snowball earth most of the water vapor is frozen out of the atmosphere and the ocean is effectively removed from the equation be being covered with permanent sea ice.
The earth with an atmosphere but no ocean would be a frozen wasteland. Without greenhouse gases it would be colder but not much colder so long as a liquid ocean covered most of the surface. Where non-condensing greenhouse gases are very important is in a snowball earth episode. On a snowball earth volcanoes continue to spew CO2 and dark ashes. On a snowball there are no CO2 sinks so CO2 keeps building up in the atmosphere. Ashes also accumulate as some float so when ice surfaces partially melt in the summer it concentrates the ash on the surface making it darker and darker. After millions of years of that a tipping point is reached. So non-condensing greenhouse gases are the kindling which ignites the water cycle. Once the water cycle is ignited it keeps the earth unfrozen (most of the time) and is self-regulating through cloud formation which caps the maximum temperature preventing a runaway greenhouse. It’s quite elegant and works so well that for most of the earth’s history, even though the sun has increased its output 10% over geologic time, the earth stays warm and green from pole to pole. Episodes where there is permanent ice cover at the poles are rare. If anything right now the big climate danger lurking around the corner is the end of the Holocene Interglacial period and unless one finds hunting wooly mammoths over frozen tundra to be a good way to earn a living then we should welcome what little additional warming that anthropogenic greenhouse gases can give us and be concerned about what happens when we no longer have a way of fluffing up the earth’s temperature enough to maybe avoid the return of mile-thick glaciers as far south as New York City.

davidmhoffer

snip – both you and Dave Springer need to take your arguments elsewhere – I’m sick of this moderating this war between you two – Anthony

Richard M

Why do you only consider radiation? The GHG-less atmosphere will receive energy by conduction. Since the atmosphere has low emissivity that heat will not be radiated away quickly as it can be with GHGs. However, once it gets warm enough it will start conducting heat back to the surface. Where is this equilibrium point? Is it 255 K and if so, why?
I’ll admit I don’t have any training in this area so maybe there is a simple explanation. I’ve never seen it though and can’t help feeling this could a positive feedback situation where the Earth would heat up.

Stephen Wilde

Dave Springer said:
“On a snowball earth most of the water vapor is frozen out of the atmosphere and the ocean is effectively removed from the equation by being covered with permanent sea ice.”
How could that happen when solar shortwave continues to be received into the oceans from equator poleward ? It is that which maintains our liquid oceans and not non condensing GHGs.
Removing non condensing GHGs would actually INCREASE such solar input to the oceans because it would no longer be absorbed by those gases on the way down through the atmosphere and thereby be converted from solar shortwave which DOES penetrate the ocean surface to infrared longwavewhich DOES NOT penetrate the ocean surface.
On that basis non condensing GHGS result in a COLDER oceanic equilibrium temperature for a given level of solar input to the system than would otherwise have been the case.
Only the energy content of the air is raised by non condensing GHGs but that extra energy is all in latent form and serves only to speed up the water cycle.
In contrast the energy content of the oceans is actually lowered.
However the total system energy content for the system as a whole in response to a given solar energy input remains pretty much unchanged because the atmospheric Greenhouse Effect is many magnitudes smaller than the Oceanic Hot Water Bottle Effect.

Dave Springer

@Stephen Wilde
I just read your treatise:
http://climaterealists.com/attachments/ftp/TheSettingAndMaintainingOfEarth.pdf
I had no idea you were a member of the Royal Meteorlogical Society!
I swear by all that is Holy and my mother’s eyes too that I hadn’t read your treatise before arriving at the same conclusions.
The only caveat I would add to it is that the earth isn’t entirely covered by ocean so there is still some validity in the atmospheric greenhouse effect particularly at the surface of the rocks where we live and work. On average the ocean is the big kahuna but on average we live in continental interiors far enough removed from the ocean so that we experience some warming due to greenhouse gases. That warming though simply isn’t enough to throw the entire system into a catastrophic tailspin. Perhaps it might be enough, given the greatest effect is in higher latitudes over continental interiors, that it can extend the Holocene Interglacial through the peak of the Milankovitch cycle without glaciation getting the upper hand this time. In point of fact I’m very hard pressed to come up with anything at all in the way of negative consequences from much higher atmospheric CO2 level. The earth is pretty much green from pole to pole when it is far higher and unless one actually likes barren rocks and ice one should ardently adore the prospect of more CO2.

davidmhoffer

Dave Springer;
Adding insult to injury the ocean doesn’t absorb any significant energy from downwelling infrared from greenhouse gases because the LWIR energy is completely absorbed in a skin layer just a few micrometers deep which doesn’t mix downwards but rather evaporates and carries the LWIR energy immediately away as latent heat of vaporization.>>>
This would be true of still water with no impurities. In windy or rainy conditions, the surface tension layer doesn’t exist for the most part as the surface must be relatively still for a period of 5 to 7 seconds before the skin layer reforms. Ocean surfaces subjected to wind are covered about 15% in sea foam or more. Sea water also containe silt, algae and other impurities which are brought to the surface by turbulence and which are good absorbers in the IR spectrum.

albertalad

First, I think the entire model is flat wrong. (From American Thinker) Certified Consulting Meteorologist Joseph D’Aleo and computer expert E. Michael Smith appeared together on KUSI TV [Video] to discuss the Climategate — American Style scandal they had discovered. This time out, the alleged perpetrators are the National Oceanic and Atmospheric Administration (NOAA) and the NASA Goddard Institute for Space Studies (GISS).
Perhaps the key point discovered by Smith was that by 1990, NOAA had deleted from its datasets
all but 1,500 of the 6,000 thermometers in service around the globe. For example, Canada’s reporting stations dropped from 496 in 1989 to 44 in 1991, with the percentage of stations at lower elevations tripling while the numbers of those at higher elevations dropped to one. That’s right: As Smith wrote in his blog, they left “one thermometer for everything north of LAT 65.” And that one resides in a place called Eureka, which has been described as “The Garden Spot of the Arctic” due to its unusually moderate summers.
Overall, U.S. online stations have dropped from a peak of 1,850 in 1963 to a low of 136 as of 2007. In his blog, Smith wittily observed that “the Thermometer Langoliers have eaten 9/10 of the thermometers in the USA[,] including all the cold ones in California.” But he was deadly serious after comparing current to previous versions of USHCN data and discovering that this “selection bias” creates a +0.6°C warming in U.S. temperature history.
Willis Eschenbach’s WUWT essay, “The smoking gun at Darwin Zero,” and it plots GHCN Raw versus homogeneity-adjusted temperature data at Darwin International Airport in Australia is another excellent article outlining huge problems with “averaging” temperatures with mostly fake data. Furthermore, Smith cited boatloads of problems and errors he found in the Fortran code “adjustments” written to accomplish this task, ranging from hot airport stations being mismarked as “rural” to the “correction” having the wrong sign (+/-) and therefore increasing when it meant to decrease or vice-versa.
The real chicanery begins in the next phase, wherein the planet is flattened and stretched onto an 8,000-box grid, into which the time series are converted to a series of anomalies (degree variances from the baseline). Now, you might wonder just how one manages to fill 8,000 boxes using 1,500 stations.
Here’s NASA’s solution:
For each grid box, the stations within that grid box and also any station within 1200km of the center of that box are combined using the reference station method.
Even on paper, the design flaws inherent in such a process should be glaringly obvious.

Is there a reason why the author, who refers to him/herself as “I”, continues to remain unknown?