In Kramm & Dlugi On Illuminating the Confusion of the Unclear I pointed out that the authors of Scrutinizing the atmospheric greenhouse effect and its climatic impact are in agreement with climate science on the subject of “back radiation” from the atmosphere contributing to the surface temperature.
No surprise to people familiar with the basics of radiative heat transfer. However, Kramm & Dlugi are apparently “in support of” Gerlich & Tscheuschner, who famously proposed that radiation from the atmosphere affecting the temperature of the ground was a violation of the second law of thermodynamics. A perpetual motion machine or something. (Or they were having a big laugh). For more on the exciting adventures of Gerlich & Tscheuschner, read On the Miseducation of the Uninformed..
The first article on the Kramm & Dlugi paper was short, highlighting that one essential point.
Given the enthusiasm that new papers which “cast doubt” on the inappropriately-named “greenhouse” effect are lapped up by the blogosphere, I thought it was worth explaining a few things from their complete paper.
If I sum it up in simple terms, it is a paper which will annoy climate scientists and add confusion to scientifically less clear folk who wonder about the “greenhouse” effect.
And mostly, I have to say, without actually being wrong – or not technically wrong (note 1). This is its genius. Let’s see how they “dodge the bullet” of apparently slaying the “greenhouse” effect without actually contradicting anything of real significance in climate science.
Goody & Yung’s Big Mistake
Regular readers of this blog will know that I have a huge respect for Richard M. Goody, who wrote the seminal Atmospheric Radiation: Theoretical Basis in 1964. (The 2nd edition from 1989 is coauthored by Goody & Yung).
However, they have a mistake in a graph on p.4:
Kramm & Dlugi say:
..This figure also shows the atmospheric absorption spectrum for a solar beam reaching the ground level (b) and the same for a beam reaching the temperate tropopause (c) adopted from Goody and Yung [30]. Part (a) of Figure 5 completely differs from the original twin-peak diagram of Goody and Yung. We share the argument of Gerlich and Tscheuschner [2,4] that the original one is physically misleading..
I have the same argument about this one graph from Goody & Yung’s textbook. You can see my equivalent graph in 4th & 5th figures of The Sun and Max Planck Agree – Part Two.
There is nothing in the development of theory by Goody & Yung that depends on this graph. Kramm & Dlugi don’t demonstrate anything else in error from Goody & Yung. However, I’m sure that someone who wants to devote enough time to the subject will probably find another error in their book, or at least, an incautious statement that could imply that they have carelessly tossed away their knowledge of basic physics. This is left as an exercise for the interested reader..
To clarify the idea for readers – the energy emitted by the climate system to space is approximately equal to the energy absorbed from the sun by the climate system. This is not in dispute.
Kramm & Dlugi point out that one should be careful when attempting to plot equal areas on logarithmic graphs. Nice point.
Kepler & Milankovitch
Kramm & Dugli spend some time deriving the equations of planetary motion. These had been lost by climate science so it is good to see them recovered.
They also comment on Milankovitch’s theory in terms that are interesting:
Thus, on long-term scales of many thousands of years (expressed in kyr) we have to pay attention to Milankovitch’s [33] astronomical theory of climatic variations that ranks as the most important achievement in the theory of climate in the 20th century [10].
The theory definitely has a lot of mainstream support as being the explanation for the ice ages. However, as a comment to be developed one day when I understand enough to write about it, there isn’t one Milankovitch theory, there are many, and of necessity they contradict each other.
Interesting as well to suggest it as the most important achievement in the theory of climate last century – as the consequence of accepting Milankovitch’s theory is that climate is very sensitive to small peturbations in radiative changes in particular regions at particular times. In essence, the Milankovitch theory appears to rely on quite a high climate sensitivity.
Anyway, I’m not criticizing Kramm & Dugli or saying they are wrong. It’s just an interesting comment. And excellent that Kepler’s theories are no longer lost to the world of climate science.
Energy Conversion in the Atmosphere & at the Surface
The authors devote some time to this study (with no apparent differences to standard climate science) with the conclusion:
..Note that the local flux quantities like Q(θ, φ), H(θ, φ), G(θ, φ) and RL↑(θ, φ) are required to calculate global averages of these fluxes, but not global averages of respective values of temperature and humidity.
An important point.
They also confirm – as noted in Kramm & Dlugi On Illuminating the Confusion of the Unclear – that the energy balance at the surface is affected by the energy radiated by the atmosphere. Just helping out the many blog writers and blog commenters – be sure to strike Kramm & Dlugi off your list of advocates of the imaginary second law of thermodynamics.
The Gulags for Everyone? – Climatology Loses Its Rational Basis
The authors cite this extract from the WMO website about the “greenhouse” effect:
In the atmosphere, not all radiation emitted by the Earth surface reaches the outer space. Part of it is reflected back to the Earth surface by the atmosphere (greenhouse effect) leading to a global average temperature of about 14°C well above –19°C which would have been felt without this effect.
This website statement is incorrect as the radiation emitted by the Earth’s surface is absorbed and re-emitted by the atmosphere – not reflected. This is a very basic error.
Kramm & Dlugi say:
Note that the argument that “part of it is reflected back to the Earth surface by the atmosphere” is completely irrational from a physical point of view. Such an argument also indicates that the discipline of climatology has lost its rational basis. Thus, the explanation of the WMO is rejected..
[Emphasis added]
Well, we could argue that if one person writing a website for one body writes one thing that is not technically correct then that whole discipline has lost its rational basis. We could.
Seems uncharitable to me. Although I have to confess that on occasion I am a little bit uncharitable. I wrote that Gerlich & Tscheuschner had lost their marbles, or were having a big laugh, with their many ridiculous and unfounded statements. We all have our off days.
I think if we want to uphold high standards of defendable technical accuracy we would say that the person that wrote this website and the person that reviewed this website are not technically sound as far as the specifics of radiative physics go. I’m hard pressed to think it is justified to cast stones at say Prof. Richard M Goody for this particular travesty. Or Prof. R. Lindzen. Or Prof. V. Ramanathan. Or Prof. F.W. Taylor. Otherwise it might be a bit like Stalin with the Gulag. Everyone and their mother gets tarred with the sins of the fellow down the road and 30 million people wind up digging rocks out of the ground in a very cold place..
But let’s stay on topic. If indeed there is one.
The Main Point
Now that we have found a graph in Goody that is wrong, a website that has a mistake and have rediscovered Kepler’s equations of motion, we turn to the main course.
Kramm & Dlugi turn to perhaps their main point, about the surface temperature of the earth with and without radiatively-active gases.
As a clarification for newcomers, average temperature has many problems. Due to the non-linearity of radiative physics, if we calculate the average radiation from the average temperature we will get a different answer compared with calculating the radiation from the temperature at each location/time and then taking the average.
For more on this basic topic see under the subheading How to Average in Why Global Mean Surface Temperature Should be Relegated, Or Mostly Ignored
First citing Lacis et al:
The difference between the nominal global mean surface temperature (TS = 288 K) and the global mean effective temperature (TE = 255 K) is a common measure of the terrestrial greenhouse effect (GT = TS – TE = 33 K).
The authors develop some maths, of which this is just a sample:
Using Eq. 3.8 and ignoring G(θ,φ) will lead to:
<Ts> = 23/2Te/5 ≈ 144K (3.9)
for a non-rotating Earth in the absence of its atmosphere, if S = 1367 W/m² , α (Θ0, θ, φ) = αE = 0.30 and ε(θ, φ) = ε = 1 are assumed [2]
Ts = 153 K if αE = 0.12 and Ts = 155 K if αE = 0.07
It might surprise readers that these particular points are not something novel or in contradiction to the “greenhouse” effect. In fact, you can see similar points in two articles (at least) on this blog:
– In The Hoover Incident we had a look at what would happen to the climate if all the radiatively-active gases (= “greenhouse” gases) were removed from the atmosphere. Here is an extract:
..And depending on the ice sheet extent and whether any clouds still existed the value of outgoing radiation might be around 1.0 – 1.5 x 1017 W. This upper value would depend on the ice sheets not growing and all the clouds disappearing which seems impossible, but it’s just for illustration.
Remember that nothing in all this time can stop the emitted radiation from the surface making it to space. So the only changes in the energy balance can come from changes to the earth’s albedo (affecting absorbed solar radiation).
And given that when objects emit more energy than they absorb they cool down, the earth will certainly cool. The atmosphere cannot emit any radiation so any atmospheric changes will only change the distribution of energy around the climate system.
What would the temperature of the earth be? I have no idea..
Notice the heresy that without “greenhouse” gases we can’t say for sure what the surface temperature would be.. (It’s definitely going to be significantly lower though).
– In Atmospheric Radiation and the “Greenhouse” Effect – Part One:
..The average for 2009 [of outgoing longwave radiation] is 239 W/m². This average includes days, nights and weekends. The average can be converted to the total energy emitted from the climate system over a year like this:
Total energy radiated by the climate system into space in one year = 239 x number of seconds in a year x area of the earth in meters squared..
ETOA= 3.8 x 1024 J
The reason for calculating the total energy in 2009 is because many people have realized that there is a problem with average temperatures and imagine that this problem is carried over to average radiation. Not true. We can take average radiation and convert it into total energy with no problem..
[Emphasis added]
The point here is that the total emitted top of atmosphere radiation is much lower than the total surface emitted radiation. It can be calculated. In that article I haven’t actually attempted to do it accurately – it would require some work (spatial and temporal temperature across a year and the longwave emissivity of the surface around the globe) – it is a straightforward yet tedious calculation. (See note 2).
A note in passing that this difference between the top of atmosphere radiation and the surface radiation is also derided by the internet imaginary second law advocates as being a physical impossibility because it “creates energy”.
Now I am not in any way a “representative of climate science” despite the many claims to this effect, it’s just that the basics are.. the basics. And radiative transfer in the atmosphere is a technical yet simple subject which can be easily solved with the aid of some decent computing power. So I have no quarrel with anything of substance that I have so far read in textbooks or papers on radiative physics. Yet I appear to have stated similar points to Kramm & Dlugi.
Perhaps Kramm & Dlugi have not yet stated anything controversial on the inappropriately-named “greenhouse” effect.
They take issue with what I would call the “introduction to the greenhouse effect” where a simple comparison is drawn. This is where the “greenhouse” effect is highlighted as “effective temperature”.
It could more accurately be highlighted as “difference in average flux between surface and TOA” or “difference in total flux between surface and TOA”
Is it of consequence to anything in climate science if we agreed that the difference between the TOA radiation to space and the upward surface radiation is a better measure of the “greenhouse” effect?
Kramm & Dlugi comment on a paper by Ramanathan et al:
“At a surface temperature of 288 K the long-wave emission by the surface is about 390 W/m², whereas the outgoing long-wave radiation at the top of the atmosphere is only 236 W/m² (see Figure 2 [here presented as Figure 17]). Thus the intervening atmosphere causes a significant reduction in the long-wave emission to space. This reduction in the long-wave emission to space is referred to as the greenhouse effect”
As discussed before, applying the power law of Stefan and Boltzmann to a globally averaged temperature cannot be justified by physical and mathematical reasons.
Thus, the argument that at a surface temperature of 288 K the long-wave emission by the surface is about 390 W/m² is meaningless.
Just for interest here is how Ramanathan et al described their paper:
The two primary objectives of this review paper are (1) to describe the new scientific challenges posed by the trace gas climate problem and to summarize current strategies for meeting these challenges and (2) to make an assessment 0f the trace gas effects on troposphere-stratosphere temperature trends for the period covering the pre-industrial era to the present and for the next several decades. We will rely heavily on the numerous reports..
We could assume they don’t understand science basics, despite their many excellent papers demonstrating otherwise. Or we could assume that someone writing their 100th paper in the field of climate science doesn’t need to demonstrate that something called the “greenhouse” effect exists, or quantify it accurately in some specific way unless that is necessary for the specific purpose of the paper.
However, this is the genius of Kramm & Dlugi’s paper..
Dodging the Bullet
Casual readers of this paper (and people who rely on the statements of others about this paper) might think that they had demonstrated that the “greenhouse” effect doesn’t exist. They make a claim in their conclusion, of course, but they haven’t proven anything of the sort.
Instead they have written a paper explaining what everyone in climate science already knows.
So, to clarify matters, what is the emission of radiation from the top of atmosphere to space in one year?
ETOA= 3.8 x 1024 J
What is the emission of radiation from the surface in one year?
Esurface = ?
My questions to Kramm & Dlugi:
Is Esurface significantly greater than ETOA ?
Obviously I believe Kramm & Dlugi will answer “Yes” to this question. This confirms the existence of the greenhouse effect, which they haven’t actually disputed except in their few words at the conclusion of their paper.
Hopefully, the authors will show up and confirm these important points.
Conclusion
The authors have shown us:
- that a graph in the seminal Goody & Yung textbook is wrong
- Kepler’s laws of planetary motion
- that a website describes the “greenhouse” effect inaccurately
- that without any “greenhouse” gases the effective albedo of the earth would be different
- the average temperature of the earth’s surface can’t be used to calculate the average upward surface radiation
However, the important calculations of “radiative forcing” and various effects of increasing concentrations of radiatively-active gases are all done without using the “33K greenhouse effect”.
Without using the 33K “greenhouse” effect, we can derive all the equations of radiative transfer, solve them using the data for atmospheric temperature profiles, concentration of “greenhouse” gases, spectral line data from the HITRAN database and get:
- the correct flux and spectral intensity at top of atmosphere
- the correct flux and spectral intensity of downward radiation at the surface
We can also do this for changes in concentrations of various gases and find out the changes in top of atmosphere and downward surface flux. (Feedback and natural climate variations are the tricky part).
The discussions about average temperature are an amusing sideshow.
They are of no consequence for deriving the “greenhouse” effect or for determining the changes that might take place in the climate from increases or decreases in these gases.
Notes
Note 1: I didn’t check everything, so there could be mistakes. As the full article makes clear, not much need to check. I don’t endorse their last paragraph, as my conclusion – and article – makes clear.
Note 2: The calculation in that article for total annual global surface radiation doesn’t take into account surface emissivity. The value of ocean emissivity is incorrectly stated (see Emissivity of the Ocean). There are probably numerous other errors which I will fix one day if someone points them out.
I add the comment in case it’s not clear – the challenge of correctly identifying surface temperature without any “greenhouse” gases, is more challenging than identifying the surface temperature with pre-industrial concentrations of CO2 doubled.
And the temperature change for doubled CO2 is a very difficult question because it relies on understanding feedbacks and climate variability. Some argue that it is an impossible question to answer. More on that in other articles on this site.
Why is no radiatively-active gases “more challenging” than doubling CO2? Simply because the changes are much larger. Going from current CO2, methane, ozone, N2O, etc to zero is a much bigger change than doubling CO2.
Ray Pierrehumbert forwards a similar argument in this recent comment and provides some specifics about why this is so.
Sorry, wrong link. This is the correct one
Thanks for this article.
I would like to take the opportunity to try to explain in “layman’s” terms why the so called “greenhouse” effect does NOT violate then 2nd law of thermodynamics. I’ll start by suing a simple example from real life: if you feel cold you can wrap a blanket around your. This blanket will make you feel warm; it will “heat you up”. Naturally the blanket does not create any heat; it only isolates you from the surroundings and keeps your body warmer, while the surrounded air will become cooler in corresponding amount. The total amount of heat stays the same in the system “you + surrounding air”.
Now think about a layer of the atmosphere, close to the earth. It contains, among other “greenhouse” gases, a certain amount of carbon dioxide, CO2. Let’s say that the amount is c1, at an initial, random stage. The outgoing IR radiation from the warm surface of the earth will be absorbed by this CO2 at certain wavelength regions. Let’s furthermore anticipate that 99.9 % of this radiation is absorbed at a height h1. Now, we increase the amount of CO2 up to a level c2 More IR radiation is now absorbed and the height at which 99.9 % of this radiation is absorbed decrease from h1 to h2. At the same time the atmosphere above h2 will cool down in corresponding amount, in order to keep the total energy in the system constant (due to the 2nd law of thermodynamics).
Now, as the gas in the layer below h2 warms up it will also expand somewhat so that the level h2 will increase closer to h1. At the same time the gas will cool down, according to the gas law. The gas above h2, which already has cooled down a bit, will now contract.
What I describe above in very simple steps will not happen in discrete steps but as a continuous process until equilibrium is reached. The final equilibrium state will thus be a state where the lower gas layer, up to h2, has warmed slightly, while the upper layer above h2 has cooled slightly. As warm air rises up, there will be more convection and exchange of air between these two levels than before, of course.
I don’t know what the end effect – the effect on climate – will be. And I will not even try to deduce it. I only want to say that there is no violation of any thermodynamics or any other physical laws in this simple model.
Cheers
Kenneth
Kenneth,
I like the analogy you have given!
Sod,
With respect to the above analogue. Do calculations of the affect of “greenhouse gases” on the temperature take into account Convection or this is effect neglible?
Many thanks and Happy New Year!
SOD: I’m sure Steve McIntyre sympathizes with your difficulties with trying to unravel the “truth” while others seek to make it more obscure. I appreciate your efforts.
On page 990 (when discussing Ramanathan’s explanation for the greenhouse effect), Kramm says:
“As discussed before, applying the power law of Stefan and Boltzmann to a globally averaged temperature cannot be justified by physical and mathematical reasons. Thus, the argument that at a surface temperature of 288 K the long-wave emission by the surface is about 390 W·m–2 is meaningless.”
How wrong is it to use the average global temperature in such calculations? I created a data set of 1000 normally distributed temperatures with a mean of 288 degK and a standard deviation of 10.6 degK. Two standard deviations is 261 degK (-12 degC) to 309 degK (36 degC), a generous spread that ought to cover the problem. Using the data set to calculate surface emission (emissivity = 1) and then averaging produced an average emission of 392 W/m^2. The same data set with the temperature averaged before calculating the emission gave 289 W/m^2.
Ramanathan describes the greenhouse effect as the difference between the outward TOA flux observed from space – 236 W/m2 – and surface flux, “miscalculated” to be 290 W/m2. Kramm completely dismisses a greenhouse effect of 54 W/m2 because of an approximate calculation with a likely error of about 3 W/m^2. If Ramanathan made a dubious calculation, it was Kramm’s job to get the real gridded global temperature data and show precisely how big the error is.
The radiation is proportional integral T^4. At different temperatures can given specify any local temperature T with Tm +DT, with integral DT = 0. For the radiation is then:
Integral T^4 = integral (Tm + DT)^4 =
Tm^4 Integral (1 + Dt / Tm)^4 =
= Tm^4 [1 + 4 integral (DT / Tm) + 6 integral (DT / Tm)^2 + 4 integral (DT / Tm)^3 + integral (DT / Tm)^4]
The first integral is the mean, the second integral is read definition = 0, the third integral is positive, but small at small DT / Tm, the fourth Integral smaller still (almost 0 for definition), the fifth smaller.
So at low DT / Tm, the integral T^4 is only slightly larger than integral Tm^4
Ebel,
this is an old hat. The linearisation of the power law of Stefan and Boltzmann was already used in numerical weather prediction models several decades ago to avoid to iteratively determine the surface temperature on the basis of an energy flux balance.
Jochen: I don’t have many old hats at my fingertips, so I found this one quite elegant. Thanks for showing it.
Kramm,
my derivation has little to do with a linearization, just the linear term is eliminated.
SoD
love your work but dont understand the really technical stuff. I don’t know if you pick up on comments on earlier threads – I know it must be difficult – but I have just posted a query on the “Why Global Mean Surface Temperature Should be Relegated, Or Mostly Ignored” thread and I note there is another unanswered post on that thread
kind regards
Frank says
“How wrong is it to use the average global temperature in such calculations? I created a data set of 1000 normally distributed temperatures with a mean of 288 degK and a standard deviation of 10.6 degK. Two standard deviations is 261 degK (-12 degC) to 309 degK (36 degC), a generous spread that ought to cover the problem. Using the data set to calculate surface emission (emissivity = 1)”
Is this a realistic set of temperatures?
What about the Antartic where averages are in the -50C range.
emissivity = 1 is also pushing it a bit what about deserts?
It would be an interesting exercise to do a re-run with these wider limits.
Bryan: Antarctica is 3% of the earth’s surface, 2 standard deviations covers 95%. The highest of the 1000 datapoint EXCEL generated at random for me was 319 degK (46 degC) and the low happened to be 193 degK (-80 degK).
If you don’t like my assumptions, please do the calculations yourself (Tool/Data Analysis/Random Number Generator) and show me why I’m wrong.
The temperature term is raised to the four power, so the mean of the fourth power can be different from the fourth power of the mean. Emissivity isn’t raised to any power, so it doesn’t have this problem. 70% of the surface is ocean with an emissivity of 0.99 and most of the land is 0.95-0.99 and all of it is >0.92. home.comcast.net/~snyderwc/ijrsemis.pdf The error again is trivial
If you can run the model with double CO2, it surely can’t be difficult to run it without any CO2? What’s the result?
Can you point me to a simple but basically correct open-source 1d radiative-convective model?
Trenberth, Fasullo & Kiehl (2009) did the calculation using actual values from around the globe every 6 hours with emissivity, ε=1.0.
The value of upward radiation averaging first all of these temperatures = 389 W/m2.
[ σ<T>4 = 389 W/m2 ]
The value of upward radiation calculating each flux value, σT4, and then averaging = 396 W/m2.
[ <σT4> = 396 W/m2 ]
The argument against going to the trouble of computing the average of εσT4 for each location was given as this reason –
The upward longwave radiation from the surface = emitted + reflected radiation = εσT4 + (1-ε)Ra
where Ra = downward radiation from the atmosphere.
So if we consider typical values like:
– surface temperature, T = 288K (15’C)
– downward radiation = 330 W/m2
– emissivity, ε = 0.95
the actual value of upward longwave radiation = 0.95 x 390 + 0.05 x 330 = 387 W/m2 vs the assumed value for unity emissivity = 390 W/m2
– i.e., error = 1%.
(Note that their paper appears to have an error in their note on emissivity of water, citing Wilber. Wilber et al plotted emissivity for 4-16 μm as their paper was aimed at satellite measurements of the surface. Citing from my own authoritative article, The Emissivity of the Ocean:
Now, in the case of Trenberth, Fasullo & Kiehl they have a different purpose from ours. Ours is clarifying whether such a thing as the “greenhouse” effect actually exists. (Actually, whether Kramm & Dlugi have demonstrated that it doesn’t).
In our case we only want to compare the radiation emitted by the surface with the radiation emitted by the atmosphere [clarification added: “by the atmosphere to space”] (see my question to Kramm & Dlugi near the end of the article).
So in the case of our mission here an emissivity = 0.95 means an error of 5% for actual emitted radiation compared with the value from assuming emissivity = 1.0.
Trivial to demonstrate that the emissivity of the earth’s surface cannot be 0.60 (the value needed to make the emitted surface flux = climate system flux into space), given that the ocean has an emissivity approx. 0.95.
Or strictly speaking, slightly less trivial to demonstrate that the emissivity of the earth’s surface cannot be such that the total energy emitted by the surface in one year is equal to the total energy emitted by the atmosphere in one year.
We’ll, I’ve found something but it’s all fortran…
Maybe somebody could clear up a few things, without me having to crawl through the code.
I’ve also read an older article, concerning models:
I’m really just interested in the “first order forcing”. My best guess is that the models are actually correct and only the communication is weird.
After running several scenarios, we get the formula for radiative forcing at the top of atmosphere:
ΔF = 5.35 ln (C/C0)
The formula has a singularity, for a totally valid input (C = 0), which indicates that it isn’t actually the correct relationship.
What does radiative forcing at the TOA mean, i.e. how is it determined from the model state? There’s only outgoing long wave radiation and incoming solar there.
Why is “radiative forcing” used as a unit, because to determine it, one needs to know the temperature of the atmosphere, so why not just state the temperature response directly, e.g. at the tropopause or surface?
Is outgoing long wave radiation a boundary condition? It shouldn’t be, as enough photons will leave the TOA automatically.
How is the height of the tropopause determined, naturally from the physics, or parametrized?
Is the temperature of the tropopause warming and/or is its height rising; because both should cause surface warming, so what exactly is going on?
Is the stratosphere actually cooling with more CO2, but warming with more aerosols?
The simple log ratio formula fails at low concentration because the response is linear rather than logarithmic at low concentration. The log ratio is approximately correct for concentrations of CO2 greater than ~20 ppmv.
The IPCC has defined radiative forcing as the forcing at the tropopause after allowing the stratosphere and above reach steady state. Since convection plays essentially no role above the tropopause, the time to reach steady state for the upper atmosphere is on the order of a few months.
Since temperature increases in the stratosphere, the tropopause is defined as the point where the temperature stops decreasing. The tropopause is not a bright line, though. It’s a boundary layer between the troposphere where convective heat transfer is important and the stratosphere where it isn’t. Also, because the temperature in the stratosphere increases with altitude, forcing reaches a maximum at the tropopause. If the stratosphere were not allowed to relax to the new steady state, forcing would decrease with altitude above the tropopause.
A forcing is calculated before the temperature of the surface and the troposphere is allowed to change after an instantaneous increase in, say, CO2. The sensitivity of the climate to the forcing, i.e. how much the temperature will change, is a completely separate issue.
Both an increase in CO2 and a loss of ozone contribute to stratospheric cooling. Volcanic aerosols cause a short term increase in stratospheric temperature. I think there may also be a longer term small cooling effect, but that’s just my opinion. There is some evidence that stratospheric ozone is at least no longer decreasing as the bad CFC’s go away. If stratospheric ozone recovers, we might actually see some warming depending on the relative rates of CO2 and ozone increase.
Radiative Forcing is nonsense for global warming. The truth is ” It’s a boundary layer between the troposphere where convective heat transfer is important and the stratosphere where it isn’t.” The temperature gradient in the troposphere is nearly independent of the concentration of CO2. The tropopause is where the stratification of the air is unstable in the stratosphere is due to the growing temperature gradient. Because in the stratosphere is no convective heat transport, is there radiation equilibrium. Higher CO2 levels will scale the radiative transfer equation and the critical point of the temperature gradient is achieved at a lower pressure of Tropopausen. This follows a thicker troposphere with a larger temperature difference across the troposphere. To the earth’s radiation balance is distributed to keep, is the additional temperature difference is 3 / 4 on the cooling of the stratosphere and 1 / 4 on the warming of the surface.
The thinner cooler stratosphere has a lower radiation intensity, no higher (“radiative forcing”).
Without the UV heating from above (ozone layer) in the upper stratosphere layers would decrease the temperature throughout the stratosphere – but with a low temperature gradient.
Thanks for your time.
“A forcing is calculated before the temperature of the surface and the troposphere is allowed to change after an instantaneous increase in, say, CO2.”
Are they really solving the stratosphere independently of the troposphere? How could that be possible, as the CO2 is added very slowly? The dynamics between troposphere and stratosphere should be very important.
“The sensitivity of the climate to the forcing, i.e. how much the temperature will change, is a completely separate issue.”
This is my biggest issue, because it seems so backwards. How can it be a “completely separate issue”?
Do you agree, that there can only be a flux (in addition to solar), once the temperature of the atmosphere is above 0 K? So if you initialize everything at 0 K, how do you calculate the radiative forcing?
My guess is, that it’s somehow based on the change in optical depth, which is temperature independent, and the previous temperature?
“forcing reaches a maximum at the tropopause.”
This is the infamous fingerprint. Assuming no H2O, as it could change the laps rate, shouldn’t the maximum forcing be at the surface, where you have the maximum optical depth and the maximum temperature?
“Both an increase in CO2 and a loss of ozone contribute to stratospheric cooling.”
I see how aerosols and ozone cause warming, by absorbing shortwave solar, but shouldn’t CO2 be neutral, as it warms by absorbing upwelling infrared and equally cools by emitting infrared? Maybe it’s just an artifact of everything being lifted upwards.
@Jochen Ebel
That’s what I’m thinking, but to quantify it, you have to run a model, so the question is: are the models fundamentally correct, and only the language of “radiative forcing” is dubious, or are the models fundamentally incorrect?
“Without the UV heating from above (ozone layer) in the upper stratosphere layers would decrease the temperature throughout the stratosphere – but with a low temperature gradient.”
That’s what we have on Mars and Venus, where we have no stratosphere and mesosphere, so ozone seems to be very important, too; even though it’s no greenhouse gas.
iya
As far as I know, the models are not computed with the solar forcing and therefore should expect basically correct. But if the distortions caused by the simplifications (for models are necessary) are not too large, is the real problem.
iya
Also on Mars and Venus is a stratosphere – an atmosphere with greenhouse gases without stratosphere there is not. The Tropopausendruck on Venus is about 0.4 mbar, similar to Mars and the partial pressure of CO2 of Tropopause of earth in mid-latitudes is at about 0.16 mbar.
Mars and Venus may have a stratosphere, but I was mainly referring to the temperature profiles:
Earth atmosphere is _on_average_ more isothermal.
Ozone raises the temperature in the stratosphere, so the emissions from CO2 from the stratosphere increase, and the tropopause and surface temperature decreases?
In other words, ozone makes the atmosphere more isothermal on average and thus reduces the greenhouse effect?
The influence of ozone on the surface temperature is low.
Better the tropopause is seen as a function of pressure :
http://www.datasync.com/~rsf1/vel/1918vpt.htm
http://www.daviddarling.info/encyclopedia/M/Marsatmos.html
ozone acts as a greenhouse gas especially in the troposphere, where it is a product of engine exhausts. It is handled in various regional and global climate models.
FWIW to pick another nit, there is reflection of thermal radiation by clouds (and even by Rayleigh scattering from the atmosphere, it is just that it is not large compared to emission from thermally excited greenhouse gases.
Dr. Halpern (aka Eli Rabett)
Tropospheric ozone is formed in photochemical processes that are initiated by the emission of nitric oxide (NO) and its fast conversion to nitrogen dioxide (NO2). The photo dissociation of the NO2 molecules generates oxygen atoms (3PO) which react with molecular oxygen (O2) under the presence of a third body to generate O3 molecules. In the absence of other chemically active species, there will be a photo-stationary state between NO, NO2, and O3 usually called the Leighton relationship.
Highly reactive hydroxyl radicals are generated by the O3 photolysis.The oxidation effect of these radicals contributes to acid formation and, by complex reactions with non-methane hydrocarbons, leads to the formation of peroxy radicals. Peroxy radicals oxidize – in competition with ozone – NO to NO2. Therefore, they cause a shift of the photo-stationary state and enable a net ozone production. Consequently, O3 is not a product of engine exhausts.
Nitrogen species, of course, are released in combustion processes. However, nitric oxide is also emitted by soils. Hydrocarbons are also emitted by forest canopies. This means that ozone has not only anthropogenic, but also natural origin. This recognition was already one of the topics of the international ozone conference held in La Jolla in 1993.
Ozone is counted as a so-called greenhouse gas because of its 9.6 my band located in the atmospheric window.
Scattering of infrared radiation plays a notable role only in case of the small crystals of cirrus clouds especially in the highly transparent range of the atmospheric window. In case of water clouds scattering of infrared radiation is completely insignificant. Water clouds absorbs and emits like black bodies. In the presence of water cloud the atmospheric window is nearly closed.
There are, of course, limits to obliviousness, but Gerhard is perhaps not aware of them. NOx is a direct product of engine exhausts, mostly because some N2 reacts in the hot explosion in the internal combustion engine. While there are natural sources, in metro areas they are overwhelmed by that produced from cars.
Large cities will be quite happy to hear that the excess ozone is not a product of engine exhaust according to Gerhard Kramm. Everyone else will simply roll their eyes
iya:
The relationship is an empirical one. It is applied to the useful values within the range of pre-industrial to quadrupled CO2.
It is not a precise value anyway and is simply a curve fit of values solved numerically using the radiative transfer equations.
It is a “ready reckoner” for the range of interest.
Automobiles contributed significantly to smog and ozone formation in the Los Angeles basin. But it was as much branched hydrocarbons as it was nitrogen oxides. The California Air Resources Board in its infinite wisdom initially decided that hydrocarbons and carbon monoxide (because it was toxic presumably) needed to be reduced in vehicle exhausts. At the time there was no catalyst for the reduction of nitrogen oxides. Combustion temperature was increased and air was injected into the exhaust ports of car engines. The result was an increase in nitrogen oxide emissions. Smog got worse as there were still plenty of sources of hydrocarbons other than cars. And in cars, the major source of hydrocarbons was the fuel tank, not the engine. So now gas pumps in California have these ungainly hoses so that the vapors pumped out by gas going into the tank are directed back into the underground tanks and the vent line to the fuel tank has an activated carbon filter that is supposed to capture most of the vapors emitted while the engine isn’t running.
I wish we had those ungainly hoses where I live. Ozone is the worst air pollutant and it comes from hydrocarbons – mostly emitted while the tank is being filled with gasoline, not when the gasoline is burned by the engine. Limits on hydrocarbons emissions from engines used to be 0.4 g/mi and they think its now down to about 0.1 g/mi. At 25 mpg, the engine releases 2.5 to 10 g of hydrocarbon per gallon of gas burned. The air in the gas tank is saturated with gasoline vapor that is displaced as the tank is filled. Since gasoline is a mixture whose volatility is adjusted with the season, it doesn’t have a well defined vapor pressure. If one takes ethanol as a model, its vapor pressure is about 0.1 atm (76 mm Hg) at 25 degC. 46 g/mole * 0.1 mole EtOH/mole air * 1 mole air/22.6 L air * 0.95 L/qt * 4 qt/gal = 7.7 g EtOH/gallon of air saturated with EtOH displaced from the tank upon filling. Of course, the idiots who spill some gas while “topping off”, can easily release far more. So, we spend hundreds of dollars per car engineering, building and testing catalytic converters, but skip the ungainly hoses and don’t educate the public about the relative importance of spillage and emissions.
iya,
For calculating forcing from doubled CO2, the CO2 isn’t added gradually. It’s an instantaneous doubling while retaining the same temperature and humidity profile in the troposphere but not the stratosphere. And that’s why sensitivity to forcing is a separate issue. For a given forcing, we don’t know how much the surface temperature will change because that’s not part of the forcing calculation.
Ozone is a greenhouse gas, just not a well-mixed one because it’s not stable. It has a strong absorption band centered at about 1050 cm-1. If the Archer MODTRAN interface were working, I could give you an estimate of its importance.
At 0 K, the forcing is 342 W/m² reduced by whatever the albedo of the surface would be. 342*(1-α) where α is the albedo (reflectivity) for solar radiation). Forcing is calculated as the difference in emission before and after addition of greenhouse gas. At 0 K, there is no emission. If you assume an albedo of 0.3, which probably wouldn’t be the case at 0 K, the forcing would be 239.4 W/m².
You should probably spend some time reading the key articles here as they would probably answer most of your questions.
“radiative forcing” is an unchanged troposphere:
Click to access ar4-wg1.pdf
“… Radiative forcing is computed with all tropospheric properties held fi xed at their unperturbed values ….”
Umm, that’s what I said.
Obviously not all of the tropospheric properties are held fixed. The CO2 partial pressure changes.
But keeping the troposphere unchanged is obviously not a good model of reality. I wanted to know how the models work, and your answer reinforces my suspicion that they could be sloppy, whereas Jochen Ebel said the models don’t use any “forcing calculation”.
What’s seldom mentioned is that greenhouse gases would not raise the surface temperature in an isothermal atmosphere, so it’s essential that everything is solved simultaneously, especially the temperature profile at every time step.
Ebel,
you are right. It did not take a closer look on your formulae. You also considered an additional term in the development of T^2 by a a Taylor series. However,The integral you considered reads in your notation:
INT (T^4)
However, you have to tell us what the differential of this integral is. If this should be a surface integral as usually considered in global averaging then the integral must read
INT_A (T^4) dA
where A is the surface of the earth and (T^4) dA is the differential of the integral.
The global average {…} is given by
{T^4} = 1/A INT_A (T^4) dA
This means that only the global average of T^4 is considered, but not the global average of T. These is a pair of different shoes. In principle, this integral only characterizes the global average of the infrared radiation emitted by the earth’s surface, if an relative emissivity of eps = 1 is considered because multiplying this equation by Stefan’s constant provides
sigma {T^4} = sigma/A INT_A (T^4) dA
If T = T_r + DT so that
T^4 = T_r^2 (1 + DT/T_r)^4
any development of (1 + DT/T_r)^4 by a Taylor series does not change the physical meaning of the integral. Note that the globally average surface temperature is still given by
{T} = 1/A INT_A (T) dA
Kramm
A binomial should not be confused with a Taylor series.
Moreover, {T} = T_r
and then a write error is corrected. Instead T^4 = T_r^2 (1 + DT/T_r)^4 is T^4 = T_r^4 (1 + DT/T_r)^4
Ebel,
obviously, your knowledge is based on the paper of Trenberth et al. (2009, TFK) that I sent to you a couple of months ago. The formula of TFK is only valid for eps = 1, where the skewness must be equal to zero, i.e., the temperature deviations must be Gaussian-distributed.
If eps < 1 as in most cases it is indispensable to build the surface average by considering
eps(r) T(r),
both quantities depend on the position vector r. From this point of view, it is not necessary to discuss the formula of TFK further. Therefore, I did not pay any attention to it. I recommend that someone who believes that the assumption eps = 1 is appropriate should read some textbooks on micro-meteorology and micro-climatology.
Here are typical values for various surfaces:
water: eps = 0.92 – 0.97
dry sand: 0.84 – 0.90
wet sand: 0.91 – 0.95
concrete: eps = 0.71 – 0.90
black gravel roads: eps = 0.88 – 0.95
old snow: eps = 0.82
fresah snow: 0.99
long grass: 0,90
short grass: 0.95
tundra: eps = 0.90 – 0.99
The textbooks of Tim Oke (1987), John Garratt (1992), and Roger Pielke sr. (1984, 2002) contain more data.
At a temperature of about T = 288 K a reduction of eps by 0.01 results in a decrease of the emitted radiation by 3.9 W/m^2. For the purpose of comparison: The net anthropogenic radiative forcing for the period from 1750 to 2005 – as reported by the WG1 of the IPCC – amounts to 1.6 W/m^2.
Equation (2.17) of Kramm and Dlugi (2011, KD) describes the structure of local energy flux schemes (here formulated for bare soil). All these fluxes have to be globally averaged. None of these globally averaged energy fluxes depends on a globally averaged surface temperature.
iya:
The calculation of radiative forcing is a specific calculation for a specific purpose.
This is essentially about the solution to the radiative transfer equations as various GHGs change in composition. This is a computationally very intensive exercise (given the 2M+ spectral lines in the HITRAN database and the change in spectral line width vs atmospheric pressure).
GCMs by contrast solve their complete equation set for each grid cell at each time step – as you describe.
I haven’t dug into what level of sophistication the GCMs have for the radiative transfer equations but it certainly isn’t a line by line solution for each grid cell at each time step, as this would soak up a massive proportion of the computational time for little comparative return. (I would assume that they would use band models or look up pre-calculated values, no doubt one of our knowledgeable readers can shed some light on this)
You are correct that the radiative transfer isn’t calculated with even a band model for the GCM’s. It’s some form of parameterization, i.e. more than a look up table, but I don’t know the details. I do know that a few years back when there was an inter-model comparison, some of the models were off by quite a bit, 20% or more, on their calculations compared to line-by-line, but I think that’s been fixed.
Gerhard Kramm:
But here we are discussing whether the inappropriately-named greenhouse exists, so for the purpose of comparison the emission of radiation to space from the climate system, Rc = 239 W/m2 globally annually averaged (note 1), and the emission of radiation from the surface is:
Rs = σ/n x ΣεiTi4
– where i is 1:n
And as:
σ/n x ΣiTi4 = 396 W/m2
it is clear by inspection that for the values of longwave emissivity of the earth’s surface, it is impossible for Rs = Rc.
Note 1: Strictly speaking the measured outgoing longwave radiation will include some surface reflected radiation but we don’t need to get to that level of detail for the purposes of this exercise.
But for other reasons I am interested in what values are currently used in climate models for surface longwave emissivity, and what happens to calculations of radiative forcing (changes in net flux at the tropopause for increases in radiatively-active gases) as longwave emissivity is changed.
SoD,
I only answered to Ebel.
Your question about the definition of the so-called atmospheric greenhouse effect is, indeed, the key question. As documented by Gerlich & Tscheuschner (2009) and Kramm & Dlugi (2011) there are many different definitions of the atmospheric greenhouse effect. This is already a bad indication. Most of them are rather inappropriate. They even do not define what usually is called an effect.
My co-author and I, for instance, considered the explanations of this greenhouse effect given by the AMS and the WMO. These explanations quantify the effect by two different temperatures. One of them is the globally averaged near-surface temperature of about {T} = 288 K, and the other one is the temperature, T_e, of the radiative equilibrium for the Earth’s surface in the absence of the atmosphere. For a planetary emissivity of eps = 1 and a planetary albedo of a = 0.3 one obtains T_e = 255 K. The Difference DT = {T} – T_e = 33 K is then called the greenhouse effect. From a physical point of view this is sheer nonsense because these two temperature are neither comparable nor energetically relevant.
Gerlich & Tscheuschner (2009) already demonstrated that the globally averaged surface temperature amounts to {T_s} = 144 K if eps = 1 and a = 0.3 is considered. This result is correct because they calculated the temperature for a radiative equilibrium on a local scale and then globally averaged over all local results. Gerlich & Tscheuschner also mentioned that the ground heat flux has to be taken into account.
Indeed, without this ground heat flux one will never obtain the correct value for {T_s}. This ground heat flux is relatively small. However, if we try to predict it an the basis of Fourier’s law on heat conduction, it is necessary to considered the lower boundary conditions, usually the temperature at a certain depth d at which this heat flux becomes negligible. At this depth the temperature does not change during a certain period. This means that the energy flux balance at the surface of a planet having no atmosphere is connected – via the ground heat flux – to a heat reservoir which is so large that it does not allow to change the temperature at its outer edge, namely the depth d.
Our Moon is a nearly perfect instance for a planet in the absence of its atmosphere. Let us consider the results of Vasavada et al. (Icarus 141, 179–193, 1999). On their Figure 2 they showed the surface temperature at the Moon’s equator for one Moon day. At noon the temperature is of about 400 K. Then, the surface temperature decreases to 130 after 6 Moon hours and nearly 100 K after 18 Moon hours. Then, the surface temperature increases to nearly 400 K. The averaged surface temperature for the Moon’s equator would be 225 K or so. Note that the temperature at the depth d corresponds to 255 K or so (see Fig. 4 of Vasavada et al.).
If we calculate this surface temperature without the ground heat flux, the surface temperature at the Moon’s equator between 6 and 18 Moon hours would be equal to zero. In such a case the averaged surface temperature for the moon’s equator would be 165 K or so. This means that – due to the heat reservoir – we have a 60 K higher averaged surface temperature at the Moon’s equator if the ground heat flux is considered.
I estimated the Moon’s averaged surface temperature on the basis of an approximate formula elementary derived and found a value of nearly 200 K +/- 10 K. This is close to the observed value of Monstein (2001).
For the Earth in the absence of its atmosphere the averaged surface temperature would be similar. It is clear that this averaged surface temperature is comparable with the {T} = 288 K. This means that the difference of DT = 33 K is a senseless house number.
And that’s one of the major straw man arguments in G&T. 144 K only applies if the heat capacity of the surface is zero or the planet doesn’t rotate or transfer energy from one hemisphere to the other so the unilluminated side has the temperature of the CMB, 2.72 K. But neither is true. The surface of the planet has a very large heat capacity, especially the part covered by the ocean, and it rotates once every 24 hours. The diurnal temperature variation of the sea surface is on the order of tenths of a degree. You still have latitudinal temperature variation, but even then in the depths of winter, the lowest temperature on the Antarctic Plateau at the Vostok station was -89.2 C or 184 K. It’s a little hard to imagine that the average temperature of the planet could be 144 K even with an IR transparent atmosphere, which is pretty much the case for the Antarctic in the winter, when the lowest recorded temperature is for a small area of the planet is much higher than that. For any real surface, the average temperature would be greater than 144 K.
The Earth’s moon, on the other hand, does behave more like the G&T example because the surface has a low heat capacity and has a solar day 28 times as long. Even then, the lunar surface doesn’t approach the CMB temperature except possibly for deep craters at the poles that are permanently in shadow. The Diviner mission mapping the temperature and the emissivity spectrum of the lunar surface (which is related to lunar geology, thus the name Diviner) has measured temperatures at the lunar south pole at maximum solar exposure as low as 25 K.
Gerhard Kramm says
“Gerlich & Tscheuschner also mentioned that the ground heat flux has to be taken into account. ”
DeWitt Payne says
“And that’s one of the major straw man arguments in G&T. 144 K only applies if the heat capacity of the surface is zero”
Surely if then, as G&T suggest, you add the ground heat flux you will get more realistic temperatures
Surely if then, as G&T suggest, you add the ground heat flux you will get more realistic temperatures
Then why didn’t they calculate that rather than publishing a number that is much less relevant to the Earth with its atmosphere and oceans than the superconducting surface number of 255 K? The latitudinal emission profile of emission to space is even flatter than the surface, btw. It really doesn’t take much latitudinal heat transfer to make the temperature profile flat enough such that there is only a couple of degrees difference between the limit of superconductivity and the actual average temperature.
DeWitt Payne asks
…”Then why didn’t they..(G&T).. calculate that rather than publishing a number that is much less relevant to the Earth .”..
G&T produced a falsification paper dealing with various popular versions of the CO2 driven greenhouse effect.
It was never their intention to supply their own climate model.
Kramm &Dlugi have moved things along with equation 2.17.
The real explanation of how our climate functions is to identify the various storage mechanisms within an oscillating system.
Given storage, their can be larger energy flows within the Earth/atmosphere system than the solar supply and long wave emission would suggest.
Fig 11 page 962 shows just such a plausible system.
Science of Doom,
The basic point of those people that state back radiation cannot heat the ground are correct if the net average global temperature values, rather than locally varying locations, are considered. There are local atmospheric lapse rates lower than the adiabatic lapse rates, and even some with reversed signs, but when average ground and atmospheric temperature values are considered, average heat transfer is from the ground to the atmosphere and space, since, on the average, the atmospheric temperature above the ground is lower than the average ground temperature. It is also true that HEAT TRANSFER cannot go from a cooler body (via radiation, conduction, or convection) to a warmer body without violating the second law. That does not mean some energy (radiation) can’t go from the colder to warmer body, only that the NET radiation has to be from warmer to colder. In that case, back radiation is not heating the ground. The increase in ground radiation and back radiation in the presence of greenhouse gases is a RESULT of the greenhouse gas effect, not a cause of the ground heating. The ground heats only because the greenhouse gas raises the elevation of outgoing radiation, and the lapse rate due to a sufficiently mixed atmosphere does the rest.
I am sure that the confusion has two sources. The first is as I stated, that local variations could have the atmosphere heating the ground (actually by conduction, convection and back radiation) if the air above the ground is warmer than the ground. This is possible locally, but not on average. The second is clearly the confusion between energy transfer (which can be by-directional with radiation), and heat transfer, which is always hot to cold.
I am sure the people that keep using the second law argument are referring to the average values, and if not, should.
Interesting…I’m afraid I’m still not clear on this and perhaps you or SoD could point me to a post that would be more likely to help me(it’s been awhile since I read most SoD posts).
One analogy I saw recently was courtesy of a Mr.Cotton, who is apparently happy to spam websites with his views (and threaten libel when his views are criticized), but doesn’t allow comments on his site.
Mr.Cotton gave what I thought of as an incomplete view of ground to atmospheric to space radiation- dropping billiard balls onto a slightly tilted billiards table with the end railing removed. In my interpretation of his view the balls may bounce around but eventually all must leave at some point, so no temperature rise or heat gain could be gained by the “bouncing around”.
I thought this could be made closer to correct by having several short bumpers at the open end of the table. As some continuous rate of billiard balls is dropped onto the table (short wave radiation reaching the ground), adding more bumpers will cause more to remain on the table at anyone time (i.e. heat accumulating as longwave radiation is not leaving the system as fast as otherwise would have occurred in the absence of the bumpers), while presumably a new equilibrium might be reached to allow pool balls in to equal pool balls out. In this still incomplete analogy the balls interact with the bumpers and bounce back, as long wave radiation may interact with the atmosphere and be radiated downards some of the time. The balls bouncing back are “building up” on the table, so the backradiation in this analogy would be the source of increasing temperature, as it is radiation that would otherwise have left, but was “bounced” back by interacting with the atmosphere and being reradiated.
So is the backradiation the same thing as saying “the radiation that would otherwise have left to space but didn’t and therefore is still around, thereby raising the temperature more than would otherwise have occurred”? If so, I’m not sure why you couldn’t be correct by saying the backradiation is the source of the extra radiation that raises the temperature…A related question would be, by what mechanism does having a higher,colder radiating layer cause increased temperature, if not because it is preventing radiation from leaving as effectively (and it can only prevent radiation from leaving as effectively by interacting and backradiating some of it)?
Sorry if I’m not very precise in my terminology (liberal arts major), but pointers and guidance would be appreciated…
I need to add that my points do not make me agree that greenhouse gases do not result in ground heating. They do. It is the back-radiation arguments that is used as cause of increase that is wrong.
Leonard: What you may really be saying is that the existence of a greenhouse effect depends on your definition of the term “greenhouse effect”.
If the greenhouse effect refers to warming of the surface by DLR from GHG, the greenhouse effect probably can’t operate at locations where the local lapse rate is convectively unstable – any increase in DLR will result in a corresponding increase in convection and no temperature rise. Since the planet’s surface as a whole receives more energy by radiation (SWR+DLR) than it can emit to space – making the whole system convectively unstable – this may limit warming globally. When the weather (and diurnal and seasonal cycles) create cooler areas with shallow lapse rates, there is an opportunity for DLR to warm the surface. However, if the mean global lapse is on the threshold of instability, the heat not present in cool areas must be found in – and then convectively lost from – warm areas that are unstable.
If one uses Ramanathan’s definition of the greenhouse effect (surface OLR minus TOA OLR), observations show that the greenhouse effect exists. However, this “greenhouse effect” exists because the most of the radiation emitted to space originates high in the atmosphere, which is much colder than the surface. DLR arriving at the surface (mostly emitted from GHGs below 1 km) arguably has nothing to do with the temperature difference between the surface and critical emission level; textbooks show that this difference is controlled by the lapse rate.
If one defines the “greenhouse effect” to be the mechanism by which increasing GHGs high in the atmosphere force the characteristic emission level to rise (so that the planet can maintain radiative equilibrium), then the surface will warm IF the lapse rate remains the same (or decreases). Since no one appears to use the term “greenhouse effect” to refer to this mechanism of GHG-mediated warming, why is the term greenhouse effect still used?
Atmospheric Greenhouse Effect
Both sides of the argument generally stated miss the basic point of an atmospheric greenhouse gas causing a higher ground temperature. In order to understand what is occurring, you first have to understand the cause of the atmospheric lapse rate. This has been explained often and well, including on wiki: http://en.wikipedia.org/wiki/Lapse_rate Please read that before proceeding.
Solar energy is the source of energy input to the Earth surface and atmosphere (with a very small added effect from underground radiation heating of the Earth, but this is ignored here). When sunlight is absorbed on the Earth, this short wave radiation heats the Earth (oceans, ground and atmosphere). The warmed Earth radiates nearly as a black body at longer wavelengths. If the temperature average is long term constant, the average outgoing long wave thermal radiation energy has to match the absorbed solar incoming energy. If the temperature is increasing or decreasing, there has to be storage or release from water, ground, and atmosphere, but the levels of this unbalance (if any) is significantly smaller than the atmospheric greenhouse effects for the cases examined here, so will be ignored in the present write-up.
Most of the energy from the warmed Earth is not transported directly from the ground and oceans to space by radiation. If the ground and oceans radiated directly to space, the average amount of ground level radiation to space would have to match the average solar input, and this would determine some average ground temperature.
This is where the atmospheric greenhouse effect comes in. Since the Earth’s atmosphere does contain absorbing (and radiating) gases at the thermal optical wavelengths, there is considerable absorption and re-radiation throughout the atmosphere. In addition, atmospheric convective heat transfer from ground level and convective transport of evaporated water carry most of this energy from the ground up to the higher atmosphere, and condensing water vapor also releases the latent heat of the water vapor also at higher altitudes. The presence of the absorbing gases (and aerosols and water droplets) reduces the net surface radiation heat transfer rate out over the no greenhouse case. The absorption by and radiation from these gases and particles, combined with atmospheric convection, carry the absorbed solar energy (from the surface and directly absorbed by the atmosphere) to a range of altitudes where radiation to space finely occurs. The net average outgoing radiation to space has to match the net absorbed solar radiation if average surface temperature is not changing much.
If the average of the locations of outgoing radiation to space is used as a reference single location for black body radiation to space, the S-B relation can determine an effective temperature for this average effective altitude, and this effective temperature has to be the same as the average surface for the case of no greenhouse gas, but with the surface albedo was the same. We thus raised the altitude of the location of the S-B evaluated temperature. We now go back to the adiabatic lapse rate, which is a GRADIENT, not a level of temperature. By forcing the value of temperature on a single level of the atmosphere, and using the adiabatic lapse rate to calculate the ground temperature, we have found the cause of increased ground temperature. It is the adiabatic lapse rate CONBINED with the increased elevation of outgoing radiation. That is all there is to the process.
Back radiation is not a cause of the increased temperature; it is a result of the process. Net radiation is always from warm to cool, so back radiation cannot transfer HEAT from cooler to warmer, even though radiation can go both ways. It is the net energy transfer that is only important. While it is true that the lapse rate is not always the adiabatic lapse rate, and the ground can actually be cooler than the atmosphere (at night), I am only referring to the global average values, where the ground level is warmer.
Leonard and SOD: I agree with Leonard’s outline of why GHG’s must warm the earth, which is also used elsewhere by SOD. So why does the IPCC (AR4 FAQ 1.3, for example) and sometimes SOD persist backing the traditional greenhouse effect. Although DLR exists, the traditional greenhouse effect certainly can’t warm the surface where the lapse rate is unstable (an objection that might apply to the planet as a whole). It is plagued by hairsplitting between the colder atmosphere “warming” vs “transfers heat to” the surface; the latter violating the 2LoT. It’s all so unnecessary.
Leonard,
That’s one explanation of why there’s a greenhouse effect, but it does nothing to quantify it, as the effective altitude of emission is a mathematical construct that probably contains less information than the global average surface temperature and is not directly measurable. DLR, on the other hand, is necessary for constructing a surface energy balance and, even more importantly, it is directly measurable both as a total quantity and as an emission spectrum. It is a direct consequence of the concentration and vertical distribution of greenhouse gases, temperature and pressure. There would be no DLR in a perfectly transparent atmosphere. There would be a lapse rate.
Leonard Weinstein,
I agree 100% with your description & explanation (re January 14, 2012 at 4:36 pm).
Also, adding ghg’s doesn’t change the surface energy balance much at all initially. It does create an energy imbalance in the atmosphere. With less energy being radiated to space than is being absorbed, the atmosphere warms. That causes an energy imbalance at the surface with more energy being absorbed than radiated. Then the surface warms to correct that imbalance. That’s also why the kinetics are slow. It takes a long time to warm the upper ocean.
The term “greenhouse effect” is perfectly valid because what you’ve done is reduce the effective emissivity of the atmosphere. Replacing IR transparent windows on a greenhouse with IR opaque windows means a greenhouse radiates less energy. To restore the balance, the greenhouse must warm until thermal losses through the walls and increased radiation and thermal loss from the warmer windows restores balance.
I can see exactly this effect with my experiments. A box with a glass window is warmer inside by at least 20 C than a box with a polyethylene film window. But when I point an IR thermometer at the windows of each box, the radiative temperature of the box with the glass window is a good 20 C lower than the box with the polyethylene film window. If the walls and windows were perfectly insulated, the radiative temperature would be the same for both boxes, but the box with the glass window would be even warmer because now the glass window would be at the same temperature as the bottom surface of the box with the polyethylene film window.
The precise details in the atmosphere are different, but the principle is the same.
Don’t think that a small change in the lapse rate would prevent surface warming either. Increasing the temperature at the tropopause by 1 C while keeping the surface temperature fixed will not cause the radiation to space to increase anywhere near as much as an increase of temperature of 1 C at the surface.
Leonard Weinstein: “By forcing the value of temperature on a single level of the atmosphere, and using the adiabatic lapse rate to calculate the ground temperature, we have found the cause of increased ground temperature.”
But isn’t the mechanism of the increased altitude of the “radiating to space layer” the increased absorption and backradiation of the GHGs? And isn’t the actual cause of the increased temperature the increased amount of radiation still hanging around due to backradiation?
At the least it seems like two sides of the same coin, and not incorrect to also say that the backradiation is leading to higher temps than would otherwise be observed. Or am I missing the mechanism?
And to continue to pummel the deceased equine:
In an horticultural greenhouse (or the Wood experiment) there is a temperature gradient between the inner surface of the greenhouse and the window when exposed to direct sunlight. By decreasing the IR transparency of the window, one effectively moves the height of emission from the inner surface toward the window and increases the temperature of the inner surface. So I ask again: Why do you think the name ‘greenhouse effect’ is inappropriate to describe the atmosphere?
DeWitt Payne,
This is not a straw man argument. Obviously, you are not familiar with the determination of the temperature of a surface element. Equation (2.17) of Kramm & Dlugi (2011) describes the energy flux scheme that is customarily solved in any state-of-the-art numerical model of the atmosphere to obtain the surface temperature of bare soil. The temperature obtained is, of course, only valid for the local scale. Since the solar insolation depends on latitude the predicted temperature depends on latitude, too.
If vegetation covered the surface it is, by far, more complex, but there are several numerical modules to handle it. I already developed such a module during the eighties of the past century.
If the Earth has no atmosphere the fluxes of sensible and latent heat and the down-welling infrared radiation can be ignored in this Eq. (2.17). This means that the temperature of the surface element is determined in a similar manner. Vasavada et al. (1999), for instance, did it for Mercury and Moon. If the averaged surface temperature for the Moon’s equator is of about 225 K, the corresponding temperatures for negative and positive latitudes are lower.
The speed of rotation plays no role if the storing and releasing of heat is ignored. The depth of Moon’s layer penetrating by heat during its daytime may differ from that of the Earth in the absence of its atmosphere, but this is not a big problem. One can handle it because the physical processes of heat conduction in porous media does not depend on Earth days. Horizontal transport of heat within the soil is rather inefficient so that it plays no notable role.
The formula for the temperature T_e of the radiative equilibrium for the Earth having no atmosphere reads
T_e = ((1 – a) S/(4 eps sigma))^0.25
Here, S is the solar constant, eps is the planetary emissivity, a the planetary albedo, and sigma is Stefan’s constant. This formula documents that no effect of heat storage is considered. It is used for the Earth, but also for the Venus (see Pierrehumbert, 2011). In case of Venus the speed of rotation amounts to 116 Earth days. This means that the Moon has a much faster speed of rotation than the Venus.
Do you believe that in case of the Earth having no atmosphere oceans could exist? From a physical point of view this is very unlikely.
Exactly, no effect of heat storage is considered. Because that formula applies only to a superconducting sphere. But no real surface has a heat capacity of zero or is a superconductor. Heat will diffuse into the surface when it is exposed to sunlight and diffuse back out again when it isn’t. For a rotating body, that means the average temperature will never be as low as 144 K. Nor will it be 255 K assuming an emissivity of 1 and an albedo of 0.3. Suppose instead of a rock and soil surface, we had a nickel/iron sphere with an albedo of 0.3 and a thermal emissivity close to 1. Would that sphere have an average temperature of 144 K? Not hardly, especially if it were rotating at any reasonable rate.
It must read:
“In case of Venus the speed of rotation amounts to 116 Earth days per rotation.”
The planetary rotation rate of Venus is irrelevant considering the cloud layer rotates at a much more rapid rate. As a result of the turbulent mixing this causes, the surface temperature is nearly constant over the whole planet.
DeWitt Payne,
in case of the Venus in the absence of its atmosphere as considered by Pierrehumbert (2011) there would be no clouds.
Best regards
Gerhard
DeWitt Payne,
for the Earth in the absence of its atmosphere I calculated a globally averaged surface temperature of nearly 190 K +/- 10 K. However, the result depends on the albedo. This quantity is not known. A planetary albedo of 0.3 is only valid for the entire Earth-atmosphere system.
Nevertheless, the 255 K are completely irrelevant.
Best regards
Gerhard
I keep forgetting to copy long posts in case they somehow get lost. I’ll try again.
The temperature of 255 K is not irrelevant at all. In fact it’s very close to the effective temperature of the Earth as observed from space. Air and water circulation move energy from the equator to the poles. As a result, the the polar regions emit more radiation than they receive from solar radiation and the tropics emit less. (See graph. Note the data are re-plotted from Grant Petty as a function of sine (latitude) to make the result more proportional to surface area) This makes the effective emission temperature to space greater than 240K over 95% of the surface area (see graph). And that makes the average effective temperature very close to the isothermal maximum.
But the surface temperature is a lot higher than 255K. Something makes this happen. A change in radiative transfer from the surface to higher altitude because of absorption of radiation causes the effective emission altitude to be higher than the surface for most wavelengths for most of the planet. That’s much higher for the CO2 band. It’s colder at higher altitude so there is less emission than at the surface. Radiative and convective energy transfer explain with good precision and accuracy the observed features of the atmosphere, especially including IR emission spectra of the atmosphere observed from the surface and high altitude.
I have my own questions for you concerning the G&T paper:
1. Do you believe that energy balance diagrams such as in TFK2009
G&T section 3.7.2
2. Do you believe that G&T are correct in 3.5.5 when they state:
How then is it possible that the assumption of LTE is used to accurately calculate molecular gas emission spectra every day?
3. Do you believe that G&T’s invocation of MHD theory in 4.2.1 for planetary atmospheres is valid? It has absolutely nothing to do with absorption and emission of radiation at normal atmospheric temperatures.
4. Do you believe that Wood’s results in 1909 are correct in spite of their nearly immediate rebuttal by Charles Greeley Abbot and their failure to be replicated recently, most notably by Stanford Professor Emeritus Vaughan Pratt? That casts a lot of doubt over the entire Section 2 of G&T, not to mention the rest of the paper.
I could go on, but I’ll stop there.
Correction:
The first line should read ‘…the average effective temperature…’. Obviously the total radiated power divided by the total radiating area, i.e. Teff for the planet will be the same value regardless of the latitudinal temperature distribution. But averaging the latitudinal temperatures corrected for surface area must be lower for a non-isothermal sphere. That’s Hölder’s Inequality. If I average the emitted power by latitude plotted in the first graph I get 237.66 W/m2 which corresponds to a temperature of 254.44K. If I average the effective temperature at each latitude as plotted in the second graph linked above corrected for surface area I get 254.12K.
These numbers were more or less eyeballed off a graph in Petty. Specifically this one: Petty Figure 1.1
DeWitt, for some reason your original comment got trapped in the spam queue, no idea why. It looks very similar to this but I can resurrect it for you if you like.
DeWitt Payne says
“The temperature of 255 K is not irrelevant at all. In fact it’s very close to the effective temperature of the Earth as observed from space.”
Agreed and this is confirmed by a SB calculation based on an Earth/Atmosphere system with an albedo of 0.3.
If however we indulge in speculations like;
1. Same Earth system except CO2 and H2O don’t radiate in the IR
2. Same Earth system but no Oceans
3. Same Earth system except no atmosphere
We would get different values for the system emissivity and therefore the value of 255 K is not unique.
So the greenhouse effect value of 33K is as G&T say a ‘meaningless number, wrongly calculated’
.DeWitt Payne says
…..”Do you believe that Wood’s results in 1909 are correct in spite of their nearly immediate rebuttal by Charles Greeley Abbot and their failure to be replicated recently, most notably by Stanford Professor Emeritus Vaughan Pratt?”….
It should be noted that Vaughan Pratt has no background in experimental physics and no longer defends the experiment quoted.
Instead he is working on a new version.
De Witt is working on his own version of Woods experiment .
It will be a startling confirmation of the IPCC version of Climate Science if DeWitt’s experiment shows a 33K difference in the two boxes.
SoD,
I think the second one is close enough to the first. Don’t bother resurrecting the first one.
Bryan,
This is basically a middle school science fair project level experiment. Nasif Nahle doesn’t have a background in experimental physics either. He’s a biologist by training, I think. Even you could do it. But you won’t because you might find out that we’re right and you’re wrong and that would ruin your day big time.
How do you know Vaughan Pratt doesn’t defend his results? It wasn’t a blog post with a comment thread. It’s a web page. I’ve had personal correspondence with him discussing some details he didn’t post, like the condensation problem, and he certainly hasn’t disavowed the results. I think he did make a mistake or two in his explanation of heat transfer through the windows, but it has no effect on his results. What he’s working on is to use actual NaCl windows to see if he can determine why Wood went wrong. But the available NaCl windows are small diameter so the experimental details are trickier. Plus he’s got other more important things to do. He had a presentation at the Fall, 2011 AGU meeting, for example.
People who believe that CO2 is a major driver of the Earth’s climate have given us many models that are supposed to explain what happened in the past and predict what will happen in the future,
The IPCC has adopted at least a dozen of these models to prepare a composite prediction of global temperatures up to the year 2100.
In climate science there is a touching faith in the strength of numbers. Apparently, all you need to prove anything is a large enough number of climate scientists, a large enough set of models or a large enough collection of temperature proxies.
My contention is that it is not quantity that matters but quality A baker’s dozen of climate models approved by the IPCC may be worthless compared to a single model that does a better job of explaining observations.
Here is a paper by someone who still believes that hard science may save us from the squishy science of the IPCC and Penn State’s Wizards of Climate. It makes me proud to know that this scientist works at the Duke University Free Electron Laser Laboratory that this aged camel helped to build.
http://scienceandpublicpolicy.org/reprint/astronomical_harmonics_testing.html
Scafetta has thrown down the gauntlet to the IPCC with its CO2 obsession. His model is clearly superior to the IPCC’s models in backcasting. It diverges sharply from the IPCC’s model with regard to forecasting. The divergence is so great that we won’t have to wait long to know which model is closest to reality.
My money is on Scafetta who may finally slay the CO2 dragon and lead us back to rational energy policies.
gallopingcamel,
Please can you explain what relevance your comment has to this article. If it doesn’t no further comment on your part is necessary.
The post was about opposing approaches to quantifying the “Greenhouse Effect” on this planet. Please note that 18 months ago I participated in an interesting debate on your fine blog when the subject was the planet Venus. I greatly appreciated the insights that you, Leonard Weinstein and DeWitt Payne provided.
It seemed highly relevant to cite a paper with a alternative hypothesis involving natural forcings that may overwhelm whatever effect CO2 has on global climate. Your comment seems to suggest that you are trending towards the Joe Romm or John Cook style of moderation that will not tolerate contrary opinions even if they are backed up by peer reviewed publications.
If so, “no further comment on my part is necessary”.
I hate to be critical of courteous commenters like yourself.
However, I do sometimes try to keep discussions somewhat related to the article. It is a policy very inconsistently applied.
It seems that comments about i) GCM accuracy and ii) the last 10,20,30 years of temperature history can be liberally sprinkled onto every article I write with vague relevance. Yet they add little to most specific discussions.
This article is about whether the “greenhouse” effect exists and specifically whether Kramm & Dlugi have demonstrated it, and what exactly they have demonstrated. 10,000 papers about effects on climate or not of incremental effects of CO2 don’t appear to me to assist with this discussion.
I have no intention of trending towards “..not tolerating contrary opinions even if they are backed up by peer reviewed publications.” and my apologies if I seemed to imply that.
gallopingcamel,
evn though I completely disagree with various comments on the paper of Kramm & Dlugi (2011), I still like the discussion here.
Best regards
Gerhard
But Scaffetta does not deny that increasing CO2 levels would cause some warming or that there isn’t a greenhouse effect at all. I believe that classifies him as a lukewarmer. Although some lukewarmers would throw him out of the tent because the lower end of his range of climate sensitivity is too far below the IPCC lower limit of 1 C/CO2 doubling. But it’s still greater than zero.
Gerhard Kramm on January 10, 2012 at 7:18 pm:
All of which is very interesting and as I said in the article, apart from the conclusion I don’t disagree with the serious points in your paper.
I also like to have a dig at people for sloppy definitions and a little satire goes a long way in getting me through the day. I especially liked your Planck joke on Lacis et al and I’m sure they appreciated it as well..
But I can’t see how your conclusion:
– follows given that you understand radiative physics.
In fact, I was inspired by your conclusion to write a new article: The Rotational Effect.
I’m sure the point will be clear.
My question to you – given that:
– a) the outgoing spectra of the earth’s radiation is clearly affected by, and the outgoing flux is reduced by, the radiatively-active trace gases
– b) the atmospheric flux at the earth’s surface is clearly emitted from radiatively-active gases and is mostly absorbed, so must affect the surface energy balance
Surely you believe there is a “greenhouse” effect, however inappropriately named?
– Perhaps you would like to argue that the “no greenhouse” effect is impossible to quantify.
– Perhaps you would like to argue its value cannot be easily quantified.
– Perhaps you would like to argue that its current value requires some serious calculation of surface longwave emissivity and a redoing of the Trenberth, Fasullo & Kiehl (2008) calculation of upward emission of thermal radiation.
These may all be valid points, but surely, as you understand the spectra of OLR and DLR and the radiative transfer equations you cannot say there is no effect of these trace gases?
Some clarification would be very much appreciated.
Bryan,
240 W/m2 times 5.1E14 m2 = 122.4E15 W or 122.4 PW. The largest energy transfer I know of is the meridional transfer which peaks at 5 PW seasonally about latitude 40 N or S with the phases in the opposition in the two hemispheres. That involves massive circulation of air and water. I think we would have noticed if there were larger cycles than this.
Science of Doom,
The last thing I want to do is to lower the quality of discussion on this site. If I have drifted “Off Topic” then I apologise and request that a thread be started for evaluating the predictions of models or mathematical analyses versus observations,
Has there been any discussion of Nikolov & Zeller on this blog? They seem to think that when it comes to calculating the size of a “Greenhouse Effect” the mass of a planet’s atmosphere is more important than the chemical composition. Whether you agree or disagree it appears to be a testable hypothesis.
DeWitt,
Folks like Scafetta (ACRIM satellite) and Kirkby (the CLOUD experiment) work with hard science. It would not be fair to label either of them warmist, lukewarmist or —-er [Unfortunate moderator’s note on labels etc, see Etiquette]. They will go with whatever their measurements show. I would like to see many more like them studying climate related issues.
gallopingcamel:
There have been articles about models, the last one in that series was Models, On – and Off – the Catwalk – Part Three– an introductory look at chaos in climate.
Now that we have the “recent comments” pane down the right hand side it is easy for people to restart discussion because other readers will see that a new comment has been made.
Not that I have noticed and I haven’t read their paper.
So because of your comment I found the paper and started reading it. I have reached page 5 and it’s so bad that I wonder whether it is worth finishing it let alone writing an article about it.
But I can see why it will be a popular paper.
It was just a poster but their calculated surface temperatures for several planets and moons are in good agreement with observations.
For the full text:
Bryan,
255 K is the upper limit for an isothermal sphere with an emissivity of 1 receiving an average of 240 W/m2. Hölder’s Inequality requires this Limiting cases are often used to compare to the properties of objects in the real world even if the conditions, such as being isothermal and having unit emissivity, are not possible for a real world object. Other limiting conditions are also useful. For example, the average temperature for a rotating sphere with unit emissivity with infinite surface heat capacity and zero thermal conductivity so it’s isothermal at each latitude, assuming the axis of rotation is perpendicular to the orbital plane, but the temperature decreases as you move away from the equator, is 252K. The latitudinal temperature profile is far steeper than the Earth with the poles at 2.72 K. But even then, it’s only 3 K less than the average for an isothermal sphere. Since 70% of the planet is covered by water which has a very high heat capacity, the diurnal temperature variation isn’t really all that much. So a sphere with the thermal characteristics of the Earth (This is a thought experiment. Please don’t raise the objection that there is no such animal in the real world.) but with a perfectly transparent atmosphere would have an average temperature even closer to 255 K.
If you reduce the emissivity, the temperature goes up. According to TFK2009, 184 W/m2 of sunlight reaches the Earth’s surface and 23 W/m2 is reflected. That’s an absorptivity of 0.875. If we assume that’s also the average emissivity in the thermal IR for the surface, which is pretty much a worst case assumption, the isothermal sphere temperature goes up to 264K. That’s still way less than the actual average surface temperature. In fact, to get a surface temperature of 288K with emissivity alone requires that the emissivity be less than 0.62. Considering that 70% of the planet is covered by water with an emissivity greater than 0.9, the rest of the planet would have to have a negative emissivity to get down to 0.62.
Moving heat around won’t get you there. The upper limit is still an isothermal sphere.
DeWitt Payne you say
….”255 K is the upper limit for an isothermal sphere with an emissivity of 1 receiving an average of 240 W/m2.”….
This is due to an emissivity of 0.3
…..”If you reduce the emissivity, the temperature goes up. According to TFK2009, 184 W/m2 of sunlight reaches the Earth’s surface and 23 W/m2 is reflected. That’s an absorptivity of 0.875. If we assume that’s also the average emissivity in the thermal IR for the surface, which is pretty much a worst case assumption,”……..
Well for the new surface arriving solar IR (previously cloud/atmosphere absorbed) the absorptivity of would be almost unity, implying an even higher temperature.
However folk can have a grow up discussion about a realistic temperature if the GHE were not there.
What seems to me irrational is the insistence that without the GHE the average surface temperature would drop by 33K.
Is it possible that other means of energy storage in an oscillating system such as shown in fig 11 Kramm & Dlugi could make a contribution/
Correction
“This is due to an emissivity of 0.3”
Should be
This is due to an albedo of 0.3
Bryan: One can fairly assert that there are serious problems with all attempts to calculate what the earth would be like without GHGs and that comparison between the real world and that any world calculate with paper and pencil will be problematic. However, Lacis et al published a paper in Science using an AOGCM to predict what would happen if all of the CO2 (not even all of the GHG’s) were removed from the atmosphere. This model has rotation, oceans, clouds, realistic surface temperatures, surface heat capacity, radiative transfer, convection, etc – everything one would want in a no-GHG model (except this was no-CO2). The AOGCM produces an earth without CO2 that is 35 degK colder AND a reasonable version of the current earth. There are justifiable concerns about whether an AOGCM can calculate the warming expected for 2XCO2 with the accuracy needed to advise society about future climate change, but there is no doubt that removing all CO2 will produce a large reduction in temperature and that removing all GHGs will produce a bigger decrease. The methodology behind -33 degK figure can be ridiculed, but IMO the magnitude and sign of the change are perfectly sensible. Further argument about the limitations of various no-GHG models therefore appear pointless.
Summary of Lacis paper and link to pdf for full article : http://www.giss.nasa.gov/research/briefs/lacis_01/
DeWitt Payne you say
…..”This is basically a middle school science fair project level experiment. Nasif Nahle doesn’t have a background in experimental physics either. He’s a biologist by training, I think. Even you could do it. But you won’t because you might find out that we’re right and you’re wrong and that would ruin your day big time.”……
I’m sure you will produce a better report on the Wood experiment than Vaughan.
However the smart money will still be on Wood often described as the best experimental physicist that America ever produced.
On seeing your final report I will try to replicate your results.
Wood never gave the dimensions of his boxes, nor how much cotton he used to insulate the walls of the boxes. There’s even ambiguity about the exact configuration of the glass and rock salt windows. He may have been a great experimental physicist, but this was not one of his better efforts.Charles Greeley Abbot didn’t believe Wood was correct.
Your faith in the correctness of Wood’s results is touching, but misplaced. It’s also clearly confirmation bias. Wood managed to screw up a middle school science fair level experiment. Deal with it.
Leonard Weinstein
Atmospheric Greenhouse Effect
If raising the effective radiating altitude were to warm the surface via the lapse rate, it could do so only by changing the lapse rate?
Tz = Ts – z*r z is altitude, r is constant lapse rate
-delta Tz = delta Ts – deltaz*r
delta Ts = deltaz*r – delta Tz = 0
This might be an opportune time to ask whether Prevost’s 1792 theory of radiative exchange has been experimentally demonstrated. The 1960’s vintage text “Principles of Modern Physics”, generally replete with descriptions of such demonstrations, in Prevost’s case merely notes that the theory “asserts” etc. If there has been any advance since then, SOD would surely have brought our attention to it.
At the time, accepting the theory on trust avoided the question: How do bodies, with no means of communication between them, know when to radiate and when not to – specifically, what would cause radiation to cease at thermal equilibrium? But bodies are never separated by nothingness. They are always surrounded by an electromagnetic field comprising waves of different amplitudes and frequencies. Radiation is triggered by interaction between these waves and the body’s surface atoms. It seems entirely plausible that some interactions might constitute a trigger and others might not.
I dont understand the stated problem with the Goody figure (top panel), the y axes indicates ‘nomalized’.If the blackbody Bgamma (spectral irradiance) are plotted versus the log of gamma (wavelength) and are normalized to the peaks, then thats what you get.
The normalized peak values are 1.0. The actual peaks ratio by (Tsun/Tearth)^5 or (5780/300)^5 and correspond to the values in the Bgamma formula at the wavelengths by the Wein displacement law, or gamma max=b/T where b=2.8977685e-3 m*K. The two normalized curves are identical and only shifted in the x axis
At least I dont think there is a problem with the top graph, Goody is still tops.
Andrejs Vanags:
I think this graph is more like reality:
Note that it is just one possible sample of absorbed solar radiation at one azimuth angle and one climate albedo.
The important point is that the graph shows energy per unit wavelength.
Look back at Goody’s graph – the solar radiance is across just 4 μm, while the terrestrial radiance is across almost 100 μm.
So if you do a rough estimate and multiply the peak by the width the absorbed solar radiation is (very approximately) 25x lower in value than the emitted terrestrial radiation. But it should be equal in value.
It just looks the same because to the eye the areas are the same. Our eyes are not attuned to equating areas on logarithmic graphs.
Andrejs, frequency is better than wavelength for such things because photon energy is linearly proportional to it whereas it is inversely proportional to wavelength.
But Eli has a question of Bryan and Gerhard. What do you think heat is and how do you distinguish it from other forms of energy?
Anyone willing to learn a little Python can download and experiment with my various homebrew radiative convective models to address questions raised here. Just go to PlanetaryClimateBook.org . For that matter, most of the issues that have come under discussion in this thread are resolved in one place or another in my book, Principles of Planetary Climate. It’s not exactly light reading but a lot easier to get through, I think, than Goody and Yung.
The main issue that comes up if you remove all greenhouse gases from the Earth’s atmosphere (but leave the N2 and O2 behind so as to keep atmospheric heat transport pretty efficient) is that the oceans would freeze, leading to additional cooling from increase of surface albedo. And even then, you’d have clouds in the atmosphere which would still have a significant greenhouse effect. So, if you’re thinking about thought experiments removing the greenhouse gases from the atmosphere, you also have to put a lot of thought into just what experiment you want to do, what you want to do about oceans and ice, and just what it is you hope to illustrate with the thought experiment. I think the most relevant experiment for illuminating Earth climate is the one Aiko Voight did (rediscovered by Lacis et al, who were ignorant of the prior work) — take out the CO2 from the atmosphere, and you wind up in a globally glaciated Snowball.
People interested in observations that demonstrate the clear physical reality of the greenhouse effect, as revealed in actual observed top-of-atmosphere spectra, might be interested in my Physics Today article, “Infrared Radiation and Planetary Temperature.” There is a public-access copy on the Publications section of geosci.uchicago.edu/~rtp1 .
Dear Dr. Pierrehumbert,
Let us consider an atmosphere completely transparent in the IR-range. This means that the IR radiation emitted by the Earth’s surface (i.e., terrestrial radiation) is not affected by so-called greenhouse gases by assuming that no absorption/emission bands exist in the IR range. Thus, there is no down-welling IR radiation. Then, we would have:
Top of the atmosphere:
(1 – a_E) S/4 – L_u = 0 (1)
Earth’s surface:
(1 – a_E – A_a) S/4 – H – E – L_u = 0 (2)
Here, S is the solar constant, a_E is the albedo of the Earth-atmosphere system in the solar range, L_u is the terrestrial radiation, A_a S/4 is the solar radiation absorbed by the atmosphere, where A_a ist the respective absorption coefficient, H and E are the fluxes of sensible and latent heat, respectively. All fluxes are, of course, globally averaged. Combining these two equations yields then:
A_a S/4 + H + E = 0 (3)
Consequently, in such a case the energy absorbed by the atmosphere in the solar range must be transferred to the Earth’s surface, i.e., W = H + E must be directed downward to balance the radiation, A_a S/4, absorbed by the atmosphere in the solar range. To guarantee such a strong (globally averaged) downward directed flux W would require inconceivably strong temperature inversions. I wonder whether this is your “greenhouse effect” or not.
If we further assume that W = 0, we would for the Earth’s surface:
(1 – a_E – A_a) S/4 – L_u = 0 (4)
This means that the so-called effective temperature (whatever it means) of this kind of planetary radiative equilibrium would result in
T_e = {(1 – a_e -A_a) S/(4 eps_E sigma)}^0.25 (5)
Assuming a_E = 0.3, A_a = 0.23, and eps_E = 1 yields then:
T_e = 231 K
In accord with Eq. (1), there would be an imbalance at the top of the atmosphere expressed by
(1 – a_E) S/4 – L_u (T_e) = A_a S/4 (6)
Because of such a great imbalance the Earth would probably lose its atmosphere within a short period.
The numbers of this thought model of an atmosphere completely transparent in the IR-range underline that any assumption that excludes the fluxes of sensible and latent heat is rather inadequate. The uncertainty inherent in the determination of these fluxes is so large that any effect of an energy imbalance of 0.58 W/m^2. as diagnosed by Hansen et al. (2011) for the period 2005 – 2010, may be assessed as noise.
Sincerely yours
Gerhard Kramm
If you leave oxygen in the atmosphere to absorb solar UV, then you must also have ozone. Ozone has a band in the thermal IR which will balance emission and absorption. The stratosphere will still increase in temperature with altitude, just like now, but the temperature range won’t be all that different, especially since the tropopause will have a lower temperature.
The fluxes of sensible and latent heat are of course important in the surface energy balance. That is why they are included in every climate model, from GCM’s down to the simplest radiative-convective model. When the turbulent coupling is very effective, a detailed surface balance can be replaced by the assumption that the surface temperature is very close to the overlying air temperature (as explained in Chapter 6 of my book, which is all about the relative roles of turbulent fluxes and radiative fluxes in the surface balance).
But none of this has much bearing on the way greenhouse gases affect the surface temperature of a planet. If you deal with the top of atmosphere energy budget, it’s all radiative, so the calculation is much simpler. As is the incontrovertible proof of the greenhouse effect from observations of top of atmosphere spectra. Incontrovertible at least if you subscribe to the First Law of Thermodynamics. Even people who are wobbly on what the Second law means should at least be able to grasp the First Law.
Dear Dr. Pierrehumbert,
recently, Hansen et al. (2011) stated:
»The basic physics underlying this global warming, the greenhouse effect, is simple. An increase of gases such as CO2 makes the atmosphere more opaque at infrared wavelengths. This added opacity causes the planet’s heat radiation to space to arise from higher, colder levels in the atmosphere, thus reducing emission of heat energy to space. The temporary imbalance between the energy absorbed from the Sun and heat emission to space, causes the planet to warm until planetary energy balance is restored.«
A similar argument can be find in the paper of Ramanathan et al. (1987); Jim Hansen was one of the co-authors.
First of all, this argument is incorrect because neither the globally averaged fluxes of sensible and latent heat nor the globally averaged net radiation in the infrared range, DL_u (i.e., terrestrial radiation minus down-welling radiation) are functions of the surface temperature. Second, there is no constant ratio between W = H + E on the one hand and DL_u on the other hand. ). A reduction of DL-u by F = 0.58 W/m^2, as diagnosed by Hansen et al. (2011) may easily be compensated by H and/or E to fulfill the energy flux budget for the Earth’s surface. The same is true in case of any other of these flux terms. Note that even the Bowen ratio = H/E is not constant.
Sincerely yours
Gerhard Kramm
Dear DeWitt Payne,
of course, ozone has an absorption/emission band in the atmospheric window at 9.6 my. H2O and CO2 have also various absorption/emission bands in the infrared range. Thought models serve to analyze the behavior of a system even under nearly absurd conditions.
Remember, the Earth in the absence of its atmosphere is a thought model, too. It serves to quantify the so-called atmospheric greenhouse effect by 33 K.
Sincerely yours
Gerhard Kramm
Gerhard Kramm,
Re your comment of February 15, 2012 at 7:43 pm where you cited Hansen et al (2011). They said:
You took issue with the comment for a number of reasons.
But please confirm a few points so we can confirm exactly what you disagree with:
1. You are not questioning the physics of increasing opacity increasing the radiation to space from higher levels.
2. In the first instance, if the altitude of radiation to space increased this would reduce the flux to space because the temperature at a higher altitude is colder.
3. As soon as the flux to space reduced then this would have a cooling effect and so we have to consider feedback which is very complex and who knows what the final result is.
ROTFL. If there are no greeenhouse gases and
Eli,
It seems that Dr. Kramm is now wondering how to answer this comment:
> Again, should a response [sic.] to such statements? Sorry, my time is too valuable to response to [Eli]’s “bla bla blubber”.
http://metaclimate.org/2012/04/14/arguing-with-stupid-people/#comment-6841
Below your write: “When the turbulent coupling is very effective, a detailed surface balance can be replaced by the assumption that the surface temperature is very close to the overlying air temperature …
But none of this has much bearing on the way greenhouse gases affect the surface temperature of a planet.”
Our host and many others say that increasing GHGs will increase DLR emitted from near the surface, which must increase surface temperature. However, we don’t know if the additional energy delivered to the surface by enhanced DLR will leave the surface via convection, or – after the surface warms – via radiation, or by some combination of the two. If an increase in DLR results in an 0.25% increase in surface temperature (0.7 degK), upward surface radiation will increase 1% or 4 W/m2. Unfortunately, this surface temperature increase could have been caused by a DLR increase of 5,12 or 40 W/m2 and the surface energy balance could be restored by convection increases of 1, 8, or 36 W/m2 respectively. There is a dramatic difference between 10% and 80% of enhanced DLR ending up as surface warming. When the greenhouse effect (and water vapor feedback) is described in terms increased DLR arriving at the surface, we need to know how much of the excess energy will leave the surface by each route before we know how much the surface will warm. Right now, K&T say roughly 97 W/m2 leaves the surface by convection and 63 W/m2 (396-333) by net radiation.
The proportion of energy leaving the surface by radiation and convection is obviously not fixed. If one slowly added GHG’s to an atmosphere that had none, all of the increased DLR would go into warming the surface so the added energy from DLR can escape as radiation. Eventually an unstable lapse rate will develop. Once convection begins, convection can remove some, most, an increasing fraction, or hypothetically all of the energy from increasing DLR. Most of the surface of the planet is convectively stable; the average of 97 W/m2 of upward flux by convection appears to be mostly zero W/m2 combined with a few sites (the ITCZ, isolated thunderstorms) where thousands of W/m2 is escaping upward. This isn’t an ideal situation for climate models with grid cells several degrees in latitude and longitude. I’m interested in knowing if current climate models partition the upward flux in agreement with observation (K&T energy budget) and whether we should have confidence in their ability to do so after CO2 has doubled.
I accept that increasing GHGs will raise the characteristic emission level and warm the surface via the lapse rate. I’m questioning the role DLR emitted near the surface plays in the greenhouse effect in general and especially in water vapor feedback.
Frank,
I’ve written too much about DLR and surface temperature as a consequence of the unscientific theories circulating on the internet about the (imaginary) second law of thermodynamics.
Leonard Weinstein keeps pointing this out. (And I keep reminding him that I agree with his explanation of the “greenhouse” effect).
You attribute this to me:
“..increasing GHGs will increase DLR emitted from near the surface..”
This is not necessarily true as I explained in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Five.
The TOA balance is where changes in radiatively-active gases really have an effect. Changes in TOA balance inevitably lead to heating or cooling in the first instance.
Thereafter, feedback as a result of the heating or cooling is what determines the final surface temperature.
Millet, you don’t have to change the lapse rate. The effective radiating temperature is constant so long as the planetary albedo stays constant, since
sigma * (Trad**4) = absorbed solar radiation per square meter. So if you keep Trad fixed and the lapse rate fixed, then you increase the surface temperature when you increase the altitude of the radiating level zrad:
Ts = Trad + r*zrad
Increase zrad and you increase Ts. What could be simpler?
(Explained in, dare I say it, Chapter 3 of Principles of Planetary Climate. I am sure this argument appeared explicitly and in detail in the original addition of Goody’s book, but it seems to have been taken out, or at least truncated, in the Goody and Yung revision)
raypierre,
It depends on where the fixed lapse rate is anchored: at the surface or at the radiating altitude. With increased radiating altitude, the former anchor implies a steepening of the graphical representation of the lapse rate – a backward-sloping line from the surface – and no change in surface temperature; while the latter anchor implies a right-ward line shift and a warmer surface. The surface warming would have to come from atmospheric radiation, introducing the controversial conflict with thermodynamic law.
Do you think the lapse rate is anchored at the radiating altitude? Why?
I don’t “think of it” as being anchored at the radiating level, that’s the way it has to be to satisfy the top of atmosphere radiation balance. That comes directly out of the definition of the effective radiating temperature and the definition of the radiating level. When you talk about the “lapse rate” as being anchored, I assume you actually mean the “temperature profile,” or more precisely, the (T,z) intercept at z = zrad. The lapse rate (slope) for a convecting layer is fixed by thermodynamics — dry thermodynamics in the case under discussion.
Raypierre,
A belated thankyou for drafting your book online. From that source and SOD’s excellent site, I believe I understand how the effective radiating temperature is derived and how, via the Ideal Gas laws, this translates to pressure and, thence, to altitude to arrive at a coordinate in (T,z) 2-D space. Could you confirm that this coordinate is notional, the planet’s real effective radiating (T,z) coordinate being lower and to the right of it?
Do I understand you correctly: the notional coordinate is the origin of the temperature profile which extends, at a thermodynamically determined “lapse rate”, downwards to the right to intercept the surface; and upwards to the left to intercept the tropopause, thus fixing temperatures at those altitudes?
On the other hand, the term “lapse rate” connotes a falling away of temperature from the surface to the tropopause suggesting the surface (T,z) coordinate or (T,0) as the origin of the temperature profile. In turn this suggests that a coordinate (T, z+dz) would lie on a steepened temperature profile. Is this not feasible?
Gerhard Kramm,
I am hoping you will answer the question posed towards the end of the article:
Looking forward to clarification of your thoughts on this.
scienceofdoom, did Dr. Kramm ever specifically answer your question? If so, I have missed it. Please direct me to his response, if he made one.
Longwave up is still greater than longwave out into space…
Click to access Wild_FriM.pdf
Daniel,
He did not.
Dear Daniel,
yesterday, I received an e-mail in which the sender argued that the NASA scheme of the global energy flux budget (http://upload.wikimedia.org/wikipedia/commons/4/47/NASA_earth_energy_budget.gif) does not contain the down-welling infrared (IR) radiation. This, of course, is a misinterpretation of this scheme because the so-called net radiation in the IR range is considered. This IR net radiation is the difference between the emitted radiation and the absorbed down-welling radiation. (The notion “back radiation” unsuitable).
I used the following example to document that the down-welling radiation must exist.
According to this NASA scheme the IR net radiation amounts to 21 % of the solar input at the top of the atmosphere, i.e., 71 W/m^2. If no down-welling IR radiation would exist this 71 W/m^2 would be the globally averaged emitted radiation. Thus, this meaning would be absurd.
Yesterday morning, the temperature at the Fairbanks International Airport was – 18 degrees C. This value corresponds to 240 W/m^2. The true surface temperature, of course, differs from that temperature, but not so much, even though strong temperature inversions of 20 K/100 m may occur. The relative emissivity of fresh snow is close to 100 %.
Most surface temperatures between 60 degrees North and 60 degrees South are usually higher than – 18 degrees C. This means that the emitted radiation by the largest part of the Earth’s surface (strictly spoken emitted by the water and land masses adjacent to the surface) is still higher than 240 W/m^2.
The surface temperatures of the polar regions may be lower than this temperature of -18 degrees C. Thus, let us consider the temperature that corresponds to 71 W/m^2, namely 188 K if we assume a relative emissivity of 100 %. Such a temperature was, indeed, observed at Vostok Station, Antarctica. Thus, we may conclude that the emitted radiation, on global average, is much higher than 71 W/m^2. Consequently, without any down-welling IR radiation, an IR net radiation of 71 W/m^2 would be impossible.
Furthermore, the physical basis of the radiative transfer equation on a microscopic scale underlines that the down-welling IR radiation has its origin in the emission of photons by molecules, where spontaneous and induced emission have to be considered (see Einstein, 1917). The interferograms as published by Hanel et al. (1972) also documents that the signals have their origin in the emission of radiation to space.This emission is related to the atmosphere and the Earth’s surface. It can be illustrated the best by the emission related to ozone in the 9.6 my band (see Figures 11 to 14 of Hanel et al, 1972). This means that the notion “trapping of radiation” is highly awkward.
Einstein’s considerations were extended by Milne (1928). He not only considered absorption, spontaneous and induced emission of photons by molecules, but also inelastic and super-elastic collision between molecules and other particles like atoms, ions and electrons. Milne showed that Einstein’s considerations are valid as long as the assumption of a local thermodynamic equilibrium (LTE) is fulfilled. Milne’s Eq. (20) is used in the literature for describing the breakdown of the LTE (see, e.g., Goody & Yung, 1989, Lenoble, 1993, Liou, 2002). We may assume that the assumption of LTE is acceptable up to a height of about 60 km above ground. Consequently, we may use Planck’s radiation law as the source function in the Schuster-Schwarzschild equation if we are dealing with the radiative transfer of IR radiation in this atmospheric layer. Milne’s Eq. (24) serves to distinguish between monochromatic radiative equilibrium for the region of the upper atmosphere where the density is very low (the mean free path is in the km range) and the monochromatic radiation under LTE conditions. Note that monochromatic radiative equilibrium means that the monochromatic radiation absorbed by molecules is re-emitted uniformly in direction.
Consequently, the down-welling IR radiation generally exists. On global average, it is of about 60 to 70 W/m^2 lower than the emitted radiation. Only the IR net radiation is a part of the global energy flux budget at the Earth’s surface.
It is well known from the literature that CO2 causes cooling rates especially in the stratosphere and the mesosphere. I suggest to read the paper of Feldman et al. (2006).
Now, the other side of the coin:
My co-author Dr. Dr. habil. Dlugi and I showed that the same value of the IR net radiation can be computed using various pairs of global temperatures for the surface and the atmosphere. The reason is simple. There is no thermodynamics that is based on globally averaged temperatures. None of the energy fluxes that contribute to the global energy budget of the system Earth-atmosphere depends on such global temperatures.
The globally averaged surface temperature is a weak signal of the global energy budget, but not the cause. Most definitions and descriptions of the so-called atmospheric greenhouse effect only serve to disguise this fact.
Furthermore, the down-welling radiation is not a synonym for this awkward greenhouse effect. We often observed downward directed heat fluxes in the atmospheric surface layer. But on global average, this heat flux is upward directed. The same is true the the case of the latent heat flux and the IR net radiation flux.
Finally, in physics, a definition of an effect is clear. This is the basis for any reproduction of this effect. The numbers of definitions and explanations of the so-called atmospheric greenhouse effect underline that this is not a physical effect, but an inappropriate description of the global energy budget by inserting globally averaged temperatures.
Dr. Kramm,
Wow! So much verbiage and hand waving, so little content.
Simplified models with constant global temperature put a lower bound on the size of the effect. Hölder’s Inequality requires that the global average temperature for a non-uniform temperature distribution that still radiates the same total energy must be less than for a globe with a uniform temperature.
Since there must be a net flow of thermal energy from the surface to the atmosphere and space, an increase in atmospheric radiative flux to the surface caused by an increase in atmospheric emissivity from an increase in radiatively active gas concentration, CO2 e.g., requires an increase in upward radiative flux, i.e. an increase in surface temperature. Similarly, a decrease in upward radiation at the top of the atmosphere caused by the increased width of the CO2 absorption band will cause an increase in atmospheric temperature. That will further increase the downward flux from the atmosphere to the surface,
CO2 does indeed cool the stratosphere. But emission to space from the stratosphere and absorption of emitted radiation from the surface and lower atmosphere in the stratosphere is small compared to total emission.
Your comment has nothing to do with physics, but with faith. Even simplified models must be based on correct equations. What you called are not simplified models, but wrong models.
The Earth’s surface has no uniform temperature. Therefore, the application of the Stefan-Boltzmann law on a globally averaged surface temperature is wrong because Stefan’s constant is not a natural constant. It is based on two integrations:
(1) The integration over the entire spectrum, i.e., from zero to infinity, to determine the radiative intensity, and
(2) the integration of the radiative intensities over the adjacent half space, where the these intensities are considered as isotropically distributed.
The latter is in integration over a vector field, This means that the Stefan-Boltzmann law can only be applied to a temperature of a small surface element comparable with a small hole necessary to observe cavity radiation.
The so-called effective radiation temperature of 255 K for the Earth in the absence of its atmosphere is a meaningless number. If we apply this physically inappropriate concept to the Moon, a nearly perfect example for a planet without an atmosphere, we will obtain nearly 270 K. The globally averaged surface temperature of the Moon, however is less than 200 K. This result is based on satellite observations and model simulations. We cannot observe the distribution of the Earth’s surface temperature in case of the absence of its atmosphere. But we can perform model simulations in a similar manner as in case of the Moon, where we have to pay attention that a Moon’s second is nearly 29.5 times larger than an Earth second. This can be handled by a variable transformation.
In both cases not only radiative fluxes in the solar and in the IR range have to be considered, but also the soil heat flux. Consequently, the rotation of the planet has to be included. The stupid calculation of the effective radiative temperature does not include the rotation of the planet and the soil heat flux.
No climate modeler would be so stupid to assume a uniform temperature for the Earth’s surface. To simulate the local Earth’s surface temperature in case of the presence of the atmosphere, a similar scheme has to be used. Beside the fluxes mentioned before, such a scheme also contains the down-welling IR radiation and the fluxes of sensible and latent heat. In case of tall vegetation like forest, such schemes become really complex. Have you ever developed such schemes? I have.
Your description of the radiative behavior of the CO2 molecule is not in agreement with Einstein’s paper.
Dr. Kramm,
I don’t see anything about globally averaged temperatures in this work by Wild et.al., just radiation measurements at multiple points across the earth. Would you be more comfortable not using the “greenhouse effect” terminology and just describe how the global energy budget has been altered by increased CO2 (and water vapor as a feedback), leading to an increase in W/ m^2 at the surface? Isn’t the object to find the best way of understanding and describing physical reality?
Click to access Wild_FriM.pdf
http://www.iac.ethz.ch/edu/courses/master/modules/radiation_and_climate_change/download/Lecture7_2013
Click to access Wildetal_IRS2012_GlobalEnergyBalance.pdf
Dear Daniel,
I replied to the question whether the longwave radiation outgoing from the Earth’s surface greater is than that emitted to space, but not to the ppt presentation by Wild et al.
In our Table 2 fifteen different authors (or author groups) were listed. This table is based on that of Kiehl and Trenberth (1997), where some additional information was inserted by Dlugi and me. None of these sources listed in Table 2 gave any evidence that the opposite would be true. This means that the results Wild et al. document in detail a fact that is known since many decades.
Mauritsen et al. (2012) stated,
»during a development stage global climate models have their properties adjusted or tuned in various ways to best match the known state of the Earth’s climate system. These desired properties are observables, such as the radiation balance at the top of the atmosphere, the global mean temperature, sea ice, clouds and wind fields.«
Thus, I do not further pay much attention to the results provided by GCMs. Such climate predictions are only the results of speculation using numerical models.
Do you really believe that in twenty years or so the next generation of climate modelers will try to confirm the results published during the past three decades? I do not. The next generation will also try to publish its climate predictions. This cannot mainly be done on the basis of confirmation. Thus, climate modelers like Washington and Hansen will be cited, if ever, as former modelers who also tried to simulate the Earth’s climate. Have you ever checked how good the prediction of a serious weather event was twenty or thirty years ago?
Dr. Kramm,
I don’ think the climate modeling is about the prediction of serious, individual weather events. And yes, I think the science historians will be intensely interested in how well the current climate models performed with regard to climate changes in the next 20-30-40+ years. The history of science has good long-term memory. My own prediction is that Gerlich and Tscheuschner will not fare well in that historical analysis.
This is true. According to Ed Lorenz (1975), weather prediction is mainly related to initial conditions (prediction of first kind) and climate prediction is mainly related to boundary conditions (prediction of second kind). But the atmospheric modules of both type of models are nearly identical.
Radiation fluxes are routinely measured close to the Earth’s surface using pyranometers and pyrgeometers and by satellite-borne radiometers. The fluxes of sensible and latent heat are not routinely measured by eddy covariance techniques. They are calculated on the basis of parameterization schemes. Consequently, there is a large degree of inherent uncertainty. This is quite understandable because the eddy covariance techniques only allow an limited accuracy. Errors of 10 to 20 W/m^2 (and even higher) are always possible. Based on special field campaigns, micrometeorologists found imbalance terms in the energy flux schemes for the Earth’s surface of more than 100 W/m^2.
Prof. Dr. Hans von Storch argued in an interview carried out by the German magazine Der Spiegel (http://www.spiegel.de/international/world/interview-hans-von-storch-on-problems-with-climate-change-models-a-906721.html):
»…no one has been able to provide a compelling answer to why climate change seems to be taking a break. We’re facing a puzzle. Recent CO2 emissions have actually risen even more steeply than we feared. As a result, according to most climate models, we should have seen temperatures rise by around 0.25 degrees Celsius (0.45 degrees Fahrenheit) over the past 10 years. That hasn’t happened. In fact, the increase over the last 15 years was just 0.06 degrees Celsius (0.11 degrees Fahrenheit) — a value very close to zero.«
It is time to think about the role of climate modeling because a lot of money is used for rather inadequate modeling, but the knowledge of the governing physical processes does not increase because there is not enough money to support both modeling and field campaigns. Without a better knowledge of these governing processes we must not expect better results provided by weather forecasting models and GCMs.
Dr. Kramm,
Has climate change “taken a break”? Probably not. Later in the interview, Dr. Von Storch says,
Storch: There are two conceivable explanations — and neither is very pleasant for us. The first possibility is that less global warming is occurring than expected because greenhouse gases, especially CO2, have less of an effect than we have assumed. This wouldn’t mean that there is no man-made greenhouse effect, but simply that our effect on climate events is not as great as we have believed. The other possibility is that, in our simulations, we have underestimated how much the climate fluctuates owing to natural causes.
SPIEGEL: That sounds quite embarrassing for your profession, if you have to go back and adjust your models to fit with reality…
Storch: Why? That’s how the process of scientific discovery works. There is no last word in research, and that includes climate research. It’s never the truth that we offer, but only our best possible approximation of reality. But that often gets forgotten in the way the public perceives and describes our work.
SPIEGEL: But it has been climate researchers themselves who have feigned a degree of certainty even though it doesn’t actually exist. For example, the IPCC announced with 95 percent certainty that humans contribute to climate change.
Storch: And there are good reasons for that statement. We could no longer explain the considerable rise in global temperatures observed between the early 1970s and the late 1990s with natural causes. My team at the Max Planck Institute for Meteorology, in Hamburg, was able to provide evidence in 1995 of humans’ influence on climate events. Of course, that evidence presupposed that we had correctly assessed the amount of natural climate fluctuation. Now that we have a new development, we may need to make adjustments.
SPIEGEL: In which areas do you need to improve the models?
Storch: Among other things, there is evidence that the oceans have absorbed more heat than we initially calculated. Temperatures at depths greater than 700 meters (2,300 feet) appear to have increased more than ever before. The only unfortunate thing is that our simulations failed to predict this effect.
SPIEGEL: That doesn’t exactly inspire confidence.
Storch: Certainly the greatest mistake of climate researchers has been giving the impression that they are declaring the definitive truth. The end result is foolishness along the lines of the climate protection brochures recently published by Germany’s Federal Environmental Agency under the title “Sie erwärmt sich doch” (“The Earth is getting warmer”). Pamphlets like that aren’t going to convince any skeptics. It’s not a bad thing to make mistakes and have to correct them. The only thing that was bad was acting beforehand as if we were infallible. By doing so, we have gambled away the most important asset we have as scientists: the public’s trust. We went through something similar with deforestation, too — and then we didn’t hear much about the topic for a long time.
SPIEGEL: Does this throw the entire theory of global warming into doubt?
Storch: I don’t believe so. We still have compelling evidence of a man-made greenhouse effect. There is very little doubt about it. But if global warming continues to stagnate, doubts will obviously grow stronger.
SPIEGEL: Do scientists still predict that sea levels will rise?
Storch: In principle, yes. Unfortunately, though, our simulations aren’t yet capable of showing whether and how fast ice sheets in Greenland and Antarctica will melt — and that is a very significant factor in how much sea levels will actually rise. For this reason, the IPCC’s predictions have been conservative. And, considering the uncertainties, I think this is correct.
SPIEGEL: And how good are the long-term forecasts concerning temperature and precipitation?
Storch: Those are also still difficult. For example, according to the models, the Mediterranean region will grow drier all year round. At the moment, however, there is actually more rain there in the fall months than there used to be. We will need to observe further developments closely in the coming years. Temperature increases are also very much dependent on clouds, which can both amplify and mitigate the greenhouse effect. For as long as I’ve been working in this field, for over 30 years, there has unfortunately been very little progress made in the simulation of clouds.
SPIEGEL: Despite all these problem areas, do you still believe global warming will continue?
Storch: Yes, we are certainly going to see an increase of 2 degrees Celsius (3.6 degrees Fahrenheit) or more — and by the end of this century, mind you. That’s what my instinct tells me, since I don’t know exactly how emission levels will develop. Other climate researchers might have a different instinct. Our models certainly include a great number of highly subjective assumptions. Natural science is also a social process, and one far more influenced by the spirit of the times than non-scientists can imagine. You can expect many more surprises.
SPIEGEL: What exactly are politicians supposed to do with such vague predictions?
Storch: Whether it ends up being one, two or three degrees, the exact figure is ultimately not the important thing. Quite apart from our climate simulations, there is a general societal consensus that we should be more conservative with fossil fuels. Also, the more serious effects of climate change won’t affect us for at least 30 years. We have enough time to prepare ourselves.
SPIEGEL: In a SPIEGEL interview 10 years ago, you said, “We need to allay people’s fear of climate change.” You also said, “We’ll manage this.” At the time, you were harshly criticized for these comments. Do you still take such a laidback stance toward global warming?
Storch: Yes, I do. I was accused of believing it was unnecessary to reduce greenhouse gas emissions. This is not the case. I simply meant that it is no longer possible in any case to completely prevent further warming, and thus it would be wise of us to prepare for the inevitable, for example by building higher ocean dikes. And I have the impression that I’m no longer quite as alone in having this opinion as I was then. The climate debate is no longer an all-or-nothing debate — except perhaps in the case of colleagues such as a certain employee of Schellnhuber’s, whose verbal attacks against anyone who expresses doubt continue to breathe new life into the climate change denial camp.
SPIEGEL: Are there findings related to global warming that worry you?
Storch: The potential acidification of the oceans due to CO2 entering them from the atmosphere. This is a phenomenon that seems sinister to me, perhaps in part because I understand too little about it. But if marine animals are no longer able to form shells and skeletons well, it will affect nutrient cycles in the oceans. And that certainly makes me nervous.
—————–
The vast majority of climate scientists have not “gambled away… the public’s trust”. It has been a tiny minority, well-funded by fossil fuel and other interests, who have impeded the science by sowing propaganda, the Merchants of Doubt, as Oreskes puts it. There is true skepticism, vital in science, and there is pseudoskepticism, employing scientifically dishonest tactics such as cherry-picking data with short- term noise.
http://www.skepticalscience.com/graphics.php?g=47
http://www.skepticalscience.com/global-cooling-january-2007-to-january-2008-intermediate.htm
Note Figure 9
“Figure 9: A visual depiction of how much global warming heat is going into the various components of the climate system for the period 1993 to 2003, calculated from IPCC AR4 5.2.2.3. Note that focusing on surface air temperatures misses more than 90% of the overall warming of the planet.
In fact Meehl et al. (2011)found that climate models expect ‘hiatus decades’ to occur, during which surface temperatures don’t warm significantly because more heat is transfered to the deap oceans. This is what appears to have happened over the first decade of the 21st Century.”
Dear Daniel,
I know this interview. It is not necessary to repeat it here. I listed the URL address so that the interested reader can find the interview.
Dr. Kramm,
I did not post this post this additional portion of von Storch’s interview for your benefit — I assumed that you were familiar with it. I posted it for the benefit of others (because you quoted rather selectively from the interview). So that others could see that von Storch doesn’t think that climate models are fundamentally flawed (but need to be improved). That he thinks, “We still have compelling evidence of a man-made greenhouse effect. There is very little doubt about it.” And that, “Among other things, there is evidence that the oceans have absorbed more heat than we initially calculated. Temperatures at depths greater than 700 meters (2,300 feet) appear to have increased more than ever before. The only unfortunate thing is that our simulations failed to predict this effect.”
Given the latter, his statements that climate change has taken a break and global warming stagnating are nonsensical.
And i don’t see your response to the evidence I provided that there is no pause in global warming.
In any case, I want to make certain that I understand you correctly. My understanding is that you agree that the longwave radiation outgoing from the Earth’s surface greater is than that emitted to space, or as scienceofdoom puts it, E-surface is significantly greater than E-TOA. Do you agree? Can you answer in a “yes” or “no” fashion?
Dear Daniel,
I do not discuss the results of speculations.
Dr. Kramm,
So the manufacturers of all non-contact thermometers aren’t actually measuring temperature? All of those instruments calculate a temperature using either the Stefan-Boltzmann equation or the Planck equation. And the field of view is a lot larger than a small hole in a cavity. A pyrgeometer has a field of view of 2π steradians Of course you could say that, since even a Hohlraum isn’t a perfect black body, the Planck and Stefan-Boltzmann equations aren’t valid anywhere since real objects don’t have constant emissivity with wavelength either. But nobody in the real world would care and they would continue to use their instruments. And engineers would still use the S-B equation to calculate heat transfer.
The optical pyrometer is, in fact, the official IPTS-90 instrument for measuring temperatures above the freezing point of silver, 961.78C using the Planck equation to calculate temperature. See paragraph 3.4 here.
You should climb down from your ivory tower of academic physics and spend some time in the real world.
Obviously, you do not under stand that the temperature measurement using a thermometer is a local measurement, but not a global one. I suggest to read textbooks on radiation.
Dr. Kramm,
Can you please respond to my last post?
Dr. Kramm,
Obviously you do not understand that it is not necessary to measure the temperature at every point on the planet to calculate a gridded temperature field for the surface and thus the global distribution of emitted radiation and that the local emission and temperature can be integrated using finite difference methods over time, space and wavelength to calculate a good approximation of the global totals and averages. Measurements from orbiting satellites, while not precise enough to determine the global imbalance between absorbed SW and emitted LW radiation, certainly don’t falsify the hypothesis that’s referred to as the enhanced greenhouse effect. The same goes for measurements at the surface.
Similarly, even though there are relatively few locations that measure atmospheric and surface radiation emission and absorption, the agreement with calculated values for a given atmospheric profile of both the total radiation measured with pyrgeometers and pyranometers as well as atmospheric emission spectra measured with FT-IR spectrophotometers gives quite good confidence that the atmospheric radiation transfer theory behind the greenhouse effect is on sound footing.
Out of curiosity, do you believe that the ARGO system can measure changes in global ocean heat content using only a few thousand instruments?
You referred to the average temperature of the lunar surface previously. You do realize that we have only measured the lunar surface temperature by contact thermometers in a few locations and the rest of the measurements are satellite based. So if you don’t believe that can be done for the Earth, how can you say that the average surface temperature of the moon is not the same as it would be for a globe with uniform temperature with the same albedo? I agree that it’s not. It’s the temperature that you expect from, (and can calculate relatively easily) a slowly rotating sphere with a low surface heat capacity and an albedo of about 0.1.
I do not reply to physical nonsense.
Dr. Kramm,
I am not certain what you find speculative.
In fact, what is speculative is what you quoted from von Storch (that “climate change seems to be taking a break)…
In any case, I wish you would please answer this question in a straightforward manner:
Do you agree that the longwave radiation outgoing from the Earth’s surface greater is than that emitted to space, or as scienceofdoom puts it, E-surface is significantly greater than E-TOA. Do you agree? Can you answer in a “yes” or “no” fashion?
The global energy budget is based on physics, but not on “yes” or “no”.
Dr. Kramm,
By the way, I have read a book on radiation: Grant Petty, A First Course in Atmospheric Radiation(2nd edition). I highly recommend it.
I have Chandrasekhar (1960), Liou (2002), Petty (2004, 2006), Bohren & Clothiaux (2006), and Vardavas & Taylor (2007) in my private Library. In addition, I am working with Kondratyev (1969), Goody & Yung (1989), Lenoble (1993), and Thomas & Stamnes (1999). Stamnes was a professor at UAF until his retirement in 2000 or so.
I have published some papers on radiation. One of them is dealing with the derivation of a general form of Wien’s displacement law using dimensional analysis. The radiation laws of Wien (1896), Rayleigh (1900), Planck (1901) are only special cases of this general version.
Do you really believe that you are qualified enough to examine me?
Gerhard Kramm,
Yes.
Questioning ideas, asking for evidence & derivations and asking for resolution of apparent contradictions are all available to anyone on this blog. As explained in About this Blog.
There is no church (argument from authority) here. The only right that the moderator reserves is to use is to prevent “debate” about basic physics in standard textbooks (which is just a personal preference, explained in Etiquette).
So in that sense basic physics is accepted as a given.
I’m sure you know more than almost everyone commenting on this blog about radiative physics. Which makes being unwilling to answer the question that started this thread, and was posed in the article, all the more fascinating.
Please, read the papers of Einstein (1917), Dirac (1927), and Milne (1928) first. There is a fine translation of Einstein’s paper from German into English (http://www.informationphilosopher.com/solutions/scientists/einstein/1917_Radiation.pdf). Dirac’s paper can be found under
Click to access 243.full.pdf
and that of Milne under
http://adsabs.harvard.edu/full/1928MNRAS..88..493M
Also helpful are the papers of Fowler & Milne (1925) and Tolman (1925) regarding the “principle of detailed balancing”. Both papers were published in the Proceedings of the National Academy of Sciences.
OK. scienceofdoom, did Dr. Kramm answer your question yet?
I see his statement, “Consequently, the down-welling IR radiation generally exists. On global average, it is of about 60 to 70 W/m^2 lower than the emitted radiation. Only the IR net radiation is a part of the global energy flux budget at the Earth’s surface.”
This looks like half of the answer. But is he willing to compare the net longwave radiation emitted from the earth’s surface to that emitted to space?
(The psychology is fascinating. Or perhaps Dr. Kramm feels qualified to examine me on the psychology…)
I already compared it. Read the paper of Kramm & Dlugi (2011).
scienceofdoom, sorry I did not see your response before I posted mine.
And I would not mind if Dr. Kramm wishes to examine me on the psychology!
No, I am not in expert in that discipline. My discipline is theoretical meteorology. But I am also well familiar with atmospheric measurement techniques.
Gerhard Kramm on December 8, 2013 at 5:22 am:
To whom were you suggesting this course of action? If it was me, what question or debate was reading these papers going to clear up?
Then on December 8, 2013 at 5:24 am:
The question at the end of this article (repeated in the comments specifically to you) was:
Are you saying you have already compared the (global annual) outgoing longwave radiation from the top of atmosphere with the (global annual) emitted thermal radiation from the surface? You compared it in Kramm & Dlugi 2011?
If this is the comparison you refer to when you stated: “I already compared it”, then I cannot find it in your 2011 paper. Please can you help us by identifying the page number and section. Do we really need to read Dirac 1927 to find where you compare the two global annual values?
I know and you know that Esurface is significantly greater than ETOA, and we both know that this is the greenhouse effect and we both know that you don’t want to come out and say it.
Thus continuing the Gerlich and Tscheuschner joke. But why not say it? Come on. You’ve all had your day in the sun. It’s been hilarious.
But don’t you think the joke has been running for long enough?
I mean, other people reading this article and the comments might start to think you haven’t understood basic maths or radiative physics 101, let alone read Dirac 1927 or Chandrasekhar 1960. I know you understand this subject.
Well, it’s up to you.
You have already made the comparison, Dr. Kramm? Then it should be no problem for you to summarize here and answer the question:
Is the longwave radiation outgoing from the Earth’s surface greater than that emitted to space — is E-surface significantly greater than E-TOA?
Having many books in the bookshelf is a good start, but proves nothing, Knowing a large number of things is also good as long as the knowledge is generally correct.
Referring to great scientists from distant past has in these discussions very often been a sign of being that far behind in the understanding of physics – and in very many cases also a sign of misunderstanding what those great scientists have really been saying.
The same people do also very often refuse to answer direct questions, probably because they don’t have answers that would not directly reveal the emptiness of their position.
We have all these symptoms very visible in this thread again.
Yes, the psychology is fascinating…
Daniel Wirt,
I believe in pop psych terminology it would be called “d3ni@l”. (spelling altered to try to avoid moderation) You can see similar examples at other web sites where Dr. Kramm has participated like Rabbett Run where the subject is surface integrals. Given his penchant for declaring concepts that he doesn’t like “physical nonsense” (like integrating over gridded temperatures on a spherical surface), it’s interesting that he apparently believes that the rotation rate of the moon has no effect on its surface temperature.
Another person, who shall remain nameless, with whom I’ve interacted is similarly afflicted. His view on atmospheric emission from CO2 is based entirely on his fundamental misapprehension that the units ‘partial pressure’ and ‘partial pressure*path length’ are the same. They’re not. Partial pressure is a measure of concentration while partial pressure*path length is a measure of quantity. I’ve pointed him to Beer’s Law, for example, to no avail.
SOD wrote:
“You attribute this to me:
“..increasing GHGs will increase DLR emitted from near the surface..”
This is not necessarily true as I explained in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Five.
..With increasing pCO2, DLR (back radiation) remains constant and yet TOA flux reduces..
The TOA balance is where changes in radiatively-active gases really have an effect. Changes in TOA balance inevitably lead to heating or cooling in the first instance.
Thereafter, feedback as a result of the heating or cooling is what determines the final surface temperature.”
Could this be an artifact of your model? If essentially all of the DLR in your model originated from the lowest layer of the atmosphere, the flux of DLR isn’t going to change with increasing CO2 in your model because each layer is isothermal. The emissivity of CO2 at most wavelengths is already near 1, so raising the mixing ratio won’t change emissivity much either.
In the real world, higher GHGs will mean that the DLR photons reaching the surface were emitted from a lower warmer altitude, so I still anticipate more of them.
My understanding of the major errors of mainstream climate science greenhouse effect:
1. assuming the radiative temperature of a body with an atmosphere is measured at the planetary surface and not the integrated mean of surface+atmopsphere.
2. assuming Tyndall measured warming of gases that failed to transmit IR, when the reality is absorption and instananeous reemission.
3. assuming radiative equilibrium exists in a physical system where conduction, convection and radiation server to tranport heat according to the laws of thermodynamics
4. failing to properly describe the physical mechanism of the “greenhouse theory”
5. failing to demonstrate the validity of the “greenhouse theory” in a physics lab.
I see no good reason so far to disagree with Gerlich and Tscheschner or Kramm and Dlugi.
blouis79,
We’ll start with item 3.
Please demonstrate this claim – “that climate science assumes radiative equilibrium exists in a physical system where conduction, convection…etc“
Radiative thermal equilibrium is only valid between bodies in a vacuum, where there is no possibility conduction and convection. It is valid to compute a radiative equilibrium temperature of the earth (solid+atmosphere) with the sun, but not the earth (surface-atmosphere) with the sun.
blouis79,
Read the request – demonstrate your claim that climate science assumes…
If I said blouis79 assumes that gravity doesn’t exist and you asked me to prove this ridiculous point, I would need to demonstrate that you assumed it, not that gravity existed.
Your assertion is incorrect – plain to see for people who have read a few atmospheric physics textbooks.
So now you need to go ahead and demonstrate your assertion. Textbooks, papers, etc.
Try reading the standard equations using Stefan Boltzmann to derive the earth surface temperature. All standard texts say the same thing. The fact that the term exists for “surface” temperature assumes the earth’s surface-atmosphere is what is in radiative equilibrium.
You said on current climate science:
It is a specific claim about climate science that is untrue.
I’m giving you the opportunity to produce a textbook or paper where this assumption is claimed.
It appears that you have never read a textbook on atmospheric physics, but this is a science blog so you have the opportunity to demonstrate your claim.
Is your vague and unrelated response:
– your best “proof” of your original assertion?
Ramanthan quoted by Kramm and Dlugi for example (the standard description):
At a surface temperature of 288 K the long-wave emission by the surface is about 390 W·m–2.
How is this calculated?
I could just as easily quote:
who makes the same incorrect assumption that the surface of the earthminuatmosphere is in radiative thermal with the sun.
blouis79,
So you don’t understand your own assertion or basic physics.
“3. assuming radiative equilibrium exists in a physical system where conduction, convection and radiation server to tranport heat according to the laws of thermodynamics” is unrelated to the question about whether the surface emission of thermal radiation is higher than the emission of the climate system to space.
Climate science does not assume radiative equilibrium exists in the atmosphere.
In fact, elementary atmospheric physics textbooks spend considerable time explaining:
– what the temperature profile would be like if radiative equilibrium existed
– how this is unstable to convection
– how the lapse rate is calculated (see Potential Temperature)
– typical atmospheric profiles and where and how convection occurs
– and also why this means that radiative equilibrium cannot dominate in the lower atmosphere (the troposphere)
Radiative equilibrium means that net heat transfer through the atmosphere by radiation would be zero.
This is unrelated to your comment about average emission of thermal radiation from the surface vs from the climate system.
I don’t think there is much point going through your other “major errors of mainstream climate science greenhouse effect“.
All of that atmospheric physics is largely irrelevant to whether there exists a “greenhouse effect” and how mainstream climate science incorrectly estimates its magnitude.
Gerlich and Tscheschner and Kramm and Dlugi appear to have valid arguments that a “greenhouse effect” is baseless.
Translation – “I have no idea what I’m writing but anyway I still think the same as I did before“.
People are welcome to their opinions. But opinions are pretty uninteresting. This is a science blog.
If you have something of substance to write about this article and what specifically Kramm & Dlugi have or haven’t proven then you are welcome to put your ideas forward.
If you want to vote for, or cheer, your favorite team then there are much better blogs with much wider audiences. Don’t do it here.
I have explained in this article – with reference to Kramm & Dlugi’s paper – that they haven’t actually proven anything not already agreed with by mainstream climate science.
I have claimed that the global annual emission of radiation by the surface is much higher than the global annual emission of radiation by the climate system to space. And I have asked them to comment. So far no response.
If you have something useful to contribute to this important discussion (and that doesn’t include your opinion or your vote), then go ahead.
Where’s the missing heat? The direct heat from the Sun is missing from the AGWScienceFiction energy budget comic cartoon; you’ve taken out thermal infrared, heat, which does heat matter and substituted shortwave, light, which doesn’t.
This energy budget is gobbledegook.
I don’t know what universe you live in, but in this one, energy is energy. SW radiation from sunlight is absorbed by the surface. Absorption increases the energy content. An increased energy content usually results in increased temperature. Some sunlight is reflected from the surface, which is why you can see it, but unless you have a mirror finish surface, most near IR, visible and ultraviolet light from incident solar radiation is absorbed. On average, only about 10% of solar radiation is reflected by the Earth’s surface. The rest is absorbed. Clouds reflect more sunlight than the surface. The end result being about 70% of incident solar radiation is absorbed and 30% is reflected.
1. Not understanding the publishable work in the article…
2. Technically, reflection of electromagnetic radiation is absorption and re-emission ― along with a specific momentum condition.
2. Technically, reflection of electromagnetic radiation is absorption and re-emission ― along with a specific momentum condition.
Wrong!
Saying “Wrong!” without explanation or citation is extremely annoying.
You might want to acquire a copy of Feynman, R.P., QED: The Strange Theory of Light and Matter and read the chapter on reflection and refraction.
Mr. Berberich,
obviously, you are one of the simple-minded backseat drivers from Germany. I only recommend: Read a textbook on radiative transfer.