Spencer: Earth sans greenhouse effect – what would it be like?

What If There Was No Greenhouse Effect?

by Roy W. Spencer, Ph. D.

http://riverdaughter.files.wordpress.com/2009/07/globe.jpg

Weatherless world - a bit like this maybe? "Cloud Free Globe" Image by Planetary Visions Limited. Click image for details and larger version available

The climate of the Earth is profoundly affected by two competing processes: the greenhouse effect, which acts to warm the lower atmosphere and cool the upper atmosphere, and atmospheric convection (thermals, clouds, precipitation) which does just the opposite: cools the lower atmosphere and warms the upper atmosphere.

To better understand why this happens, it is an instructive thought experiment to ask the question: What if there was no greenhouse effect? In other words, what if there were no infrared absorbers such as water vapor and carbon dioxide in the atmosphere?

While we usually only discuss the greenhouse effect in the context of global warming (that is, the theory that adding more carbon dioxide to the atmosphere will lead to higher temperatures in the lower atmosphere), it turns out that the greenhouse effect has a more fundamental role: there would be no weather on Earth without the greenhouse effect.

First, the big picture: The Earth surface is warmed by sunlight, and the surface and atmosphere together cool by infrared radiation back to outer space. And just as a pot of water warming on the stove will stop warming when the rate of energy gained by the pot from the stove equals the rate of energy loss by the pot to its surroundings, an initially cold Earth would stop warming when the rate at which solar energy is absorbed equals the rate at which infrared energy is lost by the whole Earth-atmosphere system to space.

So, let’s imagine an extremely cold Earth and atmosphere, without any water vapor, carbon dioxide, methane or any other greenhouse gases – and with no surface water to evaporate and create atmospheric water vapor, either. Next, imagine the sun starts to warm the surface of the Earth. As the surface temperature rises, it begins to give off more infrared energy to outer space in response.

That’s the Earth’s surface. But what would happen to the atmosphere at the same time? The cold air in contact with the warming ground would also begin to warm by thermal conduction. Convective air currents would transport this heat upward, gradually warming the atmosphere from the bottom up. Importantly, this ‘dry convection’ will result in a vertical temperature profile that falls off by 9.8 deg. C for every kilometer rise in altitude, which is the so-called ‘adiabatic lapse rate’. This is because rising warm air parcels cool as they expand at the lower air pressures aloft, and the air that sinks in response to all of that rising air must warm at the same rate by compression.

Eventually, the surface and lower atmosphere would warm until the rate at which infrared energy is lost by the Earth’s surface to space would equal the rate at which sunlight is absorbed by the surface, and the whole system would settle into a fairly repeatable day-night cycle of the surface heating (and lower atmosphere convecting) during the day, and the surface cooling (and a shallow layer of air in contact with it) during the night.

The global-average temperature at which this occurs would depend a lot on how reflective the Earth’s surface is to sunlight in our thought experiment. ..it could be anywhere from well below 0 deg F for a partially reflective Earth to about 45 deg. F for a totally black Earth.

So, how is this different from what happens in the real world? Well, notice that what we are left with in this thought experiment is an atmosphere that is heated from below by the ground absorbing sunlight, but the atmosphere has no way of cooling…except in a very shallow layer right next to the ground where it can cool by conduction at night.

Why is this lack of an atmospheric cooling mechanism important? Because in our thought experiment we now have an atmosphere whose upper layers are colder than the surface and lower atmosphere. And what happens when there is a temperature difference in a material? Heat flows by thermal conduction, which would then gradually warm the upper atmosphere to reduce that temperature difference. The process would be slow, because the thermal conductivity of air is quite low. But eventually, the entire atmosphere would reach a constant temperature with height.

Only the surface and a shallow layer of air next to the surface would go through a day-night cycle of heating and cooling. The rest of the atmosphere would be at approximately the same temperature as the average surface temperature. And without a falloff of temperature with height in the atmosphere of at least 10 deg. C per kilometer, all atmospheric convection would stop.

Since it is the convective overturning of the atmosphere that causes most of what we recognize as ‘weather’, most weather activity on Earth would stop, too. Atmospheric convective overturning is what causes clouds and rainfall. In the tropics, it occurs in relatively small and strongly overturning thunderstorm-type weather systems.

At higher latitudes, that convection occurs in much larger but more weakly overturning cloud and precipitation systems associated with low pressure areas.

There would probably still be some horizontal wind flows associated with the fact that the poles would still be cooler than the tropics, and the day-night heating cycle that moves around the Earth each day. But for the most part, most of what we call ‘weather’ would not occur. The same is true even if there was surface water and water vapor…but if we were able to somehow ‘turn off’ the greenhouse effect of water vapor. Eventually, the atmosphere would still become ‘isothermal’, with a roughly constant temperature with height.

Why would this occur? Infrared absorbers like water vapor and carbon dioxide provide an additional heating mechanism for the atmosphere. But at least as important is the fact that, since infrared absorbers are also infrared emitters, the presence of greenhouse gases allow the atmosphere — not just the surface — to cool to outer space.

When you pile all of the layers of greenhouse gases in the atmosphere on top of one another, they form a sort of radiative blanket, heating the lower layers and cooling the upper layers. (For those of you who have heard claims that the greenhouse effect is physically impossible, see my article here. There is a common misconception that the rate at which a layer absorbs IR energy must equal the rate at which it loses IR energy, which in general is not true.)

Without the convective air currents to transport excess heat from the lower atmosphere to the upper atmosphere, the greenhouse effect by itself would make the surface of the Earth unbearably hot, and the upper atmosphere (at altitudes where where jets fly) very much colder than it really is.

Thus, it is the greenhouse effect that continuously de-stabilizes the atmosphere, ‘trying’ to create a temperature profile that the atmosphere cannot sustain, which then causes all different kinds of weather as the atmosphere convectively overturns. Thus, the greenhouse effect is actually required to explain why weather occurs.

This is what makes water such an amazing substance. It cools the Earth’s surface when it evaporates, it warms the upper atmosphere when it re-condenses to form precipitation, it warms the lower atmosphere through the greenhouse effect, and it cools the upper atmosphere by emitting infrared radiation to outer space (also part of the greenhouse effect process). These heating and cooling processes are continuously interacting, with each limiting the influence of the other.

As Dick Lindzen alluded to back in 1990, while everyone seems to understand that the greenhouse effect warms the Earth’s surface, few people are aware of the fact that weather processes greatly limit that warming. And one very real possibility is that the 1 deg. C direct warming effect of doubling our atmospheric CO2 concentration by late in this century will be mitigated by the cooling effects of weather to a value closer to 0.5 deg. C or so (about 1 deg. F.) This is much less than is being predicted by the UN’s Intergovernmental Panel on Climate Change or by NASA’s James Hansen, who believe that weather changes will amplify, rather than reduce, that warming.

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306 thoughts on “Spencer: Earth sans greenhouse effect – what would it be like?

  1. “But eventually, the entire atmosphere would reach a constant temperature with height.”
    Why wouldn’t the adiabatic expansion mechanism then continue to convey heat downwards (the air would not be motionless because of diurnal effects and thermal inhomogeneity), to restore and maintain (nearly) the adiabatic lapse rate of -9.8 K/km? Surely this mechanism moves heat more effectively than conduction?

  2. Seems like the Coriolis Effect from tropics to mid-latitudes would still mix things up quite a bit, but it’s interesting seeing how the GHG’s create a vertical stirring force locally.

    So, does this idea map to Venus, where the extreme heat occurs because it has no water vapor to create a circulation that can “cool” things off?

  3. Roy:
    “There is a common misconception that the rate at which a layer absorbs IR energy must equal the rate at which it loses IR energy, which in general is not true.)”

    I would strike that sentence or expand upon it. The terms ‘rate’ and ‘energy’ are being used loosely here, although, it’s clear that you can easily be right with judicious selection of definitions. I don’t think you need it, and, I think you added that sentence because it’s actually another essay you want to write.

  4. “Invariant (13:56:45) :

    What would we talk about without the weather?”

    Somebody would invent a catastrophic scenario that can only be averted by giving said person lots of gold so said person can go and try to figure out ways to avert it. Each time said person comes back said person tells the people “It’s even worse than i thought and i need some more gold to do more research.”

  5. “Why would this occur? Infrared absorbers like water vapor and carbon dioxide provide an additional heating mechanism for the atmosphere. But at least as important is the fact that, since infrared absorbers are also infrared emitters, the presence of greenhouse gases allow the atmosphere — not just the surface — to cool to outer space.”

    You don’t need the greenhouse gases to cool the atmosphere, oxygen and nitrogen are infared emitters according to the Planck black body radiation effect.

    So the atmosphere cools without the greehouse gases.

    thanks

  6. I am now very confused.

    1) IR – is emitted by any thing that is above 0 deg Kelvin
    so not only does the surface of the earth emit IR but ANY gas; liquid or solid that is above 0K does so to.

    2) Coriolis effect; the difference in ground heating (caused by the reduced w/m^2 as you approach the poles) will generate cyclones or anti-cyclones -(can’t work out which – I think anti in the N & cyclonic in the S hemispheres) – so there would be some fairly large perturbations as these Coriolis storms built up

    3) Since the atmosphere would be above 0K the space facing layers would radiate IR up AND down (well through a full sphere) – how efficient I am not at all sure – it would depend on how similar to a black body the gas mixture was – there was a blog here before Christmas that took us through some of the Black body stuff.

    4) In equilibrium; the (outer shell of atmosphere of the) earth would re-radiate exactly the same amount of energy as it receives. (Ignoring the heat trapped in the centre of the earth).

    Sorry I just do not see a static atmosphere; so ‘weather’ and ‘Climate’ would still occur. The only way for there to no weather would be to either
    a) be a very small planet/non-rotating planet
    b) no atmosphere (or both !)

    Given the Coriolis force is enough to spin the water in a small sink (except on the equator) I just can not see how a lack of GHC would prevent weather/climate at all. Is it not perhaps the case that the GHG actually mitigate the Coriolis storms by generating substantial non-Coriolis air flows ?

  7. “This is what makes water such an amazing substance. It cools the Earth’s surface when it evaporates, it warms the upper atmosphere when it re-condenses to form precipitation, it warms the lower atmosphere through the greenhouse effect, and it cools the upper atmosphere by emitting infrared radiation to outer space. These heating and cooling processes are continuously interacting, with each limiting the influence of the other.”

    So it’s not the greenhouse effect, it’s the automatically adjusting air-con effect.

    Thanks Dr Roy, great explanation.

  8. Roy is talking about the planet Mars.

    Unfortunately the notion that the lower atmosphere “warms” the surface is physically wrong – no more than double glazing “warms” the inside of a house

  9. Please correct me if I’m wrong. (Anyone.)
    If the adiabatic lapse rate is only maintained by GHGs, then an increase in GHG would increase the actual observed temperature decline with altitude…
    (Which if my grandma’s rule of thumb is still valid, is much less than 10`per km.)
    So more GHG = more snow at altitude, greater albedo effect… hey presto, already the beginnings of a self-correcting mechanism?

  10. Thank you Dr. Spencer, as always you clear the air –so to speak. O/T: Given your replacement’s emphesis on AGW, what’s he really trying to limit? Is there one manmade greenhouse gas that Hansen has some special hatred for? I know from personal experience that the upper atmosphere is full of manmade chemicals that nature never intended to be there. What’s the most offending? Is that Hansen’s demon too?

  11. Very interesting thought experiment. The majority of the population has little or no understanding as to even the basics of the atmosphere. A simple question I like to ask is “what heats the atmosphere?”. Most people say the sun, but that is not necessarily correct. My answer used to be that the sun heats the earth and the earth radiates that heat to the atmosphere. That is the short answer, and many here know that it is far too simplistic. It does however make people aware that even the basics are difficult to comprehend. Add water vapor (the most prevalent of GHGs) and the answer becomes much more complex. Then start adding all the other variables. Very informative article and worthy of further contemplation. Thank you Dr. Spencer.

  12. Dear Dr. Roy W. Spencer,

    In this imagined world without greenhouse gases – how long would it take to establish equilibrium again if the world was cooled by 1 ºC?

    Best Regards,

    Invariant

  13. “bob (14:18:37) :
    […]
    You don’t need the greenhouse gases to cool the atmosphere, oxygen and nitrogen are infared emitters according to the Planck black body radiation effect.

    So the atmosphere cools without the greehouse gases.”

    Every material emits radiation given the temperature is hot enough. This is not the question. For a good explanation see Willis Eschenbach’s Steel greenhouse writeup:
    https://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/

  14. It’s really nice to see someone of stature putting out this information.

    One assumption though was that clouds were not a part of the ‘what if’ scenario. Of course they wouldn’t exist with no water vapor but their effect is great anyway. They’re responsible for nearly 0.22 of the overall 0.31 albedo, reducing the total incoming power that must be balanced. Also, they are going to emit in a continuum rather than simply h2o vapor spectral wavelengths. Essentially though, they also provide a lower temperature ‘surface’ much higher above sea level.

    My other concern is that in the basics, the lapse rate fundamentals ignores radiative power loss and absorption and assumes adiabatic.

    I believe that Roy has stated many times in the past that the water cycle is the most important aspect by far. At the surface, convection, including the latent heat from evaporation, h2o averages roughly around 100 W/m^2 of energy transfer at the surface. By the tropopause, that amount has reduced to effectively 0. This is from a conservation of energy (power) estimate based on a simple one-dimensional model. This helps define our lapse rate value as it has to have conservation of energy (power) on the short term. That’s not to denegrate the advection effect.

    One of the factors that has bugged me is that with the increase of ghgs in the atmosphere, that doesn’t increase any visible light coming in which warms the lower oceans. All of the increase in incoming power to the oceans will be IR and have no penetration into the ocean. That suggests the added heat results in more water evaporation which increases the convection and should lead to greater cloud cover which should increase albedo and reduce incoming solar (some concept of Lindzen’s iris effect concept). In no case should that incoming IR result in heating the oceans lower down. Heat doesn’t flow from cold to warm and all physical phenomenon is working against heating the water from the top.

  15. blokeinfrance (14:27:07) :

    The lapse rate is maintained by the PVT relationships of air. If you heat an element of air, it will decrease in density. Then, archimedes principle will cause it to rise and cool (adiabatically) until its density again matches that of the surrounding air. Thus, even with a transparent atmosphere the sun will heat the earth, the earth will heat the layer of air next to the earth by conduction, causing it to become buoyant, it will rise, etc, etc, etc. Without water vapor though, the process would be more like conditions over dry deserts, where convection extends to higher altitudes and clouds do not necessarily form.

  16. The greenhouse effect can be physically explained without the greenhouse gases.

    “Here, using a different approach, it is shown that GE can be explained as mainly being a consequence of known physical laws describing the behaviour of ideal gases in a gravity field”

    Hans Jelbring, The “Greenhouse Effect” as a Function of Atmospheric Mass

    http://www.ingentaconnect.com/content/mscp/ene/2003/00000014/F0020002/art00011

    http://www.tech-know.eu/NISubmission/pdf/Politics_and_the_Greenhouse_Effect.pdf

  17. Surely the oceans would have convective effects even in you model sans water vapour? How would the variable heating of different land and sea masses affect your model?

  18. Aagh, let me try again. Surely the oceans would have convective effects even in your model sans water vapour?

  19. is this excerpt to be be taken as current scientific theory, or a prediction from the ipcc?

    “And one very real possibility is that the 1 deg. C direct warming effect of doubling our atmospheric CO2 concentration by late in this century will be mitigated by the cooling effects of weather to a value closer to 0.5 deg. C or so (about 1 deg. F.)”

    i.e. is it agreed that the atmospheric co2 WILL double, and the warming WILL be 1 deg. C ?? among scientists?

  20. John A

    Unfortunately the notion that the lower atmosphere “warms” the surface is physically wrong – no more than double glazing “warms” the inside of a house

    If you have to be pedantic, yes.
    In reality, the lower atmosphere slows down the rate at which the surface loses heat, thereby making it ‘warmer’ than it would otherwise have been.

  21. Roy,

    Well done, this is likely to bemuse, confuse and hopefully in the end enlighten a lot of people. It will also I expect raise more questions than can be adequately answered.

    Most people, I include myself, would have to lie down in a darkened room for a few hours, if they thought hard enough to get to grips with the issues rasied by an IR transparent atmosphere, and juxtapose it against a IR grey one.

    Best Wishes

    Alex

  22. If the atmosphere would be without any GHG would it be heated and cooled only from the earth surface. That would result in that the atmosphere over time would be heated close to the earths maximum day temperature. NOT the average temperature. Observe that is the maximum temperature not the average maximum temperature.
    Warmer air raising, colder air sink. A cooling only from the bottom of the atmosphere is not very efficient an the warmer air will be kept in altitude.
    Cold floor at home anyone but still warm at the ceiling?
    The lapse rate would of course be working but the “average” atmosphere temperature would be decided from where it is heated.
    A greenhouse effect without ANY GHG.

    Adding any GHG or cloud will increase radiation = cooling capacity of the atmosphere. Yes, adding radiation capacity to the atmopsher will cool the atmosphere.
    This is precisly the opposite from general AGW theory.

    But in line with Dr spencers theory that cloud is a negative forcing.

  23. Roy could you answer a few questions,my physics needs help.

    1. What is the “turn-over rate”, the rate of absorption of infra-red vs emission for a given molecule of H20 or CO2? Would it be more correct to think that added GH gasses add more layers that absorb and emit thus slowing down the rate of cooling vs “trapping heat”?

    2. How does the cooling rate via absorbing and emitting heat waves when there is no convection, compare to a rate of cooling when there is convection? Does extra CO2 resulting in heating by absorbing heat waves, cause increased convection and that increased convection allows heat to more quickly escape into the stratosphere and to some degree offset heating by absorption? Are there papers that researched this?

    3. When a CO2 molecule that has absorbed infra-red, then collides with say an O2 molecule, transferring some kinetic energy, will the CO2 still emit the same wavelength it absorbed, or a different wavelength.

  24. I am going to have to call BullSh*t on this!

    The major disruption of stable air masses he proposes will still exist. They are still going to be the Lunar declinational tides, that move the heat off of the Equator into the mid latitudes. Unless he also proposes to remove the Moon, and it’s influence from the total equation, as they have done for the forecast models the NWS uses.

    The atmosphere of Venus has the sun side thermal expansion, and poleward spiral movement to effect what polar cooling goes on, that discribes what will happen to the Earth, with out the moon, not the CO2 / water vapor he is going on about.

    Without removing the Moon’s influence, as well as the GHG’s, there will still be the perturbation of large masses of warmed surface air, moved off of the equator into the mid latitudes, with the attendant Coriolis Effects, added into the momentum, still churning the global circulation.

    What these people seem to NOT understand, is that the tidal effects of the Moon, are the major driving mechanism of the Weather. He thinks he is removing the Lunar tidal influences simply by taking away the GHG’s feed backs to the system.

    When the overall driving forces that create the global circulation are put into the weather / climate equations in their proper strengths, and interactions we will be able to come up with methods, that will be able to forecast longer terms, (5 to 7 days) than the time it takes for the Moon to go from North to South, or back again.

    Quote “Since it is the convective overturning of the atmosphere that causes most of what we recognize as ‘weather’, most weather activity on Earth would stop, too. Atmospheric convective overturning is what causes clouds and rainfall. In the tropics, it occurs in relatively small and strongly overturning thunderstorm-type weather systems.

    At higher latitudes, that convection occurs in much larger but more weakly overturning cloud and precipitation systems associated with low pressure areas. /Quote

    It is the convective over turning, due to the tidal displacement, that mixes the air having high thermal and moisture differentials, causing the rapid precipitation, that results in the lowered pressure along a front, in proportion to the precipitation rates.

    It is the combination of the interplay between the heat retention of the GHG’s and the variation in the cooling effects, of the Lunar declinational tides spreading the heat and moisture off of the Equator, that is the weather short term.

    Decade length periods, of climate shifts are due to the 18.6 year Mn long period, of the changes in declinational angle at 27.32 day cycles of culminations, interacting with the synod conjunctions of the outer planets, that produce the patterns, they cannot model, with just the physics of the atmosphere considered.

    The response I will get from the mainstream, is that I have it backwards.

    For their immense budget, huge payroll, and years of study, they cannot get a consistent 10 to 30 day forecast.

    From my work, on less than a total $60,000 budget (of my own funds) over 25 years, I can show ~80% accurate daily forecasts for the next 4 years, I think the proof is in the pudding, so to speak.

    http://www.aerology.com/national.aspx

    Is where you can find the mentioned daily maps by my method.

  25. blokeinfrance (14:27:07) :
    Roy is referencing the Dry adiabatic lapse rate at 10 deg C per km roughly. On average the lapse rate in the lower atmosphere approximates the Saturated adiabatic lapse rate which in lower levels is around 2/3 of the Dry. Which ought to be a clue about the importance of the dominant minor atmospheric constituent gases.

    I’ll have to think hard about the rest of his article.

  26. Invariant (13:56:45) :

    What would we talk about without the weather?

    We would be talking about the burglars who stole the weather and tried to pawn it at Copenhagen. Fortunately for us, the hot items cooled substantially and all they could produce was a blinding snowstorm. It went over like a ton of ice off the high-dive at the YMCA And, just like the Titanic, they are still plowing about in the dark and short on the lifeboats.

  27. Re: peter_dtm (14:19:11) :

    “IR – is emitted by any thing that is above 0 deg Kelvin
    so not only does the surface of the earth emit IR but ANY gas; liquid or solid that is above 0K does so to.”

    Not so, at least in practical terms. Try looking for measurements of the IR spectrum of Helium, I doubt you will find much data as it does not radiate readily below the visible, and hardly at all at any wavelength when at earthlike temperatures.

    Alex

  28. I like the lava lamp analogy of how our climate works. The system is so chaotic, it can never be modeled with any reasonable degree of certainty for distant future projections. The current generalized model of sun, ocean, and atmospheric interaction is probably as good as it’s going to get. Scientists should try to model a simple lava lamp first, to see if their models can predict with reasonable accuracy where blobs of all sizes of lava will be at any given time across all temperature ranges in 3D space. If they can do that, I’ll consider their climate models with a modicum of trust. Until then, NO.

  29. Re¨ vigilantfish (14:57:43) :

    “Surely the oceans would have convective effects even in you model sans water vapour? How would the variable heating of different land and sea masses affect your model?”

    Roy wrote:

    So, let’s imagine an extremely cold Earth and atmosphere, without any water vapor, carbon dioxide, methane or any other greenhouse gases – and with no surface water to evaporate and create atmospheric water vapor, either.

    Alex

  30. Dr. Spencer,

    OT, but while you are here, I would appreciate it if you would clarify a statement made by Lord Monckton. Were the equations to derive temperature anomolies from the satellite MSUs calibrated using the surface data? If the surface data was adjusted incorrectly, could this have created an error in the lower troposphere data?

  31. Re; pochas (14:46:12) :

    “The lapse rate is maintained by the PVT relationships of air. If you heat an element of air, it will decrease in density. Then, archimedes principle will cause it to rise and cool (adiabatically) until its density again matches that of the surrounding air. Thus, even with a transparent atmosphere the sun will heat the earth, the earth will heat the layer of air next to the earth by conduction, causing it to become buoyant, it will rise, etc, etc, etc.”

    I think you will find that for convection to be maintained in the long term you need not just heating from below but cooling from above. It is the cooling from above that is lacking in an IR transparent atmosphere.

    Alex

  32. Nice article. The earth, with its eccentric orbit around the sun, its rotation period, the inclination of its axis, the composition of its atmosphere and oceans, its strangely huge moon, its geography, geology and topology, etc., is ideally suited for life as we know it. The more I think about it, the more convinced I am that that there are way too many coincidences for the whole thing to be just a coincidence. Whoever it was that planned all this is obviously much more powerful and intelligent than we are and they will not suffer us to destroy it. And no cockamamie climate hypothesis conjured up by imperfect and dishonest men and women will change that.

    Just a thought.

  33. if i had to pick two processes it would be the sun and the ocean. then it gets complicated. to say the least.

  34. I may have missed it in the verbiage above, but my impression, unscientific though it may be, is that the ROTATION of the Earth about its axis every 24 hours, at speeds approaching 1,000 miles/hour at the Equator, and the angular momentum therefrom, have something to do with the WIND, which is an aspect of weather, at least around here it is, but what do I know, not being a climatologist and all.

  35. We may have long abandoned the bone in the beard, peer-reviewed shamanism of the past but we still seem to be caught in the twin headlights of conceit and consensus group-think when it comes to the “We’re all going to die” mantra!
    Today’s Science may turn out, once again, to be yesterdays superstition. Who knows? Without the benefit of a time machine, we’ll never know!
    As a small and rather insignificant species of sentients let us keep nibbling away at the margins of Nature that keep us ticking along. Adequate foodstuff, shelter, happiness come to mind!
    As for the big stuff e.g. Why does big momma Gaia hate us so much, is it ‘cos we is bad, forget it folks.
    Irrespective of how many £3 monthly contributions, to adopt a trilobite(sp?), the most-liberal of dinosaurs once made, they still got wiped out!
    The reason that we can still argue, make love and blog is because Natures dice have rolled in our direction thus far.
    No amount of taxpayers pennies, cast into the accounts of advertising companies, will make one iota of difference to what happens next.
    It does, however, make an enormous change to the fortunes of those companies favoured by our political masters.
    I would walk 500 miles and I would walk 500 more, if I truly believed that not driving my car would avert a catastrophe. I just don’t believe that is the case. I also believe that I’m being robbed.

  36. The people should have been warned we would be in for another brutally cold winter this year. There was plenty of scientific evidence prior to the fact. The people could have prepared themselves better and many people could have been saved. The warmists have blood on their hands, or should I say, frozen blood on their hands. The victims families should file a class action law suit against the forecasting agencies and people should be fired for not doing the job we hired them to do.

    I take no pleasure in posting articles of increased death due to global cooling, I only post them to make a point, for people to be outraged as I am, and for truth to Not be hidden.

  37. Dr. Spencer,

    I have a question speaking of temperatures, radiation and conduction. Not so much convection. In the hot summer, in Oklahoma it gets to be 100+ for usually 10-30 days. Setting in the shade on my patio you can just feel the hot IR radiation off the brown fences, roofs and the patio concrete. Uncomfortable! I recently put an atomizer in the tree at the far edge. This atomizer turns a few gallons per hour to a super fine mist over the patio.

    My question, when the atomizer is turned on, there seems to be a marked drop in the temperature you perceive, I mean immediately, before the evaporation of the air and evaporation off the hot concrete has occurred and the air has begun to cool. I have always thought this was related to the absorption of the IR radiation because the mist is between myself and the fences, roofs and concrete. Since I’m sitting in the shade, the visible spectrum is reduced and most radiation would be in the IR portion. Does water vapor then absorb a very large portion? It’s a weird effect. Of coarse, after 10-15 minutes it then feels 85 degrees not 105 but by then the patio is lightly wet and the heat in the concrete has dispersed and the air around has cooled.

    Could the immediate drop be strictly IR absorption of the water vapor and droplets? Does water absorption bands absorb that much? Never have been able to pin that down.

  38. “Cold Lynx (15:14:10) :
    […]
    Adding any GHG or cloud will increase radiation = cooling capacity of the atmosphere. Yes, adding radiation capacity to the atmopsher will cool the atmosphere.
    This is precisly the opposite from general AGW theory.”

    Attention: as explained by Willis in The Steel Greenhouse, your “GHG cloud” will radiate (to cool down) upwards and downwards. So a cooling down of the cloud leads to a slight warming up of the earths surface! (Which in turn will radiate upwards, warming up the cloud again etc…)

  39. While we usually only discuss the greenhouse effect in the context of global warming (that is, the theory that adding more carbon dioxide to the atmosphere will lead to higher temperatures in the lower atmosphere), it turns out that the greenhouse effect has a more fundamental role: there would be no weather on Earth without the greenhouse effect.

    As Dick Lindzen alluded to back in 1990, while everyone seems to understand that the greenhouse effect warms the Earth’s surface, few people are aware of the fact that weather processes greatly limit that warming. And one very real possibility is that the 1 deg. C direct warming effect of doubling our atmospheric CO2 concentration by late in this century will be mitigated by the cooling effects of weather to a value closer to 0.5 deg. C or so (about 1 deg. F.) This is much less than is being predicted by the UN’s Intergovernmental Panel on Climate Change or by NASA’s James Hansen, who believe that weather changes will amplify, rather than reduce, that warming.”

    James Hansen has headed NASA’s Goddard Institute for Space Studies since 1981. Prior to that, his Wikipedia page says that “[a]fter graduate school, Hansen continued his work with radiative transfer models and attempting to understand the Venusian atmosphere. This naturally led to the same computer codes being used to understand the Earth’s atmosphere. He used these codes to study the effects that aerosols and trace gases have on the climate.” This is quite worthy of note.

    It seems Hansen’s views of the effects of greenhouse gases on the Earth’s atmosphere may have been influenced by his earlier research interests. (For the benefit of those who may not know, the atmosphere of Venus consist of 96% CO2, and the greenhouse effect makes it the hottest planet in the Solar System.)

    One can only speculate whether there would have been any greenhouse gas scare or an AGW movement at all, if the person who headed one of the leading institutions in climate science for 30 years ago wasn’t an expert in the atmosphere of Venus.

    Would we have the AGW debate we are having now if Richard Lindzen was the head NASA GISS, instead of James Hansen? And just how Climate Science would have been shaped if Lindzen had the vast resources that Hansen enjoyed for the last 30 years.

  40. Peter (15:12:36) :

    John A

    Unfortunately the notion that the lower atmosphere “warms” the surface is physically wrong – no more than double glazing “warms” the inside of a house

    If you have to be pedantic, yes.
    In reality, the lower atmosphere slows down the rate at which the surface loses heat, thereby making it ‘warmer’ than it would otherwise have been.

    Its not pedantic to be consistent with the laws of physics.

    What Roy Spencer is talking about is what would happen if the Earth had a thin isothermal atmosphere. But the radiative properties of the atmosphere depend on its composition.

    DirkH (14:42:14) :

    Every material emits radiation given the temperature is hot enough. This is not the question. For a good explanation see Willis Eschenbach’s Steel greenhouse writeup:
    https://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/

    Unfortunately Willis’ “Steel Greenhouse” is unphysical rubbish. Putting hot food in a Dewar flask does not cause the food’s temperature to rise – it simply reduces the rate at which the food cools.

  41. wayne (16:20:07) : Sorry, correction myself again.
    “Could the immediate drop be strictly IR absorption of the water vapor and droplets?”
    Should be ‘by’, not ‘of’.

  42. Fascinating material, Dr. Spencer, thank goodness for people like you, Dr. Lindzen, and Dr. Pielke to leaven all of the alarmist nonsense, and return common sense to the discussion.

    You are all mentioned in a wonderful article in a magazine for young people:
    http://www.buffalobeast.com, Pants on Fire (forgive the lewd implication).

  43. RE: bob (14:18:37) :

    “You don’t need the greenhouse gases to cool the atmosphere, oxygen and nitrogen are infared emitters according to the Planck black body radiation effect.

    So the atmosphere cools without the greehouse gases.”

    Gases are not blackbodies!

    To the limited extent that O2 has an IR spectrum one should include it as acting weakly as a greenhouse gas. Just imagine a Helium only atmosphere and you will have something like an GHG free, IR transparent atmophere.

    Alex

  44. All exchanges happen in the whole range of wave lengths. Our limitations as observers do not condition the phenomena ocurring in nature around us. They happen without our consent.

  45. “Mike D. (16:13:33) :
    […]
    I may have missed it in the verbiage above, but my impression, unscientific though it may be, is that the ROTATION of the Earth about its axis every 24 hours, at speeds approaching 1,000 miles/hour at the Equator, and the angular momentum therefrom, have something to do with the WIND”

    In the beginning the Earth stood still. And the atmosphere stood still.
    Then came a cosmic billard queue and set the Earth in rotating motion with a 1000 miles an hour. As the atmosphere was not affected by this, it came to be that there was a 1000 miles/hour wind.

    Actually, this didn’t last too long as friction set in and accelerated the atmosphere until it had exactly the same speed as the rotating earth. The earth slowed down a tiny bit to keep the angular momentum in balance.

    There is no absolute speed, speed is relative. The atmosphere would rotate with the planet.

  46. Has anyone postulated a mechanism for the “flow,” for lack of a real word, of CO2 particles in the atmosphere?

    Back in the days of the chlorofluorocarbon scare, the New Yorker managed to publish a readable article in which they explained how those little CFC beasties managed to get up to the ozone layer, how they engaged in chemical interactions that “ate” the ozone, why the “ozone holes” were over the poles and so on. Lots of wonderful stuff. I haven’t seen anything comparable for the CO2 particles that supposedly cause global warming. Does anyone know of postulated mechanisms that are taken to be important by some researchers?

    I doubt that there is a postulated mechanism that is taken seriously. I just read an in article in “Science News” which argued that there has been no increase in the CO2 concentration in the last 150 years. Obviously, if that conclusion has merit then there is no mechanism because, if it existed, it would have no effect.

    If there is no mechanism that has some support, then the Climategaters were doing only temperature reconstruction from historical records. That is the extent of their science, I take it.

  47. “David L. Hagen (16:34:54) :
    […]
    The new climate theory of Dr. Ferenc Miskolczi”

    Oh. I guess that settles the debate for good, then.

  48. The cyclic processes of evaporation/condensation and freeze/thaw are the energy exchange controlling factors that result in weather and climate change in this water world of ours. These processes would continue without any atmospheric CO2 .

  49. GHG act as a buffer. The IR still ends up in space, and is not trapped, just delayed, like traffic. In the end, everyone gets home in space. The net energy flux of IR is still bottom to top.

    Not sure why the upper atmosphere should cool since after a steady state is reached, just as much IR is released to space though the upper atmosphere.

    Also the upper troposphere has not warmed even though there is more CO2 to capture outgoing IR. I suppose the density is quite low, so perhaps the GHG effect is minimal there, also because there is little water vapor at that altitude, and H2O is the most important GHG. In the desert, it gets cold in the evening, even with all that CO2, since there is not much humidity.

    We have geothermal heat, coriolis forces on wind and ocean currents, moons influence on tides, energy being captured for photosynthesis, changing albedo, heat transport to poles from tropics, latent heat, adiabatic expansion, solar variability, air exchanges with the stratosphere, all of which influence on the weather and climate. Simple models do not work, and computers are not fast enough to handle more complex models .

    A 1 deg C temperature rise due to CO2 is a 0.37% temperature rise, yet a doubling of CO2 is only a 0.038% increase in atmosoheric CO2. Thats an order of magnitude difference.

    I would love to see an energy or heat content balance broken down by components in the atmosphere , O2, CO2, H20, latent heat, etc by altitude, and the net fluxes upward and downward. I mean, how much heat relative to total atmospheric heat is a result of CO2’s IR absorption at a given moment in time.

    The article kind of muddies the water since the real issue is CO2 (and I am am Spencer fan), but it does point out how important H20 is. Just don’t confuse H20’s importance with CO2.

  50. “DirkH (17:08:26) :
    Oh. I guess that settles the debate for good, then.”

    To elaborate further for all who don’t want to look through Ferenc’s slides, the key sentence is:

    “If the system energetically could increase its
    surface temperature, it need not wait for our
    anthropogenic CO2 emissions, since another
    GHG, water vapor, is available in a practically
    infinite reservoir, in the surface of the
    oceans.”

    And as far as i understood it, the system tries to reach an
    optimum point were exactly 1/3 of the IR radiation is
    coming back to earth; it can’t do any better so that’s the optimum.
    As the transmission function has exactly one maximum,
    it will go there. Ferenc compares his theoretical assumptions
    with experimental data and concludes that earths atmosphere is
    working close to the optimum.

    At least that’s my understanding. Didn’t see these slides before,
    didn’t really get the point of his theory before. It’s beautiful.

  51. The greenhouse effect can be physically explained without the greenhouse gases. There would be weather without those radiation absorbing gases and we wouldn’t have to account for the thermophysically questionable surface warming backradiation.

    Hans Jelbring, The “Greenhouse Effect” as a Function of Atmospheric Mass

    http://www.ingentaconnect.com/content/mscp/ene/2003/00000014/F0020002/art00011

    http://www.tech-know.eu/NISubmission/pdf/Politics_and_the_Greenhouse_Effect.pdf

  52. Dr. Spencer,

    Not sure if I understand the distinction between these two processes since they are both primarily water vapor. It is easier for me to visualize water vapor functioning as a greenhouse when it simply is not energized enough to vent that energy convectively by rising into the cooler upper atmosphere and condensing.

    Q: I understand the argument that C02 in low concentration has insufficient heat capacity to create catastrophic warming. And I can visualize that available IR is absorbed by water vapor within the first (X) feet of the surface until it is consumed, but:

    What would happen if C02 was in concentration on par with water vapor? I should think it would begin to exert itself somewhere in a much higher concentration.

  53. I found this to be a very interesting article (I like Dr. Spencer’s work), although I do not believe the so-called Greenhouse Effect Theory works anything like what I most often see being described. I don’t believe the so-called Greenhouse Effect Theory has the ability to heat anything, but instead slightly inhibits cooling or heat dissipation. I also believe that even the most conservative estimates citing a temperature differential between Greenhouse and non-Greenhouse are grossly over estimated. Meaning, the claims that we are 33C warmer with a Greenhouse Effect than we would be without, is grossly over estimated, and I believe the actual figure would be closer to single digits, if at all. The so-called Greenhouse Effect Theory does nothing more than slow the rate of cooling (inhibiting, or slowing, energy transfer).

    – The Plinko Effect Theory –

    The way I like to think of it is like this. Imagine for a moment a very stable atmosphere, without any wind or air movement at all. Now, release a ball filled with hydrogen or helium, this representing Infrared Radiation. The ball will swiftly float straight upward, accelerating until it reaches terminal velocity. Now, imagine GHG’s being represented by a matrix of static balls evenly spaced throughout that atmosphere (density of balls representing GHG concentration). Now, release another helium ball (IR). What happens? It bounces back and forth through the static balls (GHG’s), still gaining altitude, never descending, but ping-ponging between the static balls like a plinko-chip game (price is right). Any energy transfer that occurs simply spawns the same mechanism upward. The upward moving balls can never transfer energy downward.

    Now, one might say, well the IR ball hit a GHG ball and bounced back down. Well, yes, that is possible, however, remember that there are other GHG balls bellow that the IR ball will likely plink off of and bounce right back up again, continuing its ascension as before.

    Now, since our atmosphere is not static, and air can move somewhat upward and downward (vertical mixing), it is possible to get some of the balls moved to a lower altitude for a short period of time, but they will always persist in rising. So, at most, one could expect a very slight rise in the total density of lower altitude balls (very slight, and probably equates to more like 1C or 2C, not 33C). You are never able to increase the density of balls at the surface without first directly increasing the rate at which the surface releases those balls. The heat source is always the surface, and GHG’s can only slow the dissipation, and perhaps ever so slightly increase the density of balls near the surface through the so-called Plinko Effect Theory.

    Personally, I believe this is a little more accurate representation of what really happens in our atmosphere than does the so-called Greenhouse Effect Theory.

    The Earth is not warm because of GHG’s .. and Venus is not hot because of CO2 .. can’t work that way.

    My imagination at work … yikes… ;-)

  54. almost forgot… I also left an email on your site asking if UAH Global Mean Temp is calibrated to surface records, and is there a risk that upward adjustments in the surface record would affect your results?

  55. Different approach to the question.

    What global climate forces brought on the Holocene? And how did those climate forces settle to maintain the Holocene?

    What effect would greater or lesser CO2 have in that context?

    If there are no answers to the first two questions, then how can the third question be answered?

    Well, it can be answered by a look at the climate record of the Holocene, and so far the answer would be that CO2 has no discernible effect outside of normal variance within the Holocene.

    If that’s true, then the forces that shaped and maintain the Holocene are not substantially effected and certainly not overridden by CO2.

    The human effect on climate might be real, but it’s not substantial enough to be quantified, and not substantial enough to override the climate forces that maintain the Holocene.

  56. I’d like to add another explanation about the mechanism described by the remarkable sentence by Ferenc M. Miskolczi .

    For the moment, forget about CO2. Water vapour absorbs IR even better, that is why the IPCC always puts an emphasis on the water vapour “feedback”.

    So earth heats up due to the greenhouse effect caused by water vapour. Now this will cause more IR radiation from the surface upwards and more water vapour.

    This process continues for a while. Earth heats up, more radiation, more water vapour. Feedback.

    But as we have learned: The absorption spectrum is saturated pretty fast and further increase of the concentration of a GHG has only a logarithmic effect on the increase in greenhouse effect. (A doubling in GHG leads to a constant addition in reflected IR)

    So at a certain point, the feedback reaches the area of “diminishing returns”. For each new increase in temperature, more water vapour will rise into the atmosphere but on each feedback cycle the radiative effect of the added water vapour will decrease.

    At least that’s how i understand it. And i find that an absolutely marvellous piece of work.

  57. Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow. Strange that a scientist from NASA would so mislead. All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.

  58. “When you pile all of the layers of greenhouse gases in the atmosphere on top of one another, they form a sort of radiative blanket, heating the lower layers and cooling the upper layers.”

    Are we really adding any additional layers by adding CO2 to the atmosphere? If there is a saturation point of the infrared spectrum already in effect, the likely scenario is that the CO2 simply replaces other existing infrared absorbers and has no net effect at all. You cannot make a blanket more effective by squishing more insulation into the same few layers it already has. So, unless you can show how adding CO2 to the atmosphere in fact adds a layer of insulation between earth surface and outer space, the argument seems flawed. It is much more likely that adding 10 times the current CO2 content would actually equal the 1C increase in temperature than a simple doubling. I have no science to back this, just plain simple instinct on the fact that the earth is 4.5B years old, CO2 content has been 20 times as high as today while temperature at the time was comparable or even lower than today’s, and if there was a feedback mechanism for greenhouse effects, it would have already taken the earth to boiled ocean temperatures.

    The rest of the article is cool and I dig it. I just get sick and tired of people trying to explain that CO2 adds to the greenhouse effect 1C per doubling as though there is no possible point of there being a saturation point.

  59. “Paul (17:42:38) :
    Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow.”

    They don’t have much precipitation up there or do they? BTW doesn’t Mars has a CO2 rich atmosphere? So there’s surely a greenhouse effect on Mars.
    wikipedia about Mars: “The atmosphere on Mars consists of 95% carbon dioxide…”
    Here i guess the wikipedia is not wrong….

  60. Paul (17:42:38) :
    “All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.”

    and yet here you are

  61. peter_dtm (14:19:11) :

    Given the Coriolis force is enough to spin the water in a small sink (except on the equator) …

    The only serious study I have ever seen on this debunked it quite effectively. The researcher started with several ‘sinks’, ie large containers with central drains, and left them for over 30 minutes to ‘settle’. This was the only way to ensure there was no effect from initial movement (which does some debunking already). His results then showed that the number of clockwise and anti-clockwise flows for all tests were statistically equal. I am not certain where he was based, but I am pretty certain in the US.

    No idea where he got the research grant from. Probably claimed some future nebulous disaster, or something ;)

  62. “Paul (17:42:38) :

    Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow. Strange that a scientist from NASA would so mislead. All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.”

    Maybe someone with an ignorance problem should go read about the actual Martian atmosphere content. Seems to me that the main gas in the atmosphere on mars is… wait for it… if you like to remain ‘ignorance is bliss’ stop reading now… CO2. oh, man, I bet that hurts like hell. Oh well, better luck next time Warmonger.

  63. John A (14:22:37) :

    Roy is talking about the planet Mars.

    Unfortunately the notion that the lower atmosphere “warms” the surface is physically wrong – no more than double glazing “warms” the inside of a house

    Perhaps phrased incorrectly.
    Neither warms the earth or house, but it does change the rate at which the house or earth changes temperature.

    Steve

  64. DirkH (17:52): Mars does have a mostly CO2 atmosphere, but because of the very low surface pressure, it has little radiative influence and *** in the absence of a lot of dust ** the temperature of the surface of mars is very close to the radiative temperature (the mean temperature required to balance the absorbed solar radiation with outgoing IR). Dust is the main radiative forcing agent of the Mars atmosphere, but except during large dust storms, radiation from dust does not significantly heat the surface.

  65. “astonerii (17:51:38) :
    […]
    if there was a feedback mechanism for greenhouse effects, it would have already taken the earth to boiled ocean temperatures.”

    See my comment above. Think about an echo effect in music: When you have an echo with half the amplitude of the original and add it to the input, you get a limes of 2*input even though the echoing proceeds endlessly. This is not even dampened by a logarithmic function. With GHG’s we have logarithmic dampening of the feedback due to the saturation effects so it very quickly ebbs.

    IMHO the IPCC has intentionally overestimated this vastly to make sure there’s a scare story. But a (water vapour) feedback is in principle logical.

  66. Paul (17:42:38)

    “Just ask the Martians where the winds surely do blow.”

    I knew it!
    …and stop calling me surely.

  67. This is what makes water such an amazing substance. It cools the Earth’s surface when it evaporates, it warms the upper atmosphere when it re-condenses to form precipitation, it warms the lower atmosphere through the greenhouse effect, and it cools the upper atmosphere by emitting infrared radiation to outer space (also part of the greenhouse effect process). These heating and cooling processes are continuously interacting, with each limiting the influence of the other.

    Just some of teh properties. Other properties, that are in fact (or also) essential to life are:

    1. The extremely rare property (one of 5 substances, I think?) of the solid being less dense than the liquid. This allows ice to float, thus protecting water creatures (as all were at one time) from dying when air temps get too low, as well as breaking rocks into smaller rocks, and then soil, by getting into cracks and freezing.

    2. Its very good abilities as a solvent. As I recall, life as we know it could not exist without this property. I recall alcohol is also a very good solvent, but its toxicity to most known life prevent it from being useful (apart from for entertainment of some higher life forms).

    3. high surface tension

    4. Heat capacity (evident here)

    lots more I cannot recall….

    Think more dearly of that humble glass of water next time you drink one, without it, we’d not be here!

  68. Paul (17:42:38):

    “you might not want to use this site as your only education if this post is representative of the state of its science.”

    Aside from the fact that Dr Spencer has forgotten more climate science than you will ever learn, you should be aware that this “Best Science” site encourages all points of view, including yours.

    Compare that with the typical climate alarmist sites, which actively censor points of view that do not buy into their AGW scare.

    Any sites that have to censor opinions that are contrary to the Party line do not have truth on their side. So stick around here, if you think you have credible arguments. You can comment and discuss the issues; eventually the bogus arguments fall by the wayside, and what we’re left with is more or less the truth.

    Go ahead, give it a try. If you think Dr Spencer is misleading you, make your case. You could start by defining “weather”, so we’re all on the same page; weather isn’t just wind. When we talk about ‘weather’, there are usually clouds involved. Maybe you could tell us how to make clouds without H2O.

  69. “But eventually, the entire atmosphere would reach a constant temperature with height.”

    No way Watts. The planet still rotates, so there would still be wind. And with wind blowing across oceans (we have to assume zero evaporation for your hypothetical, but some liquid has to be part of the model) and mountain ranges you get wind patterns that will be random.

    The gas giants have no CO2 or H2O, mostly Nitrogen, and they have some ean storms with changing patterns.

  70. Air pressure, cloud cover and a variety of non ghg related factors seem to be the main heat retaining factors, and its forgotten that even if there were no ghg;s, heat would sit in the atmosphere for quite some time.

  71. I tell a lie. the Coriolis force has been proved to affect draining sinks – but only when left for a week!

    http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html

    Is it possible to detect the Earth’s rotation in a draining sink?

    Yes, but it is very difficult. Because the Coriolis force is so small, one must go to extraordinary lengths to detect it. But, it has been done. You cannot use an ordinary sink for it lacks the requisite circular symmetry: its oval shape and off-center drain render any results suspect. Those who have succeeded used a smooth pan of about one meter in diameter with a very small hole in the center. A stopper (which could be removed from below so as to not introduce any spurious motion) blocked the hole while the pan was being filled with water. The water was then allowed to sit undisturbed for perhaps a week to let all of the motion die out which was introduced during filling. Then, the stopper was removed (from below). Because the hole was very small, the pan drained slowly indeed. This was necessary, because it takes hours before the tiny Coriolis force could develop sufficient deviation in the draining water for it to produce a circular flow. With these procedures, it was found that the rotation was always cyclonic.

  72. Paul (17:42:38) :

    Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow. Strange that a scientist from NASA would so mislead. All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.”

    If you actually read the article instead of being in such a tearing hurry to post your cheap shot you would know that there is a valid reason for Martian winds without a greenhouse effect, the author was explicit.

  73. “What if there was no greenhouse effect? In other words, what if there were no infrared absorbers such as water vapor and carbon dioxide in the atmosphere?”
    =====================================
    Marie Curie quote:
    “I am among those who think that science has great beauty. A scientist in his laboratory is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale.”

    she probably didn’t believe in fairy tales, or “what if’s”

  74. Paul (17:42:38) :

    Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow. Strange that a scientist from NASA would so mislead. All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.

    Interesting. I, for one, find WUWT to provide a great deal of valid science and science discussion. Perhaps that is only because I actually knew something before I started visiting the site.

    Others have pointed out your error in referring to Mars as an example of your extensive knowledge. Hence, I shall not repeat that revelation. I will ask though; do you know of a planet, which has an atmosphere, that does not contain any greenhouse gases?

  75. You cannot have a watery planet without “greenhouse gasses”; those oceans evaporate and form clouds, etc.

    Dr. Spencer is having some fun with a “spherical planet”

  76. Lindzen and Choi publish in 2009 that asignificant proportion of radiation isn’t affected by ghg’s and that radiation is emitted and re-emitted over and over – in other words, that ghg’s don’t trap heat that leads to a heat accumulation. Radiative atmospherics studies as though its emitting from a black body with a two dimensional surface, almost forgeting that most radiation goes straight through ghg’s, specifically c02 – the difference between gases and two dimensional surfaces is that gases have more dimensions so lose/emit heat much more effectively: So the speculation is that if there were no ghg’s, the surface temperature would be the same, but weather patterns would be different, and the upper troposphere would be slightly cooler.

  77. pft,
    You are correct that the upper layer radiation out (including from gases at the upper level plus direct radiation from the ground) would equal the absorbed input at equilibrium. The only time it is lower is while the ground temperature (or energy storage in the oceans) is increasing. Since it stopped increasing the last few years, and ocean storage seems low to slightly negative, the upper layer radiation has to approximately match the input. The only way that can be reduced is for the input level (Solar energy) to be lower also.

    The comments on black body radiation for gases is not valid. The fairly narrow spectral lines due to molecular energy states such as vibration are the only way molecular gases absorb or emit at the low temperatures encountered in the atmosphere. Oxygen and Nitrogen have a few weak lines of interest, so would cause some greenhouse effect. However, the gases would not absorb a significant amount of the ground radiation, so direct radiation to space would cool the ground to a lower temperature.The net lapse rate with just these gases would depend on the result of the combination of diffusion and convection under the lower re-radiation effects.

  78. Paul (18:01:41) :

    Ok Paul. You say “Mars does have a mostly CO2 atmosphere, but because of the very low surface pressure, it has little radiative influence Mars does have a mostly CO2 atmosphere, but because of the very low surface pressure, it has little radiative influence…”.

    Since Mars atmospheric pressure is ~1/100 of Earth and since Earth only has 380PPM of CO2 compared to 90% on Mars, this make Earth CO2 partial pressure tiny compared to on Mars.

    I guess you are saying CO2 has basically no radiative influence at all on Earth. It that right?

  79. Roy W. Spencer, Ph. D.

    I think this post was a bad idea for your ‘street cred’ Roy.

    The scenarios you suggest are impossible, even in a ‘thought experiment’. For example:

    There is no way that a planet with so much water would ever generate an atmosphere without water vapour (WV), as even ice sublimates. Though, if there were no ‘radiative gasses’ in the atmosphere, the atmosphere would neither radiate, or absorb, radiation more than its natural LTE (local thermodynamic equilibrium) temperature equivalent (again, a most unlikely scenario, given the expected gasses from any ‘planetary surface warming’ of a rotating planet [I exclude satellites, or ‘moons’, as they tend to undergo gravitational loss of atmosphere to their ‘parent’ body]).

    Your statement “there would be no weather on Earth without the greenhouse effect.” seems so wrong. Without the temperature ‘hot spot normalisation’ ameliorated by radiative influence, the ‘normalisation’ of temperature ‘hot spots’ is left solely to the ‘thermals’ that cause ‘weather’. So! In a ‘radiative gas-less Earth’, only ‘surface albedo’ rules with its associated level of increased thermal convection! I can’t reconcile this within your scenario Roy. Especially when LTE is disturbed by lack of radiative influence, (this is almost unheard of) as it’s always there where an atmosphere exists.

    This is half of what I want to say, but it’s both late for me and should be enough for an initial query.

    Best regards, suricat.

  80. All:

    What we all generally consider “weather” is driven by thermodynamical instabilities. These are generally driven by differential heating or cooling. Some of this (e.g. upper atmosphere cooling) is certainly directly related to greenhouse gases (and radiation to space from non-gases such as cloud), but many other processes (e.g. heating at the equator cooling at the poles) also produce instabilities. Mars certainly has weather and has a very feeble greenhouse.

    http://www.ozgate.com/infobytes/mars_weather.htm

  81. Well, what do you know, my grade school science book was right, we do live in a mostly closed loop world. It’s amazing how many lay people believe in AGW, but have no idea that the earth can and does actually have mechanisms to cool as well as warm this place we call home.

    Needless to say most of the higher theories that get discussed here just goes right over my head (not a climate scientist), but I’ve noticed that generally when people have AGW discussions, I rarely see much common sense applied to anything. (The reasoning that we are running out of water just dumbfounds me…).

    I would assume that the good old-fashioned, well tested physics rules would still apply. I do realize that external inputs will cause all sorts of chaotic I/O, but still…

  82. RE: Alex Harvey (16:39:03) :

    Alex, all matter emits blackbody radiation, although you are right that gases are not blackbodies.

    Some poster here seem to confuse a substances Infared emmision spectrum with its absorption spectrum, they are two separate and different things.

    Oxygen is not at all a weak greenhouse gas as it does not absorb infared radiation, as the bonds in the oxygen atom are of too high an energy to be excited by the low energy of infared.

    Infared radiation is only strong enough to cause bending of triatomic and larger molecules, which is why carbon dioxide, water and methane are important. No diatomic molecules are considered greenhouse gases for this reason.

  83. “suricat (18:53:50) :
    […]
    The scenarios you suggest are impossible, even in a ‘thought experiment’. ”

    Hmmm… that’s a wild statement.

    “There is no way that a planet with so much water would ever generate an atmosphere without water vapour (WV), as even ice sublimates.”

    In reality, you would be right. But we are in a thought experiment.

    ” Though, if there were no ‘radiative gasses’ in the atmosphere, the atmosphere would neither radiate, or absorb, radiation more than its natural LTE (local thermodynamic equilibrium) temperature equivalent (again, a most unlikely scenario,”

    In reality, it would not be unlikely, it would be right out. But we are in a thought experiment.

    ” given the expected gasses from any ‘planetary surface warming’ of a rotating planet [I exclude satellites, or ‘moons’, as they tend to undergo gravitational loss of atmosphere to their ‘parent’ body]).”

    Well, let’s just say as much radiation goes out as goes in.

    “Your statement “there would be no weather on Earth without the greenhouse effect.” seems so wrong.”

    Yes.

    ” Without the temperature ‘hot spot normalisation’ ameliorated by radiative influence, the ‘normalisation’ of temperature ‘hot spots’ is left solely to the ‘thermals’ that cause ‘weather’. So! In a ‘radiative gas-less Earth’, only ’surface albedo’ rules with its associated level of increased thermal convection! I can’t reconcile this within your scenario Roy. Especially when LTE is disturbed by lack of radiative influence, (this is almost unheard of) as it’s always there where an atmosphere exists.”

    Surface albedo affects upward reflexion. The thought experiment says that there are no greenhouse gasses, that means no gasses that stop part of the radiated spectrum of frequencies from leaving the planet. Thus, the reflected or emitted radiation from the surface cannot warm up parts of the atmosphere, thus there would be no radiation-caused temperature differences, so no convection.

    My take.

  84. No weather without so-called greenhouse gases? Jupiter is mostly hydrogen and helium and yet the Great Red Spot has persisted for centuries.

    And how is it possible that the internal temperature of Jupiter with no CO2 is greater than the surface of Venus? I’ve asked this question to a couple of professors at my local university and never gotten a reply.

  85. Sounds a bit like Snowball Earth, which required millions of years of CO2 spewing vulcanism to thaw.

  86. DirkH (18:01:56) :

    I think you and I see eye to eye on this. I just think that the Earth has already reached its limit on greenhouse forcing for the amount of energy that is put into the system from both the solar and the internal molten core energy that is available.

  87. wayne (18:51:41) :

    Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth, they are not nearly as effective as a greenhouse gas because the total atmospheric pressure is much lower. The higher density of gas in Earth’s atmosphere works to spread the absorption of IR by CO2 over more of the wavelength scale. Consider building a fence out of 2×4’s spaced every 8″ (rough cut). 50% of the light hitting the fence from the side will make it through the fence. Alternatively, consider using 1 x 4 spaced every 4″. Same amount of wood, but no light would get through. This is how it works for CO2 (and H2O) on Mars and on Earth. The same amount of CO2 (or H2O) is more efficient on earth because of all the N2 and O2 colliders (this is called pressure broadening. There is a reasonable wiki page http://en.wikipedia.org/wiki/Spectral_line but it could use to be updated to discuss the role of broadening on climate.

  88. @john J. Jupiter emits more energy than it receives in solar radiation. One therefore is drawn to the conclusion that there is something going on deep in the core of the planet.

  89. Alex Harvey (16:01:44) :

    You wrote: “I think you will find that for convection to be maintained in the long term you need not just heating from below but cooling from above. It is the cooling from above that is lacking in an IR transparent atmosphere.”

    True enough. In a planet with a transparent atmosphere the “weather” would be driven by heat transport from the equator to the poles, as already mentioned by other posters, giving Mars as an example. Dr. Spencer mentions it as well, although he seems to minimize it.

  90. In a sense, isn’t every gas a greenhouse gas, able to absorb and retain part of the energy that it receives in the form of heat and radiate the rest?

  91. All right…I’ve got some fodder for weather lectures coming up in a few weeks. Thanks!

    I wonder how many parent complaints I’ll get this time?!

  92. Paul (18:58:16) :

    Mars certainly has weather and has a very feeble greenhouse.

    ———–

    The weather on Mars is by direct observation. The “feeble” greenhouse effect on Mars is interesting as there is about 30 times as much mass of CO2 over each square meter of Martian surface as there is on Earth.

    Now please tell us why we should be worried about a little more CO2 in Earth’s atmosphere especially as we have more than enough water vapor.

  93. Since the moon is about as far away from the sun as earth, and it has no atmosphere, that might be a good place to look for a comparison.

    “…the temperature of the Moon can dip down to -153°C during the night. Oh, but you’re going to want to keep some cool weather clothes too, since the temperature of the Moon in the day can rise to 107°C.”
    http://www.universetoday.com/guide-to-space/the-moon/temperature-of-the-moon/

    So, we see that it is NOT the “greenhouse” effect that “warms” the earth, but that the atmosphere has a cooling effect on daylit surfaces, while the surfaces not lit are kept from losing their heat too fast.

  94. Dr. Spencer;

    It’s not a doctoral dissertation; it’s a fine and elemental primer, elegant in its simplicity. I’ve seen the objections in some comments, but I think they miss the point.


  95. Jim Steele (15:22:08) :

    Roy could you answer a few questions,my physics needs help.

    1. What is the “turn-over rate”, the rate of absorption of infra-red vs emission for a given molecule of H20 or CO2? Would it be more correct to think that added GH gasses add more layers that absorb and emit thus slowing down the rate of cooling vs “trapping heat”?

    2. How does the cooling rate via absorbing and emitting heat waves when there is no convection, compare to a rate of cooling when there is convection? Does extra CO2 resulting in heating by absorbing heat waves, cause increased convection and that increased convection allows heat to more quickly escape into the stratosphere and to some degree offset heating by absorption? Are there papers that researched this?

    3. When a CO2 molecule that has absorbed infra-red, then collides with say an O2 molecule, transferring some kinetic energy, will the CO2 still emit the same wavelength it absorbed, or a different wavelength

    The ‘turnover rate’ for a ghg is going to be equal when the continuum temperature and the gas temperature are the same. If the gas is hotter, you’ll get emission lines instead of absorption lines.

    probably not. the layers are an approximation anyway. If you have a parcel of gas with a higher concentration, you will have greater absorption and greater emission for its temperature. Note the absorption isn’t really dependent on the temperature while the emissions are.

    a decrease in radiative heat transfer results in an increase in temperature differential and an increase in temperature differential is going to increase the rates of heat transfer via convection and conduction. The decrease in radiative transfer from more ghgs does occur but since increasing ghg concentrations will increase emissivity it’s not purely blocking. both effects must be taken into account. Also, co2 blocking really only changes things in clear sky conditions because clouds block much more.

    a co2 or ghg molecule will absorb a photon (or can absorb a photon) and it can emit the same wavelength or it can emit a different wavelength photon or photons or it can convey that energy to another molecule, such as O2. For emissions, the same thing happens. One winds up with LTE, local thermodynamic equilibrium where all molecules in the gas sample in a small area have the same temperature. That temperature fills energy states according to the boltzman distribution which is what establishes the blackbody distribution curve for a particular frequency.

  96. So, all the heat of the atmosphere is radiated away by H2O and CO2, and none of it by molecular N or O?
    I build my house at 200 metres elevation and I never have to wear a coat even at night at 60 degrees latitude.
    That CO2 is one potent cooler!

  97. Paul (19:34:32) :

    wayne (18:51:41) :

    Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth, they are not nearly as effective as a greenhouse gas because the total atmospheric pressure is much lower.

    Yes, and Venus has 90 atmospheres which is where CO2 driving
    temperature came from. That, along with the Snowball Earth
    hypothesis has been driving this train wreck.

  98. If the rotation of the Earth does not affect the atmosphere, why are there trade winds? And if wind is not a transfer/transmisson of energy, then what is it? Mixing, chaos, ebb and flow — got to have some effect.

    I mean, I like black boxes and over-simplified models as much as anyone. But if the horse is missing a leg, it can’t run.

    E pur si muove.

  99. At the risk of making a fool of myself again, I need to explain what I meant when I asked about the effects of oceans. Imagine that there are oceans on this planet, but that they have a layer of impermeable saran wrap on top that prevents evaporation. The differential heating of the oceans and the heat-retentive properties of water would result in air circulation: one does not need to consider the evaporative tendencies of water in this model, in the spirit of Dr. Spencer’ thought experiment. I guess I cannot quite imagine the value of a theoretical model which is so unlike the earth, given the vast amounts of H2O on our planet that play both primary and differing roles (according to state and location) in determining climate. Even without water, does Dr. Spencer’s model assume that the entire substrate of the earth is homogenous, with no hills or elevations or differing properties for absorbing and reflecting heat? As Robert of Ottawa points out above, Dr. Spencer is having fun with a spherical planet.

  100. One more time. “Friends don’t let friends do Wikipedia.”
    A Wikipedia quote causes the reader who is interested in the subject matter any number of hours of additional research. Just say no to Wikipedia references.

  101. Five sources of confusion for me. I’ll refer only to the lead article by Roy, not including posts.

    1. There is mixed use of statics and dynamics. e.g. should not “an initially cold Earth would stop warming when the rate at which solar energy is absorbed equals the rate at which infrared energy is lost”. Should this not read about “total energy” rather than “rate”?

    2. What concept of temperature is used? Temperature is physically first related to motion at the atomic scale, so as the atoms/molecules became more dilute, a thermometer placed in them would record a different result.

    3. Following from 2, might the thought experiment please be continued to an altitude of say 700 km above Earth, showing how lapse rates and re-rediation etc. produce the standard curve to the top of the thermosphere?

    4. “infrared absorbers are also infrared emitters” – IIRC, there is an energy change in this process. i.e emissions are less energetic and the surplus energy shows up as heat. Is this significant? The magnitude varies via quantum physics for different substances.

    5. “This is because rising warm air parcels cool as they expand at the lower air pressures aloft, and the air that sinks in response to all of that rising air must warm at the same rate by compression”. Is this a zero sum game, or do you include, for example, frictional effects?

  102. ginckgo (21:08:23) :

    You obviously understand nothing about epistimology, cosmology, theology or science. When you’ve finally evolved a brain, come back and we’ll discuss the matter of the age of the universe and the nature of reality. In the mean time, however, see if you can prove that the universe, in it’s entirety, was not created six and a half minutes before you read this. Ignore the time stamp. The universe was created that way. Go ponder.

  103. John J. (19:24:10) :

    No weather without so-called greenhouse gases? Jupiter is mostly hydrogen and helium and yet the Great Red Spot has persisted for centuries.

    And how is it possible that the internal temperature of Jupiter with no CO2 is greater than the surface of Venus? I’ve asked this question to a couple of professors at my local university and never gotten a reply.

    ShrNfr (19:42:03) :

    @john J. Jupiter emits more energy than it receives in solar radiation. One therefore is drawn to the conclusion that there is something going on deep in the core of the planet.

    Actually, I heard long ago in college it is simple compression. There is great gravity, it would like to compress all those gas molecules down, and as they are compressed they give off their heat. IIRC Jupiter emits about 1.6 times the energy it gets from the Sun.

    And the Great Red Spot is shrinking. There is also now the Little Red Spot, which may grow to be the larger one. Click on the link, read about some Climate Change on Jupiter!

  104. Hmmph. Frost in Florida. The Weather Channel keeps talking about some blizzard in New England. No snow here on the Connecticut Western Shore. Climate: it’s all local.

  105. “there would be no weather on Earth without the greenhouse effect.”

    OM[snip]G is that a stupid statement. I really wish Spencer would stop trying to help.

    Without the greenhouse effect sunlight would still warm the ground. The atmosphere in contact with this ground would be warmed. The equators would still be warmer than the poles, leading to a difference in air pressure. Heated water would still evaporate over the seas lowering air pressure there. That moisture would still condense into rain.

    All the effects would cause wind, rain, clouds, snow, and all the other things we call weather.

  106. An interesting article to read and it works as a thought experiment. I had to keep kicking myself to get rid of the instinctive temperature gradient I expect between the hot earth surface and the cold of space.

    A bit of a leap from a thought experiment to putting out a figure to it though:

    “And one very real possibility is that the 1 deg. C direct warming effect of doubling our atmospheric CO2 concentration by late in this century will be mitigated by the cooling effects of weather to a value closer to 0.5 deg. C or so (about 1 deg. F.)”

    Is there any math or whatever leading to the 0.5 C mitigation? I’d hope it’s not a figure plucked out of the air*.

    Since 1900 the surface temperature has increased by – give or take a bit and an argument – just under 1 C. If a temperature increase of this order causes increased weather creating negative feedback would it show up in weather records of the twentieth century – perhaps a piece of research would show if there’s observable evidence?

    * sorry for the weak pun

  107. bob (14:18:37) :
    “Why would this occur? Infrared absorbers like water vapor and carbon dioxide provide an additional heating mechanism for the atmosphere. But at least as important is the fact that, since infrared absorbers are also infrared emitters, the presence of greenhouse gases allow the atmosphere — not just the surface — to cool to outer space.”

    You don’t need the greenhouse gases to cool the atmosphere, oxygen and nitrogen are infared emitters according to the Planck black body radiation effect.

    No they aren’t, they can only emit via the same spectral lines as their absorption spectrum.

    Oxygen is not at all a weak greenhouse gas as it does not absorb infared radiation, as the bonds in the oxygen atom are of too high an energy to be excited by the low energy of infared.

    Again not true as the O2 Raman spectra show us, it’s not the energy that’s the factor but the absence of a dipole in a homonuclear diatomic!

  108. Inks,

    Kick yourself again. The earth isn’t some uniform flat plain. Different surfaces absorb light with differing efficiencies. Light sand absorbing less than dark rock. Water absorbs differently than land. Sides of mountains facing sunward more than those facing away. Equator more than poles. The earth rotates. Many other factors.

    “but the atmosphere has no way of cooling”
    This is another false claim by Spencer.

    Substances can radiate frequencies for which they are transparent. Glass is transparent to red light yet if you heat it enough it will radiate light at that frequency. So the atmosphere without GHG will continue radiate heat to space.

    There is absolutely no way that if you eliminated the ability of all gases on earth to act as greenhouse gases that it would eliminate weather. In fact, GHG contribute next to nothing with regards to causing wind, rain, snow, etc.

    If all gases were transparent to infrared we could just move the earth closer to the sun to achieve a planet with liquid seas, and plenty of weather.

    I think I understand now why Spencer is a creationist. He’s not very good at understanding models and processes.

    I’m a AWG skeptic. This article is just bad science.

  109. All gases absorb heat. It is a rule. Like all liberals think they are smart. But only one of these is true.

  110. Brian Macker (23:05:06) :
    I’m a AWG skeptic. This article is just bad science.

    I agree with you. False scenarios profit no one.

  111. Nice Thought Experiment BUT:
    fails to deal with the oceans effectively: lets expand his idea we have a low volatile oil on the ocean preventing evaporation, the ocean 70 % of the planets surface would be effectively a black body suface, and would heat to what ? 40 – 50 deg c during the cloudless day, but only to the depth of a metre or so, at night that heat would be released at the same rate as it was absorbed. my guess is that at night the temperatures would fall to – 40 or so deg effectively freezing the entire ocean which would then no longer be a black body.
    Spend a night in the sahara desert you begin to get the idea.

    A nice way of creating a usefull debate!! I will have to think about this some more

  112. Thank you Dr. Spencer for the some deep insight. I for one can follow your gist and ignore factors obviously occurring in the real world and alter my view in a hypothetical sense to simplify a system down to the core points being discussed. Once again thanks.

    Here’s a supplement paper I never had stumbled upon concerning excess radiation absorbance in clear atmosphere and clouds and handled differently in most models of that time. Have no idea if these factors have changed in current day models.
    http://people.aero.und.edu/~dong/Valero_JGR_2000.pdf
    Interesting. Don’t know if even more massive simultaneous tests have occurred recently. This answered the question I asked you near the top of these comments.

  113. From Dr. Spencer’s post (emphasis added):

    So, let’s imagine an extremely cold Earth and atmosphere, without any water vapor, carbon dioxide, methane or any other greenhouse gases – and with no surface water to evaporate and create atmospheric water vapor, either.

    And I am reading how many posts here saying Spencer must be wrong (or perhaps someone else is) because water vapor would…?

    What am I missing?

    To me, he seems to basically be describing Venus, which although it has CO2 in abundance it does not really function as a GHG in that planet’s atmosphere as CO2 does in ours, you could replace it with nitrogen for about the same effect.

    Perhaps the picture above, showing oceans thus surface water, is throwing people off?

  114. D. King (21:19:05) :

    ” Paul (19:34:32) :

    wayne (18:51:41) :

    Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth”

    I get about 30 x as many over any square meter on Mars. Would you care to justify your number?

  115. Mike Borgelt (23:36:40):

    Exactly. Paul was saying because the low pressure on Mars, I’m assuming partial pressure, that CO2 on Mars has no effect on temperature or weather at 90% component. I’m questioning why a much lower partial pressure for CO2 on Earth would have any effect either if his statement is correct about Mars. Curiosity, isn’t it.

  116. I have not read all the posts so it is possible someone else commented in a similar vein.
    In the article it is mentioned that there will be thermal conduction from the heated surface to the air. If you consult text books on heat transfer (eg Perry’s Chemical Engineering Handbook) this is actually called natural convection where the heat transfer is proportional to a heat transfer coefficient determined via the Nusselt number and the temperature difference. Natural convection is the cause of thermals and these can manifest as Willi Willis or Tornadoes. If there are winds the heat transfer is called forced convection (involving the Prandtl and Reynolds numbers) which results in much higher heat transfer and can be higher than the heat transfer by radiation. Note there are winds on Mars.
    Someone else mentioned that oxygen and nitrogen do absorb and emit some radiation in the infra-red wavelengths but their main absorption/emission is in the UV and visible light range. The sky has a blue colour looking up from the surface and I understand it also looks blue from space.
    I think a much more interesting analysis would be if there is no CO2 and the atmosphere is composed of oxygen, nitrogen and water vapour. From the many articles I have read, discounting IPCC information, it appears the climate would be very little different.

  117. Paul (19:34:32) :

    “Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth, they are not nearly as effective as a greenhouse gas because the total atmospheric pressure is much lower. ”

    I believe you are flat out wrong about this:
    Assuming a Mars surface partial pressure of CO2 of 6hPa on average (this is at the low end of the variable surface pressure on Mars and 95% of the atmosphere is CO2) and Earth at 1013hPA of which the partial pressure of CO2 is 0.58hPa (390ppmv and CO2 has 1.51 times the molecular mass as oxy-nitrogen) this would make the number of molecules of CO2 above each square meter of mars TEN times that over each square meter on Earth, however pressure is WEIGHT and Mars has only 0.38 the surface gravity of Earth so you need 2.63 times as much mass to get the pressure so we get at least 26.3 times as many molecules of CO2 over each square meter of Mars as on Earth. And that was the low end of the martian surface pressure so around 30 x seems reasonable.

    And yet the greenhouse effect on mars is “feeble”?

    As for this:

    “The higher density of gas in Earth’s atmosphere works to spread the absorption of IR by CO2 over more of the wavelength scale. The same amount of CO2 (or H2O) is more efficient on earth because of all the N2 and O2 colliders (this is called pressure broadening. There is a reasonable wiki page http://en.wikipedia.org/wiki/Spectral_line but it could use to be updated to discuss the role of broadening on climate.”

    OK great, but isn’t one of Gavin’s arguments at RC that extra CO2 in Earths atmosphere causes extra pressure broadening? Just how much extra pressure broadening do you get by doubling CO2 from a partial pressure of 0.44hPa to 0.88 hPa(corresponding to CO2ppmv going from 290 to 580ppmv) out of a total pressure of over 1000hPa?

    I’m really pleased you’ve cleared that up that it is the TOTAL pressure that causes pressure broadening of absorption spectra minor constituent gases of the atmosphere like CO2 and not the partial pressure of CO2.

    Denis Wingo might like to comment on this.

  118. This is a very good article. I wonder anyone has ever attempted to model or estimate the state of the atmosphere during the ancient period, very similar to Dr. Spenser’s thought experiment, when geological evidence indicates that the earth may have frozen over all the way to the equator. Is it possible that the tropopause descended all the way to the surface in this event?

    As it has become fashionable of late to assume carbon dioxide to be the cause of all things related to the greenhouse effect, I now wonder if volcanic CO2 was really the most likely reason for the end of the ice-cube earth period.

  119. Mike Borgelt (23:36:40):

    Also you asked about the numbers:

    The 1/100th atmospheric pressure came from Google on Mars atmosphere stating 10 mbar. Earth is about 1000mbar. Didn’t write down the source.

    The 90% CO2 on Mars is commonly cited, I just followed suit.

    The 380PPM of CO2 on Earth was rough average of what I tend to see on cite and current papers and articles.

    Exactness here is not necessary to press the question.

  120. I would like to point out here that thermodynamics is a self contained description of nature and works wonderfully well until it hits dimensions of hbar or coherent effects as in superconductivity, superfluidiy etc.

    Thermodynamics treats radiation well, and this at a time where nothing was known of infrared absorption bands and dipole molecules and such, all in the realm of quantum mechanics and hbar sizes.

    To say that a body of matter will only radiate heat away only if the molecules consisting it have infrared absorption lines is making a total confusion between classical thermodynamics and quantum mechanics, that displays the confusion in the heads of climatologists and I suspect leads to double countings, like that nice oven by Peden, http://www.vermonttiger.com/content/2008/07/nasa-free-energ.html .

    I want to remind everybody that the ideal gas is really tiny billiard balls, not heat factories of infrared, and the heat of the ideal gas is the motion of these within it.
    The radiation is given by Wien’s law (~1890 before quantum mechanics) http://en.wikipedia.org/wiki/File:Wiens_law.svg and the black body radiation are all classical thermodynamics.

    I hope this settles that all things that have temperature radiate.

    It is not that there does not exist a statistical quantum mechanical description of what really happens when molecules and photons shake hands. Tom Vogt once gave me a dense precis of what happens and how finally infrared photons absorbed and being held tight by a molecule end up as kinetic motion and heat of the gas . It is not simple, it is not just dipole, it is complicated. BUT all matter radiates according to the laws of classical thermodynamics.

  121. Mike Borgelt (00:05:29) : “The same amount of CO2 (or H2O) is more efficient on earth because of all the N2 and O2 colliders (this is called pressure broadening. …”

    What I don’t get is at the point after IR absorption, a CO2 molecule will ‘braoden’ to ANY other molecule, O2, N2 and CO2 molecules also. So I see this as a null statement. Am I wrong?

  122. kuhnkat (16:08:26) :

    kuhnkat, thank you for leading me here;

    http://climatechange1.wordpress.com/

    I have bookmarked it, and will read it again and again. Never
    before have I found a more interesting article about what drives the climate.

    Finally someone that understand that the most important thing is to understand whether the wheels drive the pistons, or whether the pistons drive the wheels.

    The AGW’ers thinks the wheels drives the pistons.

  123. Wayne: see my post at 00:05:29.
    I think a factor of 30 is worth resolving.

    D. King (00:48:54) I thought we were talking about Mars not Venus and it is rather surprising that the Martian atmosphere has around 30 times as many molecules of CO2 above each square meter of surface as has Earth.

  124. anna v (00:14:54) :

    You sound more versed in thermodynamics than myself. Honestly. Please help clarify my view if you know.

    Real but somewhat a thought experiment. Take a single molecule in empty space at rest, no momentum. A photon at correct frequency is absorbed by that molecule, knocking an electron a shell higher. I assume that until it drops back the molecule now has momentum. When the electron drops back down, here my big question, seems it must be ejected exactly in the same direction that it was traveling before it was absorbed cancelling the momentum. Is that a correct view? The answer eludes me.

    According to your answer, I might have a following question.

  125. Here is a link to an article at RealClimate.org that shows that total CO2 absorption is saturated on earth over the spectrum range of about 13.5 to 17 microns at 1xCO2 (280 ppm, I believe) and would be saturated over the range of 13 to 17.5 microns at 4xCO2 (1120ppm). This is why I prefer to think of CO2 as a scarf rather than a blanket.

    I believe that total CO2 overhead is equivalent to a layer of pure CO2 about ten feet thick at sea-level.

    http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument-part-ii/

    Here is a naked link to an image that shows the full picture of radiation through the atmosphere.

  126. Nick Stokes:
    ” the adiabatic lapse rate of -9.8 K/km? Surely this mechanism moves heat more effectively than conduction?”

    By definition, no. Adiabatic implies without exchange of heat.

  127. Mike Borgelt (01:01:05) :
    For one Mike, I’m agreeing with your flow. The 30x is your computation and number. Are you asking for me to check your math/logic? Maybe you can answer D. King.

    D. King (00:48:54) :
    Yes, I was speaking of Mars. Nothing to do with Venus.

    My question was on statement by Paul way back. No one has posted a yes or no yet. Refollow from Paul down. Keep logic simple. It’s a simple question.

  128. I have heard personally from Prof. Taro Matsuno (one of the best theoretical meteorologists in Japan) that there has been no simulation in which CO2 concentration is set to be zero. He said that such simulation had to be carried out although researchers had interests only in cases with increased CO2.

  129. >Roy is talking about the planet Mars.

    But Mars has weather. It has both local scale (e.g. dust devils) and synoptic scale (planet wide dust storms) weather.

    I really wonder where the energy comes from for those dust storms without the storage capacity of water vapor, but they do happen.

    ++PLS

  130. Mike Borgelt (01:01:05) :
    Well, the thread title is:
    Spencer: Earth sans greenhouse effect – what would it be like?
    So we’re off thread, but I was trying to point to Venus as the
    origin of the AGW runaway greenhouse effect scare. They beat
    this drum and always leave out pressure, as part of the equation.
    Mars is another good example. The pressure on Mars is 1/100-150th
    that of Earth. So I don’t think Mars is in any danger of thermal
    runaway or reaching a “Tipping Point”.

  131. I haven’t read all the comments, so apologies if this question has been asked (and answered):
    All atmospheric text books teach about the vertical temperature gradient – the adiabatic lapse rate – which is a result basically of reducing pressure with height. There is nothing I have read which implicates a greenhouse mechanism driving this. Some planetary atmospheres may not even contain green house gases but still have the same temperature profile.

    The problem with Dr Spencer’s article is that he simply makes an assertion that greenhouse gases are responsible for the temperature gradient, without giving the physics to explain it. So, I find myself in the position of not being able to accept a statement on trust, going against everything I believe, without a credible explanation.

  132. wayne (01:08:21) :

    anna v (00:14:54) :

    You sound more versed in thermodynamics than myself. Honestly. Please help clarify my view if you know.

    Real but somewhat a thought experiment. Take a single molecule in empty space at rest, no momentum. A photon at correct frequency is absorbed by that molecule, knocking an electron a shell higher.

    Right here we are not talking of thermodynamics, the system you are describing is a quantum mechanical system, where there are potential wells and energy levels. These are nonexistent in thermodynamics.

    So lets see the quantum mechanical problem.

    I assume that until it drops back the molecule now has momentum.

    Energy and momentum have to be conserved: the molecule will acquire some momentum and the photon will kick the molecule up to a higher energy level. A pregnant molecule.
    When the electron drops back down, here my big question, seems it must be ejected exactly in the same direction that it was traveling before it was absorbed cancelling the momentum.
    No, this is not correct. The decay will have a characteristic time of electromagnetic decays, and the direction will be probabilistic, in a type of antenna like pattern, depending on which state has absorbed the photon. Most often two or three or more, much softer photons come out depending on the energy levels available for the molecule as a whole, contributing to thermalization by the kick back of conserving momentum for each decay.

    Again this is the quantum mechanical picture.

    To this statistical quantum mechanics has to be applied, behavior of i.e. large numbers, and then one can start comparing the view derived this way to the thermodynamic view.

  133. Is this kind of thought of experiment not a perfect use for a GCM? I’d be surprised that this kind of experiment has not been run in a model already. As more complicated processes such as moisture have been omitted it could even be spun up to equilibrium in a fairly basic model giving a good insight to what kind of weather we would have in this situation and also look at the alternatives such as including water vapour but being IR transparent and other variations. Breaking down the weather system into more basic components and running experiments in models, which could never be seen in real life, does seem a good way to provide insight into the importance of the individual processes and interesting thought experiments at the same time. Obviously the interaction of the individual processes produces many other complexities in reality.

  134. Moderator please bear a long one.

    anna v (02:34:06) :

    OK! That’s the key. I know if there are many emission lines, the momentum will be split between the photon(s) of lower wavelength and some residual momentum may reside in the molecule. But conservation of momentum must always be preserved. One place or the other(s).

    Please follow. Think only of the original parcel of momentum and keep track of it.

    I have read literally a hundreds of papers concerning this broad subject. But I kept having a reoccurring catch in all of the pure logic used. Let’s take this as Einstein would, one infinitesimal thing at a time.

    Take a special IR photon, properties set by me, carrying energy thus momentum, leaving a spot on the equator and heading directly zenith to keep this pure.

    The momentum carried by this photon, one way or the other must be preserved. The photon may be absorbed by a molecule in proximity if wavelength allows, that molecule hits other molecules so momentum of the molecule changes and is distributed, this can occur many times. But mother nature by her physics is so frugal with her accounting of her energy and her momentum that she will not miss the tiniest portion of her precious energy and momentum.

    That momentum from that zenith heading photon may be divided and scattered over many molecules or subdivided into components of other photons in various directions but the SUM of the net effects of that lonely photon’s momentum will end up in portions of two states. One component’s portion (can be zero) escapes into space carried by the original OR divided between some other photon(s) in some direction(s) possibly at different wavelength(s). The other possible state is to cause an infinitesimal but real and exact expansion of Earth’s atmosphere by increased momentum of a molecule(s). This will initially manifest as an increased pressure but eventually will be expansion. The sum of the momentum of these two states (speaking only of the original photons momentum), seems to me MUST be equal to the original momentum of that lone photon to meet conservation laws.

    If the above is correct, from here on only speaking of that original parcel of momentum. If the photon didn’t encounter any interaction on its way up, it merely escapes into space. End of story, momentum preserved. However, if it had any interaction and the portion of momentum escaping into space (can be zero) is less than the original, the only other possible state is an expansion of the atmosphere by the remaining portion of the original momentum.

    If I’m still right to this point, you can now view that photon’s momentum generically as radiative pressure. And any layer of the atmosphere as a near spherical membrane that this momentum must cross, one way or the other to satisfy conservation of the momentum.

    The gist of the above is to say that energy, thus momentum, of outgoing photons cannot be absorbed and re-radiated IN A NADIR direction without also expanding the atmosphere, thus, by thermodynamic laws cooling the atmosphere in an equal amount of the heat trapped.

    I’m stuck on this point. Reoccurs in my mind every paper I read and until I can get a understandable answer, I don’t feel an added portion of CO2 that traps additional heat can help but to expand the atmosphere thus cancelling any effect. Some papers support this view but from other directions. I tried to make mine simple.

    Any help, corrections or comments?

  135. RE: Vincent: 02:17:21) :

    I believe the only thing that can force the Earth’s atmosphere to follow the adiabatic lapse rate is an active convection process. Note that this lapse rate stops at the tropopause.

    Convection can only occur if the upper air is cooler than the wet-air lapse rate. If the atmosphere were perfectly transparent — no clouds or dust, it could not cool by thermal radiation. In that case, all such radiation must come from the earth’s opaque surface. The condition that Dr. Spencer describes is perhaps a ‘perfect inversion’ condition. The stratosphere would extend down to the surface.

    The only mechanism that I can imagine that might force convection in that case would be the movement of modified arctic air toward the tropics, but it seems to me that this process would not make the earth’s surface warmer except in the arctic regions. Just remember that the lapse rate is an upper limit, not a lower limit to the rate that temperature decreases with altitude in a stable atmosphere. We usually think of convection as being forced by heating at the surface, but cooling from above is required to keep the process going.

  136. The last line of my previous post should have read:

    We usually think of convection as being forced by heating at the surface, but cooling above is required to keep the process going.

  137. Venus. It has a lot more atmosphere than Earth, wrapped around a planet roughly the same size as Earth.

    What nobody has bothered to mention here is one Venusian day is 243 Earth days.
    The surface speed at the equator is only about 6.5 kilometers per hour, some humans could actually run fast enough to stay in one spot, assuming said human was wearing an environment suit capable of withstanding molten lead temperatures and 92 atmospheres pressure… ;)

    If it had a rotational period quite a lot faster, it’d likely be much cooler. Venus also rotates in the opposite direction from the other planets. There are many theories as to why, mostly involving some sort of large impact, but there’s no evidence of such on Venus’ current surface, which appears to have been all jumbled up and overturned at some point in its history. (Anyone ever bother to think its present condition is because of the impact that knocked it spinning the opposite direction and the hit was so massive the surface disruption completely erased the impact site and the surface hasn’t changed a bit since it solidified post-impact?)

    The slow rotation might be a factor in why it’s kept so much atmosphere. Other theories says it’s because Venus doesn’t have a large moon (or any moons at all) to cause strong tides that would’ve long ago stripped away the excess gasses.

    The magnetic field of Venus is much weaker than Earth’s. As has been observed on Earth, the field has an effect on the amount of cosmic rays and various types of Solar radiation reaching Earth’s atmosphere and surface. With the weaker magnetic field and being closer to the Sun, plus the slow rotation, no moon… there’s virtually nothing to compare Venus to Earth with respect to greenhouse effect or anything else to do with the atmosphere.


  138. Mike Borgelt (23:36:40) :

    D. King (21:19:05) :

    ” Paul (19:34:32) :

    wayne (18:51:41) :

    Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth”

    I get about 30 x as many over any square meter on Mars. Would you care to justify your number?

    2

    01

    2010
    wayne (23:59:15) :

    Mike Borgelt (23:36:40):

    Exactly. Paul was saying because the low pressure on Mars, I’m assuming partial pressure, that CO2 on Mars has no effect on temperature or weather at 90% component. I’m questioning why a much lower partial pressure for CO2 on Earth would have any effect either if his statement is correct about

    Mars has a different diameter and a different mass, hence the gravitational acceleration g is different. It’s atmsophere at the surface is only about 1/100 that of Earth but has 90 to 95% co2. The optical path depends upon the total number of absorbing moleculars of a type in that path. The math will tell you that there is 30 to 40 times the number of molecules of co2 present in the atmosphere of Mars than of Earth. That’s 5 doublings of concentration above and beyond that of Earth. On Earth, a doubling of the molecular count is going to produce an incremental increase of power absorption (in clear skies looking down at an altitude for a straight radiative portion of the problem).

    That said, if one looks at the average Martian orbit and its albedo and does a simple incoming radiative calculation for a blackbody and compares it to measured temperatures, one discovers that there is no warming present due to the co2 that is obvious. Whatever exists is basically 0.

    The difference being, as mentioned, is that the pressures of both the co2 and other constituents of the air are much lower than lower in Earth’s atmosphere. This is the pressure broadening which smears out the line emissions and absorption likelihoods so that more spectral area is affected. Note that having a high peak and narrow width has little effect compared to a lower peak with greater width when both are pretty much total absorption at the peak after a very small path length.

    When one looks at a simple Earth model and accepts h2o in vapor and cloud form being 90% of the ghg effect of 33 degree C rise over a blackbody of similar albedo (0.31), that’s almost 30 degrees C worth and leaves co2 and all the other ghgs a whopping 3 degree C contribution with roughly equal amounts for each time there is a doubling or halving of the total number of a particular molecule’s concentration – as long as that halving doesn’t change so the optical path to extinction becomes large compared to the size of the atmosphere or layers of the atmosphere.

    If one looks at clear skies with no clouds, that 90% fraction due to h2o drops significantly and co2 approaches closer to 20% and water closer to 70%, leaving some percentage left for all the other ghg molecules.

    Concerning Anna V’s comments, I don’t think you can separate out the radiative thermo from the advent of the quantum mechanics as this is where the classical broke down. Planck’s radiation law introduces that insidious little constant, h, although it is still thought of as being in the classical realm. The blackbody continuum exists for all matter in liquid and solid states (at least sorta). There one has all sorts of interactions between molecules that allow for quantum states ad naseum. Clouds and particulates provide tiny bits of liquids and solids that are no longer limited to only atomic or molecular spectrums but as they get smaller in size, one may not maintain a true BB spectrum – which actually describes the Boltzman distribution or likelihood for atoms and molecules being in a given energy state at a given temperature. If one applies this distribution to the absorption spectra of a molecule, one gets the emission spectra.

    With gases that aren’t hot, one has the pressure broadening and a doppler shift broadening associated with temperature. The Sun’s photosphere, compared to Earth’s surface, a moderately decent vacuum at 6000k produces pretty much a BB continuum for that temperature as mostly hydrogen gas wells up rather hot and dumps its radiative load cooling down and returning below that thin “surface” or few kilometers of radiative area.

    Cool hydrogen gas is not going to radiate like that. You’ve got the 21cm line based upon flipping spin states but basically, nothing in the visible or IR. In order for the hydrogen to emit in the visible, it must be raised to higher energy states as the electron dropping to the lowest energy state is going to emit in the uV. That’s why (hydrogen alpha) pink hydrogen emitting nebulae exist only where there are bright uV emitting stars nearby. IR (and microwave) tend to depend upon molecular vibrations and rotation modes, unless the atoms or molecules are heated sufficiently to get above the lower energy states.

    Just like the qm and classical, while I like Dr. Roy’s presentation and simplifications as an explation, it does have its problems and I’m not sure just how much one can keep that simplified and come conceptually close to describing the system. As for affecting the weather with no ghgs, it certainly would have serious effects. Not having h2o vapor would have serious impacts on the pressure differentials and hence the circulation as well as about everything else from albedo to convection.

    If one were simply to drop all but h2o, it’d hardly be noticed, just a few degrees. Maybe that would be enough to trigger an iceage or snowball Earth and then again, maybe it would not without massive extra forcings.

  139. Paul (17:42:38) :

    Wow. No greenhouse = no weather? Just ask the Martians where the winds surely do blow. Strange that a scientist from NASA would so mislead. All you skeptics out there: you might not want to use this site as your only education if this post is representative of the state of its science.

    Erm, the atmosphere of Mars is 95% CO2, or nine times the absolute concentration of CO2 on Earth. Since you apparently feel free to insult (wrongly, as it happens), I feel free to mention that I now know, by virtue of your demonstrated ignorance, just how much credence to give anything else you might say in future.

  140. wayne (03:13:52)

    That seems plausible but operates counter to the general wisdom that an expansion of the atmosphere may occur but that such an expanded atmosphere is at a higher temperature due to a new equilibrium having been set by the increased length of time the solar energy remains in the Earth system before it is released back to space.

    So, one might have an expanded atmosphere but with a higher total energy content than before so a higher temperature will be recorded. You would only see cooling from expansion if the total energy content remained as before but in fact it doesn’t because the increase in the time taken for energy to negotiate the system means that there is more energy in the system to show a higher temperature notwithstanding the expansion.

    I hope that makes sense.

  141. Where do all of you get the idea that only CO2 and Water Vapor can absorb and emit radiation? Nitrogen and Oxygen can also perform this trick.

  142. John J. (19:24:10) :

    No weather without so-called greenhouse gases? Jupiter is mostly hydrogen and helium and yet the Great Red Spot has persisted for centuries.

    And how is it possible that the internal temperature of Jupiter with no CO2 is greater than the surface of Venus? I’ve asked this question to a couple of professors at my local university and never gotten a reply.

    Change your university. Jupiter has minute traces of rock dust, methane and water. In the terrific mass and pressure of Jupiter’s atmosphere, even a minute trace amounts to a huge amount. You may have noticed that Jupiter’s atmosphere is not transparent. It absorbs radiation and therefore also emits it. The planet’s core is about 20,000C, three times hotter than Earth’s. Without wanting to divert a year or two to study the physical processes in Jupiter’s atmosphere, it is nevertheless clear that you haven’t got a professor-stumping question there.

  143. Wayne, I think your basic analysis of the individual photon’s momentum is correct, but it is already taken account of in saying that the atmosphere heats (which means expansion). It is often the case that there are numerous ways of looking at the same thing in physics, especially a ‘bulk’ way (thermodynamics) and a microscopic way (looking at actions of individual particles). Since thermodynamics arises out of the statistical properties of ensembles of particles, these two ways of analysing a problem are exclusive: you can’t take an argument about one photon or molecule and import it into a thermodynamic argument.

    Heat is a thermodynamic property of an ensemble; individual particles have mass and velocity. Heat is uncoordinated (statistically randomised) velocities of a large number of particles. Thus from about your third-last paragraph you go off the rails by confusing the microscopic reasoning with the statistical thermodynamic reasoning. Also, nothing in either argument shows the claim in your third-last that the cooling will be to an equal amount. It won’t. The air will heat, expand, then convect (rise) and thus cool.

  144. wayne (03:13:52) :

    Moderator please bear a long one.

    anna v (02:34:06) :

    OK! That’s the key. I know if there are many emission lines, the momentum will be split between the photon(s) of lower wavelength and some residual momentum may reside in the molecule. But conservation of momentum must always be preserved. One place or the other(s).

    Please follow. Think only of the original parcel of momentum and keep track of it.

    Conservation of momentum is not the same as conservation of energy, in that momentum is a vector and can add up to 0.

    We are in the quantum mechanical framework: once the photon is absorbed, the momentum conservation is taken up by the molecule and it is riding happily away at a constant velocity, until it interacts with another molecule or force. Conservation of energy from the same interaction says that there is potential energy in the molecule, the energy left over from the one that became kinetic to conserve momentum.

    Take a special IR photon, properties set by me, carrying energy thus momentum, leaving a spot on the equator and heading directly zenith to keep this pure.

    The momentum carried by this photon, one way or the other must be preserved. The photon may be absorbed by a molecule in proximity if wavelength allows, that molecule hits other molecules so momentum of the molecule changes and is distributed, this can occur many times. But mother nature by her physics is so frugal with her accounting of her energy and her momentum that she will not miss the tiniest portion of her precious energy and momentum.

    That momentum from that zenith heading photon may be divided and scattered over many molecules or subdivided into components of other photons in various directions but the SUM of the net effects of that lonely photon’s momentum will end up in portions of two states. One component’s portion (can be zero) escapes into space carried by the original OR divided between some other photon(s) in some direction(s) possibly at different wavelength(s). The other possible state is to cause an infinitesimal but real and exact expansion of Earth’s atmosphere by increased momentum of a molecule(s). This will initially manifest as an increased pressure but eventually will be expansion.

    See, this is what I mean about mixing up systems. Pressure is a thermodynamic variable, entering into the PV=RT formula. In the quantum mechanical frame the excess momentum of one or n molecules will become excess kinetic energy which after millions of similar interactions will appear in the quantum statistical formula which eventually at the limit will manifest as temperature and pressure in the medium, gas in this case.

    The sum of the momentum of these two states (speaking only of the original photons momentum), seems to me MUST be equal to the original momentum of that lone photon to meet conservation laws.

    No. Once a photon has been absorbed by raising the energy level, rotational vibrational or whatnot, of the molecule, it disappears. Photons are not conserved, there is no photon conservation number. Lets keep it simple , one photon hits one molecule and is absorbed, and the molecule gets a kick in the direction of motion of the photon. The deexcitation of the molecule, suppose it happens with one photon for simplicity, will introduce a new conservation of momentum. The molecule will go one way and the photon the other, but the direction will have no connection with the original photon’s direction. It will be random in direction within a probability distribution given by the state it occupies, and the molecule will kick in the opposite direction. The original momentum conservation law was satisfied by the increased velocity of the molecule that originally absorbed it. After deexcitation,the molecule will have the vector sum of the original momentum plus the opposite momentum to the exiting photon.

    If the above is correct, from here on only speaking of that original parcel of momentum.
    Well, it is not.
    If the photon didn’t encounter any interaction on its way up, it merely escapes into space. End of story, momentum preserved. However, if it had any interaction and the portion of momentum escaping into space (can be zero) is less than the original, the only other possible state is an expansion of the atmosphere by the remaining portion of the original momentum.

    Once again, expansion and atmosphere are macroscopic thermodynamic concepts and variables. In this large thermodynamic collective, the increase in the average velocity of molecules manifests as temperature and is connected to pressure through PV=RT in gases.

    If I’m still right to this point, you can now view that photon’s momentum generically as radiative pressure. And any layer of the atmosphere as a near spherical membrane that this momentum must cross, one way or the other to satisfy conservation of the momentum.

    You are ignoring the fact that infrared photons coming from the ground up are neither coherent nor unidirectional, particularly as the surface of the earth is fractal, though one could see a radiation front forming, if there were no atmosphere, which could be described as having radiation pressure, I do not see what conservation of momentum has to do with it.

    The gist of the above is to say that energy, thus momentum, of outgoing photons cannot be absorbed and re-radiated IN A NADIR direction without also expanding the atmosphere, thus, by thermodynamic laws cooling the atmosphere in an equal amount of the heat trapped.

    Well, the last time I solved a thermodynamics problem was in 1960, and though it is true that the temperature of the gas will rise , and from PV=RT the pressure or the volume will grow, I cannot tell off hand how the “cooling” and “equal amount of heat trapped” will figure in this.

  145. RE: kadaka (23:28:44)

    “To me, he seems to basically be describing Venus, which although it has CO2 in abundance it does not really function as a GHG in that planet’s atmosphere as CO2 does in ours, you could replace it with nitrogen for about the same effect.”

    I believe you are missing the point. Dr. Spencer is describing a planet with a *perfectly transparent* atmosphere — no greenhouse gasses, no clouds, and no dust in the upper atmosphere. Water vapor is one of the most effective greenhouse gasses. It also acts as a natural refrigerant in the lower atmosphere.

    I do not think Venus can be said to have a transparent atmosphere. Even though the atmosphere of Venus is 97% carbon dioxide, I suspect that most of the greenhouse effect there is due to sulfuric acid in the atmosphere which also causes the optical haze preventing our view of the surface. H2SO4 is a relatively complex molecule with many more possible quantum energy states than CO2. (I wonder how much anthropogenic H2SO4 is being added annually to our atmosphere.)

  146. I think this exercise shows the difference between engineers and theorists. Engineers have a great deal of trouble letting go of so many real world issues. That is very good, however, I find the difference rather enlightening. ;)

  147. Oh no… someone posted a link above (http://theevolutioncrisis.org.uk_testimony2.php) where one can read Dr Spencer’s less than enlightened views on evolution and the historicity of the Biblical Gospels, among other things. I must admit I was quite shocked by what I read. I can’t avoid being sceptical of anything he writes on climate science from now on, even if it isn’t related to his religious/anti-evolutionist views.

  148. “John A (16:34:15) :
    […]Unfortunately Willis’ “Steel Greenhouse” is unphysical rubbish. Putting hot food in a Dewar flask does not cause the food’s temperature to rise – it simply reduces the rate at which the food cools.”

    I didn’t see this comment… but a word of defense is necessary. First, Willis postulated an energy source inside his imaginary planet to explain surface radiation, he used radioactive decay as an example. Your analogy with the hot food storage is invalid. Please read it properly.

    Second, i don’t care much about the peculiarities of his entire setup – what was important for me was his explanation of the Stefan-Boltzmann law which defines the relationship between surface temperature and upward radiated flux, and most importantly the 50:50 splitting up of this flux by the steel shell / GHG shell above a greenhouse-affected surface.

    His steel shell experiment explains in clear terms that it doesn’t matter of which material your shell is made when it completely absorbs and re-radiates a certain part of the spectrum; it will re-radiate to the inside and to the outside of the shell in equal parts. And here Willis’s Gedankenexperiment meets nicely with the work of Ferenc Miskolczi. And that’s why it’s important.

    I don’t want to be brash but i think it’s important to understand this if you want to understand the thermodynamics and the energy balance. Because it deflates the feedback / tipping point voodoo claims made by the AGW proponents.

    For all latecomers here’s the link to the Steel Greenhouse writeup again.
    https://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/

  149. Re: bob (19:17:07) :

    “RE: Alex Harvey (16:39:03) :

    Alex, all matter emits blackbody radiation, although you are right that gases are not blackbodies.

    Some poster here seem to confuse a substances Infared emmision spectrum with its absorption spectrum, they are two separate and different things.”

    Thanks, this has to be answered with some care. It is true that absorption and emission spectra for the same molecule are different things, but that is not to say that a molecule can emit radiation at frequencies that it can not absorb radiation or vice versa.

    There is thought experiment that covers this, of which I cannot recall all the details, but basically it would allow for heat to flow from a colder bodies of gas to warmer bodies, if I recall correctly.

    Also the spectra come into alignment when radiative equilibrium is attained.

    The situation with mixtures of gases is a little more complicated as radiation absorbed by CO2 can be passed thermally to H2O and emitted at frequencies that CO2 simply could not.

    But finally, if anyone is saying that a gas like CO2 can emit radiation with a continuous spectrum, such as a black body does, then that is not the case.

    It is true that the black body spectrum is important when calculating the emissions from a gas, as the temperature of the gas changes the relative (and absolute) intensities of the radiation at different frequencies. But that is not the same as saying it radiates like a blackbody does. Not in my book anyway.

    Alex

  150. While the notion of putting food in a good insulator will reduce the time it takes for the food to cool, the Earth has two sources of heat continually applied. The big one is the Sun, the lesser one is the geothermal heat. If you increase the insulation for the Earth, it will heat up from either of these sources. If somehow you created a perfect insulator – even if the Sun totally went away, the geothermal heat would raise the surface to thousands of degrees and the whole Earth would reach true thermal equilibrium – and it would be above the temperature of molten lava everywhere. Right now, the heat flow at all points above the interior of the Earth is such that there is a large temperature differential from the inside to the outside. If ultimately enough insulation could be used to bring the heat flow down to zero, that temperature differential would decrease to zero and the temperature would average out, to thousands of degrees.

  151. Gregg E – I think the explanation is that the rotation rate of an inner planet was determined by the final few collisions of larger pieces that created the planet. There is a theory that a Mars-sized world collided with early Earth creating the moon.

    Venus’ atmosphere contains four times the nitrogen of Earth’s. If both planets had similar origins, then the early Earth collision theory explains the loss of 3/4 of Earth’s primordeal atmosphere. The CO2 on Earth was removed by chemical (and later biological) action in the oceans. Venus was presumably too hot to have oceans so the CO2 stayed in it’s atmosphere. The slow rotation of Venus would have made the sun-facing hemisphere even hotter.

    Note also that Venus’ rotation rate is phase-locked with Earth, such that the same face of Venus always faces the Earth when Venus and Earth are closest in their orbits.

  152. Mike Borgelt (00:05:29) :
    Paul (19:34:32) :

    “Good question about the CO2 and the answer is not so straight forward. Although there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth, they are not nearly as effective as a greenhouse gas because the total atmospheric pressure is much lower. ”

    I believe you are flat out wrong about this:
    Assuming a Mars surface partial pressure of CO2 of 6hPa on average (this is at the low end of the variable surface pressure on Mars and 95% of the atmosphere is CO2) and Earth at 1013hPA of which the partial pressure of CO2 is 0.58hPa (390ppmv and CO2 has 1.51 times the molecular mass as oxy-nitrogen) this would make the number of molecules of CO2 above each square meter of mars TEN times that over each square meter on Earth, however pressure is WEIGHT and Mars has only 0.38 the surface gravity of Earth so you need 2.63 times as much mass to get the pressure so we get at least 26.3 times as many molecules of CO2 over each square meter of Mars as on Earth. And that was the low end of the martian surface pressure so around 30 x seems reasonable.

    And yet the greenhouse effect on mars is “feeble”?

    As for this:

    “The higher density of gas in Earth’s atmosphere works to spread the absorption of IR by CO2 over more of the wavelength scale. The same amount of CO2 (or H2O) is more efficient on earth because of all the N2 and O2 colliders (this is called pressure broadening. There is a reasonable wiki page http://en.wikipedia.org/wiki/Spectral_line but it could use to be updated to discuss the role of broadening on climate.”

    OK great, but isn’t one of Gavin’s arguments at RC that extra CO2 in Earths atmosphere causes extra pressure broadening? Just how much extra pressure broadening do you get by doubling CO2 from a partial pressure of 0.44hPa to 0.88 hPa(corresponding to CO2ppmv going from 290 to 580ppmv) out of a total pressure of over 1000hPa?

    I’m really pleased you’ve cleared that up that it is the TOTAL pressure that causes pressure broadening of absorption spectra minor constituent gases of the atmosphere like CO2 and not the partial pressure of CO2.

    Here’s a comparison between CO2 spectra at earth and martian conditions, note the extra broadening:

  153. Spector,

    Thanks for your explanation. I think the idea that a perfectly transparent atmosphere cannot cool by thermal radiation would probably account for the peculiarity of a zero lapse rate. I had assumed that the top of atmosphere must be continually cooling by radiation into space and must be colder than the ground, but obviously not.

  154. “John A (16:34:15) :
    […]Unfortunately Willis’ “Steel Greenhouse” is unphysical rubbish. Putting hot food in a Dewar flask does not cause the food’s temperature to rise – it simply reduces the rate at which the food cools.”

    DirkH has already commented on this, but I would just add that to make a correct analogy with Wilis’ steel shell, the flask would need to contain a heating element. In that case it would definately get warmer.

  155. Nick Stokes (13:53:50) :

    “But eventually, the entire atmosphere would reach a constant temperature with height.”
    Why wouldn’t the adiabatic expansion mechanism then continue to convey heat downwards (the air would not be motionless because of diurnal effects and thermal inhomogeneity), to restore and maintain (nearly) the adiabatic lapse rate of -9.8 K/km? Surely this mechanism moves heat more effectively than conduction?

    There won’t be any mechanical reason for convection in an isothermal atmosphere as a rising parcel would be found very quickly at a temperature lower than its surroundings. Even on a planet with pretty active convection such as ours the environmental lapse rate is not adiabatic. Another way to think of this is, the convection acts as a heat engine. It has only a hot reservoir, though. Without a cold reservoir in which to expel waste heat the engine will stop running its cycle.
    bob (14:18:37) :

    “Why would this occur? Infrared absorbers like water vapor and carbon dioxide provide an additional heating mechanism for the atmosphere. But at least as important is the fact that, since infrared absorbers are also infrared emitters, the presence of greenhouse gases allow the atmosphere — not just the surface — to cool to outer space.”

    You don’t need the greenhouse gases to cool the atmosphere, oxygen and nitrogen are infared emitters according to the Planck black body radiation effect.

    But you do need an emissivity above zero. Nitrogen and oxygen have an emissivity of effectively zero. There would be some radiation emitted in the acceleration that occurs when molecules collided, but that would be effectively nil at the temperatures we are talking about here. Anthony suggested that oxygen has some weak IR bands, and thus may have some very small emissivity. However, the atmosphere that Dr. Spenser posits would have some interaction with sunlight in the UV, and he didn’t include that effect.

    So the atmosphere cools without the greehouse gases.

    thanks

  156. Cripes! Some of bob’s post got attached to the end of mine. Without an edit facility these are endless errors like this for me. The atmosphere contemplated will not cool without IR emitters.

  157. anna v (05:42:08) :

    Thanks much for the pointers. Everything you said is correct. I’m familiar with QM. Everything you have pointed I realize. I know of duality also.

    How do I put this and stay very simple and pure without numbers? Can’t talk a book worth here.

    But this question requires someone so versed in QM & TD they can visually and logically separate a complex system into a single special case that can be exactly (to constants precision) computed and tracked.

    I am going to give that special photon’s momentum a value, one, in a transformed unit system that I am going to keep secret (really irrelevant). I have a program with all of the equation in all of science so I can compute anything to adequate precision.

    That original special photon travels up X distance and interacts with a molecule because energy levels and the frequency match. All of the momentum is transferred to the molecule, no more photon. I compute molecules position after specific time. The molecule ejects two low level photons, one in this direction one in that direction and a fraction of the momentum still resides in the molecule (no added rotations). I compute. I now have three pieces of the original momentum. I add them up. It’s one with the vector pointing strait up. The molecule bumps another molecule, another split billiard style and one molecule is now spinning, compute, now five pieces. They all add to one and the vector is still strait up.

    Get my gist here. It may be that science in universities has become so complex in scientists and students minds that simple core underlying cases cannot be discussed and/or computed without bringing in the hundreds of complex macro-level laws which let us compute things in the real world that otherwise would be impossible. It’s as if most I talk to are unable to go back to the basics. Maybe it’s not even taught anymore. If so, it may time for me to exit science (I’m kidding).

    It takes great effort to take a complex system and refine and simplify back to the core laws. But those laws are the foundation of science. Conservation of energy and momentum still apply.

    Re-read post above keeping it purely simple and see if the point being made is true (or false). Anna, I do appreciate your help.

    Moderator please bear a long one.

    Anna:

    OK! That’s the key. I know if there are many emission lines, the momentum will be split between the photon(s) of lower wavelength and some residual momentum may reside in the molecule. But conservation of momentum must always be preserved. One place or the other(s).

    Please follow. Think only of the original parcel of momentum and keep track of it.

    I have read literally a hundreds of papers concerning this broad subject. But I kept having a reoccurring catch in all of the pure logic used. Let’s take this as Einstein would, one infinitesimal thing at a time.

    Take a special IR photon, properties set by me, carrying energy thus momentum, leaving a spot on the equator and heading directly zenith to keep this pure.

    The momentum carried by this photon, one way or the other must be preserved. The photon may be absorbed by a molecule in proximity if wavelength allows, that molecule hits other molecules so momentum of the molecule changes and is distributed, this can occur many times. But mother nature by her physics is so frugal with her accounting of her energy and her momentum that she will not miss the tiniest portion of her precious energy and momentum.

    That momentum from that zenith heading photon may be divided and scattered over many molecules or subdivided into components of other photons in various directions but the SUM of the net effects of that lonely photon’s momentum will end up in portions of two states. One component’s portion (can be zero) escapes into space carried by the original OR divided between some other photon(s) in some direction(s) possibly at different wavelength(s). The other possible state is to cause an infinitesimal but real and exact expansion of Earth’s atmosphere by increased momentum of a molecule(s). This will initially manifest as an increased pressure but eventually will be expansion. The sum of the momentum of these two states (speaking only of the original photons momentum), seems to me MUST be equal to the original momentum of that lone photon to meet conservation laws.

    If the above is correct, from here on only speaking of that original parcel of momentum. If the photon didn’t encounter any interaction on its way up, it merely escapes into space. End of story, momentum preserved. However, if it had any interaction and the portion of momentum escaping into space (can be zero) is less than the original, the only other possible state is an expansion of the atmosphere by the remaining portion of the original momentum.

    If I’m still right to this point, you can now view that photon’s momentum generically as radiative pressure. And any layer of the atmosphere as a near spherical membrane that this momentum must cross, one way or the other to satisfy conservation of the momentum.

    The gist of the above is to say that energy, thus momentum, of outgoing photons cannot be absorbed and re-radiated IN A NADIR direction without also expanding the atmosphere, thus, by thermodynamic laws cooling the atmosphere in an equal amount of the heat trapped.

    I’m stuck on this point. Reoccurs in my mind every paper I read and until I can get a understandable answer, I don’t feel an added portion of CO2 that traps additional heat can help but to expand the atmosphere thus cancelling any effect. Some papers support this view but from other directions. I tried to make mine simple.

    Any help, corrections or comments?

  158. Phil. (08:21:46) :
    Sorry about the error — yes there is more CO2 per sq m, but as your spectrum shows, the low total pressure greatly reduces the radiative forcing by CO2 compared to earth.

    But this is really all beside the point — the main point about reference to Mars is that in the absence of heavy dust, the surface temperature is close to the planetary radiative equilibrium temperature (such that IR emission from the surface is balanced by solar heating == e.g the definition of an inefficient greenhouse). Despite this, Mars has a highly dynamic atmosphere.

    [The main reason Mars has such an inefficient greenhouse, is 1) very low humidity (therefore IR opacity is very low in the thermal IR; CO2 absorption covers only ~10% of the thermal emission spectrum even on earth with its larger pressure broadening) and 2) the low total pressure reduces the efficiency of all greenhouse gases (including H2O and CO2). ]

  159. Alex Harvey (08:00:19) :

    “The situation with mixtures of gases is a little more complicated as radiation absorbed by CO2 can be passed thermally to H2O and emitted at frequencies that CO2 simply could not.”

    There’s something in that observation. However, the colling of c02 leads surrounding molecules to warm up, and can only do so when it emits at the bandwidth that receiving molecules like oxygen can accept them, though this isn’t the case with H2o, so co2 doesn’t thermalize with h2o – mainly because the thermal excitation of c02 is a tiny part of total heat in the system. In a given volume of air, for each co2 molecule there are about 3000 nitrogen and oxygen molecules, and only around 5% of c02 molecules will be excited at 15C – so the chances of c02 colliding with anoter c02 are quite rare, and it is like molecules which are the most efficient t transmitting radiation. That changes the entire ration of excited cow molecules in a volume of air to the nitrogen and oxygen ones. c02 in th ebending mode doesn’t have the energy to excites a h2o molecule, although it does in the symmetric streching mode – only it has to be at such a high energy that isn’t even found at 35C. As said above, radiation and molecules move in 3 dimensions so for c02 molecules in the upper troposphere where the greenhouse effect is said to be at its mst active, we run into another conundrum: There are even fewer c02 molecules per volume of air that oxgen and nitrogen and the temperature in the mid-upper troposphere indicates that c02 absorbs heat outside of its peak 15 microns, to the shoulders where it coincides with the small peaks of oxygen and nitrogen’s small heat retaining effect – and then there are millions more molecules that co2 has to compete with.

  160. Incidentally, there can be up to 31% h20 in a volume of air and this is where heat is intercepted by h20, leaving c02 little, if any heat to intercept. water vapour like molecules tend to collide and vibrate more with each other, and transfer energy to each other more efficiently. (C02 capture of heat is quite a rare occurence in the atmosphere)

  161. Well… having spent about 2 hrs on this post and blog, I can only come to one conclusion: while it has all been very entertaining, it only shows how intensely complicated it all is, and how far-fetched it is to imagine that the entire thing can be driven merely by small changes to CO2 levels. Most of the above still seems seriously counter-intuitive to me. Methinks the chaotic nature of earth’s systems (per definition as I understand it: multiple non-linear mathematical models interacting) will ultimately prove to be beyond man’s intellect.

    As for the (patently extremely simplistic) current state of the art: After initially starting out, some years ago, as merely skeptical, I now doubt even the fundamental premises. I doubt that CO2 levels have actually increased due to man’s efforts… I doubt that earth’s temperature has recently increased beyond margin of error… I doubt the very veracity of the greenhouse effect in this context. Data is suspect.. analyses flawed… motives uncertain.

    Perhaps some sense will ultimately come from disciplines other than climate research, hopefully less tainted by agendas other than science. Here’s hoping… (but still reading all this! Keep up the good work!)

  162. I believe the most likely source of outgoing radiation from the upper atmosphere is from solid or liquid particles at the cloud-tops as I believe they emit radiation over a much broader spectrum of wavelengths than gases as a result of their solid or liquid bonding energy states. The problem I see for emissions from the primary gases in the atmosphere is the high probability of re-absorption by the same gases higher up. Perhaps this is the reason for the progressive warming below the stratopause.

    I expect that radiation from trace gases just below the tropopause would have a higher chance of getting out because this radiation would be less likely to have an absorption encounter with another molecule of the same gas.

    A transmission plot for outgoing radiation emitted from the equatorial tropopause (at 55,000 ft) should show much wider transmission windows as I estimate that over 90 percent of the mass of the atmosphere is below 55,000 ft. based on the reduced pressure at that altitude.

    As I said earlier, perhaps the best real approximation of Dr. Spencer’s conjecture is the ancient ice-cube or Ice-Ball Earth climate catastrophe indicated in the geological record.

  163. At the end of Dr. Spencer’s thought experiment world, “the rest of the atmosphere would be at approximately the same temperature as the average surface temperature”. If the average surface temperature turned out to be around the freezing point of water, then the N2 and O2 at, say 30,000 feet elevation, would be floating around happily at 273 deg Kelvin day after day right there on the edge of space.

  164. Re: P Wilson (11:17:15) :

    “Alex Harvey (08:00:19) :

    “The situation with mixtures of gases is a little more complicated as radiation absorbed by CO2 can be passed thermally to H2O and emitted at frequencies that CO2 simply could not.”

    There’s something in that observation. However, the colling of c02 leads surrounding molecules to warm up, and can only do so when it emits at the bandwidth that receiving molecules like oxygen can accept them, though this isn’t the case with H2o, so co2 doesn’t thermalize with h2o – … ”

    Sorry, it is a mixture of gases, so they also strive for thermal equilibrium through contact, i.e. collisions. Even if two gases have no overlap in their spectra when mixed that is still the case.

    Alex

  165. Ron House (05:31:04) :
    Sometimes I don’t write enough to be clear, not wanting to be too long in post!
    Precision is the key. This is somewhat theoretical. If I have a conglomerate of gases, and at one instance I know the temperature is exactly 20.000… to 99 places. Along comes a photon that is totally captured by one of the molecule. I know the temperature has increased no matter how tiny its influence may be, maybe in the 63rd digit. The pressure after one pico second will be increased pressure locally but since Earth has no top on its atmosphere, that pressure over time will be expressed as expansion of volume (but maybe not totally, would have to look that up). That’s what I mean when I silently ‘mix’ systems.

  166. JER0ME (17:56:12) :
    sorry I have lived Norht AND South of the equator and can assure you that Coriolis affects the way the water drains down th plug hole.

    Aged 16 went from UK (54N) to Zambia (12S) – almost the very 1st thing I did was confirm that the water went down the plug in the opposite direction to the UK.

    Experimental science by observation,

    Later over the years I repeated the test – on ships – so I do not know what & why the experiments you cite produced anomalous results.

    However easy experiment if you are not on/near the equator :

    go to the kitchen/bathroom fill a sink with water – pull the plug – observer which way the water spins.
    repeat several times – repeat at friends houses work etc.

    Next experiment :

    Fill sink with water (very full) stir water so there is a gentle flow in the OPOSITE direction to that observed above – pull plug & observe what happens.

    Now – if the Coriolis force is NOT responsible explain the OBSERVED result (every time I have done this is results in the flow direction being reversed as the water drains down the plug hole)

    Observation by repeating the experiment trumps/confirms theory every time

  167. Paul (19:34:32) :

    “there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth”

    No. The surface pressure on Mars ranges from 30 Pa (Olympus Mons) to 1155 Pa (Hellas Planitia), with a mean nominal pressure of 600 Pa. 95.72% of the atmosphere is carbon dioxide, so the partial pressure can be as low as 29 Pa and as high as 1105 Pa. The surface gravity of Mars is 0.376 g. Should we place this atmosphere in a terrestrial gravity environment, the pressure range would be 76 Pa – 2940 Pa, with a mean of 1527 Pa.

    The partial pressure of the same gas on Earth as of now is about 57 Pa. So there are 1.34 – 51.58 times more molecules of CO2 above any sq meter on Mars than on Earth, mean value 26.8.

    An up to fifty times thicker carbon dioxide envelope more than makes up for lack of pressure line broadening. Even the highest point has more CO2 above it than on Earth, sea level. The same can not be said about highest point of Earth, Mt. Qomolangma, where CO2 partial pressure is only 18 Pa. Olympus Mons has four times as much carbon dioxide above it, although it is the highest mountain in the entire solar system, peak 27 km above mean surface level.

  168. Spector (05:44:30) :

    RE: kadaka (23:28:44)

    I believe you are missing the point. Dr. Spencer is describing a planet with a *perfectly transparent* atmosphere — no greenhouse gasses, no clouds, and no dust in the upper atmosphere.

    Nah, not really. Spencer concludes the Earth would be essentially isothermal, as Venus is. There is the lack of water vapor, as with Venus. The CO2 atmosphere is basically an inert gas. From there, examining this simpler system without the preconceptions of how Earth’s atmosphere operates, I can see better what he is talking about. The sulphuric acid clouds and haze do act as an insulator, but then that is only one layer to remove for the thought experiment. Without it the planet would likely be cooler, but otherwise resemble the thought experiment model.

    Then, the questions begin. Here it is proposed convective overturning would cease. Yet convection is what drives the Venusian climate. Do the properties of the CO2 as an infrared absorber and emitter make the difference? Here it is argued the Earth would become isothermal. Venus is isothermal, with the convective overturning. Are the sulphuric clouds and haze keeping Venus isothermal? Etc. Just doing the thought experiment from a different starting point, ditching certain preconceptions, and examining what different questions, and what same ones, will arise.

  169. Folks, I think Mars is a good planet for comparison to Earth as far as greenhouse effect goes. At least most of the confounding factors (water, clouds)are not present, the atmosphere is transparent in visible light and the planet has about the same axial tilt and rotational period.

    My point about the amount of CO2 on Mars vs Earth is that the calculation is easy to do properly so we should at least get that right when talking about greenhouse effect on Mars.

    If what Paul (10:10:58) said in his post is true then Mars might approximate Roy’s hypothetical Earth with obvious problems for Roy’s little thought experiment.

    It also raises problems for the warmies if CO2 covers only 10% of the IR spectrum on Earth and the pressure broadening depends on total pressure not partial pressure of CO2. Doubling CO2 will only increase total pressure on Earth from 1013.25 hPa to 1013.69hPa at most but in reality less than that as the “O2” part of the CO2 comes from the oxygen in the atmosphere at least in part.

    My question is, does doubling CO2 and causing a total pressure increase by a factor of 4 parts in 10,000 really cause a significant increase in pressure broadening ?

    I think this is a significant question as a large part of the warmie case seems to depend on this.

  170. Robert E. Phelan:

    If you actually read the link I provided, you’d notice that it is Spencer’s own article describing his belief that the biblical creation story is plausible. But I’m glad that you agree that anyone who is a young earth creationist should not be trusted to have either a brain nor an understanding of science. So we can safely ignore anything that Spencer says.

    Not that the article above is actually wrong, but it most certainly is a red herring.

  171. Roy W. Spencer.

    You wrote: “Importantly, this ‘dry convection’ will result in a vertical temperature profile that falls off by 9.8 deg. C for every kilometer rise in altitude, which is the so-called ‘adiabatic lapse rate’.”

    I don’t see how this can be ‘adiabatic’ any more as you’ve taken out all the water and water vapour (WV) that provides the stability for the atmosphere to act as an adiabat. We’re looking ‘mostly’ at low stratospheric properties here aren’t we, but at surface altitudes where convection ‘will’ occur.

    You wrote: “This is because rising warm air parcels cool as they expand at the lower air pressures aloft, and the air that sinks in response to all of that rising air must warm at the same rate by compression.”

    Not quite. A ‘rising warm air parcel’ cools by ‘expansion on rising, mixing and radiation’, but you’ve taken out the radiative gasses so it cools more slowly! Thus, convection is doubly enhanced as there can be no latent factor either without water in the atmosphere.

    You wrote: “Eventually, the surface and lower atmosphere would warm until the rate at which infrared energy is lost by the Earth’s surface to space would equal the rate at which sunlight is absorbed by the surface, and the whole system would settle into a fairly repeatable day-night cycle of the surface heating (and lower atmosphere convecting) during the day, and the surface cooling (and a shallow layer of air in contact with it) during the night.”

    Completely nonsensical. Without radiative gasses in an atmosphere, the atmosphere reacts as a ‘black body’ also, but with a variable depth. The atmosphere also plays its part in cooling the planet!

    I’ll not go on. While I tend to concur with your desire to convey understanding, this surely can’t be the way to do it!

    The whole point is that just by removing radiative gasses from a model doesn’t remove all of the ‘greenhouse effect’ (GHE). For example! If another mass object (the atmosphere) is interposed between the void and a body radiating as a ‘black body’ (the Earth), the interposing body (the atmosphere) always shares some of the energy from the radiating ‘black body’ (the Earth). Thus, the atmosphere radiates a black body radiation at a reduced rate. This is a property of ‘insulation’!

    Much as I’ve tried to, I really can’t follow your scenario.

    Best regards, suricat.

  172. Re: suricat (16:15:19) :

    “Without radiative gasses in an atmosphere, the atmosphere reacts as a ‘black body’ also, but with a variable depth. The atmosphere also plays its part in cooling the planet!”

    The atmosphere does not react like a black body and if it does not have a significant emission/absorption spectra when at earthlike temperatures it will not significantly radiate and will not significantly cool the planet.

    There is a belief that all warm masses must radiate when at earthlike temperatures, but some gases do not unless you want to nit-pick over miniscule amounts. If a gas does not absorb thermal radiation from a source with an earthlike temperature it will not radiate when at an earthlike temperature.

    Gases don’t just radiate, they have to have a machanism by which they radiate, and if they have a mechanism by which they can radiate at a specific frequency and they must have a mechanism to absorb at that frequency.

    Alex

  173. “Berényi Péter (13:51:12) :

    Paul (19:34:32) :

    “there are about the same number of molecules of CO2 above any sq meter on Mars as on Earth”

    No. The surface pressure on Mars ranges from 30 Pa (Olympus Mons) to 1155 Pa (Hellas Planitia), with a mean nominal pressure of 600 Pa. 95.72% of the atmosphere is carbon dioxide, so the partial pressure can be as low as 29 Pa and as high as 1105 Pa. The surface gravity of Mars is 0.376 g. Should we place this atmosphere in a terrestrial gravity environment, the pressure range would be 76 Pa – 2940 Pa, with a mean of 1527 Pa.

    The partial pressure of the same gas on Earth as of now is about 57 Pa. So there are 1.34 – 51.58 times more molecules of CO2 above any sq meter on Mars than on Earth, mean value 26.8.

    An up to fifty times thicker carbon dioxide envelope more than makes up for lack of pressure line broadening. Even the highest point has more CO2 above it than on Earth, sea level. The same can not be said about highest point of Earth, Mt. Qomolangma, where CO2 partial pressure is only 18 Pa. Olympus Mons has four times as much carbon dioxide above it, although it is the highest mountain in the entire solar system, peak 27 km above mean surface level.”

    the pressure broadening is affected by both the broadening of the same molecule type and the composite of all the other molecular types in the atmosphere. My recollections are that the Earth composite or air broadening is on about the same order of magnitude as that of the self broadening or the effect of other co2 molecules upon a co2 molecule. That being the case, then an atmosphere at 1 atm. (Earth sea level) has a much greater broadening effect than a maximum Martian pressure of 0.01 atm.

    while I’ve never tried to run a full calculation on the martian atmospheric column, what I’ve seen from Earth’s is something along the lines of 3.5 W/m^2 for a co2 doubling at 70km with clear skies – which is ballpark of the warmer claims. Despite this significant effect on Earth that appears to be good for possibly almost a degree rise in temperature, the effect on Mars with the equivalent of 5 extra doublings over that of the Earth’s co2 amount is evidently around 1 degree or less for the total ghg contribution which is essentially totally co2. This shows that the actual pressure lower down in the atmosphere is important as well as the fact that co2 itself has rather little effect on temperature, even when there is no h2o vapor to reduce the co2 effects.

  174. Alex Harvey.

    You wrote: “The atmosphere does not react like a black body and if it does not have a significant emission/absorption spectra when at earthlike temperatures it will not significantly radiate and will not significantly cool the planet.”

    I concur. Though we’re stuck with the presentation that precludes emission/absorption as made by Prof. Spencer!

    You wrote: “There is a belief that all warm masses must radiate when at earthlike temperatures, but some gases do not unless you want to nit-pick over miniscule amounts. If a gas does not absorb thermal radiation from a source with an earthlike temperature it will not radiate when at an earthlike temperature.”

    When at an Earth-like temperature does what? An Earth-like temperature is way above the temperature of the ‘void’, but seeing as any radiative energy transfer is prohibited in this model I guess it must defer to kinetic contact (with the void?). Ask Roy for clarification. Though I’ve not seen his participation in this thread yet.

    I reiterate that; any mass above absolute zero temperature radiates its temperature signature until its mass temperature returns to absolute zero (though this is unobtainable).

    Your last paragraph has no meaning here. Radiative theory is by-passed with this model. Perhaps we can link up elsewhere.

    Best regards, suricat.

  175. Radioactive Man (Norway) (07:14:37) :

    Oh no… someone posted a link above (http://theevolutioncrisis.org.uk_testimony2.php) where one can read Dr Spencer’s less than enlightened views on evolution and the historicity of the Biblical Gospels, among other things. I must admit I was quite shocked by what I read. I can’t avoid being sceptical of anything he writes on climate science from now on, even if it isn’t related to his religious/anti-evolutionist views.

    Well, you’d be shocked at what Clerk Maxwell had to say about origin of Earth and its age, and scripture, etc., etc., and yet he was “pretty good” physicist–I think he helped organize a few things in electrodynamics.

  176. I read my earlier post and it seemed quite unclear, so let me try again.

    I hadn’t thought of the impact of GHGs on convection until I read Spencer’s speculation here. It is a very fruitful thought I believe, because there is the idea that convection is inevitable as long as there is a warm surface, which we find through Spencer’s model atmosphere, is not so. There won’t be any mechanical reason for convection in an atmosphere with a lapse rate even slightly below the adiabatic value, as a rising parcel would be found very quickly at a temperature lower than its surroundings, and conduction, even though a slow process, would make the environmental lapse rate slightly below adiabatic (eventuall isothermal). However, I suggested that another way to think of this is as follows: Convection is a heat engine. Without greenhouse gases, though, it would have only a hot reservoir (the surface). Greenhouse gases provide the cold reservoir for this heat engine and without a cold reservoir in which to expel waste any heat engine will stop running its cycle (to do otherwise would violate the second law). Without greenhouse gases the only possible temperature structure is isothermal up until, at great height in Spencer’s model atmosphere, nitrogen and oxygen absorb UV, and make a temperature structure like our stratosphere.

  177. Just some comments on Spencer’s model. Since it excludes water in any form that means no clouds or ice, I’ll assume a N2 atmosphere since any O2 allows for O3 which of course is a GHG. In that case our first issue is the albedo, in the absence of clouds etc it’s reasonable to use the lunar value (~0.15). Given that you’d expect a Lambertian temperature distribution (cos^0.25) with a maximum near local noon of about 350K and about 200K at the edge of the illuminated disc. The major loss from the surface by far will be bb radiation which will not interact with the atmosphere on its way out. While illuminated the surface will transfer some heat to the atmosphere via conduction, but this will be very thin because of the low thermal conductivity of air, when the surface passes out of illumination it will cool by radiation and cool the layer above it by conduction causing an inversion (such as happens at the poles). It’s likely that there would be circulation due to differential heating but its scale will be very small.

  178. wayne (10:08:59) :

    If you take one molecule and proceed as you do, yes, if the momentum of the system photon-molecule is 1(vector) it will be 1all the way. If it interacts in any way with another molecule at rest, it will still be 1 ( vector) as a system.

    The problem comes when you try to extrapolate from the individual quantum mechanical picture to the thermodynamic one.

    This goes through quantum statistical mechanics, i.e. the average behavior of ten to the twentieth something particles, all having random directions, and unlimited number of photons all having random directions 360 degrees. It is only then that you can talk of volume and pressure, i.e. thermodynamic quantities.

    In order for quantum effects, i.e. the simple picture you are advocating, to become macroscopic you have to have coherence, i.e., the photons involved to be in a lock step, in phase, as with lazers. This is not the case in the atmosphere.

  179. anna v (22:03:07) :

    wayne (10:08:59) :

    Come to think of it, even with a billiard ball like gas, where again you could apply your simple model, one molecule with vector momentum 1 hits the other whichis at rest, and sends it in the vertical direction , the total momentum will still be vector 1. To go to the macroscopic case you have to go through classical statistical mechanics which comes out with the average behavior that is pressure and volume.

  180. RE: kadaka (14:10:43)

    “Spencer concludes the Earth would be essentially isothermal, as Venus is.”

    I am sorry, but the atmosphere of Venus is not isothermal. In fact, the tropopause is at an altitude of about 90 Km or 300,000 ft. and as we go down from this level, the absolute temperature rises from about 150 to 750 degrees K. The surface pressure is on the order of 90 atmospheres. Venus does not appear to be a candidate for Dr. Spencer’s thought experiment — I think conditions during the Ice-Ball Earth period might be a far better fit.

    Just check this link:

    http://www.daviddarling.info/encyclopedia/V/Venusatmos.html

  181. I see 2 problems with this article .
    .
    First Roy says :
    There is a common misconception that the rate at which a layer absorbs IR energy must equal the rate at which it loses IR energy, which in general is not true.
    .
    In LTE (local thermodynamical equilibrium) the rate of emission of any frquency (f.ex the IR 15µ of CO2 vibrational spectrum) is necessarily equal to the rate of absorption of the same frequency .
    This is due to the fact that the population of each quantum level is given by the Maxwell Boltzmann distribution . This distribution depends on the energy (frequency) of the considered quantum level and on the temperature .
    That’s why for a layer in LTE , we have a constant temperature from which follows that the rates of absorption must necessarily match the rates of emission .
    If they didn’t , it would mean that the populations of any quantum level vary with time what contradicts the hypothesis that the layer is in LTE .
    So on the contrary in the general case these rates must match because the relevant part of the atmosphere is in LTE .
    .
    Second point is that the average temperature is irrelevant . A GHGless planet , (f.ex let’s imagine a pure helium atmosphere) could have a brutal weather .
    To simplify , let’s imagine that the planet doesn’t rotate .
    As the surface would be violently out of radiative equilibrium at every point , the surface temperatures would cover n vast range going from over 100°C on the day side to below 100°C on the night side .
    These huge temperature differentials would create extremely violent atmospheric horizontal flows between the day and night halves .
    So this planet would establish heat dissipation patterns which would involve heat transfers from the day half to the night half whic would look like mega storms .
    .
    If we allow the planet to rotate , the pattern would change as the Coriolis force and the variation of irradiation with time would probably transform these storms in more complex rotating hurricane like structures .
    So definitely depending on the speed fo rotation and the thermal properties of the atmosphere (heat capacity , thermal conductivity , density) the planet would exhibit a large range of probably very violent weather features .

  182. Re: TomVonk (02:37:24) :

    “That’s why for a layer in LTE , we have a constant temperature from which follows that the rates of absorption must necessarily match the rates of emission .
    If they didn’t , it would mean that the populations of any quantum level vary with time what contradicts the hypothesis that the layer is in LTE .
    So on the contrary in the general case these rates must match because the relevant part of the atmosphere is in LTE .”

    This is just not true. Constant temperature requires rate of energy in, equals the rate out. Heat a gas by another means and it can have a net radiative output and a constant temperature. This is the case for the atmosphere the radiative deficit being made up from sources like latent and sensible heat.

    Alex

  183. anna v (22:03:07) :
    anna v (22:16:24) :

    Yes, yes, Anna.

    Read my reply to Ron House (05:31:04) first.

    If you can, keep thermodynamics and QM in mind but by my careful definition, drop them for a minute. Go back to the basic laws they are built on.

    And my only point of all of that was to press the problem I have with radiation and the way it’s currently viewed in science many places and papers, irregardless of whether you speak of classic, thermodynamically, or QM. I’m staying away from angles so sine and cosine factors don’t get dragged in to the conversation. The ‘other’ molecules can have angular velocities but their velocities are irrelevant in my case. I’m not tracking their velocities and therefore momentum. Radiation emitting from the sun will, irregardless of how many interaction and collisions occur, press down on the gases. And, radiation emitting from the surface of the earth will press upwards on the gases, even if a gas (like CO2) has absorption bands in proper frequencies and absorption is occurring. (Of coarse, allowing for the angles created).

    I read statements about upward dwelling IR being absorbed by CO2, heating it, and it re-radiating (50% minus dip) back down to the surface and that traps the heat. That to me that totally violates conservation of momentum without accounting for the upward pressure which, since there is no ‘top’ on the atmosphere, will expand it, if pressure preserved in the long run. You have basically have created heat from nothing. Photon leaves surface, absorbed, molecule has v of one upward. Molecule emits photon down and absorbed by ground, molecule has v of two upward. The affect on the ground is null. The molecule has velocity up and therefore heat but from what? Nothing!

    We can speak of energy, and of coarse you must in certain cases, and energy must always also preserve, but you lose the vector components which is vital to my point, but science lets me to take that view if I define it that way and in this specially defined view.

    Now, do you now see a little deeper in my example. Dr. Spencer’s example brought all of this to mind again and I thought this a place to clarify if someone knew enough to grasp, it seems you do.

  184. anna v (22:16:24) :

    Oh, forgot to mention… this of coarse only occurs if the photons interact in some way when passing thru! No interaction, no effect.

  185. Anna:

    Now think this. A experiment on CO2 in a lab. The gas is in a enclosure of some sort, lets say flask. Irradiate it. It heats. It can’t expand. Pressure goes up and temp goes up.

    Now do same experiment in a topless flask, which we probably can’t do in the lab. The gas can now expand as it heats. I am not that versed in TD enough to answer that question but the results will differ. Do you know in what way? Temp will go up once but CO2 can’t keep absorbing if it’s already in an excited state. A one time increase, right?

  186. “”Alex Harvey (03:17:28) :

    Re: TomVonk (02:37:24) :

    “That’s why for a layer in LTE , we have a constant temperature from which follows that the rates of absorption must necessarily match the rates of emission .
    If they didn’t , it would mean that the populations of any quantum level vary with time what contradicts the hypothesis that the layer is in LTE .
    So on the contrary in the general case these rates must match because the relevant part of the atmosphere is in LTE .”

    This is just not true. Constant temperature requires rate of energy in, equals the rate out. Heat a gas by another means and it can have a net radiative output and a constant temperature. This is the case for the atmosphere the radiative deficit being made up from sources like latent and sensible heat.

    Alex
    “”
    I think Tom Vonk and I are in agreement here, but perhaps neither of us have explained things successfully.

    There is conservation of energy present so if the power in doesn’t balance the power out, there will be a change in internal energy – like a change in temperature or phase change. That includes latent & ssensible heat or conduction and convection as well as radiative. This is not the issue being covered.

    What is being covered is that for a parcel of air with ghgs (a thin shell), the emission curve is actually going to be equal to the absorption curve multiplied by the maxwell boltzman black body emission curve such that where there is absorption likelihood of 1 (total absorption) for the parcel then there is an outward emission equal to that of a blackbody at that wavelength and where there is an absorption likelihood of 0, there is no emission. Tom describes it in qm terms that the maxwell boltzman distribution is the distribution of energy states for the gas at its temperature.

    LTE, local thermodynamic equilibrium is referring to the fact that in a tiny area, all molecules will be at the same temperature due to energy sharing by thermal collisions. It this were not the case, the N2 molecules might be at 300k while O2 molecules might be at 320k and the co2 molecules in that tiny area might be at 390k or 220k. That is, there would not really be a unique temperature for any tiny local region.

    A consequence of this emission absorption relationship is that if the parcel were at the same temperature as the surface (assuming only one parcel for a moment) then there would be no absorption spectra seen and if the parcel were at a hotter temperature, then there would be emission lines present. Finally, if the parcel of air were cooler, there would be absorption lines present but rather than the maximum absorption being one or the output power at a maximum absorption wavelength being zero, the outgoing spectrum would show the power output at these maximum absorption wavelengths as being at the rate of emission of a black body curve for the temperature of the parcel.

    A final factor is that the parcel’s outward emission would be the same as its downward emission such that the absorption of radiant energy would be E and the outward emission E and the downward emission of power would be E, assuming the temperature was the same as the surface – that gives 1 E in and 2 E out – an imbalance. That means the temperature of the the parcel would have to drop to the level such that energy is conserved. If it’s in an area where there is convection bringing in more energy, then that temperature can be higher. However, one has a lapse rate defined here without convection.

    If you have the same T for space above as for Earth below, then you have balance where the parcel reaching T as there is 2 E coming in and being absorbed and 2 E going out by emission and that means and no convection going on since there is no delta T. Note it is a thin and tiny parcel or the geometry will make things rather confusing and complex.

  187. >> ginckgo (21:08:23) :

    So what was earth’s climate like 200,000 years ago, Dr Spencer? Oh, that’s right, God hadn’t created it yet…
    <<

    If you actually read the link you provided you will note than Dr. Spencer never stated or implied that the Earth was less than 200,000 years old; his statement supports the big bang creation theory. So much for your pathetic ad hom attempt. Why is it that Big Climate seems to put forth ad hom attacks as their only 'science'?

  188. Re. suricat (19:44:33) :

    “I reiterate that; any mass above absolute zero temperature radiates its temperature signature until its mass temperature returns to absolute zero (though this is unobtainable).”

    But for many simple gases like N2, that signature is “effectively” no emission.
    Incredible as it may seem such gases have virtually no radiative emissions when at earth-like (e.g. room) temperatures.

    Yes, it is true that N2 does have IR emission/absorption spectra but the peaks are few (very few compared to CO2) and they are tiny (about 10 orders of magnitude smaller). The are also well off to the high wavenumber end for earthlike (~290K) temperatures.

    It is effectively IR transparent, so much so that it is used to backfill to obtain standard pressure when measuring the spectra of other gases. To all intents and purposes it cannot lose heat by radiating it away, when at earthlike temperatures. An atmosphere consiting of N2 would fit the bill of being free of the GH effect. Unless one wishes to be difficult.

    Alex

  189. Re. cba (05:40:39) :

    I do not have a problem with your explanation and near the end you point out that the absorption does not match emission when the radiative field from above is deficient as is the case here. That is correct, but the statement I objected to states something that neither of us seems to agree with.

    Alex

  190. Thanks to Dr Spencer for providing us with the opportunity to learn something. As the scientists would say “This discussion raises the question: Could a planet with a transparent atmosphere have more violent weather than one with abundant water and plenty of CO2?” Haven’t we noticed a decline in hurricanes and tornados in recent years? If heat can exit the atmosphere at low latitudes, doesn’t that mean there is less heat to be rejected at the poles?

  191. anna v (04:58:10) :

    Oh, I’m rolling! That’s a great one!! Exactly. It’s scientifically impossible. CO2 cannot increase heat period from re-radiation.

    Another thing I never hear in the conversions is the lifetime of the CO2 molecules and their heat, molecular level. It begins is life inside engine cylinders and furnaces mainly. Totally excited and HOT!! Do you think the radiation from the sun can further heat this CO2. I hardly think so!!

    All but a small fraction of this excess heat (above ~60ºF global average) will radiate to space in the same way my hot patio concrete will. On the average these CO2 molecules will also end up in a mixed excited state radiating this difference also into space.

    Along with the understanding above of re-irradiation effect, being impossible, I seem to end up with absolutely no abnormal heating from CO2 at all in the long run. Only a one time heat gain equal to the temperature of all engines, furnaces, homes, and offices in this world. Sounds large but really is minuscule. Might be wrong but can’t locate any more heat.

    Thanks Anna. Its much clearer now.

  192. Re: TomVonk (02:37:24) :

    I think that you need to show more details regarding temperature differences between light and dark sides, and in the case of a rotating earth of temperature gradients in general.

    Without the GH effect it is neither clear how, or why, the temperature of the atmosphere would change much even if the surface temperature rocketed up and down. There is a lot of radiative coupling between the surface and the atmosphere that would be missing in a world free of the GH effect.

    During night conditions the atmosphere cools itself and and provides heat to the surface but the GH effect is significant in this process. With the surface cooler than the atmosphere convection is not going to provide much heat transfer and that leaves diffusion which is relatively feeble.

    During day conditions, convection would be significant but it may just tend to raise the average temperature of the atmosphere above that of the surface, leading to a bit of a standoff.

    It is not at all clear to me how large temperature gradients are going to be created and maintained. So I think you need to show more mechanism in this area.

    Alex

  193. Hi my name is Emily, Wayne is my grandpa, my best grandpa.
    I heard about the global warming stuff and I think that it is all a hoax. My Grandpa said all that they want is money from other people. Oh, and by the way… I loved the energy-free oven. The part I loved most about it was the ”Chicken not included”. Don’t tell my Grandpa i wrote.

  194. alex,

    I’m not sure what Tom Vonck was referring to in his post. (I’m fairly familiar with Tom and english is his second language but I know better than to capriciously tangle with his command of the physics fundamentals). I suspect he may be referring to the einstein coefficients being equal under LTE. Whatever he meant with his statement, it’s not going to violate conservation of energy.

  195. Well however, or by whatever mechanism, the atmosphere warms; and I’ll buy Dr Spencer’s GHG free atmosphere model, that warm atmosphere WILL cool by thermal radiation (at all levels in the atmosphere). That atmospheric emitted LWIR, should by all accounts be isotropic (at emission), so only a part of it is returned to the surface; the rest escapes to space (in the GHG free atmosphere). In fact the amount escaping to space should be about 50% since we have built in no LWIR absorption mechanism into the atmosphere; so both the upwards, and downwards thermal radiation experience no secondary atmospheric absorption.

    So the planet should cool by direct thermal radiation from the ground, as well as thermalr adiation from a conduction heated atmosphere. Note that convection would also come into play in transporting the conductive heated air to higher altitudes, until it too cools by radiation.

    I couldn’t agree more with Dr Roy, that a GHG free atmopsphere would give a quite different planet. Well if the angle of the H2O molecule was 180 degrees, instead of 104.xx it would be quite different too, but we wouldn’t have to worry about it, because there wouldn’t be any life on this planet, if that were so.

  196. The emission of gases in the atmosphere, is spontaneous emission (all directions) or induced emission (in the same direction as the inductor photon)? I think it is mostly induced.

  197. So what would be the source(cause) of induced emission ? I can understand that an excited GHG moleculec ould subsequently re-emit the IR photon; so long as the density is low enough so the mean free path is long enough; but otherwise I would expect that absorbed energy would be shared with the main atmosphere gases in collisions due to temperature. I’ve read that the normal thermal emission, is due to acceleration of charge in atoms/molecules moving due to thermal collisions.

    Alex Harvery above: “”” Alex Harvey (06:41:56) :

    Re. suricat (19:44:33) :

    “I reiterate that; any mass above absolute zero temperature radiates its temperature signature until its mass temperature returns to absolute zero (though this is unobtainable).”

    But for many simple gases like N2, that signature is “effectively” no emission.
    Incredible as it may seem such gases have virtually no radiative emissions when at earth-like (e.g. room) temperatures. “””

    ….asserts that N2 doesn’t emit much in the way of thermal radiation. Now I realize that the Black Body Radiation sets an upper bound to the emissions from matter due solely to its temperature; but I am intrigued by Alex’s assertion that the emission is negligible in the case of N2; he says 10 orders of magnitude less than CO2.

    How is that level Alex compared to the BB theory for that temperature.

    I’m intrigued by Alex’s information; is that due to some extreme symmetry of electric charge distribution in N2 Alex, or what is the Physics behind its low emission.

    Obviously gases do radiate as evidenced by the sun; but I have a hard time believing that the main radiation from the atmosphere (earth) is due to emission from GHGs rather than from the bulk of the atmopshere.

    Others have suggested that during molecular collisions, the conditions might be such as to admit radiative transitions that might normally be forbidden for isolated molecules (of ordinary atmospheric gases).

    If Alex can steer us toward any lterature, it would be helpful.


  198. Alberto (12:20:30) :

    The emission of gases in the atmosphere, is spontaneous emission (all directions) or induced emission (in the same direction as the inductor photon)? I think it is mostly induced

    you’ve just practically said the sky is a laser. Both collisions and spontaneous emission are going on extremely rapidly with good likelihoods that any absorption can be converted to thermal energy.

    There is a problem with the assertion that a molecule or atom can radiate as long as it is above absolute 0. This isn’t the case. They can only radiate at their spectral lines – and if the energy of the atom or molecule is lower than the lowest spectral line it can’t radiate. The BB curve will show the energy distribution for the energy states of the atoms or molecules at that temperature. Solids, liquids, and gases at sufficiently high temperatures can achieve the BB curve because the excited states include all those myriads of high transition numbers.

    The Bohr theory is very instructive in this. Ground state associated transitions form the lyman series and that is in the uV. Visible hydrogen emissions are the balmer series. Each series is an infinite series. In order to emit in the visible, the atom must be excited by uV or enough heat to raise it beyond the excited state necessary to achieve uV emissions. Failure to raise it to that level results in no emission (ignoring the 21cm line which is related to spin).

  199. I think cba is close to the facts.
    There seems to be an opinion that CO2 will absorb all the emitted IR from the surface. That is not correct if one looks at the spectra of each of the gases. Water vapour has a much wider spectra than CO2. On the NASA website I found a statement that water vapour will absorb eight times the IR wavelengths of CO2. By sight of the spectra that appears correct.
    Assuming that the atmosphere is 100% CO2 like Mars would mean that in excess of 70% of the surface emitted IR would be radiated directly to space. However, there will be heat transfer from the surface to the atmosphere by convection (natural and forced). This will distribute heat around the globe and where the surface temperature is lower than the gas temperature (around the dark side) the surface will be heated and radiate. Taking into account convection means that any atmosphere will cause the average temperature of the surface (around the globe) to be higher than it would be without an atmosphere (eg the moon approx 400K to 40K). Finally, the surface will be heated slightly by conduction from the nuclear reaction in the earth’s centre. This is not necessarily an even distribution and will have an effect of atmospheric movements.
    It should also be noted that water (liquid) is almost a black body (average emissivity 0.95). At present the surface of the earth is about 70% covered by water. If there is no water then the planet will be a grey body which will reflect radiation particularly in the UV and visible range.
    On earth the driver of climate is water and water vapor. CO2 makes little or no contribution.

    Happy New Year and stay strong

  200. Thanks for a wonderfully articulate article. Water seems to be the elixir that makes everything possible. Maybe the global warming oh no climate change is happening scientists, ought to go back and think about some of the most basic principles of science and have a bloody good look at how water behaves.

    CO2 = $ = centralised government + corporate dominance = more $’s for the rich.

  201. As a bemused bystander, I am astonished that N2 IR emissivity is a contentious topic amongst people with degrees in Physics. I certainly don’t have one, and I seldom stay at a Holiday Inn, so I would welcome a more intimate exposé of the low energy photon emerging from a dilute gas molecule. Since this is out of the realm of electron promotion, it’s unclear to me where the energy resides before it’s emitted. Is there something about inter-molecular bonds in dense matter that accounts for the difference? Would a lone N2 that has escaped into space keep going until a collision, without slowing down? If it emitted, would it slow down? Let’s assume that it cleverly avoided incoming photons.
    If somebody has the patience to explain the mechanics of cold gas emission in layman’s terms, I’ll be grateful!

  202. Oops! I should have said the drivers of climate are the sun (temperature about 5600K) and H2O in its phases of solid-ice, liquid-water, gas- water vapour.
    CO2 because of its very narrow radiation absorption/emission spectra (some of which overlaps with water vapour) and the very small concentration (about 380ppm or 1.3-2.0% of water vapour) has an insignificant contribution to climate.

  203. Kevin Kilty (21:01:47) :
    “Convection is a heat engine. Without greenhouse gases, though, it would have only a hot reservoir (the surface). Greenhouse gases provide the cold reservoir for this heat engine and without a cold reservoir in which to expel waste any heat engine will stop running its cycle (to do otherwise would violate the second law).”

    I disagree. There are two processes going on. There is a heat engine operating between any hot and cold parts of the surface. Tom Vonk mentioned the day and noght sides, but there are also just albedo differences on the lit surface. The temperature differentials may be not large, but there is a huge solar flux, which even with inefficient conversion still causes vigorous motion.

    The second is the adiabatic transfer, leading to the -9.8 K/km lapse rate. This is a reverse Carnot cycle, driven by the forced motion, and transfering heat downward, until the temperature grad reaches the lapse rate. This absorbs kinetic energy (from the above heat engine), but not much, since the energy just works to overcome the leakage due to thermal conduction, which is small.

    The nett result is quite different to what Roy Spencer says. Without GHG, there would still be atmospheric motion, and a lapse rate of -9.8 K/km.

    I’m travelling at the moment, but when I get back in a couple of days, I’ll post a more detailed explanation on my web site..

  204. Cement a friend (16:26:46) :
    I think cba is close to the facts.
    There seems to be an opinion that CO2 will absorb all the emitted IR from the surface.

    I’ve never seem that before, it’s clearly nonsense.

    That is not correct if one looks at the spectra of each of the gases. Water vapour has a much wider spectra than CO2.

    Yes but much sparser lines, see here (1% H2O vs 385ppm CO2): http://i302.photobucket.com/albums/nn107/Sprintstar400/H2OCO2.gif

    On the NASA website I found a statement that water vapour will absorb eight times the IR wavelengths of CO2. By sight of the spectra that appears correct.

    Running it on Modtran it looks more like a factor of two to me.

    On earth the driver of climate is water and water vapor. CO2 makes little or no contribution.

    Not true.

  205. RE: cba (15:14:41) and All

    I may have misunderstood but seeing as you use the Bohr theory of the atom you seem to be under the impression that electronic absorption and emission (i.e. an electromagnetic wave exciting an electron to a higher energy band) is relevant in any significant way to greenhouse gases. Greenhouse gases at atmospheric temperature ranges are concerned primarily with the exchange of thermal radiation within the IR region.

    The wavelength at which peak emissivity lies varies with temperature. At the temperature of the sun its peak emissivity lies in the visible/UV region. At the temperature of the atmosphere its peak emissivity lies in the IR region, more specifically between the wavelengths of 4 and 40microns. The dominant mechanism of absorption and emission at these wavelengths for gas molecules in the atmosphere is vibrational, for IR wavelengths below 10microns and rotational, for IR wavelengths above 10microns. Electronic absorption and emission as would be described by the Bohr model only comes into play significantly for UV and visible light for any molecule in the atmosphere. Hence the only time we should be concerned about electronic absorption is when it is concerned with SW radiation from the sun.

    On that subject all gas molecules will thermally radiate (i.e. emit radiation of wavelength between 0.1 and 100microns) until they reach their ground or unexcited state (being when they are at 0K). At any temperature above 0K a molecule is excited either electronically, rotationally or vibrationally or a mixture of those and this will cause it to radiate.

    Now, the emissivity of greenhouse gases is much higher in the IR spectrum than non greenhouse gases such as N2 and O2. This is due mainly to greenhouse gases such as H2O and CO2 having permanent dipole moments which means when they rotate and vibrate they emit far more IR radiation. Now given that at the temperature of the atmosphere thermal radiation occurs predominantly in the IR region then that is what makes greenhouse gases such as H2O and CO2 such dominant absorbers and emitters of radiation.

    And finally a concluding remark on thought experiments. Thought experiments are generally hypothetical concepts that cannot be verified experimentally and therefore fall within the realm of tautology rather than science. Science can still benefit from tautology however and has done in the past. Thought experiments are supposed to stimulate thought and debate to help us explore our own understanding and also perhaps formulate empirical experiments with which our scientific knowledge may be tested. The main concept from this thought experiment is that the greenhouse effect tries to cause a very large perturbation in the earths temperature distribution which would not be there in their absence and that certain (maybe not all) weather processes exist as a consequence to work against this perturbation. This would preclude positive feedbacks. Such conclusions from this thought experiment is exactly what Dr Spencer is testing empirically with his wider work on atmospheric feedbacks.

  206. George E. Smith (13:19:15) :
    I’m intrigued by Alex’s information; is that due to some extreme symmetry of electric charge distribution in N2 Alex, or what is the Physics behind its low emission.

    Obviously gases do radiate as evidenced by the sun; but I have a hard time believing that the main radiation from the atmosphere (earth) is due to emission from GHGs rather than from the bulk of the atmopshere.

    Others have suggested that during molecular collisions, the conditions might be such as to admit radiative transitions that might normally be forbidden for isolated molecules (of ordinary atmospheric gases).

    If Alex can steer us toward any lterature, it would be helpful.

    George, any freshman Physical Chemistry text should give you the basics about the homonuclear diatomics, for more detail try ‘Molecular Spectra and Molecular Structure’ by G Herzberg it’s what I used as an undergraduate but I believe there’s been a new printing (it should be cheap).

  207. RE: Oliver Ramsay (20:38:52)

    “If somebody has the patience to explain the mechanics of cold gas emission in layman’s terms, I’ll be grateful!”

    There seems to be a lot of debate going on here about the emissivity of N2 and O2 and it is understandable why. I have dug out two textbooks on the subject which I will quote directly to illustrate a point. The first is from a general fundamental thermodynamics textbook:

    ‘All bodies at a temperature above absolute zero emit thermal radiation’

    The second is from a textbook dealing with the more specific fundamentals of atmospheric radiation:

    ‘Although nitrogen and oxygen molecules can rotate, in so doing they do not radiate (much)’

    Both quotes are technically correct but the second quote is only technically correct because of the word added at the end in parenthesis. Where it not for the added ‘(much)’ then the second sentence would only be practically correct. Most text books a guess would just not bother with the ‘(much)’ and settle for being practically correct. Yes O2 and N2 radiate in the IR region but as far as our atmosphere is concerned I wouldn’t worry about it.

    The second point of confusion is in WHY molecules radiate. Individual atoms can only absorb and emit radiation by electron promotion. Some people seem to have extended this to think that molecules can only absorb and emit radiation by electron promotion but this is incorrect. In fact if the IR region it is excitation and relaxation of internal vibration and rotation states of a molecule that are responsible for the majority of the radiation emitted and absorbed. This is due to the change in acceleration (either rotational or vibrational) of charge particles. Molecules with a permanent dipole such as CO2 and H2O therefore emit far more radiation in the IR region than those molecules which would have to wait for random chaotic fluctuations to cause a temporary dipole.

    I hope that sheds some light on the issue.

  208. Alberto (12:20:30) :

    The emission of gases in the atmosphere, is spontaneous emission (all directions) or induced emission (in the same direction as the inductor photon)? I think it is mostly induced.

    There is total confusion between atomic theory which is beautifully described by quantum mechanics, quantum theory of large numbers, i.e. quantum statistical mechanics, and thermodynamics, which connects through simple statistical mechanics with quantum statistical mechanics.

    If people discussing here have had physics courses I am amazed.

    Forget quanta.

    Classical thermodynamics of the 19th century showed that all matter, which then was separate into solids, fluids and gases, radiates according to the flux=constant*T^4 law. No quanta in the derivations ( first part of my thermodynamics book,Sears,edition 1953, undergraduate thermodynamics).

    Then, at the end of the 19th century, people started thinking: the frequency distribution of the radiation, Wien law, was not exactly right, and Planck’s radiation curve emerged and the whole story of quanta etc. etc.

    Sure, an isolated molecule will not radiate if it is not in the ground state.
    Sure, it might be induced to radiate if it is in a higher state and a proper quantum passes within range, lazers work.
    BUT the atmospheric gases are statistical ensembles of incoherent, i.e. phase unknown and unknowable, origin. There is no way induced radiation at the microscopic level will get coherent in bulk in the atmosphere.

    Now about the question of temperature. Temperature comes from the kinetic energy of molecules. The inetic energy of molecules changes through collisions, even if no atom is in a higher state and can radiate and change its kinetic energy.

    What do collisions mean at the atomic level? That the wanderwaals forces http://en.wikipedia.org/wiki/Van_der_Waals_force , come within range, and very soft continuum photons are exchanged, some of them leaving through space, and diminishing the kinetic energy of the individual atom/molecule. This in the statistical mechanics language means cooling the bulk. i.e.kinetic energy into photon/EM energy.

    Surprise maybe for many here, infrared is a continuum, photons can exist in the whole spectrum etc. etc.

  209. RE: Oliver Ramsay (20:38:52)

    Sorry Oliver but I should correct my previous post. In the last paragraph I said ‘change in acceleration’. This should be ‘change in velocity’ or just plain acceleration.

  210. Correction:
    “Sure, an isolated molecule will not radiate if it is not in the ground state.”
    Sure, an isolated molecule will not radiate if it IS in the ground state.

  211. CBA :
    .
    I agree . Basically we are saying the same thing . In LTE absorption of frequency f = emission of frequency f .
    .
    AnnaV
    .
    Yes you are right , there is sometimes too much mixing between QM and standard 19th century statistical thermodynamics . It is a necessary feature of a successful blog dealing with science . I believe that it is the duty of physicists that post here to help to educate the interested people . Time spent in education is the best spent time .
    .
    Alex Harwey
    .
    You misunderstood . Probably because you have no knowledge of QM . Unfortunately radiation is precisely a domain where QM rules and without at least a basic grasp of it , you can’t hope to understand .
    So I’ll try to go to more details .
    It is the same thing as what cba wrote but explained from the QM point of view .
    A molecule has its energy levels quantified . I say levels because there are several modes – electronic , vibrationnal , rotationnal .
    If we have a large collection of molecules , they will not be all at the same energy level .
    There will be a distribution of the molecules among the energy levels (e.g a percentage X% of the total is at energy E0 , a percentage Y% is at energy E1 etc) .
    IN LTE this ditribution is given by the Maxwell Boltzmann law .
    This law depends only on the energy and temperature .
    In other words the number of molecules in the state E1 (first excited state) in a TINY volume in LTE (like cba wrote) is a constant.
    Now if there is IR radiation with frequency equal to E1-E0 (f.ex the 15µ for a CO2 molecule) , some molecules will absorb it and go from E0 to E1 .
    Doing that , they will INCREASE the %tage of molecules in the state E1 .
    But as the LTE condition is dictating that this %tage must be constant , there is NECESSARILY exactly the same number of molecules in this tiny volume that will go the other way from E1 to E0 and emit a photon .
    That’s why in LTE we have necessarily :
    absorption of frequency f = emission of frequency f .
    The troposphere is in LTE . QED .
    .
    As for the huge temperature differential and in addition to what Nick Stokes already commented .
    The night half will try to go to a radiative equilibrium which is at 3 K .
    The day half will receive all Sun energy and will also try to go to a radiative equilibrium which is above 370K at equator .
    This creates a HUGE temperature differential between the day and the night halves . The result are storms of astronomical power which try to evacuate energy from the day half to the night half .
    If the planet rotates , the differential will be lower but the flow will be much more complex (giant hurricane like structures) .

  212. Re: George E. Smith (13:19:15) :

    I haven’t got a lot of time just now. Please refer to the HITRAN data, it is not freely available at the HITRAN site. But it is here:

    http://vpl.astro.washington.edu/spectra/allmoleculeslist.htm

    Compare the area/molecule for N2 and CO2 (The scales vary from 10^-30 to 10^-18 so make sure you check the scale for each section of the spectra.

    More later, hopefulely.

    Alex

  213. RE: Nick Stokes (20:57:57): replying to Kevin Kilty (21:01:47)

    I think it is hard to call the convection system in our atmosphere anything but a heat engine. We are fortunate to have water vapor in our atmosphere to yield its latent heat of vaporization on condensation to accelerate the process. If the upper atmosphere could not radiate convected heat energy away (a big if in real world situations — this is a thought experiment discussion) then convection would be shut down by the formation of a temperature inversion that should cause the tropopause to be at or near the surface.

    I believe the basic point being made here is that convection cannot continue unless the convected heat can be radiated out from the upper atmosphere. Greenhouse trace gases could provide that outlet as they radiate as well as absorb in the ETR (Earth Thermal Radiation, 6 to 20 micron) band. I think clouds and dust in the upper atmosphere might be even more significant in broadcasting ETR energy out from the upper atmosphere.
    —–
    I note it has been reported that the altitude of the tropopause has increased several hundred feet in the past two decades and researchers including Benjamin Santer of the Lawrence Livermore National Laboratory have identified anthropogenic greenhouse emissions as the primary cause. This suggests to me that the convection engine may be becoming slightly more active to compensate for the minor reduction in the available thermal transmission bandwidth.

  214. “”
    Alex
    .. may have misunderstood but seeing as you use the Bohr theory of the atom you seem to be under the impression that electronic absorption and emission (i.e. an electromagnetic wave exciting an electron to a higher energy band) is relevant in any significant way to greenhouse gases. Greenhouse gases at atmospheric temperature ranges are concerned primarily with the exchange of thermal radiation within the IR region.
    “”

    Actually no, the purpose of the bohr example is to explain the concept that for an atom rather than a complex molecule that longer emission wavelengths are not possible without first exciting the atom to higher states. All emissions to the ground state are the Lyman series in the uV, the visible Balmer series is related to emissions ending at the first excited state and they are all still in the visible. However, with enough excitation, like heat, one can achieve a BB spectrum, like the Sun’s photosphere at 6000k but one is not going to see any emissions from hydrogen in the Earth’s atmosphere due to anything related with thermal absorption and emission. One can then infer the highly limited nature of very simple molecules which do not have tremendous numbers of vibrational and rotational states like the more complex co2, h2o, ch4 molecules.

    In other words, it’s about what is NOT happening in the atmosphere.

    “”
    alexb

    On that subject all gas molecules will thermally radiate (i.e. emit radiation of wavelength between 0.1 and 100microns) until they reach their ground or unexcited state (being when they are at 0K). At any temperature above 0K a molecule is excited either electronically, rotationally or vibrationally or a mixture of those and this will cause it to radiate.

    “”

    While I would have thought that rotational is more past 100 um and that vibrational is dominant from 1 to 100 um at Earth’s temperatures, I can’t agree on this area. You have to have internal states of excitment in order to radiate and for a gas, that is a spectrum of discrete states. Temperature is heat or external motion. If there are no excited states low enough to accept energy into one of these discrete states, then it must remain thermal and cannot ‘cock’ the molecule (like a gun hammer to detente) and ultimately generate a photon. Absolute 0 is when these molecules stop moving around at all. If there is not enough thermal energy to raise the molecule to the lowest excited state capable of emission, then you don’t have the ability to have emission even though you have above zero temperature.

    At least in the bohr case, you have the potentially counter intuitive result that the ‘lowest’ energy states only emit in the uV while a transition between higher energy states can emit in the visibile and IR but for this to happen, it has to be excited to above the 1st excited state.

    As for the rest of your post not specifically commented on here, I think we are in full agreement.

  215. “”
    Alex

    ‘All bodies at a temperature above absolute zero emit thermal radiation’

    The second is from a textbook dealing with the more specific fundamentals of atmospheric radiation:

    ‘Although nitrogen and oxygen molecules can rotate, in so doing they do not radiate (much)’

    “”
    First internal quote – key word is body – a solid or liquid. They’re not talking gas.

    Second internal quote, sounds reasonable.

    I’ve seen line graphs even in the visible for o2 and / or n2 showing these. They are individual lines that are not full absorption for the Earth’s atmosphere even for the entire thickness at their peak. Comparing with co2 that has between 20,000 and 50,000 lines bunched together in bands of full absorption over very short distances hardly makes for much of a comparison.

    I can see a beginning text ignoring the N2 O2 radiation in order to not confuse the student. That’s done all the time, with entire courses. One learns Newton’s theory of gravity first, not Einstein’s general relativity. I think nowadays though that it tends to be mentioned that Newton’s theory has been replaced even while introducing it.

    Note that the mentioned visible is absorption only as the thermal energy is insufficient to raise the molecule to emission in the visible within the Earth’s atmosphere. The energy absorbed in that area is totally thermalized then radiated in the IR where the temperature is sufficient to excite the ghg molecules.

    AnnaV

    while the van der Waals forces do provide more opportunity, I think they are mostly dominant in liquid (fluid) where you have a BB continuum. For our atmosphere, it is well described by the ideal gas law which provides good results, despite the vdW ability to provide more accurate results. For better results, one might use the vdW to describe a gas, especially if it is pressurized.

    There is an intermediate as well, called dimers. This where you can have water vapor continuum based upon groups of h2o molecules as well. Dimers may be somewhat related to vdW forces and may be a form of vdW molecules.

    I think though the vdW effects are mostly towards the very long wavelengths and low energy, far out on the tail of the BB distribution. Whether they are significant w.r.t. conduction in air, I’m not sure. If so, then they would be important for Dr. Roy’s thought experiment. I don’t think they are of significance in the real atmosphere.

    btw, my Sear’s thermo book is also the 1953 second edition, but it is the 5th printing (1964). I liked it much better than Reif which is used sometimes as an undergraduate book and sometimes as a graduate level book.

  216. AlexB,
    Thank you for that.
    I find it easier to visualize vibrational emission than rotational. Rotational seems similar to translational but I don’t see how changes in molecular velocity occur without interaction with other particles. Does N2 radiate so little rotationally because there are not opposite charges constantly changing places?

  217. TomVonk (02:05:57) :
    But as the LTE condition is dictating that this %tage must be constant , there is NECESSARILY exactly the same number of molecules in this tiny volume that will go the other way from E1 to E0 and emit a photon .
    That’s why in LTE we have necessarily :
    absorption of frequency f = emission of frequency f .
    The troposphere is in LTE . QED .

    No, the highlighted part is not correct, it is only necessary in LTE that the transition is made, not that emission occurs, in fact in the troposphere that is effected mostly by collisions not emission. It is the emissivity that equals absorptivity not “absorption=emission” (Kirchoff’s law).

  218. Pseudoscience at its best. For a real eye opener read Dr. Spencer’s “In
    Defense of the Greenhouse effect” that he references. He Say’s,
    ” I’ll admit I used to question it, too. So, many years ago Danny Braswell and I built our own radiative transfer model to demonstrate for ourselves that the underlying physics were sound.” So the model apparently confirms reality.
    But the physics is solid because all values and assumptions put into black
    body theory math is unquestioned and inviolable. Is it? A black body in
    reality is an idealized, fictional body that absorbs ALL electromagnetic radiation that falls on it and at ALL wavelengths. Well unfortuneately there is no material known that exhibits these properties so a black body is an
    abstraction. No true black body can be made real. Black body theory is
    also tied into quantum mechanics but quantum mechanics as far as I can
    tell is a failure. When was the last time you bought a new toothbrush based
    on Qm? The earth is not a black body or a grey body for that matter! The
    earth is continuously and unevenly heated due to cloud cover. Yes that one
    great sore point for modelers, clouds. No matter how many terrabytes you
    have you will never be able to come up with a an accurate algorithm to
    predict them. Uneven heating and uneven emission along with clouds
    causes chaos in the weather system. Chaos by definition defies modelling. There is much to criticize and little space to do it but in short:

    1. Mr. Spencer agrees that the term “greenhouse effect” is a misnomer.
    So he actually agrees that there is really no greenhouse effect
    taking place as in a real greenhouse but then says it has stuck so
    “get used to it.” And of course his articles are full of the term.
    Dr. Spencer ever heard of Mean What You Say And Say What You Mean?
    Incorrect wording leads to confusion. This is why many people
    believe heat is trapped in the atmosphere.
    2. His implication that heat can cool is sheer nonsense. Since when
    does a hot object cool something? The jar experiment he uses
    invalidates this. Just as nonscientific is the notion that layers of
    the atmosphere radiate heat downward. To do this the atmosphere
    must be considered as a source of heat. It is not. Black is not
    white. Net flow of heat is all that counts in the real world not the
    insensible heat referred to by Dr. Spencer. By the way if the
    atmosphere did prove to be a source of heat then overunity or
    free energy would be here already. It isn’t. Here’s the capper:
    “The Earth’s surface cools by losing heat which then chills the
    air in contact with it (nighttime). Hey, Mr. Spencer what planet
    do you live on? (lol)
    3. The earth is open to space and heat is constantly released. This
    does not qualify the earth and it’s atmosphere as a feedback
    period. Talk about positive and negative feedbacks are fantasy
    talk. There are NO experiments that have been done IN the
    atmosphere to confirm this. ERBE and CERES are only precursors
    to the work that should be done (stratosphere, mesosphere).
    Measuring only from the ground and space do not make direct
    measurements. What is going on is inferred from the data using
    algorithms. Water vapor complicates things a great deal.
    4. “The Greenhouse Effect Works For Now”, but as Dr. Spencer so
    \ aptly points out, the Greenhouse part is a misnomer and incorrect.
    So what kind of effect is it then? The retention effect?
    His claim that the theory is supprted by lab experiments is
    false. No lab can replicate the open wild.
    Now the best for the last – He claims the models give a “vertical
    temperature profile that looks very much like what we observe
    in nature. Really, then where is the hotspot shown in all the
    models. It has never been observed or recorded so poor Santer
    had to go looking for it in the noise(desperation).
    I can only conclude that Dr. Spencer is not only in serious denial
    but has succumbed to the next stage, delusion.
    Agw physics is an abstracted idea sprinkled with bits of reality
    so as to convince the masses.

    For The Misled
    Bdub

  219. Brian (09:05:08)

    ” His implication that heat can cool is sheer nonsense. Since when
    does a hot object cool something”

    If an object is radiates heat, it is losing energy and falling in temperature. Take a heated poker out of a furnace and expose it to normal room temperature. What was receiving heat is now radiating relative to its new environment until it thermalises to room temperature. Basic 2nd law of thermodynamics

  220. “The Earth’s surface cools by losing heat which then chills the
    air in contact with it (nighttime). Hey, Mr. Spencer what planet
    do you live on? (lol)”

    Well thats fairly basic. if the surface is lets say 10C, then it doesn’t radiate 10C worth of energy, as equilibrium takes place – if warming takes place at the equator then heat escapes at the poles This heat is carried by convection, not radiation and generally travels around or through greenhouse gases – the consequence is that water vapour cools by evaporation instead of retaining heat and co2 doesn’t do much anyway, which is why the temperature falls with altitude. Even if the earth were superheated, it would return to equilibrium soon as it cools more dramatically. Convection is afairly slow process, although heat tends to stay as long as it can where it is (in the atmosphere where its kept by a mix of air pressure, gravity and other such forces). Heat is not a constant. It is a form of energy that can disippate (2nd law). If you catch wind travelling 20mph across LA at a temperature of 20C, the urban area will increase that temperature to say 23C, thn on leaving the urban area, reduce back to 20C. What happende to that heat? It didn’t maintain itself as a constant, but cooled on leaving the urban zone.

    There is a myth in climatology that heat has all the properties of a solid. Like when you infer resistance and force when pulling alever, that resistance disippates as son as you let go: Energy isn’t a permanent or solid characteristic.

  221. the aforegoing is another way of saying that if there were no inaptly named greenhouse gases, then the temperatures we know would still be about the same as they don’t change the energy in the atmosphere.

  222. OK, lets talk quantum mechanics.

    What is a molecule?
    A molecule is composed of two or three or more atoms and they stay together because energetically it is advantageous to share the electrons then to be apart. Each atom will have its energy levels modified because of the communal share of electrons and many new energy levels will appear because of the extra degrees of freedom available for the electrons to organize themselves: rotational and vibrational depending on the topology of how the atoms are mainly distributed in space. These are the energy levels that absorb and radiate infrared and softer and are distinct for the molecule rather than the atom.

    Let us then have two molecules colliding. What does it mean? It means that they graze close enough so that their electron clouds can interact. Things that can happen are:

    a)the collision is elastic, so only direction changes

    b)the collision is hard enough that one of the atoms gets an electron in a higher state. This will radiate back and the molecules will lose energy

    c)a rotational energy level, or a vibrational energy level absorbs part of the kinetic energy and eventually radiates back to the ground state, maybe in cascade. One or both molecules loose kinetic energy in this way, and the photon(s) leaving has(ve) distinctive energy

    d)the electron clouds interact and one of the virtual photons of the interaction becomes real and leaves taking kinetic energy, without changing the quantum state of the molecules. One or both lose kinetic energy and the photon leaving is in the continuum.

    In a gas we have ten-to-the- twentieth- plus molecules and we need statistical tools and finally thermodynamic quantities to describe the collective behavior. All of these interactions are taking place all the time and the energy loss from departing photons is what builds up to the F=constant*T^4 behavior, where the kinetic energy is hidden in the temperature connection.

    All matter will radiate this way at the specific temperature.

    Now we come to the matter of transparency. Some molecules are more transparent to through going radiations than other molecules due to the specific spectrum described in c) above. Thus given infrared radiation from the ground the process of capture and decay will introduce a delay on the way to outer space by turning photon energy into kinetic molecular and potential and statistically appearing as an increase in temperature, or a delay in cooling. That is what is misnamed “the greenhouse effect” and the responsible molecules are mainly H2O and a bit of CO2.

    So I cannot understand the statement in the post above:

    So, how is this different from what happens in the real world? Well, notice that what we are left with in this thought experiment is an atmosphere that is heated from below by the ground absorbing sunlight, but the atmosphere has no way of cooling…except in a very shallow layer right next to the ground where it can cool by conduction at night.

    If there were no GH gasses the atmosphere would cool even better because it would be transparent to the infrared coming from the ground, and it would radiate with T^4. What happens every night in the dry deserts.

  223. anna v (13:21:20) :

    Don’t know if you are commenting back to me. I totally agree with each of your statements here. You bring in ‘all’ of the other factors happening zillions of times every second. I was careful to only address one particular aspect of this complex system. Heat in the water or ground radiated upward (angle above horizontally). That radiation must end up radiating to space in the long run (many seconds, hours or days) after bouncing for a while splitting its momentum in a zillion parts but the sum of the original parts always adding to that upward angle and velocity it started with (momentum).

    Now you have to look at all of the other processes and interactions, one by one, defined in their own ‘isolated specially defined’ case to somehow understand this very complex system. System level, ruled by quantum mechanics and in isolated special cases thermodynamics.

    Just wanted good minds out there to also think at this core level. Enjoyed the conversion, maybe more in the future on some other aspects.

  224. Here’s a quick calculation on the situation of no ghgs (and no h2o vapor)
    Incoming average power at TOA is 341.
    Earth albedo is 0.31 = 0.22 (clouds and atm) + 0.08 (average surface)
    Energy arriving at surface = 341 – reflected = 341 (1-0.08) = 314 w/m^2
    for balance, outgoing must be equal and since there’s no clouds or ghgs to block outgoing, the average outgoing power then is 314 w/m^2
    doing a reverse calculation from stefan’s law, T = 273K, roughly freezing as compared to today’s temperature of 288.2K which is 15 K lower than present.

    This is different than the vaunted 33k contribution for ghgs because of the difference in albedo. If one holds the albedo constant at 0.31, then the balancing radiation is 235w/m^2 and that corresponds to 254 K which is the 34 deg C below our current temperature level. This assumes liquid water oceans, vegetation, etc. with no ghgs but assumes cloud albedo only. Clouds will block outgoing LWR and raise the necessary temperature somewhat. For Earth to become like Mars or the Moon, the loss of liquid or solid water and vegetation would tend to average out the albedo to around 0.15 – give or take a bit. A snowball Earth would raise the albedo for most of the Earth to get the albedo more towards 0.5 and an even lower temperature.

    Whichever scenario one wants to consider, I think you’ll find that the atmospheric temperature will no longer have a lapse rate or definitely not the current lapse rate and that conduction / convection will basically maintain that for whatever emissions are happening. While there may still be a lapse rate, it won’t be the one we are familiar with. without the secondary effects that become important only after the primary has been ‘thought away’ the lapse rate would tend to zero.

    While simplfied scenarios such as Dr. Roy’s can be quite instructive on the basic concepts, it’s best not to look too closely at them because secondary effects in the real world will start to become important and the power of simplicity becomes lost in additional details that become more important than they would be in the original atmosphere.

  225. cba (14:32:20) :

    I follow you. It’s the same problem I have sometimes when reading comments on isolating examples as the one Dr. Spencer used. I try to follow some rules:

    – You must never bring aspects into thought examples that were never meant to exist in the example in the first place. Follow exactly but be lenient.

    – Assume the person knows what he/she is talking about. If you think he/she meant a different word which makes it correct in your mind, change it, don’t pick on words unless there is no way you can make the speaker correct. Then state it as a question of contention. He might (and probably does) know what he speaking of. Or, state your alternate word so others can use it and maybe make it clear to them.

    – You can go from single particle aspects to higher level aspects (as: thermodynamics) if viewed with unlimited precision as mother nature does but you can never go backwards from equations of macro system and then talk of a particles, especially speaking of vectors in momentum’s case. The macro systems are conglomerates and usually vector aspects in equations don’t exist at all.

    – Don’t speak of up radiation or down radiation, flipping them around without making sure energies (kinetic & potential) and momentum are correctly take into account and are always preserved. Such as talking temperature without also accounting for pressure and volume changes globally.

    Just my view on the subject. Helps to keeps physics conversations sane and clear for me.

  226. Re:P. Nelson (12:05:29)
    Unfortunately you do not understand the argument. Your hot poker example
    misses the point completely. The debate is about the heat of one object
    in relation to ANOTHER object. What exactly are you trying to convince
    me of? Also what did you you think I was talking about when I mentioned
    net heat flow. Your second post is nearly incomprehensible. Heat escaping
    at the poles has nothing to do with the statement.
    Here’s the point:Take a hot summer day, after a couple of hours after dark
    go put your hand on the driveway tarmac (it’s dry , no water) then put your
    other hand in the air. Does it feel as warm? I have done this countless
    times and even without a thermometer it’s easy to tell that the air is
    cooler than the ground. Go back out at midnight. The surface is cooler
    and theres no water to evaporate. Where did the heat go. How about
    straight up towards space. This is confirmed during the day while
    sitting watching the heat waves rising up from the ground. Do they
    move sideways, move up on an angle or dance the jig? No they don’t!
    Heat from the earth’s surface moves straight up causing convection.
    Why? Because if you want to talk cold, is space not at -273 degrees
    centigrade? There are no real physical barriers in the atmosphere to
    simple thermal heat escaping. Fourier’s belief that the atmosphere acts
    as the glass of a greenhouse is simply that, a belief. He did NO
    atmospheric experiments to prove it. The layers in the atmosphere
    are nature’s most efficient way of organizing heat transfer to space.
    Blankets indeed! Oh, CO2 with a concentration of .0387 percent
    by volume is NOT a viable thermostatic control for the planet. At
    this concentration CO2 molecules would have to have nuclear fission
    capabilities. Climate and weather have nothing to do with C02. The
    greenhouse effect is just leftover propaganda that Dr. Roy apparently
    needs to defend and legitimize, but really in relation to the earth its
    just a confused load of poppycock. OH and Anna V., I still want my
    Qm based toothbrush!

    Bdub

  227. anna v (13:21:20) :

    “If there were no GH gasses the atmosphere would cool even better because it would be transparent to the infrared coming from the ground, and it would radiate with T^4. What happens every night in the dry deserts.”

    I don’t do quantum much, but surely you mean that the ‘surface would cool even better’? As atmospheric IR radiative energy transfer is prohibited in this model, the atmosphere must find it more difficult to achieve the LTE that Spencer proposes. Though the prohibition of radiative energy transfer isn’t quite so disruptive as the prohibition of all water, with its latent energy transfer, that he also proposes.
    The only methods of energy transfer open to his model are convection, advection (winds) and conduction, however, the atmosphere isn’t considered a thermal conductor as it insulates heat energy when it can’t employ radiation (molecular diffusion doesn’t really count for energy transfer either).

    My guess is that Roy suggests that ‘radiation’ is limited to colisional energy transfer in his model, but without the evolution of photons?
    Without a better ‘explication’ I’m finding it hard to ‘get my head around’ this model, because TOA (top of atmosphere) becomes a closed boundary to energy transfer without EM (electromagnetic) radiation and we still have the ‘GHE properties’ of thermal inertia against insulation by atmospheric mass to cope with in his model!

    Due to the nocturnal ‘temperature inversion’, the atmosphere can only cool to greatest altitude by warming the point of highest surface altitude. This means that eventually, the planet exhibits an inverse lapse rate because the altitude of atmospheric cooling is at the greater altitudes of the planet surface (thus a near surface ‘sink’ for atmospheric energy).
    I guess that we still will encounter atmospheric dust particles that aid atmospheric warming (global dimming material) from solar insolation as well as IR.
    This can only add to atmospheric energy to the point where it becomes near to 40% of Sol’s radiating temperature source (total speculation on my part).

    Either my reading is illogical, or Roy’s model is wrong.
    I’d prefer to give Roy the benefit of the doubt, so can you tell me where I missed something?

    PS. “What happens every night in the dry deserts”: In ancient Egypt, the manufacture of ice was achieved by covering an area of desert during the daytime and uncovering it at night (or so I’m told). Without the daytime solar insolation on the sand the night-time cooling is/was able to freeze water.
    Just thought I’d add that for social interest.

    Best regards, suricat.

  228. cba (14:32:20) :
    Here’s a quick calculation on the situation of no ghgs (and no h2o vapor)
    Incoming average power at TOA is 341.
    Earth albedo is 0.31 = 0.22 (clouds and atm) + 0.08 (average surface)

    No H2O vapor = no clouds!

  229. Tom_R (06:08:52)

    Spencer says: “The possibility then presented itself that, despite all I had previously thought, Genesis, the first book of the Bible, might actually be true!”

    Of all the books in the Bible, Genesis is arguably the least accurate from a scientific stand point.

    And nowhere does he say the Genesis account is a metaphor or whatever. No, the Bible is “the most accurate and best-substantiated ancient book known to man”. Add to that his unimaginative denial of evolution.

  230. Brian (16:58:38)

    Its P Wilson, not P Nelson.

    The point about the tarmac confirms the argument: Very little radiation leaves the earth to be absorbed by co2 or any other ghg and heat up the atmosphere , regardless of what any constant says about it. Those convectional waves/currents are not at a wavelength that c02 has the sufficiency to interfere with, so what little radiation does leave the earth, which is ideologically imputed to be 235w/m2 by the said constant at – which incidentally is hotter than your body temperature as determined by the basal metabolic rate – NOT), is actually a tenth of what it is calculated to be – air is a poor conductor in any case and ghg’s too sparse to give a greater density of air that would give an increase in temperature.

    Anna – the delay between the transfer of energy from a c02 molecule and its subsequent thermalisation takes place in about a trillionth of a second. Its safe to assume that if heat retains in the atmosphere for any length of time, there are natural forces doing this such as air pressure, gravity, and convection reduction such as clouds. Its warmer during cloud cover as convection is severely reduced.

  231. suricat (17:09:04) :

    anna v (13:21:20) :

    “If there were no GH gasses the atmosphere would cool even better because it would be transparent to the infrared coming from the ground, and it would radiate with T^4. What happens every night in the dry deserts.”

    Heat loss from deserts comes mainly from the fact that they have to thermalise much more with cooler air above – the differential is much greater than elsewhere and this is where Dr Spencer is right – as the ground temperature decreases, it cools the air above it, the air contracts with cooling and floats downwards

  232. “”
    Phil. (18:19:55) :

    cba (14:32:20) :
    Here’s a quick calculation on the situation of no ghgs (and no h2o vapor)
    Incoming average power at TOA is 341.
    Earth albedo is 0.31 = 0.22 (clouds and atm) + 0.08 (average surface)

    No H2O vapor = no clouds!
    “”
    That’s why my original posts has
    “”
    Energy arriving at surface = 341 – reflected = 341 (1-0.08) = 314 w/m^2
    for balance, outgoing must be equal and since there’s no clouds or ghgs to block outgoing, the average outgoing power then is 314 w/m^2
    doing a reverse calculation from stefan’s law, T = 273K, roughly freezing as compared to today’s temperature of 288.2K which is 15 K lower than present.
    “”

    Note that the albedo is broken down between surface and atm (primarily clouds) and that the clouds, like h2o vapor, are not in Dr. Roy’s model. Without ghgs, including h2o vapor, and without clouds, that leads to a simplified average whose surface comes out as 273K which is higher than the typical -33 deg C estimate because the cloudless albedo is going to be closer to 0.08 than to 0.31. I would expect that Dr. Roy’s simple model also ignores scattering and dust effects which would be pretty much the rest of the 0.22 portion of the albedo.

  233. Radioactive Man (Norway) (07:14:37) : (http://theevolutioncrisis.org.uk_testimony2.php) where one can read Dr Spencer’s less than enlightened views on evolution and the historicity of the Biblical Gospels, among other things. I must admit I was quite shocked by what I read. I can’t avoid being sceptical of anything he writes on climate science from now on, even if it isn’t related to his religious/anti-evolutionist views.

    So, I take it we can toss out that Einstein relativity and E=MC^2 stuff too… can’t have anyone with a religious idea doing science, after all, that might lead nuclear reactors and unlimited energy and the modern world.

    I take it from your comments that Jews and Muslims ought not to be allowed into science courses since nothing they might do would be of value… After all, they too believe in Genesis /sarcoff>

    Please, take just a moment to think about intense bigotry in the statement you made and were it leads.

    Also, there is a rather fascinating book that simply takes into account relativity and finds that, adjusting for time dilation in calibrating the clock, Genesis matches rather well with “science as we know it” in chronology.

    http://www.amazon.com/Genesis-Big-Bang-Discovery-Harmony/dp/0553354132

    This topic is being discussed, but politely at:

    http://chiefio.wordpress.com/2010/01/04/darwin-expelled-and-religious-science/

    which is probably a better place for it since Anthony discourages discussion of religion here.

  234. RE: cba (06:28:58)

    ‘If there is not enough thermal energy to raise the molecule to the lowest excited state capable of emission, then you don’t have the ability to have emission even though you have above zero temperature.’

    Vibrational and rotational energy states are internal energy states of a molecule and will cause a molecule to emit discrete packets of thermal radiation down to its ground state. Radiation of the wavelengths which are termed thermal radiation are so called because they are the spectra of wavelengths that molecules emit down to thier ground state.

  235. Oliver Ramsay (08:04:48)

    ‘I don’t see how changes in molecular velocity occur without interaction with other particles.’

    I’m going to attempt an analogy here. As with all analogies if you push it too far it falls down but it is simply to make a point.

    Imagine a molecule as a small Newtons cradle in air. As the cradle swings back and forth it inevitably loses momentum through various processes such as sound. The point I’m making here is that the energy loss is inevitable. It can’t just keep going and going.

    Now the thing which is hard for us to imagine with radiation is that the energy loss requires no medium. Depsite this however if a molecule is on its own in a vacume and excited (i.e. temp above 0K) then energy loss by radiation is inevitable. Lets just consider vibration. The atoms in the molecule vibrate back and forth and this vibration will diminish over time due to thermal radiation the mechanism of which is the change in velocity of poles in the molecule.

    Now as for rotational losses I’m afraid that I have trouble picturing this one too. Rotational losses are to do with angular momentum of components of the molecule such as (but not limited to) electrons. I think mainly of the electrons as I think they are the easiest to visualise. The way I like to think of it is that an electron spinning around in a molecule which has a fairly uniform charge distribution will have a more constant angular momentum than an electron spinning around in a molecule without a uniform charge distribution. Sorry I can’t be more concrete than that.

  236. P Wilson (19:22:20) :
    suricat (17:09:04) :

    anna v (13:21:20) :

    “If there were no GH gasses the atmosphere would cool even better because it would be transparent to the infrared coming from the ground, and it would radiate with T^4. What happens every night in the dry deserts.”

    I don’t do quantum much, but surely you mean that the ’surface would cool even better’? As atmospheric IR radiative energy transfer is prohibited in this model, the atmosphere must find it more difficult to achieve the LTE that Spencer proposes.

    The quantum bla bla was in order to establish that all matter cools by electromagnetic radiation according to the law Flux=constant*T^4 . It makes no sense to say that if there are no GH gases the atmosphere has no way of cooling other than through ground conduction and convection close to the ground. The atmosphere as well as the ground have the T^4 way of radiative cooling regardless of the gas composition.

    How about heat loss on the dark side of the moon? Or is it not loosing heat because there are no gases?

    Heat loss happens in deserts because the ground radiates according to T^4 . Deserts do not get to moon temperatures because of the complicated buffer provided by the atmospheric gases. GH gasses are superior in efficiency of buffering is all. By absorbing and thermalizing they increase the heat capacity of the atmosphere. Each quantum process may take place instantaneously, but the average kinetic energy is increased statistically and thus temperature, which will be lost slowly according to constant * T^4 of the atmosphere, instead of directly at the speed of light with which the ground infrared photon leaves ( which is what happens on the moon).

  237. Brian (16:58:38) :

    OH and Anna V., I still want my
    Qm based toothbrush!

    You already have a toothbrush I suppose? I can guarantee that it is working quantum mechanically at the hbar size level. You are just seeing the quantum statistics of the large number of molecules of which your toothbrush is composed. Every little pressure is at the final end a soft photon emitted by the toothbrush interacting with the residue molecules on your teeth.

  238. Anna v, with respect, measurements and experiments have been carried out by many researchers on combustion gases containing CO2 and H2O (in closed systems) particularly by the late Prof Hoyt Hottel. You will find data and equations in text books on heat transfer (conduction, convection, radiation and phase change). Perry’s Chemical Engineering handbook gives a good summary and includes an equation for determining the absorptivity and emissivity of the total gas (which mainly comes from water vapour and CO2). The table in Perry is for temperatures in heat exchangers and will need extrapolation to lower temperature. Another book I have gives Hottel’s data in graphical form and this goes down to 100degreeF. The equation requires input of temperatures of emitter (surface) and receiver (gas) (or vice versa), the concentration of CO2 and water vapour (expressed as partial pressures) and the beam length (height of various layers of the atmosphere). I have made some reasonable assumptions in the equation and, as I hinted, I found that the absorptivity/emissivity of the CO2 component in the atmosphere insignificant in comparison to water vapour. Hottel (who wrote the section on heat transfer in Perry) has also considered and researched the effect of clouds. It should be noted that water (liquid) is close to a black body (emissivity >0.95)
    I agree with the posts mentioning the naming of greenhouse gases. The earth is not a closed system. One just has to consider leaving a car closed up in the sun. It is hot inside and maybe at first the steering wheel is too hot to touch but open all the doors the the temperatures quickly go down. The heat transfer in the closed car comes from the surfaces absorbing radiation from the sun. Natural convection then heats up the air which rises up but can not go out. The air temperature can get to in excess of 60C (There are now criminal laws about leaving children and dogs in closed cars). If there is a wind blowing when the doors are opened the car will cool much quicker. I have made measurements of heat loss with surface temperatures around 50C and find that with winds around 15km/hr that forced convection exceeds radiation. I have not made the calculations about the earths heat balance but believe that Tremberth et al have very much underestimated heat transfer by convection and evaporation and very much overestimated the absorption/emission exchange between the surface and the atmosphere.
    Everything points to CO2 in the atmosphere making an insignificant contribution to heat exchange and to climate.

  239. AlexB (21:23:36) :

    Oliver Ramsay (08:04:48)

    ‘I don’t see how changes in molecular velocity occur without interaction with other particles.’

    I’m going to attempt an analogy here. As with all analogies if you push it too far it falls down but it is simply to make a point.

    Imagine a molecule as a small Newtons cradle in air. As the cradle swings back and forth it inevitably loses momentum through various processes such as sound. The point I’m making here is that the energy loss is inevitable. It can’t just keep going and going.

    The difference between the macroscopic world and the microscopic world is in that the energy momentum and angular momentum losses happen in a quantized way. It is not a continuum.

    Do not confuse kinetic energy of an atom with the potential energy contained in its electrons. They do not mix. An atom in its ground state keeps going and going independently of its kinetic energy.

    Same with molecules, except that the vibrational and rotational levels are low enough in energy that they can be activated by the soft quanta exchanged in collisions, ( I gave a more explicit picture in a post above) thus changing their kinetic energy.

  240. Cement a friend (22:49:53) :

    I do not disagree with what your are saying. Of course there are many mechanisms and important ones and the gas composition is important.

    What started me is the proposition that the only way the atmosphere can cool is by conduction and convection in the absence of GH gasses. This is not true. The gas in the atmosphere is matter and all matter radiates according to the constant*T^4 law. The constant in this case may be small but not nonexistent as some here have been saying and as the quote I gave above assumes.

  241. Anna v, I respect your views please do not get me wrong. I am sure that you know far more about quantum mechanics than I could ever hope. Thermodynamics is a chemical engineering subject but which always deals with the macro state, so my knowledge is inferior to yours.
    One thing I have found in my past working life is, there seems to be very little communications across the various technical and scientific disciplines (I have also found lack of communications in different industries but in the same disciplines. I think it comes from too much specialisation). The so-called “climate scientists” think they know everything about what occurs in the atmosphere and ignore the vast amount of knowledge and research done outside their sphere of limited knowledge. For example the measurements made on atmospheric CO2 concentrations in botanical research (especially if it has been written in German) has been ignored by the climate pseudo-scientists. It seems to me that the latter also have little understanding of heat and mass transfer or fluid mechanics. Their “black box” models for average global conditions are meaningless. The conditions at day and night, at equator and at the poles can not be linearly averaged.
    Anyway, I wish you a happy new year.

  242. Spector (03:06:07) :
    I believe the basic point being made here is that convection cannot continue unless the convected heat can be radiated out from the upper atmosphere.

    Well, it isn’t true. A convection cell is a cycle, and the heat just has to be transferred from one place to another. It needn’t be removed at the top. The classic atmospheric circulation is the Hadley cell. Hot tropical air rises, it transported poleward, descends, and warms the cool mid-latitude surface. The source of heat is the excess of sunlight over outgoing IR in the tropics, and the sink is the corresponding deficit in mid-latitudes. Incidentally, this cell in no way requires GHG, and would work without them.

    To others, I note a lot of pointless theoretical discussions about whether O2 or N2 can emit IR in the thermal range. They can’t, but this is also a simple matter of observation, well known to Tyndall in 1862,and much more exactly confirmed since.

  243. Phil. wrote
    .
    No, the highlighted part is not correct, it is only necessary in LTE that the transition is made, not that emission occurs, in fact in the troposphere that is effected mostly by collisions not emission. It is the emissivity that equals absorptivity not “absorption=emission” (Kirchoff’s law).
    .
    This is again an example of deep misunderstanding of what LTE means .
    In order to respect the Maxwell Boltzmann distribution in LTE , once a photon is absorbed and the molecules goes from E0 to E1 it is necessary that another molecule goes simultaneously from E1 to E0 .
    It is true that it is not prescribed by what PROCESS this downward transition should take place .
    And it is also true that the gas has 2 processes at its disposal – collisional decay and photon emission .
    Of course I am well aware of all this and my original statement stays correct .
    The proof is trivial .
    .
    Obviously the Maxwell Boltzmann distribution in LTE is achieved by taling in account ALL PROCESSES that modify the distribution of the quantum states .
    And what I said about the couple absorption/emission also applies to the couple collisionnal excitation/collisionnal decay .
    In other words for every molecule that collisionnaly decays (e.g goes from E1 to E0 by collision) there is one molecule that collisionnaly excites (e.g goes from E0 to E1 by collision) .
    It is easy to see why .
    If this was not the case , there would be a net energy transfer of one species of molecules to another by collision (f.ex from CO2 to N2) .
    The result would be what cba already mentionned (but what I believe was misunderstood too) – the temperatures of 2 (or more) species in the same volume would be different .
    And that is precisely a CONTRARY of LTE !
    Actually it is the existence of collisionnal equilibrium that is the necessary and sufficient condition to have an LTE .
    .
    So what stays is that BECAUSE of the collisionnal equilibrium (e.g LTE) the rate of absorption of a frequency f is necessarily equal to the rate of emission of the same frequency f .
    Anything else is a non LTE condition where the standard thermodynamics is no more valid and one must use a quantum mechanical treatment .
    .
    AnnaV
    Yes . Strictly speaking there can be no “GHEless” atmosphere .
    Even an atmosphere made out of N2 and/or O2 only would absorb and radiate in IR .
    The mechanism is known – collisionaly induced absorption/emission .
    It is due to the existence of metastable dimers and multipole moments that exist due to collisions .
    The effect is indeed small compared to the “big” GHGs but observable even in our atmosphere for very dry conditions .
    This effect would still exist in a “GHGless” atmosphere but could no more be neglected because it would be the dominant mode of the radiative transfer .
    Obviously , due to the huge temperature differentials between the day and night halves that I already mentionned , the massive atmospheric flows would contribute more to energy transfers than radiation .
    But as this system would be as chaotic as the one our real Earth has , we all should know better than to think that a small effect has always small consequences .
    In a chaotic system it is not the case .

  244. Spector (03:06:07) :
    Kevin Kilty (21:01:47)

    I’ve now put up a post at my blog explaining why the atmospheric heat engine drives motion independently of the GHE, and why this would maintain the dry adiabatic lapse rate (more uniformly, in fact), and why the main climate circulations would persist.

  245. “”

    “”Nick Stokes (04:35:01) :

    Spector (03:06:07) :
    Kevin Kilty (21:01:47)

    I’ve now put up a post at my blog explaining why the atmospheric heat engine drives motion independently of the GHE, and why this would maintain the dry adiabatic lapse rate (more uniformly, in fact), and why the main climate circulations would persist
    “”
    And what drives your perpetual motion machine there Nick?

    I did notice one correct statement there. That was adiabatic lapse rate not relying or not being associated with radiative emissions – something that would violate the concept of being adiabatic. It’s also a failing or limitation of the ideal gas law.

    Usually in this world, parcels or balloons rise due to lower density. That is caused by moisture content and by warmer conditions. In Dr. Spencer’s discussion, the moisture content is not there, leaving only warmer conditions to permit your balloon to rise. As it rises, it expands out doing work and hence cooling off. As it rose it, the area below was forced to be filled by other air that started off cooler but when it went lower in the atmosphere, the pressure increased, doing work that warmed the replacement gas. Without the radiation, all that is available to lift the balloon or parcel is the lower density due to the heat. As the altitude pressure drop expands, that heat goes into the expansion leaving the density to reach that of the surrounding air – where the parcel no longer rises in altitude. It stops where the densities are equal and that is where the temperatures are equal (dry adiabatic conditions). There is no cooling or warming going on from outside as that violates the concept of being adiabatic. Note that the energy work activities going on include both against pressure and against the graviational effect.

    Might I suggest rereading the wiki article you reference. I think it is accurate enough to provide details.

    If you want energy transfer, you’ll have to consider the more complex case of h2o involvement.

  246. RE: Nick Stokes (02:00:20) :

    Responding to my comment “I believe the basic point being made here is that convection cannot continue unless the convected heat can be radiated out from the upper atmosphere.”

    Saying “Well, it isn’t true. A convection cell is a cycle, and the heat just has to be transferred from one place to another. It needn’t be removed at the top.”

    Yes you are right. Convection due to lateral temperature differences should be possible. Without water vapor condensation to accelerate this process and without upper atmosphere cooling, I would guess that such convection would primarily be manifested as laminar surface winds typical of conditions during a widespread temperature inversion.

    In the real world, I believe an important question is, “What fraction of the Earth’s surface heat energy is convected away to the upper atmosphere as opposed to that fraction eliminated by direct thermal radiation?” It should be possible to measure the overall ETR (earth thermal radiation) brightness of the cloud-tops as compared to the ETR from the surface.

  247. ginckgo (2010-01-02 21:08:23) :
    “So what was earth’s climate like 200,000 years ago, Dr Spencer? Oh, that’s right, God hadn’t created it yet…
    http://theevolutioncrisis.org.uk/testimony2.php

    Well, at least the “science” of origins of life is in fact nowhere to be found. As yet. Given a first replicator incorporating a universal constructor as well, darwinian evolution may be possible. However, even in this case the issue of ability to increase complexity or the lack of it thereof is far from resolved.

    Anyway, both universal constructors (Turing) and replicators (von Neumann) have a lower bound for complexity (somewhere between 50-100 kBytes). It’s an understatement that the spontaneous accumulation of that much (meaningful!) info is unlikely. Remember. Existence of replicators is a precondition to natural selection, not its consequence.

    Based on his testimony, I can’t see Dr Spencer is young earth creationist. If he were, I would consider it a serious issue. As it is, being Christian is a better starting pont to science than anything else.

    For Natural Philosopy is deeply rooted in Christianity.

    To do sciense one has no choice but have some faith in that there are at least some Laws of Nature out there to be found.

    If you do not even believe in the existence of socks, it’s pretty unreasonable to look for them under the bed or anywere else.

    The proposition “There are laws” is not a scientific one. It can’t possibly be falsified. It’s a belief.

    For a Christian, a reasonable belief. For anyone else it just comes from the blue.

  248. P. Wilson (19:11:47)

    Define what you mean by:very little, radiation, heat, ideologically imputed, and said constant. Let’s start there. On the atmosphere I only have this:inert nitrogen and oxygen are insensible retainers of heat. CO2 and all the other
    trace gases are not even worth considering when it comes to thermal heat
    retention. Compare this to water vapour and summed up so economically
    with these two conclusions by Tyndall himself. “He concluded that water
    vapour is the strongest absorber of radiant heat in the atmosphere and is
    the principal gas controlling air temperature. Absorption by the bulk of
    the other gases is negligible.” Nuff said?

  249. TomVonk (02:29:28) :
    Phil. wrote
    .
    No, the highlighted part is not correct, it is only necessary in LTE that the transition is made, not that emission occurs, in fact in the troposphere that is effected mostly by collisions not emission. It is the emissivity that equals absorptivity not “absorption=emission” (Kirchoff’s law).
    .
    This is again an example of deep misunderstanding of what LTE means

    Yes you do misunderstand the LTE.

    In order to respect the Maxwell Boltzmann distribution in LTE , once a photon is absorbed and the molecules goes from E0 to E1 it is necessary that another molecule goes simultaneously from E1 to E0 .
    It is true that it is not prescribed by what PROCESS this downward transition should take place .
    And it is also true that the gas has 2 processes at its disposal – collisional decay and photon emission .
    Of course I am well aware of all this and my original statement stays correct.

    Actually it does not.

    The proof is trivial .

    A circular argument is not a proof.
    .
    Obviously the Maxwell Boltzmann distribution in LTE is achieved by taling in account ALL PROCESSES that modify the distribution of the quantum states .
    And what I said about the couple absorption/emission also applies to the couple collisionnal excitation/collisionnal decay …………..
    Actually it is the existence of collisionnal equilibrium that is the necessary and sufficient condition to have an LTE .

    Correct

    So what stays is that BECAUSE of the collisionnal equilibrium (e.g LTE) the rate of absorption of a frequency f is necessarily equal to the rate of emission of the same frequency f .
    Anything else is a non LTE condition where the standard thermodynamics is no more valid and one must use a quantum mechanical treatment .

    So by your definition of LTE it doesn’t apply to the troposphere!
    Bear in mind that LTE is a convenient approximation not a mathematical definition and so can’t be used in the manner you are attempting to.

  250. cba (06:02:55) :
    And what drives your perpetual motion machine there Nick?

    The same as keeps the atmosphere in constant motion at present. Solar radiation, creating temperature differences, primarily latitudinal. The heat engine is driven by heat flow from the hot spots to the cold. The sources are maintained by a local excess of solar input over IR outflow; the sinks are maintained by a deficit.

    Rising air parcels, where the lapse rate is less than 9.8 K/km, are not rising through buoyancy. That works against the rise. The rise/fall is forced by the fluid mechanic consequences of the heat engine – the KE of eddies that are present through the atmosphere, and are created primarily by lateral heat advection.

    The concept of “adiabatic” here is relative. It refers to a stage where isentropic processes (eg compressive heating) are dominant. In the longer term, diffusion will always win out, so nothing in the atmosphere is truly adiabatic.

  251. anna v (00:06:39): (And all posts above.)

    Anna, could I have one more post from you. You have clarified so much for me! Have read many books but with no higher courses with professors to re-word many aspects, I could never get it all crystal clear.

    Is this basically correct in all aspects? Don’t go any deeper into finer aspects but note back if something is blatantly incorrect.

    There are two fundamentally different types of radiation from matter. One is excitational radiation. The other is energy related radiation which includes linear-kinetic, rotational, and vibrational. The rotational and vibrational only occur in molecules, not singular atoms.

    Excitational radiation occurs when a photon of matching energy, maybe even matching or higher energy with residuals(?), as photon is absorbed and electrons are promoted to higher shells. Excited matter can re-radiate as electrons drop back to lower shells at some time in the future. The excitation or absorption also imparts a linear, rotational, or vibrational momentum to the particle upon absorption per conservation laws.

    Linear energy radiation can only occur if there is interaction with other atoms or molecules. Rotational energy radiation in molecules also only occurs upon interactions with other particles. The interactions can also be with virtual particles if quanta levels and quanta interactions permit.

    Vibrational energy radiation will occur until all of this type is radiated or dispersed away to other particles (may be with the same molecule). This energy is an oscillation between kinetic and potential.

    All except excitational radiation occurs always and constantly in all matter. There are factors, such as emissivity, which affect how efficiently a certain type of matter absorbs and emits kinetic radiation. Other factors affect rates.

    While digesting all aspects discussed in WUWT, this clarity will help!

    Some talk of one of these aspects of energy (temperature) transfer but forget one or more of the others. Maybe it will help them also.

  252. RE: anna v (22:59:02)

    I know that energy is quantised thankyou anna. You will see I wrote at the start that if you push the anology too far it falls down as you have done. Regardless of weather the electrons in a molecule are still orbiting in the ground state or not they will still inevitably achieve that ground state if they are excited above it and left in isolation. Some molecules do it faster than others but N2 will still achieve its ground state inevitably if left alone in a vaccum. Even though the electrons continue to orbit.

  253. Re: anna v (00:06:39):
    Clarification: All except excitational radiation occurs always and constantly in all matter through interation/collision with other matter.

  254. sorry there nick but I was unable to see anything that even vaguely appeared to be associated with thermodynamics.

  255. cba (14:54:46) :
    Well, let me try again. A convection cell is a heat engine. Imagine an insulated room with two plates in the floor on opposite sides. One is held at 50C, one at 0C. warm air rises from the hot plate, crosses the ceiling, descends and is cooled by the cool plate, then goes on to be warmed again. A temp diff is converted to kinetic energy (and dissipated by viscosity). Classic heat engine. The Earth’s Hadley cell is just one such an arrangement on a large scale.

    Then in an atmosphere with less than the dry adiabatic lapse rate, you have the reverse. A heat pump can exist with these Carnot-like steps, visualized with a rising/falling balloon:
    1. From an initially isothermal state, you raise it rapidly by 1 km. The air expands adiabatically and cools (by 9.8 K). Because it is denser than the surrounding air, work is done to raise it.
    2. The balloon is then held still until it warms to the ambient temperature, absorbing heat from the high altitude. It expands further, doing wasted work displacing gas.
    3. The balloon is then quickly lowered 1 km. It is compressed, becoming hotter than ambient (by 9.8K), so work is needed to pull it down.
    4. Again, the balloon is allowed to cool to ambient, delivering heat to the lower altitude. The cycle can repeat.

    Like an aircon on a room without heat sources, the work required to maintain the lapse rate depends on the leakage – heat that flows back against the temp gradient, which for a room you try to block with insulation. In the air, that leakage comes from turbulent heat diffusion, maybe augmented with latent heat. But that isn’t much, and the KE generated by convective flows is enough to drive the pump effectively.

  256. “”
    Nick Stokes (16:14:04) :

    cba (14:54:46) :
    Well, let me try again. A convection cell is a heat engine. Imagine an insulated room with two plates in the floor on opposite sides. One is held at 50C, one at 0C. warm air rises from the hot plate, crosses the ceiling, descends and is cooled by the cool plate, then goes on to be warmed again. A temp diff is converted to kinetic energy (and dissipated by viscosity). Classic heat engine. The Earth’s Hadley cell is just one such an arrangement on a large scale.
    “”
    Well, the hot air over the hot plate will rise. The cool plate has a serious problem.

    “”
    Then in an atmosphere with less than the dry adiabatic lapse rate, you have the reverse. A heat pump can exist with these Carnot-like steps, visualized with a rising/falling balloon:
    1. From an initially isothermal state, you raise it rapidly by 1 km. The air expands adiabatically and cools (by 9.8 K). Because it is denser than the surrounding air, work is done to raise it.
    “”
    I’ve never seen a cold air balloon rising and floating around the sky.

    When one has a warm parcel of air or balloon, it will rise. Work is done against gravity, increasing the potential energy of this parcel for this to happen. As it rises, it will expand due to lower ambient pressure and the T will drop. This is the physical meteorology 101 explanation of the lapse rate. Otherwise, there is nothing there to do the work of raising higher density cold air balloons.

    “”
    2. The balloon is then held still until it warms to the ambient temperature, absorbing heat from the high altitude. It expands further, doing wasted work displacing gas.
    “”
    Not hardly. LOL! It’s cooler up there, perpetual motion machines don’t work. They violate the 2nd law. The expansion of the balloon has reduced the temperature until (if it’s a parcel) it reaches the surrounding air temperature, air pressure, and hence air density. This defines how high up it is going.

    “”
    3. The balloon is then quickly lowered 1 km. It is compressed, becoming hotter than ambient (by 9.8K), so work is needed to pull it down.
    “”
    hmm, more deux ex machina again. However, LOL, the temperature has reduced by 9.8k accoring to your # 2 and is the same as at the 1km alititude. When it is forced down, it heats up by that 9.8k bringing it up to the same T as the surface started.

    What you don’t have is a carnot cycle going on or a transfer of energy going on. Rather you’ve got a giant ferris wheel. You lift a bucket of air from the ground which was at ground T P and density and lift it up to the top of the wheel where the decrease in pressure dropped the T according to the ideal gas law as the pressure equalizes which puts the T at the dry lapse rate. It then proceeds down, repressuring and increasing its T to that of the surface.

    “”
    4. Again, the balloon is allowed to cool to ambient, delivering heat to the lower altitude. The cycle can repeat.
    “”
    OOPs, one doesn’t have any temperature differential to permit a transfer of heat.

    “”
    Like an aircon on a room without heat sources, the work required to maintain the lapse rate depends on the leakage – heat that flows back against the temp gradient, which for a room you try to block with insulation. In the air, that leakage comes from turbulent heat diffusion, maybe augmented with latent heat. But that isn’t much, and the KE generated by convective flows is enough to drive the pump effectively
    “”
    For your case, the heat doesn’t flow against the temperature gradient or with the temperature gradient. It doesn’t flow at all. LOL!

    If you want to comprehend a heat engine, you’ve got to deal with proper conceptual physics.
    1. heat some air, T goes up, density goes down (pv=nrt)
    2. lower density air is forced up due to the lower density
    3. It continues to rise, pressure drops, temperature drops, density rises until it reaches an altitude where it’s the same as the ambient
    4. note that some air from above is forced down. as it goes down because it’s higher density than the rising hot air.
    5. the dropping air pressurizes and increases in T as the higher altitude parcel goes down.
    6. when it reaches the surface, the pressure and T have risen to local ambient.
    7. golly gee where’s the energy transfer? There must be something else needed.

    let’s try it again.

    This time lets toss in some h2o vapor (something not included in Dr. Roy’s model simplification).
    1. we get a parcel of moist air at surface ambient.
    2. average molecular weight is 28.8 while h2o is 18. It weighs less – lower density even if T is at surface ambient.
    3. lower density parcel rises, pressure decreases, temperature drops
    4. Oh Wait! something’s different here
    5. relative humidity shoots up because it is temperature sensitive
    6. parcel becomes saturated or supersaturated, water drops out, rains out, turns into water particles, liquid or solid. there is less h2o vapor present
    7. cool dry air is denser, falls down, dry air compresses and heats up. It also rehumidifies to some extent if possible.

    ooh, what’s happening here.? Now we have liquid / solid water at the surface. Some evaporates to maintain some relative humidity for the area. Perhaps 15% for an extremely dry desert or 90% for summer on the gulf coast LA swamp area. That evaporation sucks out thermal energy into an internal phase change referred to as heat of evaporation and is greater for water than the specific heat energy required to raise liquid h2o from freezing to boiling temperatures. Of course as that moist parcel flies high where local temperatures are somewhat less, perhaps 1km altitude, the absolute humidity saturation amount drops as a function of temperature. For the h2o vapor to become liquid or solid requires that it give up this heat of fusion / heat of evaportation high up in the atmosphere, and btw, above most of the h2o vapor. That is energy being transferred from surface to high altitude.

    Of course clouds tend to rain, most of which makes it in liquid form back to the surface. Some does not, evaporating higher up instead of at the surface but never the less, absorbing energy for the phase change.

    Care for a redo?

  257. cba (18:04:12) :

    Flew sailplanes years ago, and your example is dead on. And if you fly a sailplane you will get to experience this process first hand. Sometimes violently! Just one time I almost got sucked into a cloud, mile wide cumulus, bad experience. At 4500 ft the rate of rise (by a variometer) was pegged at 1200 ft/min up. It took full flaps, side-slipping, and speeding up to red-line to drop that rate to zero. Whew! By the way, at cloud base the venalation vents were spewing HOT moist air though should have been about 70 degF at that altitude. And as you leave the cloud, just reverse all of the above states, in about 5-10 seconds! 1200+ ft/min down.

  258. I’ve got a photo in a book of a b51 that flew through a thunderstorm. It never flew again. The leading wing edge had softball size holes and dents in it.

    My 1st physics mentor got his diamond (???) rating 40 years ago. Last time I saw him (last year I think), he was still soaring.

  259. cba (19:49:02) :
    Diamond, wow! Never came close to anything like that. At about 60 hours logged a tornado destoyed all planes, school and toe-plane went to California, that was the end of my delightful experience in the 80’s.

  260. Phil. wrote :
    .
    So by your definition of LTE it doesn’t apply to the troposphere!
    Bear in mind that LTE is a convenient approximation not a mathematical definition and so can’t be used in the manner you are attempting to.

    .
    No scientific arguments beside vague handweaving ? Or is it that you really don’t know the definition of LTE ? I said exactly the contrary of your statement – the troposphere IS in LTE . If it was not , one could not define a local temperature .
    OK , here it goes in an even more simplified manner .
    1) The number of molecules in a quantum states E1and E0 is a constant in LTE . This is the result from the Maxwell-Boltzman distribution of the quantum states in LTE .
    No objection ?
    2) Transitions from E0 to E1 and from E1 to E0 for every molecule are done by 2 processes IR absorption/emission and collisional excitation/decay . Of course in reality there are many more energy levels than only 2 but it doesn’t change the principles .
    No objection ?
    3) Collisional excitation/decay is an equilibrium . I repeat – if it was not , there would be a net energy transfer from one molecule species to another .
    That leads to different temperatures in the same local volume . This would violate the LTE condition . This has nothing circular , it is a trivial result easily shown . Either you have LTE or you have collisional energy transfers out of equilibrium . You can’t have both .
    Yes the LTE is an approximation but one that has an accuracy of statistical thermodynamics which is really not discussed by anybody who has learned physics .
    No objection ?
    .
    Well now if you can’t find objections to the statements 1) to 3) above and they are all pretty basic QM since some 80 years , the necessary conclusion is :
    In LTE the rate of absorption of photons of frequency f is equal to the rate of emission of photons of frequency f
    You can be sure that if the M-B distribution of quantum states in LTE was wrong , physicists would have found out already long ago .
    But if you have some personal field theory contradicting QM , you can share it with us just for fun .

  261. Tom Vonk,

    A clarification please. When you talk of the emission = absorption for photons of frequency f, you are only talking about photons emitted and absorbed by the gas and you are not talking about photons from an external source, such as a surface at some other temperature. Is that correct?

  262. anna v (21:58:17) :

    “It makes no sense to say that if there are no GH gases the atmosphere has no way of cooling other than through ground conduction and convection close to the ground. The atmosphere as well as the ground have the T^4 way of radiative cooling regardless of the gas composition.”

    Whilst I completely concur, it also makes no sense to prohibit EM radiation from one type of EM energy transport and not another. Especially when EM radiative cooling caries the least w/m^2 of all the energy transports to the mid tropo (troposphere), where the energy can finally ‘move on’ to be effectively radiated to ‘outer space’. For example, if we look at the radiation budget proposed in Kiehl, J. T. and Trenberth, K. E., 1997;
    http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
    (AKA “the cartoon”) we see that the diagram is slightly confusing for surface to mid tropo and on to TOA (top of atmosphere) for OLR (outgoing long-wave radiation).
    If we look at OLR on the R/H/S of the diagram we see a surface OLR value of 390w/m^2, of which 40w/m^2 finds a ‘window’ through all of the atmosphere to ‘outer space’. This leaves 350w/m^2 at about the mid tropo region of altitude, but there’s only 235w/m^2 of OLR actually leaving the TOA inferring that all the OLR doesn’t actually leave Earth’s climate systems.
    However, take a look at what is a little closer to the extreme R/H/S of the diagram and we notice an entry for “Back Radiation” to the value of 324w/m^2 that is totally “Absorbed by Surface”!
    So it becomes apparent that 324w/m^2 that make the journey to between the mid tropo and TOA are actually ‘reabsorbed’ by the surface to start the journey to ‘outer space’ all over again!
    In conclusion, there are only 26w/m^2 of ‘real’ OLR in the original figure of 350w/m^2 ‘phantom’ OLR to the mid tropo region. Something’s missing!

    It would be ‘good practise’ to look again at the modes of energy transport to TOA and re-evaluate their ‘real’ share in achieving the transport of energy from the planet.
    Though, before doing that, it would also be good practise to include solar insolation to the mid tropo.

    Net energy to mid tropo that achieves ‘outer space’ includes:
    67w/m^2 absorbed from solar insolation. 24w/m^2 from thermals. 78w/m^2 from evapotranspiration (latent transport). 350w/m^2 – 324w/m^2 (+26w/m^2) from surface radiation. This is equivalent to 195w/m^2 of the mid tropo energy that leaves the planet.
    However, OLR from the mid tropo to ‘outer space’ is shown in the diagram as; 165w/m^2 “emitted by atmosphere”; 30w/m^2 emitted by cloud; 40w/m^2 emitted by the “atmospheric window”, which sums to 235w/m^2 and is 40w/m^2 more than is available at the mid tropo altitude.
    Therefore, the assumption that back-radiation is generated within the altitudes above the mid tropo region of Earth’s atmosphere must be incorrect with respect to the ‘K&T’ model. The data suggests that all altitudes are responsible for this “back radiation” as 40w/m^2 must come from within the tropo. Again, there’s something missing!

    The only rationale I’ve seen that can possibly address this is “The Steel Greenhouse”! Though, it’s impossible for that scenario to explain all the convolutions that make up the “Earth scenario”!
    Perhaps the two should be amalgamated together for the inclusion of mass shielding of radiation, or perhaps, “radiative insulation” (the missing “u” factor)?

    Finally. If we take the mediators of OLR to the mid tropo to be 67:24:78:26 to be one emission mole of OLR, this shows the total OLR as 195 to be 100% of a mole of OLR to the mid tropo. Thus, 26/195 is the ‘weighting’ of radiative forcing within this region.
    However, from mid tropo to TOA emission the molar equivalent is 165:30:40 and constitutes a molar equivalence of 235 as a 100% total radiation to space.

    PS. Spector asked for ETR (Earth thermal radiation), so I included this, but I’d imbibed a few glasses of brandy when I wrote it so feel free to find fault. Also I think the linked balance has been updated.

    Best regards, suricat.

  263. Before anyone does make this criticism, I realise that the 40w/m^2 comes from surface to TOA just after I posted. (-: embarrassed :-)

    Best regards, suricat.

  264. Nick Stokes (04:35:01) :

    Just whizzed through your site link. Sorry, but from an engineering POV I can’t accept the Wikipedia definition for the origin of the Hadley Cells. These are clearly centrifuge generations that undergo seasonal forcings from solar insolation as to their equatorial point of origin. Thus, their strong connection with the coriolis effect that is part of the centrifuge phenomenon.

    If the Hadley Cells were primarily generated by solar insolation they would continue to the poles of each hemisphere, much like the Brewer Dobson circulation.

    Best regards, suricat.

  265. Suricat,
    I am glad someone else has recognised that Kiehl & Trenberth’s global energy balance is an hypothesis aligned to the AGW/CO2 hypothesis and is not based on measurements or theory. I understand that Trenberth is named in the leaked correspondence from the East Anglia University CRU.
    There are a number of problems for example
    1/ One can not add linearly the radiation from the surface with a clear sky (no clouds) at day and night nor the radiation from and to the surface at different latitudes.
    2/ The window for atmospheric radiation from the surface should be higher (50% or more on a clear day)
    3/ Clouds cover is uneven and affects the incoming radiation from the sun, the absorbed radiation and the re-radiation both lost to space and back to the surface.
    4/ Convection (forced and natural) which distributes heat around the globe and to the atmosphere is uneven depending on the nature of the surface (eg ocean, deserts, forests, mountains)
    5/ There is storage and release of heat in the ocean over cycles lasting years eg ENSO

    No global balance short term (over one hour or one day), medium term over say one year or one sun cycle (say 11 years) or long term over centuries makes any sense because it says nothing about the mechanisms occuring, the local climate or weather at a particular time or the medium term climate outlook.

  266. Cement a friend (18:08:54) :

    I concur. It’s chaotic!

    No, I haven’t had any brandy (yet). :-)

    Best regards, suricat.

  267. TomVonk (02:09:00) :
    Phil. wrote :

    “So by your definition of LTE it doesn’t apply to the troposphere!
    Bear in mind that LTE is a convenient approximation not a mathematical definition and so can’t be used in the manner you are attempting to.”

    No scientific arguments beside vague handweaving ? Or is it that you really don’t know the definition of LTE ? I said exactly the contrary of your statement – the troposphere IS in LTE .

    And thereby lies the internal contradiction of your argument, your definition requires that absorption at a frequency f must equal emission at frequency f, since this is not true of the lower troposphere it does not meet your definition of LTE.


    You can be sure that if the M-B distribution of quantum states in LTE was wrong , physicists would have found out already long ago .
    But if you have some personal field theory contradicting QM , you can share it with us just for fun .

    Indeed, it is your illogical introduction of the concept that there must be an exact balance between emission and absorption that I object to.

  268. suricat (15:55:20) :
    anna v (21:58:17) :

    “It makes no sense to say that if there are no GH gases the atmosphere has no way of cooling other than through ground conduction and convection close to the ground. The atmosphere as well as the ground have the T^4 way of radiative cooling regardless of the gas composition.”

    Whilst I completely concur,

    It makes perfect sense to anyone conversant with Physical Chemistry, contrary to your statements above homonuclear diatomics such as N2 and O2 aren’t capable of radiatively cooling in the manner you describe.

  269. AlexB (21:27:35) :

    There was some value in the article by Spencer got two things wrong.

    Non-greenhouses gases will radiate at the infrared (not much but will). So the atmoshphere can cool directly. Now assuming that isn’t true there would still be air circulation by convection and heat transfer between the equator and the poles, between areas of different heat absorption, etc. Thus we would have wind, dust devils, trade winds, etc. Which sounds like weather to me. With no water dust would itself have effects. Dust particles can act as radiative bodies.

    Plus he even went on to ask us to imagine that water isn’t a GHG. In that case we would have rain, snow, etc. Sun hitting bodies of water would heat and one would get evaporation. Water vapor makes air less dense and it would rise. As it rose it would cool and then one would get rain.

    So the blanket statement that there would be no weather without GHG is absolutely false.

    The other stuff was interesting. Yes GHG make the air closer to the surface warmer and the higher altitudes colder. This would tend to make for the ability to have tighter convection cells where the heat is being pumped from the surface to be radiated away by the atmosphere at high elevations (instead of only being a medium to transfer heat from surface to surface).

    This stuff should be obvious to someone who understands high school physics at the A+ level. It’s disappointing that someone in the field should misunderstand this.

  270. Phil. (21:09:58) :

    Whilst they are in their diatomic form this is basically true. However, with the soft X-ray and UV components of solar insolation unchanged, O2 and N2 produces ozone and NOx etc. The atmospheric chemistry still continues with all the components that are there, but I don’t know how a, probably, elevated temperature at higher altitudes would affect the chemistry. Accelerate it perhaps? :-)

    Best regards, suricat.

  271. Re my own above;

    I have not the time to read all the comments that I got back then (2007) but some of the learned brethren at RC had a real hard time accepting that noble gases and others like N2 had no significant IR spectrum, and that the lack GHGs could result in a “dead atmosphere”.

    Alex

  272. Roy W. Spencer, Ph. D.

    This is your ‘baby’ Roy, so why don’t you clarify a few things here by participating!

    “The climate of the Earth is profoundly affected by two competing processes: the greenhouse effect, which acts to warm the lower atmosphere and cool the upper atmosphere, and atmospheric convection (thermals, clouds, precipitation) which does just the opposite: cools the lower atmosphere and warms the upper atmosphere.”

    What you describe here are parts of the same thing, “The Greenhouse Effect”!

    If you remove the ‘radiative’ attractor the rest of the system ‘takes up the slack’ in order to maintain a balance at, most likely, another level of equilibrium. However, because you’ve chosen to negate ‘radiative energy transmission’ without ‘mass energy shielding’, ‘surface pressure transition’ and ‘thermal inertia/capacity’ the scenario doesn’t become devoid of “Greenhouse Effect”. You still permit some “Greenhouse” effects!

    If you want any intelligible feedback from your post, I think you need to participate in the discussion.

    Shame on Anthony for allowing your post in the first place, or did he just report this as ‘reportage’, borne of frustration from dearth of ‘news links’ (if this is so, I’ll not expect a reply).

    Best regards, suricat.

  273. Alex Harvey (17:22:20) :

    Noble gasses! I think I empathise with your thoughts on this, though I’ve not read the posts either. A noble gas that forms an ‘amalgam’ displays totally different properties when compared to the original gas. Thus, O2 displays a variant property when compared to ozone (and ozone enjoys two states of existence, O and O3).

    These forms of oxygen seem prohibited in this thread (as they’re ‘radiative’ gasses), but realistically, they are still there, and produced (mediated) by UV and soft X-ray solar insolation.

    Best regards, suricat.

  274. Alex,

    It wouldn’t result in a dead atmosphere. Convection in the atmosphere would still occur but would merely move heat from warmer surface locations to cooler ones. This would lead to wind patterns.

    Even if water were not a GHG the evaporation and condensation of water would occur in a non-GHG atmosphere. This would significantly enhance the ability to transfer heat to the upper atmosphere with convection (because water vapor laden air is lighter, and due to heat of evaporation/condensation).

    The only thing I see GHG doing above this is to cool the upper atmosphere and warm the lower, while allowing convection to move heat to the upper atmosphere and then radiate it from the upper atmosphere to space. This would be intensified by the water based heat pumping described in the prior paragraph, and vice versa.

  275. Alex,

    Also I believe that a helium atmosphere can radiate away energy because gas is a collection of colliding atoms/molecules. The temperature determines the average velocity but there are atoms traveling much faster and slower. Collisions will rarely happen that accelerate particles at a high enough speed to radiate at a frequency that helium is compatible with. So there will be slight radiation at these higher frequencies.

    Yes, it would radiate much less than a black body. Hell, we know this for solids. For example a thermos bottle is mirrored so that it will not radiate away as much heat.

    This is also seen with glass. Black glass will glow bright cherry red at the same temperature at which clear glass only glows faintly.

    Helium should be a very poor radiator of heat at room temperature.

  276. Re Brian Macker:

    You might wait a long time before a cloud of Helium at room temperature emitted a photon. You say you believe it will radiate from some high enery states but can you quantify that in any way? For sure there is a non zero probability but are you taking about an effect big enough to be measured or merely contemplated.

    You think that convection must happen but again how much? Are you talking velocities of metres per second or metres per year?

    You need to show a mechainsm by which heat from the atmosphere is transfered to cold surface regions. Unfortuanately H2O is a GHG so that is out, and convection needs to be proved to occur against a steep inversion or that an inversion would not occur. That only leaves conduction and air is a good insulator and its conductivity falls with falling temperatures. As a reference it takes a 1K/metre (1000K/kilometre) temperature gradient to drive a ~25milliWatt/square metre flux through air at room temperatures. Compare that to the coupling due to GHG in an inversion which is measured in Watts/square metre. The average downflux due to GHGs is I believe around 200Watts/square metre. So by conduction alone we are talking homeopathic amounts.

    Please show a mechanism that will account for the amounts of flux necessary to drive the atmosphere to any significant (noticable) degree.

    Alex

  277. Guys! I’ve just reread Spencer’s post and realised why I can’t ‘get my head around it’. IT’S AN IMPOSSIBLE SCENARIO!!

    First para:
    “The climate of the Earth is profoundly affected by two competing processes: the greenhouse effect, which acts to warm the lower atmosphere and cool the upper atmosphere, and atmospheric convection (thermals, clouds, precipitation) which does just the opposite: cools the lower atmosphere and warms the upper atmosphere.”

    The first mentioned process, “the greenhouse effect” (GHE), is not defined at all, only its expected action.
    The second mentioned process, “atmospheric convection”, is wrongly defined as “atmospheric convection (thermals, clouds, precipitation)” as acting in opposition to the GHE.

    The first point here is. How can a process be defined as ‘acting in opposition’ to another process when the ‘other process’ that it acts against is ‘undefined’???
    The second point here is. “Clouds” and “precipitation” do feed a forcing into, and have parallels with, “thermals”, but they are part of the ‘hydrocycle’ that forces “atmospheric convection” and not a part of “atmospheric convection” per se. “Atmospheric convection” and “thermals, clouds, precipitation” need to be considered separately.

    This supposition is so ‘open’ as to be impossible to define without more information.

    From the GHE side of the argument; the following text of the post reveals no greater detail apart from to reinforce the activity of the process, such as “which acts to warm the lower atmosphere and cool the upper atmosphere,”. However, this similar effect is also seen within the ‘Steel Greenhouse’ scenario. Thus, the shielding of radiation by an interceding mass (which must include a/some gas/gases) constitutes as an absorber/emitter of radiation and becomes a part of GHE by default. Thus, there can be no ‘definition of atmosphere’ for this scenario.

    Hence, there is no question of ‘Earth sans greenhouse effect”, only “Earth sans atmosphere”!

    Look to Earth’s Moon with Earth revolution par annum for equivalence Roy!

    Best regards, suricat.

  278. “You need to show a mechainsm by which heat from the atmosphere is transfered to cold surface regions.”

    That’s easy. Hot air is lighter than cold air. It rises, and colder air comes in to replace it. This forms a circular cycle and as air comes down in cold regions it releases heat to the ground when it touches, and blows across it.

    “You might wait a long time before a cloud of Helium at room temperature emitted a photon. “

    Not really, most of the black body radiation from helium is due to collisions of atoms. The collisions cause acceleration’s in the electrons of the outer shell and the emission of photons.

    … and how about you ponder this. The sun is primarily helium and hydrogen and yet it emits a continuous spectrum, and is not limited to the spectral lines of those two gases. In fact the spectral lines of those and other impurities show up as decreases in emissions, absorption lines.

  279. Brian Macker (20:32:19) :
    “You might wait a long time before a cloud of Helium at room temperature emitted a photon. “

    Not really, most of the black body radiation from helium is due to collisions of atoms. The collisions cause acceleration’s in the electrons of the outer shell and the emission of photons.

    Not at room temperature, check out the Boltzmann distribution at 300K.

    … and how about you ponder this. The sun is primarily helium and hydrogen
    At 6000+K
    and yet it emits a continuous spectrum, and is not limited to the spectral lines of those two gases. In fact the spectral lines of those and other impurities show up as decreases in emissions, absorption lines.

  280. Phil. (07:51:46) :

    “Not at room temperature, check out the Boltzmann distribution at 300K.”

    On both the ‘macro’ and ‘micro’ scales, helium at 26.85 ºC (room temp of 300 ºK and surface pressure) doesn’t radiate energy to 26.85 ºC because, in ‘macro’ the temperatures are ‘~equal’ and in ‘micro’ a state of ‘~LTE’ (local thermodynamic equilibrium) exists. However!

    In the upper atmosphere (thermosphere) the local temperatures are magnitudes above room temperature and expect to radiate to ‘outer space’ (about 2.7 ºK) because there just isn’t the local mass to ‘shield’ (insulate/absorb and re-irradiate to mass) the energy transfers being made.

    Gasses radiate at a rate defined by local temperature and local ‘depth to extinction’ temperatures, thus, temperature ‘differential’ for radiant lifetime defines the rate of energy transmission for radiation. However, the possibility of molecular collision (thermalisation) shortens this ‘lifetime’ of molecular energy content into a ‘shared’ energy with surrounding molecules by ‘collision’. The ‘collision’ aspect reduces with altitude due to the increasing ‘rareification’ of molecular populations per volume per se.

    Best regards, suricat.

  281. hi Alex,

    one such mechanism may be compression due to gravity. the atmosphere is constantly compressed to a higher pressure near the surface. according to the ideal gas law the higher pressure near the surface pv = nkT will cause a higher temperature.

    therefore a sort of heat pump is generated that allows heat to flow against the temperature gradient. it does not violate the 2nd law because external work is supplied by gravity.

    btw, this also explains the temperature on Venus, also without any need of a “runaway” greenhouse effect.

    this is by no means my idea, i am merely restating the work of Thieme:

    http://freenet-homepage.de/klima/atmoseffect.htm

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