As a friend of mine in Florida says:
You can’t kill stupid, but you can dull it with a 4×2
Some ideas are so comically stupid that I thought there was no point writing about them. And yet, one after another, people who can type are putting forward these ideas on this blog.. At first I wondered if I was the object of a practical joke. Some kind of parody. Perhaps the joke is on me. But, just in case I was wrong about the practical joke..
If you pick up a textbook on heat transfer that includes a treatment of radiative heat transfer you find no mention of Arrhenius.
If you pick up a textbook on atmospheric physics none of the equations come from Arrhenius.
Yet there is a steady stream of entertaining “papers” which describe “where Arrhenius went wrong”, “Arrhenius and his debates with Fourier”. Who cares?
Likewise, if you study equations of motion in a rotating frame there is no discussion of where Newton went wrong, or where he got it right, or debates he got right or wrong with contemporaries. Who knows? Who cares?
History is fascinating. But if you want to study physics you can study it pretty well without reading about obscure debates between people who were in the formulation stages of the field.
Here are the building blocks of atmospheric radiation:
- The emission of radiation – described by Nobel prize winner Max Planck’s equation and modified by the material property called emissivity (this is wavelength dependent)
- The absorption of radiation by a surface – described by the material property called absorptivity (this is wavelength dependent and equal at the same wavelength and direction to emissivity)
- The Beer-Lambert law of absorption of radiation by a gas
- The spectral absorption characteristics of gases – currently contained in the HITRAN database – and based on work carried out over many decades and written up in journals like Journal of Quantitative Spectroscopy and Radiative Transfer
- The theory of radiative transfer – the Schwarzschild equation – which was well documented by Nobel prize winner Subrahmanyan Chandrasekhar in his 1952 book Radiative Transfer (and by many physicists since)
The steady stream of stupidity will undoubtedly continue, but if you are interested in learning about science then you can rule out blogs that promote papers which earnestly explain “where Arrhenius went wrong”.
Hit them with a 4 by 2.
Or, ask the writer where Subrahmanyan Chandrasekhar went wrong in his 1952 work Radiative Transfer. Ask the writer where Richard M. Goody went wrong. He wrote the seminal Atmospheric Radiation: Theoretical Basis in 1964.
They won’t even know these books exist and will have never read them. These books contain equations that are thoroughly proven over the last 100 years. There is no debate about them in the world of physics. In the world of fantasy blogs, maybe.
There is also a steady stream of people who believe an idea yet more amazing. Somehow basic atmospheric physics is proven wrong because of the last 15 years of temperature history.
The idea seems to be:
More CO2 is believed to have some radiative effect in the climate because of the last 100 years of temperature history, climate scientists saw some link and tried to explain it using CO2, but now there has been no significant temperature increase for the last x years this obviously demonstrates the original idea was false..
If you think this, please go and find a piece of 4×2 and ask a friend to hit you across the forehead with it. Repeat. I can’t account for this level of stupidity but I have seen that it exists.
An alternative idea, that I will put forward, one that has evidence, is that scientists discovered that they can reliably predict:
- emission of radiation from a surface
- emission of radiation from a gas
- absorption of radiation by a surface
- absorption of radiation by a gas
- how to add up, subtract, divide and multiply, raise numbers to the power of, and other ninja mathematics
The question I have for the people with these comical ideas:
Do you think that decades of spectroscopy professionals have just failed to measure absorption? Their experiments were some kind of farce? No one noticed they made up all the results?
Do you think Max Planck was wrong?
It is possible that climate is slightly complicated and temperature history relies upon more than one variable?
Did someone teach you that the absorption and emission of radiation was only “developed” by someone analyzing temperature vs CO2 since 1970 and not a single scientist thought to do any other measurements? Why did you believe them?
Bring out the 4×2.
Note – this article is a placeholder so I don’t have to bother typing out a subset of these points for the next entertaining commenter..
Update July 10th with the story of Fred the Charlatan
Let’s take the analogy of a small boat crossing the Atlantic.
Analogies don’t prove anything, they are for illustration. For proof, please review Theory and Experiment – Atmospheric Radiation.
We’ve done a few crossings and it’s taken 45 days, 42 days and 46 days (I have no idea what the right time is, I’m not a nautical person).
We measure the engine output – the torque of the propellors. We want to get across quicker. So Fred the engine guy makes a few adjustments and we remeasure the torque at 5% higher. We also do Fred’s standardized test, which is to zip across a local sheltered bay with no currents, no waves and no wind – the time taken for Fred’s standarized test is 4% faster. Nice.
So we all set out on our journey across the Atlantic. Winds, rain, waves, ocean currents. We have our books to read, Belgian beer and red wine and the time flies. Oh no, when we get to our final destination, it’s actually taken 47 days.
Clearly Fred is some kind of charlatan! No need to check his measurements or review the time across the bay. We didn’t make it across the Atlantic in less time and clearly the ONLY variable involved in that expedition was the output of the propellor.
Well, there’s no point trying to use more powerful engines to get across the Atlantic (or any ocean) faster. Torque has no relationship to speed. Case closed.
Analogy over.
The Science of Doom 
For US readers, we call it a 2X4 vs a 4X2.
Good points all, but even if you accept the basic physics, there’s a lot of leeway to argue about how much warming to expect and when.
But alas, we are mere humans who worry about years and sometimes decades, and not centuries.
“there’s a lot of leeway to argue about how much warming to expect and when.”
And whether the imagined indirect effects are valid.
And whether the impacts are exaggerated.
And what the benefits might be.
And what the population might be.
And…
“But alas, we are mere humans who worry about years and sometimes decades, and not centuries.”
There are good reasons not to solve every imagined problem which might not materialize a century or more from now when numerous intervening generations will have their own say in the matter.
I try to google 2×4 and 2×4 vs 4×2, and it seems to be about either RAM memory or cars – honestly, just, what is it? :-]
It’s a piece of wood.
It’s a wooden board of any length that measures 2 inches thick by 4 inches wide when freshly sawed from a log. After drying and planing, which is done before it is sold, the board actually measures 1.5 x 3.5 inches. See Lumber Dimensions. It’s still called a 2×4, though.
Alright, thanks!
Can the word “forcing” be misleading? It is as if it implies a cause – effect relation. And it should imply that there is noe hiatus when co2 increases. Would it be wrong to call it co2 feedback implying that it is affected by all the other feedbacks?
Nobodyknows: Chaotic systems can fluctuate in the absence or presence of outside influences. Seasonal changes in the weather are caused by the changing angle that sunlight reaches the surface of one hemisphere. Daily changes in the weather are not the result of any outside factor; whether it is sunny or cloudy depends on turbulent mixing of various parcels of air. We say that seasonal changes in weather for one hemisphere are “forced” – driven or caused by seasonal changes in the amount of sunlight reaching that hemisphere. We say that daily changes in weather represent “unforced” (natural) variability characteristic of normal weather. However, the use of the term “natural variability” can be confusing; volcanos and solar variation produce “forced natural variability”. So we have three categories: unforced (natural) variability, forced natural variability, and forced anthropogenic climate change (from GHGs and aerosols). Anything that changes the radiative balance between incoming and outgoing radiation is called a forcing.
As for the hiatus in anthropogenic global warming, it requires no explanation if unforced (natural) variability can change mean global temperature by +/-0.25 degK for a decade or more. Unfortunately, climate models rarely produce decadal fluctuations this large. Something appears to be wrong: either the models are too sensitive to forcing (due to poor representation of feedbacks), or the models properly represent unforced variability of climate, or chance resulted in a 15-year period of improbably large unforced variation in climate – occurring during more than half of the time since AOGCMs were developed. If climate sensitivity were 1.5 (instead of 3.0 observed in AOGCMs), the likelihood that unforced variability might have caused the hiatus is significantly greater.
CO2 can be both a forcing and a feedback. At the end of the last ice age, something caused the temperature to warm at the poles and that warming caused a detectable increase in CO2 beginning about 800 years later. The CO2 doesn’t appear to have caused the end of the ice age, but it should have amplified the warming (by an amount that depends on ECS).
” Anything that changes the radiative balance between incoming and outgoing radiation is called a forcing. ”
Can you give me an equation for this ? I have never found one .
BTW : I hate the word . All other domains of applied physics I know of are happy simply expressing things in terms of derivatives .
Bob,
on definition of RF:
“Radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an index of the importance of the factor as a potential climate change mechanism. In this report radiative forcing values are for changes relative to preindustrial conditions defined at 1750 and are expressed in Watts per square meter (W/m2).” (IPCC AR4)
verytallguy ,
So “forcing” has no quantitative definition . It is an analyitically useless fuzz word .
It’s clear to me, and specifically on your point, is indeed quantified, as per the quote, in W/m2. The 1750 baseline is obviously arbitrary.
Thank you for your answer. I think it is difficult to grasp the complexity of the climate system. It could perhaps be easier to understand didactically if one had a basic model as a beginning. Like an earth as waterball without greenhouse gases, and in thermodynamic equilibrium. Then build it up with land and mountains. Then all other matters could be handled as feedbacks. It is perhaps what models try to do, but don`t show in a good way..
Radiative forcing is defined quantitatively here: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html
No fuzz there.
[…] 2014/06/15: TSoD: On Uses of A 4 x 2: Arrhenius, The Last 15 years of Temperature History and Other … […]
Ill be presenting a powerpoint at the upcoming http://climateconference.heartland.org/ titled
The Basic Basics
or
How to Calculate the Temperature of a Radiantly Heated Colored Ball
( like our Earth ) .
I’ll be presenting the computations in a handful of succinct APL definitions making the point that they will run on anything from a tablet to a supercomputer on arbitrarily big data and a rather detailed model of planetary temperature could be written in just a few pages of APL expressions . .
I’ll show specifically that the equilibrium temperature of gray ball will come to the temperature calculated by summing the energy impinging on it , and that the temperature of a gray ( flat spectrum ) ball in our orbit ranges from about 276 to 281 from ap- to perihelion . I also calculate the equilibrium temperature of an ocean blue ball is slightly above 273 and explain the hypothesis behind the 33c “greenhouse effect” meme .
Finally , applying these basic computations of radiative balance to Venus , I show it would have to be 10 times the reflectivity of aluminum in the IR for its surface temperature to be its observed 2.25 times that of a gray ball in its orbit .
Hadn’t heard of Goody . If it were Dover priced like Chandrasekhar I’d have gotten it yesterday . It’s hard to know what texts are worth their price and have a reasonably direct path to the relationships you next need to unfold in the APL . .
At the conference , I will be seeking physicists and funders to finish implementing the thermostatics and then attack the dynamics to make an open web accessible quantitative modeling vocabulary in an APL , preferably my nascent 4th.CoSy .
Bob,
unfortunately, it’s very likely that your powerpoint would fall foul of this blog’s etiquette rules, viz:
“Basic Science is Accepted – This blog accepts the standard field of physics as proven. Arguments which depend on overturning standard physics, e.g. disproving quantum mechanics, are not interesting until such time as a significant part of the physics world has accepted that there is some merit to them.”
If you wanted to improve your talk you could try posting a link here and see if SoD or any of the excellently qualified commentators are prepared to help you.
Alternatively you could explain why your approach is superior to that of the accepted science eg
http://www.cambridge.org/gb/academic/subjects/earth-and-environmental-science/climatology-and-climate-change/principles-planetary-climate?format=HB
and what literature you have relied upon in developing your ideas
Good luck
I cite 3 19th century “reality rules” in my computations : Ritchie-Kirchhoff-Stewart , Stefan-Boltzmann , Planck , and add the divergence theorem to comment that inside of the surface of a radiantly heated ball will be the temperature calculated for its surface .
The fundamental relationship calculated is that an opaque ball and its radiant source are in equilibrium when the dot product of the ball’s absorption=emission spectrum with the power spectrum of the source equals the dot product of its ae spectrum with the Planck spectrum of the ball .
Totally classic ; totally experimentally testable . My Heartland talk will focus on the second , computational physics , half of the AGW.ppt you will find on my http://CoSy.com .
BTW , I add Ritchie and Stewart’s names to Kirchhoff because Ritchie did the crucial experiment in the 1830s , and Stewart had very similar analysis to Kirchhoff about the same time but never had the fame .
Bob Armstrong pops up from time to time on this blog pointing out that climate science has lost its way because of…
I refer to this link in Do Trenberth and Kiehl understand the First Law of Thermodynamics?. Interested readers can follow the thread from there.
If Bob has finally realized that the absorptivity of a body at 0.5 μm is different from an emissivity at 10 μm and this makes all the difference in the calculation then it would be nice to lead with that explanation so we don’t continue to ignore him.
On the other hand, if he hasn’t then I’m sure he will bring entertainment at his upcoming conference.
Dear SoD ,
I return because I respect a lot you do . I just want to implement the physics in well factored array programming language so I can “play” with the quantitative relationships . That requires starting with the essential equations of radiative balance .
If you ever doubted that I understood since my grad school days in the `70s that that absorptivity=emissive was a function of wavelength , clearly I have failed to communicate .
Scrolling up in the link you post , I see my major issue was undoubtedly that you are modeling an internal heat source , not an externally irradiated body . While there is some substantial geothermal energy , and at various densities around land masses add additional tera-joules , we both recognize they are minor compared to the Sun . ( Not so for Venus ) .
I would trust , if you are citing Chandrasekhar . you understand my statement of the calculation in terms of dot products . Here is a draft slide showing 3 hypothetical spectra and the equilibrium temperatures computed . If you agree with them , we are making progress . Otherwise , please give us your algorithms so I can play with them an see their quantitative predictions so experiment can settle which are correct . I’m rather certain the classics I present are relied upon every time an IR thermometer is used .
Bob says:
And yet.. The sun warms the surface of the earth through the ‘transparent’ atmosphere, but the earth’s surface does not cool to space because of the ‘opaque’ atmosphere. Instead the climate system cools to space from somewhere up in the ‘opaque’ atmosphere.
It’s the same class of problem as the internally heated body.
Note: ‘transparent’ = mostly transparent to solar radiation at 0-4 μm
‘opaque’ = mostly opaque to terrestrial radiation at 4-100 μm
Therefore, the heating is at one altitude (‘the ground’) and the cooling is at another altitude (‘a few kms up’). So matching the heating and the cooling for the same surface results in an interesting answer that has nothing to do with the climate system.
And in your graphic you have a parameter called ‘aeEarth’ = 0.61 observed.
It appears you think the emissivity of the climate system at terrestrial temperatures = 0.61. Lots of people have measured the emissivity of the earth’s surface and it’s definitely not 0.61. The emissivity of the ocean for example is about 0.96, covering about 70% of the earth’s surface. Snow and ice is pretty close to 1. Deserts are the lowest at about 0.7.
Where is your source for this observation of the earth’s emissivity?
Of course, a casual reader might think you have hopelessly misunderstand a few basics about radiation and simply tried to shoehorn ‘observed emissivity’ into your equation to get the right result..
Bob asked:
Absorbed solar radiation = 240 W/m2 = OLR (outgoing longwave radiation), globally annually averaged.
OLR is the integral of this equation (found as eqn 16 in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Six – The Equations) over the terrestrial wavelength range:
Iλ(0) = Iλ(τm)e-τm + ∫ Bλ(T)e-τ dτ [16]
—-
Which – for those who haven’t followed the intense maths:
Iλ(0) = Iλ(τm)e-τm + ∫ Bλ(T)e-τ dτ [16]
The intensity at the top of atmosphere equals..
The surface radiation attenuated by the transmittance of the atmosphere, plus..
The sum of all the contributions of atmospheric radiation – each contribution attenuated by the transmittance from that location to the top of atmosphere
—–
The reason why atmospheric transmittance comes into the equation is the very simple reason that the outgoing longwave radiation is mostly from the atmosphere, which is at a lower temperature than the surface.
SoD,
An effective emissivity of 0.61 is the emissivity that will give a flux of 240W/m² from a surface with a temperature of 288.6K. It’s not a very meaningful number.
Here’s one of my intro slides : http://cosy.com/Science/AGWppt_RealScience.jpg . I inherited the literally dog-eared copy of Griffiths Electo from my niece . As I comment , I am impressed that Griffiths spends 280 pages on statics before getting to dynamics . That’s what I want to get equally well understood and executable in succinct APL definitions first .
Let’s calculate a temperature for the lumped sphere to begin with . After all , the atmosphere is only relatively about as thick as a thick coat of paint if scaled to the size of a ping-pong ball : http://cosy.com/Science/WaterWorldCoSyLIFEeq.jpg . So , first of all , do we agree on the computations for uniformly colored opaque balls ?
As I mentioned , if the earth were simply a sphere with about the spectrum of deep water , near black body except for a notch in the blue , it would have a equilibrium temperature rather close to water’s freezing temperature , So we have closer to 15c than 33c to be explained by the atmosphere . I think it’s clear that the commonly cited.3 albedo wrt the Sun is not due simply the surface , but must be significantly due to clouds .
What matters to me , is that if you give me any spectrum , these functions will give you its equilibrium temperature .
I have not gone on to implement semi-transparent layers because it’s hard enough to get people to understand even these most basic computations . I’m more interested in programming notation and implementation itself than this stuff . That’s why I’m seeking collaborators who do know the physics and the data sources . The vertical dimension requires a few more expressions to “unfold” what are essentially called “sprites” in computer animation .You are motivating me to at least implement the temperature distribution with a single layer opaque in the IR over a surface with the spectrum of water before the conference , That , by itself I see mainly as causing the distribution of temperature to be constant between the sprite and the surface given that the surface is already near black body anyway . Again , it’s creating the well factored executable vocabulary to express the physics which specifically interests me .
WRT your second note : first come the basics . Far to few people don’t understand the most basic fact that a gray ( flat spectrum ) body will come to the same equilibrium temperature no matter how light or dark it s . Deviations from that temperature will be proportional to the 4th root of the ratio between absorptivity wrt the source(s) and emissivity across the whole spectrum .
That 0.61 is simply back calculated assuming the 0.7 absorptivity wrt the Sun to account for our approximately 3% greater observed temperature over the ~ 279 of a gray ball .
Actually , I’m more interested as a next step in “unfolding” multicolored maps over the sphere . I think that may well explain more of our 3% warming than the atmospheric effects . I’ve already done the expressions for arbitrary partitions of gray values over the sphere . A Lambertian function really needs to be mapped over that to make it realistic .
Bob,
Here are some past statements from you:
November 5, 2010 at 5:00 pm:
Is it impossible for a body to absorb 0.7 of solar radiation and emit with an emissivity of 1.0?
Only if emissivity has to equal absorptivity, which it does at the same wavelength, and at different wavelengths does not. The sun and the earth’s radiation are at different wavelengths.
June 14, 2010 at 6:12 am:
Actually both emissivity and absorptivity are different, are physical and are measured.
I also see confusion..
June 14, 2010 at 4:15 pm:
For comments on measurements of absorptivity and emissivity, see above.
Heat doesn’t “flow from the exterior of a radiantly heated sphere”. Heat, thermal radiation, from the sun, flows through the transparent atmosphere and heats the surface of the earth, not the top of the atmosphere. This is easily demonstrated by very many experimental results.
On the other hand, thermal radiation from the planet is mostly emitted by the atmosphere from some altitude above the earth’s surface, as is clearly seen by looking at the spectra of terrestrial (longwave) radiation.
So it doesn’t seem like a very good idea for someone who has made these kind of statements to try and develop educational material on how to calculate temperatures of planetary surfaces and atmospheres.
Your many comments on the “pathetic state of understanding by climate science of the basics” are quite entertaining though.
I enjoy irony, it gets me through the day.
Bob,
If you think it’s a problem for the Earth to have an absorptivity for solar radiation of 0.7 while the emissivity for LW radiation from the surface is 0.98, you’ll just love some of the coatings for passive solar water heating. The best coating out there now is TiNOX. It has an absorptivity for solar radiation of ~0.95 and an emissivity in the thermal IR of ~0.04. There are others nearly as good. In fact, it seems to be uncommon for the absorptivity in the SW to be the same as it is for the LW region of the spectrum.
DeWitt ,
0 ) Right , I hoped the table columns made the computation clear . You are right it’s not a very meaningful number , but more so than the extreme 1.0 because it corresponds to observation . The only meaningful number is the gray body ( energy density ) temperature that matters . The others are just a function of the ratios of the dot product of the object’s ae spectrum with the source and sink . No value in those hypothetical ratios when actual spectra are available .
BTW : Since energy appears and disappears inside most of the computations I do from temperature to temperature , I don’t think in terms of the , eg , 240 w%m^2 , energy terms . I even made a chart on http://climatewiki.org/wiki/Category:Essential_Physics#Stefan-Boltzmann_law to provide a reference . But I only covered the range from about gray temp to observed .
1 ) Thanks for the TiNOX link ! That’s amazing . Found this link w more details : http://www.sunmaxxsolar.com/what-is-tinox-made-of.php
By my calcs a ball clad with the stuff should come to a temp of over 600k in the sun in our orbit .
.95 % .04 />/ 23.75
r ^ % 4 />/ 2.207577
r * 279 />/ 615.914
Should be useful for , particularly manned , satellites .
But it also helps make the point which is the conclusion of my .ppt . TiNOX , the best than humanity has been able to create , produces a ratio of (only!) 2.21 times the gray body temperature .
The surface of Venus is observed to be about 2.25 times the ~ 328 gray ball temperature in its orbit . But it doesn’t have the advantage of a solar absorptivity of 0.95 . It has an absorptivity of only about 0.1 . I’ve been using the phase that for Venus’s surface temperature to be explained by the energy it receives from the Sun , it would have to be 10 times as reflective as aluminum in the IR . ( Now I will reference TiNOX instead ) .
Ergo , Jim Hansen’s assertion that Venus is an example of a “runaway greenhouse effect” simply doesn’t compute .
BTW : I happen to paraphrase Tyndall’s summary question in his 1861 lecture on one slide : http://cosy.com/Science/ClassicA~E.gif . His question was why is the following , which is the description of the innermost layer of TiNOX , true :
“Copper … is a great reflector in the infrared wave range with the highest heat conductivity.”
Not just heat but electrical .
Does anyone have a link to a lucid , quantitative , answer to Tyndall’s question ?
I’ll consider I have the thermostatics reasonably well understood when I can calculate the TiNOX properties .
SoD ,
0 ) I see how you’re getting your 240 . You’re taking the 0.7 as given . Looking at my table on ClimateWiki , I see our graybody temp maps to about 343 , and 0.7 of that is 240 . So we’re doing the same calc . It might seem odd that I’ve never thought of it that way even tho one of my slides emphasizes that computations in energy are linear .
I’ve said elsewhere that your analysis of the atmosphere is a first place I plan to look if , as I said , I find physicists and funders to make it worthwhile . Otherwise , I’ll just put my energies directly into reifying my vision for 4th.CoSy .
1 ) I’ve learned ( implemented ) quite a lot since 2010 . In particular , I’m pretty sure I hadn’t implemented the Planck function and did not realize how disjoint the solar and “local” spectra are . I was making what’s really a quibble , that all the endless parroting of the “255” number I saw did not make a notch down to 0.7 in the SW .
My response to DeWitt refers to ANY spectrum other than flat , gray . That is the only spectrum which is orthogonal to mean ae , It is far too little appreciated that a body of any shade gray from dark to light will come to the same temperature , ie , that calculated by Stefan-Boltzmann from the energy density at the body . That is the only spectrum which is useful in further computations like the ratios discussed here .
I apologize for the “non-science” comment and clearly have not acted on it . I will comment tho , that all the seriously nonscience blogs I know are on the alarmist side .
And I’ll stand by my disparagement of “word-waving” . If I can’t express it in quantitative executable notation , I ain’t interested .
You will be able to judge whether I did no more or less than what I claim when my presentation is webcast , and be able to instantly provide “peer review” .
Finally , Here’s the Planck function in terms of wavelength in Kx.com ‘s K as I will be presenting it :
Planckl : {[ WL ; T ] ( k0 % WL ^ 5 ) % ( _exp k1 % WL * T ) – 1 }
k0 : 2 * h * c ^ 2 ; k1 : h * c % boltz
I will be pointing out that that code will execute with world beating efficiency on a billion combinations of WaveLengths and Temperatures as it will on one . In fact , Kx.com is so focused on “Big Data” that they have now made their 32 bit implementation free .
The idea of considering atmosphere as a selective coating that covers the Earth surface and leads to an average emissivity of about 0.6 for IR is not new or restricted to climate skeptics, I have seen it used by many without obvious bias to either direction in the argumentation.
That it’s used by many does not make it particularly useful, my impression is that it has led to more misunderstanding than improved understanding. The issues are similar, and partly the same, as those discussed with RW recently in another thread. An essential problem is that the atmosphere is not static. It’s properties depend significantly on the temperature. More specifically it’s influence on the emission to the space might be better characterized by the difference between the surface temperature and the effective radiative temperature than by the ratio of OLR to either the emission from the surface or a black sphere at surface temperature.
The temperature differential is more stable, it changes a little with increasing GHGs. Estimating the temperature differential is possible based on the lapse rate and radiative transfer calculations that give the height distribution of port of origin of IR radiation that exits the troposphere. The only way of determining the emissivity of the Earth in the sense Bob is using is to first do the same calculation and then calculate the emissivity from the final result. Determining how the emissivity varies when GHG concentrations or the surface temperature temperature change, requires the full calculation of each case and comparison of the final results.
I wrote above that using the emissivity of the Earth may be misleading. By that I mean that people tend to make simplistic assumptions on, how the emissivity varies, and draw conclusions from that assumed variability. Such conclusions are mostly wrong, because it’s too difficult to figure out the dependence of the emissivity on GHG concentrations and on the surface temperature.
Just a small tap from a 2×4.
Does any of these scientist realize that this planet has a rather good anti-entropy mechanism working all the time, and that it continuously transforms energy in every part of the environment. In generalized terms it’s called it nature, and as far as we know it has never stopped.
tom0mason,
I’m not sure what your question is.
What’s anti-entropy?
Is there a relationship between your question and some problem with radiative physics?
And which scientists? Goody? Chandrasekhar? Planck? Beer-Lambert? All of them? Only the first, emeritus professor of planetary physics at Harvard University, Richard M. Goody is still around, aged 92.
I have no qualms with your listed scientist as far as lab work goes, or postulating what happens on a sterile, inert planet but sadly that is not here.
The anti-entropy I refer to is the processes of nature, that awkward system that gathers up low levels of any energy and matter, concentrated it, and store some away. Then at some time later releases just some of it.
Indeed the quote from above spells it out –
Does not life on this planet take some of that radiant energy and reprocesses it for it’s own needs? Is this process part of the energy ‘balance’ that is talked about, and surely it should be an energy inbalance, with nature taking for itself?
So perhaps I am misunderstanding you but when you say, “..postulating what happens on a sterile, inert planet but sadly that is not here..” it seems like you are suggesting that CO2 and other radiatively-active gases do not absorb and emit as thought by “these scientists” on earth, although they would on a sterile planet?
Or radiatively-active gases are irrelevant even though they absorb and emit.
Or something else?
The point of this article is to explain that science has found some elementary things to be true. They are true on all planets whether life exists or not. They have been known a long time. And are fundamental physics, not in dispute except in fantasy blogs.
Climate consists of many different processes, this is also true. Science is about understanding each of these processes, quantifying them and understanding how they interact.
I still don’t know what anti-entropy is. And vague assertions don’t contribute to any scientific knowledge.
The basic physics noted in this article (and described in much detail in other articles on this blog) tells us that we can work out quantitatively – from changes in radiatively-active gases – the change in the climate energy balance before any feedbacks.
The feedbacks are the key and cannot be determined from the basic physics noted here. Biological feedbacks undoubtedly have a significant effect in feedbacks, as does water vapor, atmospheric circulation, changes in sea ice and land ice, ocean circulation and many other geophysical phenomena.
tom0mason,
Sorry, living things do not decrease the entropy of the system. And entropy, for the purposes of the Second Law is a function of the system, not a local property. For any apparent reduction of entropy, such as the formation of a complicated molecule like DNA, there is a much larger increase in the entropy of the system because of the energy that was used to form the molecule.
Or take a heat pump that increases the temperature difference between the inside and outside of the house. The entropy increase from running the heat pump will always be larger than the entropy decrease from the increased temperature difference. See the Carnot cycle, for example. A heat pump does work to increase the temperature difference rather than using the temperature difference to do work. But the result is still the same, entropy increases.
tom0mason,
The anti-entropy you’re referring to must be photosynthesis. It doesn’t decrease entropy. Photosynthetic efficiency is only 6%. Hence 94% of the solar radiation becomes waste heat. This increases entropy since it started as nuclear energy in the sun, a more organized form of energy. Of course if sunlight hits a rock rather than a plant, 100% of the radiation becomes waste heat. So the increase in entropy is smaller with photosynthesis but still an increase.
Hehe, SoD looks at the specks in his opponents’ eyes, but continues to not notice the 4×2 in his own.
This very blog seeks to unravel the ‘effects’ of atmospheric radiation, a point similarly irrelevant to the central ‘climate question’: What sets and governs the global surface temperature of the Earth? Atmospheric radiation is the result of the temperature distribution within the earth system (surface to tropopause), not its governor or cause. So, even if SoD and his stalwarts here on this site are totally correct about all their claims of veracity and validity of the physics and equations of ‘atmospheric radiation’, it still has no relevance, no bearing on the main issue. It doesn’t matter. It makes no difference. Earth’s temperature is still set and governed by other processes, other mechanisms entirely: the tight interaction between solar surface heating and its convective/evaporative response. The atmosphere is a dynamic gas in a gravity field mainly heated from below, its internal heat transport completely ruled by convection (as far as the tropopause). The solar input and the atmosphere’s mass (heat capacity & weight) is all that matters. Radiation is merely a result. It’s caused. It’s governed. Ultimately it cools the atmosphere and hence the earth system to space. Put (more) radiatively active gases into it and you increase its ability to cool by radiation, you don’t lessen it.
Interested readers can see the discussion with Kristian in Visualizing Atmospheric Radiation – Part Three – Average Height of Emission
Just search for “Kristian”. Not much point me repeating my requests for scientific clarity. No point me repeating my requests for Kristian to confirm or deny the standard equations of radiative transfer.
SOD: Skeptics aren’t the only ones who make use of Arrhenius. RC wants us to believe that AGW is as old and venerated as QM. I completely agree with you that modern textbooks are far better sources – for scientists, if not for historians. The worst of the bunch are the skeptics who cite Clausius. 2×4’s for all?
http://www.realclimate.org/index.php/archives/2011/12/copernicus-and-arrhenius-physics-then-and-physics-today/
http://www.realclimate.org/index.php/archives/2006/04/gray-on-agw/
http://www.realclimate.org/index.php/archives/2005/12/natural-variability-and-climate-sensitivity/comment-page-2/
http://www.realclimate.org/index.php/archives/2007/12/les-chevaliers-de-lordre-de-la-terre-plate-part-ii-courtillots-geomagnetic-excursion/
It’s my impression alarmists are the one’s to invoke the names Fourier , Tyndall & Arrhenius w/o understanding as some sort of appeal to authority .
Skeptics are just that . They philosophically reject appeals to authority . Only data and ( to too small an extent on both sides ) theory count .
Bob: For the most part, both the skeptics (which often include me) and the alarmists are much more interested in politics than science. There is a famous quote from Schneider:
“On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but — which means that we must include all the doubts, the caveats, the ifs, ands, and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climatic change. To do that we need to get some broadbased support, to capture the public’s imagination. That, of course, entails getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This ‘double ethical bind’ we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.”
I’m sick of climate scientists (and skeptics) who don’t know how to resolve Schneider’s ethical double bind: Either they should always speak like an ethical scientist or they should warn their audience when they are choosing to speak as a knowledgeable “policy advocate”, someone whom everyone recognizes is likely to “tell scary stories”, etc. Unfortunately, too many want the respect traditionally given scientists, but not the responsibility for accuracy and caveats that goes along with it.
For someone like me, who is interested in “the truth, the whole truth, and nothing but — which means that we must include all the doubts, the caveats, the ifs, ands, and buts”, SOD is a great location to learn. Since Steve McIntyre recommend SOD to his readers several years ago, I’ve never seen any scary scenarios, simplified dramatic statements or suppression of doubt from our host. Occasionally there could be more emphasis here on the “caveats”.
You might want to check out a few of SOD’s early posts that were written before the comments from close-minded skeptics became so frequent:
https://scienceofdoom.com/2009/11/22/temperature-history/
https://scienceofdoom.com/2009/12/13/understanding-the-flaw/
My question for Bob is: Can you perform your calculations with and without the assumption that the planet’s LWR emissivity can differ from its SWR absorptivity? How much difference does this cause? If there is a significant difference, what ARE the correct values for the SWR albedo (1 – absorptivity) and the LWR emissivity of the earth? (Since 70% of the surface is covered by water and 70% of the sky is covered by clouds, the LWR emissivity of the planet depends mostly on these two materials.
It’s not like you to rant SoD, but I can understand your frustration.
However, it’s counter productive for dialogue if you ‘spam’ a sceptic with a piece of 4 x 2 because the dialogue doesn’t ‘go your way’ (I’m not suggesting that you would do this, just that even the contemplation of the act would be ‘counter productive’)! A 4 x 2 is just as likely to knock understanding out of, as it is into, the brain of an individual that is ‘confused/undecided/sceptical’.
From my meagre interactions with the web the most confusing issue seems to be the availability of information about the ‘radiative energy transmission’ at/from Earth’s surface.
Yes. Some energy from land surface is released here, but doesn’t go anywhere of importance other than near surface. Energy from ocean/sea/water surface is invisible to thermometers until its phase change from the ‘WV’ (water vapour) to liquid/ice phase much higher in the troposphere.
Here’s my conundrum. Where ‘surface radiation’ achieves ‘near surface’ transmission distance and ‘phase change from ocean (etc.)’ achieves ‘higher tropospheric’ transmission distance, which method/system offers a majority role for the ‘cooling’ of Earth’s surface?
If you swing a 4 x 2 I’ll duck. 😉
Best regards, Ray.
With physicist’s background and a couple of years participation in discussion about atmosphere and climate the general picture seems so clear that it’s difficult to remember all the erroneous ideas I had, when I first started to follow climate blogs. It should not be a surprise for me that many others keep on having problems in figuring out the role of various factors for the energy balance. Realizing that does not make it easy to explain even the basics.
SoD has made a major effort in writing posts on these issues, but the resulting volume of material is not always helpful for figuring out, what’s most essential on the basic level.
One of the basic things to realize is that most details of (IR) radiative energy transfer within the lower half of the troposphere and the surface are not essential. They affect only little the resulting surface temperature and temperature profile of the troposphere. What’s important is the origin of radiation that escapes through the tropopause, what’s the power of radiation that does not escape has a really small influence. The reason for that is that the strength of convection reacts so strongly to the temperature profile.
Very roughly:
1) Sun heats the surface
2) The surface gets warm enough to drive convection.
3) The temperature profile is determined by convection, when it’s present.
4) The temperature of the upper troposphere is determined by the requirement that OLR must balance absorbed solar SW.
The role of GHGs is to move the height distribution of the point of emission of escaping LWIR up. Only a few percent of IR emitted by the surface escapes and still much less of the IR radiated by atmospheric gases at low altitudes. Without GHGs the surface would be tens of degrees colder (how cold, depends on SW albedo). Beyond that essential point the radiative heat transfer between the surface and the troposphere as well as between different levels of troposphere are unimportant.
If the surface emissivity of IR would be much lower than it is, that would not change the temperatures much. There would be less net heat loss by IR from the surface, but that would be compensated by more convection and latent heat transfer. It’s not necessary to know well what happens near surface to understand GHE even at an approximate quantitative level. Details of weather phenomena are, however, affected by the surface emissivity.
Pekka Pirilä.
“With physicist’s background and a couple of years participation in discussion about atmosphere and climate the general picture seems so clear that it’s difficult to remember all the erroneous ideas I had, when I first started to follow climate blogs. It should not be a surprise for me that many others keep on having problems in figuring out the role of various factors for the energy balance. Realizing that does not make it easy to explain even the basics.”
I concur! You probably see my inquiry with the rhetorical content that I intended.
“What’s important is the origin of radiation that escapes through the tropopause, what’s the power of radiation that does not escape has a really small influence. The reason for that is that the strength of convection reacts so strongly to the temperature profile.”
Here I would remind you that ‘SH’ (Specific Humidity) also alters convection rate. If we take two (identical) given volumes of atmosphere from a tropical region with an extremely opposing ‘RH’ (Relative Humidity) at the same thermometer temperature, it can be seen that the volume with ‘high’ RH convects at a rate equivalent to ~4C above the convection rate of its opposing ‘twin’ (the volume with the ‘low’ RH). Thus, because the density of ‘WV’ (Water Vapour), per se, is ~3/5 the density of a ‘waterless’ atmosphere, the gaseous phase of H2O plays an important role which improves convection ‘without’ temperature change.
“Very roughly:
1) Sun heats the surface
2) The surface gets warm enough to drive convection.
3) The temperature profile is determined by convection, when it’s present.
4) The temperature of the upper troposphere is determined by the requirement that OLR must balance absorbed solar SW.”
This is so vague as to be nondescriptional Pekka. The atmospheric effect from land surface is entirely different to the atmospheric effect from ocean surface. I know you say “Very roughly:”, but Land surface and Ocean surface energy transports are entirely incompatible. For example, “3) The temperature profile is determined by convection, when it’s present.”. Ocean surface evapouration is always ‘pressent’, but land surface IR is ‘diurnal’ (fluctuates with solar SW input). IOW, land temps need smoothing, but ocean temps come ready smoothed.
“The role of GHGs is to move the height distribution of the point of emission of escaping LWIR up. Only a few percent of IR emitted by the surface escapes and still much less of the IR radiated by atmospheric gases at low altitudes. Without GHGs the surface would be tens of degrees colder (how cold, depends on SW albedo). Beyond that essential point the radiative heat transfer between the surface and the troposphere as well as between different levels of troposphere are unimportant.”
Again, your dialogue is nondescriptional Pekka. Isn’t it time that a demarkation line was drawn between CO2 and H2O? When ‘IR’ is mentioned everyone thinks of CO2, but H2O is a stronger, more prevalent (because its renewed more frequently) and more active GHG than CO2. What’s more, it’s ‘short lived’ (relatively) in Earth’s atmosphere and purges Earth’s atmosphere of undesirable compounds, such as CO2, as it precipitates from the atmosphere.
The ‘Global’ “GHGs” meme is just confuscation, whereas; “The role of GHGs is to move the height distribution of the point of emission of escaping LWIR up.” should (IMHO) be exploited for its conection with WV and its ‘latent potency’!
“If the surface emissivity of IR would be much lower than it is, that would not change the temperatures much. There would be less net heat loss by IR from the surface, but that would be compensated by more convection and latent heat transfer. It’s not necessary to know well what happens near surface to understand GHE even at an approximate quantitative level. Details of weather phenomena are, however, affected by the surface emissivity.”
I disagree. The temps are ‘as is’, but energy transport is greater. I don’t think you weigh latent ‘atmospheric’ influences with enough gravity.
Best regards, Ray.
Ray,
The main point that I tried to make is that convective energy transfer that includes latent heat transfer is always as large as it needs to be. It’s always so efficient that making it more efficient by more evaporation makes essentially no difference. It’s also always so efficient that reducing the role of IR near surface by reducing the surface albedo makes essentially no difference.
The GHE is essential, but it’s quantitatively influential only through it’s effect on the height distribution of the point of origin of IR that exits the troposphere. The properties of convection and latent heat transport determine the lapse rate. Adding WV reduces the lapse rate. That’s its influence on the non-radiative heat transfer.
Oceans and land areas are not different in the way you describe. With less evaporation there will be more convection of sensible heat. Vertical velocity of air must be increased for that, and it is increased.
Ray asked: Which method/system [convection or radiation] offers a majority role for the ‘cooling’ of Earth’s surface?
Both.
Energy can only escape to space from the planet by radiation. Unfortunately, the atmosphere is so opaque to the thermal radiation emitted by the surface that most of the energy emitted by the surface is absorbed by the lower troposphere, which radiates it back to the surface. The KT energy balance diagram shows: OLR, 390 W/m2 (40 of which escape directly to space) and DLR 333 W/m2. Since the surface receives about 160 W/m2 of energy from the sun (SWR), about 100 W/m2 of heat is carried away from the surface other means – convection. Most convective heat transfer is in the form of latent heat in water vapor – which comes from the ocean and is released when vapor condenses several km above the surface (and returns to the surface as an average of 1 m/yr of rain or the equivalent in snow).
The higher you go in the atmosphere, the less dense the air and the more transparent it becomes to thermal infrared. Consequently, the role of radiation for cooling increases with altitude and the importance of convection decreases. Convection tends to produce an average lapse rate (temperature drop with altitude) of about 6.5 degK/km. The tropopause marks the altitude at and above which convection doesn’t contribute to cooling the planet.
“Ray asked: Which method/system [convection or radiation] offers a majority role for the ‘cooling’ of Earth’s surface?”
Sorry Frank, this was a rhetorical question.
Nearly all IR from Earth’s surface doesn’t achieve radiation to space. However, the ‘latent’ deposition of energy to space is made from a higher altitude, and, because Earth’s Ocean surface outweighs Earth’s Land surface by ~7:3 respectively, Ocean surface has the majority responsibility for thermal transport.
It’s 04:30 hrs where I live now. I’ll get back.
Best regards Ray.
SoD,
Speaking of irony, my fundamental principle of human interactions is that irony always increases. This is the principle behind Murphy’s Law and the law on unintended consequences. Now if I could only come up with something that is conserved…
Going back to the article with the number of proven science arguments, that’s not the issue. The issue is that we live where water and water vapor are prevalent. Water vapor carries heat and is either released or retained when it falls as rain. The basis of AGW is that the heat is mostly retained due to the increase of co2 in the environment. I disagree with AGW. I wonder if it is worth the time to argue, however, I think that time will tell how much influence the amount of co2 has on temperature control of an open, non linear, and very complex system. You can be right in the science, but wrong in analyzing that science in a system. At each level of organization a system will exhibit all the same properties, while exhibiting new and different properties. This system is exhibiting a property that is different than what you would expect. I think that is a given. If thermal infrared is not the only heat in, why would they think that thermal infrared is the only way heat goes out? Why would they think that?
Rishrac wrote: “The basis of AGW is that the heat is mostly retained due to the increase of co2 in the environment. I disagree with AGW.”
The basis of AGW is increased absorption of OLR by 2XCO2 AND increased emission by 2XCO2, resulting in a small decrease in the flux of LWR to space and no significant decrease in SWR absorbed (until one considers changes in cloud cover).
Rishrac wrote: “You can be right in the science, but wrong in analyzing that science in a system.”
Exactly. But radiative transfer calculations don’t involve a system that is changing. You input information about the surface emitting OLR and atmosphere through which OLR passes, and calculate the flux reaching space before and after doubling CO2. That flux goes down after doubling (radiative forcing). The amount of the decrease depends on the nature of the atmosphere and clouds used in the calculation, but the flux goes down for any sensible representation.
AOGCMs could be mistaken about the magnitude of response of the whole SYSTEM to radiative forcing. The pause suggests they do. However, it is hard to evaluate the statistical significance of decadal variations in climate when we only have about a dozen decades of instrumental data (and less from space). So the pause suggests that AOGCMs get something wrong: climate sensitivity, unforced variability or recent forcing.
Rishrac asked: “If thermal infrared is not the only heat in, why would they think that thermal infrared is the only way heat goes out?”
Heat is transported by radiation, convection and conduction, but convection and conduction are impossible in space. So thermal infrared – the radiation emitted by things with temperature below “red hot” (1000 degK) – is the only way out. Ignoring radioactive decay, the only heat into our planet (including atmosphere) comes from the sun, but it is 5700 degK and emits most of its energy at visible, not thermal infrared, wavelengths.
I appreciate you comments. .. Heat can also be transformed into other things, sound for instance.
AGW has spent considerable amount of time convincing me that the shorter wavelengths, unaffected by co2, pass thru and become heat, which in their opinion causes that whole feedback and amplification thing they adhere to. Now I do disagree that visible light is the only thing put out by the sun. It puts out every energy in the electromagnetic spectrum. I have likened the climate system to a bypass band filter, tune your radio, tune the energy you want from your nearest star. (can’t really call it a high or low ) The atmosphere filters out (mostly or enough that we don’t get fried) frequencies starting at the extreme ultra violet and going on up to higher energies x rays cosmic rays.. , and at the other end, the magnetic field filters out lower energies (although there is still a lot of it) like microwaves, or least reduces or moderates them. Water is very curious as it does respond to a specific frequency. The magnetron in your microwave cooks food because food has water in it. It’s at 2054 MHz So if you go back to the Industrial revolution, and if AGW can be believed that the sun is very stable and has no affect on climate (which I think the sun does have an affect) then there is something that has changed, besides co2 levels, and that is the magnetic field of the earth has decreased 10 – 15%. Have you seen that in their analysis? I haven’t. .. I can’t believe it’s not warmer! We are over budget and there is no explanation as to how or where the heat is going. They will even prove to you that JUST co2 alone is responsible for the observed increase of ~0.5 C. (that was 4 or 5 years ago now) So all those other GHG aren’t even taken into account. We definitely have to be over budget, with or without microwaves.
.. Even so, I think the earth’s climate is a complex, evolved system, designed or naturally occurring like a lattice of salt. It is exhibiting features which we are not familiar with, else we would understand it better. I also think that under many different conditions, except in extreme circumstances, the climate is within equilibrium or forces itself to do so.
I have a few other things as well. Hopefully I’ve shed just a little light on what I think MIGHT be happening and explained it well enough that you can ponder it as well. If you want to do an experiment, take a tray of ice (put in a microwavable bowl of course) and nuke it for 3 or 4 minutes. The air temp will not increase or slightly so from the water heating up. The ice will be all water and strangely some of it warm as some of it is still cold.
Rishrac: The sun emits a large amount of infrared radiation, but only about 1% of its energy arrives at the “thermal infrared” wavelengths emits by the earth. You can see that clearly at the link below, along with the wavelengths absorbed by GHGs. We have visible, UV and infrared (called SWR, short wavelength radiation) emitted by the sun and thermal infrared (called LWR, long wavelength radiation) emitted by the earth and its atmosphere. Some gases absorb only outgoing LWR and some gases (ozone) absorb both. You might think of a GHG as a gas that has more effect on outgoing LWR than on incoming SWR.
Since the absorption and emission of radiation by gases has been studied in the laboratory under carefully controlled conditions for almost a century, we have excellent information about how radiation interacts with GHGs. (Clouds can’t be easily studied in the lab and their properties vary with cloud type and altitude).
It’s important to note — I think — that all the so-called ‘basic physics’ establishes is that increased GHGs should push the climate in a warming direction, but that’s about it. The ‘basics’ do not establish that the climate system must warm.
-verytallguy
Bob,
on definition of RF:
“Radiative forcing is a measure of the influence a factor has in altering the balance of incoming and outgoing energy in the Earth-atmosphere system and is an index of the importance of the factor as a potential climate change mechanism.-
!360 W divided by 4 is 340. About average of 100 W is reflected. And on average 240 W absorbed and 240 radiated.
Water vapor or the CO2 don’t seem to be doing any forcing- or altering the incoming and outgoing energy.
In terms of non averaged, it appears that no greenhouse gases increase the surface temperature above the temperature which caused by direct sunlight.
Or a land ground surface may heated to about 70 C, and this solely due to intensity of the solar flux of the direct sunlight.
And same sun without an atmosphere could heat same surface to 120 C.
So atmospheric gases diffuses and absorbs and re-radiates reducing amount of “forcing” done by direct sunlight.
It seems greenhouse gases are related to how much heat is lost over a given time period, but many factors other than solely gases which also affect this- different substances absorb and retain heat and do so at different rates.
Or does urban heat island effect have anything to with “forcing”?
That happens only at noon with the sun directly overhead. A lower sun angle means a lower temperature. And then you have to factor in how much the temperature drops when the sun is below the horizon. Even if the surface had infinite heat capacity, the average temperature at that location wouldn’t be that high. And the average temperature will drop as latitude increases.
In fact, a sphere with the same SW albedo and emissivity in the LW IR but no atmosphere that has low latitudinal thermal conductivity will always have a lower average temperature than an isothermal superconducting sphere with the same spectral properties. The proof is related to Hölder’s Inequality.
gbaikie wrote: “It seems greenhouse gases are related to how much heat is lost over a given time period …
You are almost right here. The amount of radiation emitted by objects (including the GHG molecules in the atmosphere) depends on their temperature (and other properties). If the amount of radiation (a form of heat) entering and leaving the earth is not in balance, the temperature will rise of fall until it is in balance. When we slow down the rate of loss of heat with increasing GHGs, the retained heat will slowly cause the earth’s temperature to rise until a new balance is reached.
gbaikie continued: “…but many factors other than solely gases which also affect this [rate of heat loss] – different substances absorb and retain heat and do so at different rates.
Radiation is the only way for the heat from the sun to escape from the earth to space. Only the factors that effect emission and absorption of radiation can influence this process. Many factors other than GHGs effect how that heat is distributed within the atmosphere, surface and ocean; controlling the rate of warming we observe on the surface and how much warming we experience.
Urban heat islands effect how much warming urban areas experience. Thermometers located in a few such areas have clearly warmed much faster than the surrounding area. Measurement of the temperature of the atmosphere and sea surface temperature from space demonstrates that these regions are warming at a rate similar to land.
gbaike
Forcing is defined as a change in flux against a defined baseline, not the absolute flux. As such, total solar radiation incident is not defined as a forcing.
The outgoing radiation flux is indeed affected by CO2. That’s the forcing, currently estimated as a change of 1.68W/m2 from 1750 levels dues to CO2 alone (IPCC AR5 fig SPM.5)
The atmosphere does of course, as you note have other influences on the local surface temperature than solely it’s absorption and emission of longwave radiation.
The UHI effect is not directly a forcing, merely an effect on observed temperatures. I’d guess urbanisation through albedo change does have some small effect.
[…] On Uses of A 4 x 2: Arrhenius, The Last 15 years of Temperature History and Other Parodies […]
[…] And there isn’t any scientific basis for disputing this “pre-feedback” value. It’s simply the result of basic radiative transfer theory, well-established, and well-demonstrated in observations both in the lab and through the atmosphere. People confused about this topic are confused about science basics and comments to the contrary may be allowed or more likely will be capriciously removed due to the fact that there have been more than 50 posts on this topic (post your comments on those instead). See The “Greenhouse” Effect Explained in Simple Terms and On Uses of A 4 x 2: Arrhenius, The Last 15 years of Temperature History and Other Parodies. […]