Hyperventilating on Venus

By Steve Goddard

The classic cure for hyperventilation is to put a paper bag over your head, which increases your CO2 levels and reduces the amount of Oxygen in your bloodstream. Global warmers have been hyperventilating over CO2 on Venus, ever since Carl Sagan made popular the idea of a runaway greenhouse effect. That was when he wasn’t warning about nuclear winter.

Sagan said that marijuana helped him write some of his books.

I bought off on the “runaway greenhouse” idea on Venus for several decades (without smoking pot) and only very recently have come to understand that the theory is beyond absurd.  I explain below.

The first problem is that the surface of Venus receives no direct sunshine. The Venusian atmosphere is full of dense, high clouds “30–40 km thick with bases at 30–35 km altitude.”  The way a greenhouse effect works is by shortwave radiation warming the ground, and greenhouse gases impeding the return of long wave radiation to space. Since there is very little sunshine reaching below 30km on Venus, it does not warm the surface much.  This is further evidenced by the fact that there is almost no difference in temperature on Venus between day and night.  It is just as hot during their very long (1400 hours) nights, so the 485C  temperatures can not be due to solar heating and a resultant greenhouse effect.  The days on Venus are dim and the nights are pitch black.

The next problem is that the albedo of Venus is very high, due to the 100% cloud cover.  At least 65% of the sunshine received by Venus is immediately reflected back into space.  Even the upper atmosphere doesn’t receive a lot of sunshine. The top of Venus’ atmosphere receives 1.9 times as much solar radiation as earth, but the albedo is more than double earth’s – so the net effect is that Venus’ upper atmosphere receives a lower TSI than earth.

The third problem is that Venus has almost no water vapor in the atmosphere.  The concentration of water vapor is about one thousand times greater on earth.

Composition of Venus Atmosphere

0.965 CO2
0.035 N2
0.00015 SO2
0.00007 AR
0.00002 H2O

Water vapor is a much more important greenhouse gas than CO2, because it absorbs a wider spectrum of infrared light – as can be seen in the image below.

File:Atmospheric Transmission.png

http://www.globalwarmingart.com/images/7/7c/Atmospheric_Transmission.png

The effects of increasing CO2 decay logarithmically.  Each doubling of CO2 increases temperatures by 2-3C.  So if earth went  from .04% CO2 to 100% CO2, it would raise temperatures by less than 25-36C.

Even worse, if earth’s atmosphere had almost no water (like Venus) temperatures would be much colder – like the Arctic.  The excess CO2 does not begin to compensate for the lack of H2O. Water vapour accounts for 70-95% of the greenhouse effect on earth. The whole basis of the CAGW argument is that H2O feedback will overwhelm the system, yet Venus has essentially no H2O to feed back. CAGW proponents are talking out of both sides of their mouth.

So why is Venus hot?  Because it has an extremely high atmospheric pressure.  The atmospheric pressure on Venus is 92X greater than earth.  Temperatures in Earth’s atmosphere warm over 80C going from 20 kPa (altitude 15km) to 100 kPa (sea level.)  That is why mountains are much colder than the deserts which lie at their base.

The atmospheric pressure on Venus is greater than 9,000 kPa.  At those pressures, we would expect Venus to be very hot. Much, much hotter than Death Valley.

http://en.wikipedia.org/wiki/File:Emagram.GIF

Wikipedia typifies the illogical “runaway greenhouse” argument with this statement.

Without the greenhouse effect caused by the carbon dioxide in the atmosphere, the temperature at the surface of Venus would be quite similar to that on Earth.

No it wouldn’t. 9000 kPa atmospheric pressure would occur on earth at an altitude many miles below sea level.  No such place exists, but if it did – it would be extremely hot, like Venus. A back of the envelope estimate – temperatures on earth increase by about 80C going from 20 to 100 kPa, so at 9,000 kPa we would expect temperatures to be in the ballpark  of :

20C + ln(9000/(100-20)) *80C = 400C

This is very close to what we see on Venus.  The high temperatures there can be almost completely explained by atmospheric pressure – not composition. If 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees.

How did such bad science become “common knowledge?” The greenhouse effect can not be the cause of the high temperatures on Venus. “Group Think” at it’s worst, and I am embarrassed to admit that I blindly accepted it for decades.

Blame CO2 first – ask questions later.

=============================

UPDATE: Lubos Motl has written an essay and analysis that broadly agrees with this post. See it here

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455 Responses to Hyperventilating on Venus

  1. Darrell says:

    Great column, and somewhat of a relief. As a teenager I read Sagan’s book where he made this claim, and it scared the hell out of me.

    I feel much better now.

  2. hippie longstocking says:

    Which of course begs the question: Has anyone looked at the overall atmospheric pressure change during this supposed unprecedented warming? No? Oh, well, that data is probably as incomplete as the temperature data anyway, so why let the climate scientologists manipulate that to fit their agenda. I’m sure one of them will model it soon enough and cry out “It’s worse than we thought!” Dolts.

    Disclaimer: The above statement was not meant to offend any real scientologists out there. I’ll get around to offending them some other time and some other place.

  3. Curiousgeorge says:

    Sorry, I must be missing something. I’ve dealt with high pressure gases for many years, and while a cylinder will heat as it is filled to say 3000 psi, it quickly cools. It does not stay hot. So there must be something else on Venus – volcanic activity perhaps is part of it – that is at work there.

  4. jack mosevich says:

    Steve: I did a search and the 1st 20 to 30 sites, including NASA, stated that Venus’s temperature is due to the runaway greenhouse effect. Your analysis is very convincing. Then I found the following which comes to the same conclusion as you with a bit more analysis. I am convinced that you are correct and that the ‘consensus’ is wrong.

    http://www.buzzle.com/articles/how-hot-is-venus.html

  5. STEPHEN PARKERuk says:

    Well thats it. I am not going to venus!

  6. Jonas N says:

    Thanks Steve, interesting post! And if correct and reasonalble, it baffles me that noone else has noted this before …

    This simply cannot be! Other people must have hade similar thoughts and estimates.

  7. The Ghost Of Big Jim Cooley says:

    Here in the UK, our Channel 4 news has been following the Catlin Jokesters in the Arctic. A journalist (I use the term loosely) has just given an appalling piece of television reporting. You can read his dire piece here: http://www.channel4.com/news/articles/science_technology/concern+over+impact+of+rising+ocean+acidity/3638487

  8. Gail Combs says:

    Quick send this information to Lord Monckton

  9. Jason Lewis says:

    What about the fact that the sunlight at Venus’ orbit is almost twice as intense as at Earth’s orbit?

  10. Robert says:

    As far as i understood it would take two things to turn Earth into a seccond Venus, and that is enough time, and about twice the amount of energy from the Sun.

    And this all to start building up the atmospheric pressure which needs a lot of time, more energy means more watervapour, more watervapour means higher pressure wich in result in an atmosphere wich is beter suited to hold an higher temperature. Once all the water in the ocean has been transformed into atmosphere the temperatures will be high enough to start the outgassing of rocks wich raises the temperature and pressure even further. Eventually Earth would look like Venus with a high pressure and CO2 rich atmosphere.

    And that will eventually happen, in a few hundred million to a billion years from now when the sun is (a bit) brighter than it is now.

    So a runaway greenhouse? Yes, but not caused by us puny humans and not tomorrow.

  11. Enneagram says:

    Once again the Flintstones’ Universe Cosmology fails!. Anyone of us can recreate a small Venus in a microwave oven.
    http://www.thunderbolts.info/tpod/2010/arch10/100223.htm

  12. PJF says:

    There is a terrestrial example of higher air temperatures resulting from greater depth / greater pressure – that of the occasional isolation and evaporation of the Mediterranean Sea:

    http://en.wikipedia.org/wiki/Messinian_Salinity_Crisis

    It would be interesting to know what the atmospheric temperature on Venus is at the height equivalent to one Earth atmospheric pressure.

  13. Henry chance says:

    That explains why women are from Venus and men come from Marrs.

  14. Denis Hopkins says:

    That is one of the most interesting articles I have read on here in the 3 years I have been visiting….. Thanks… Just goes to show how we accept things if they are repeated enough. The trouble is that young people will only hear one argument and it, in time, becomes accepted wisdom. There is always the need to be sceptical.

    By the way, on that point “climate deniers” have often been called “flat-eathers”. Most people believe that Columbus was thought to be mad to attempt the voyage west to India because he would “fall off the Earth”. My understanding is that this was a myth put about by Washinton Irvine in the 19th century. Columbus could not get funding because everyone knew the Earth was round. They knew its diameter. They knew you could not carry enough provisions for such a journey to India. Anyone who lives near the coast will see the hulls of ships disappear before the masts. Yet still we think that they thought the Earth was flat in 1490. Despite Erastothenes measuring the diameter in 200 BC to within 1% of today’s accepted value.

  15. CRS, Dr.P.H. says:

    I believe that the presence of sulfuric acid in the clouds of Venus also contributes to its greenhouse effect. Dr. Richard Lindzen touched upon this during his colloquium presentation at Fermilab National Laboratories.

    It’s in one of the 9 parts on Youtube: http://www.youtube.com/watch?v=gMkyjyk-VEk

  16. Jimbo says:

    Talking of atmospheric pressure, co2 and temperature look at mars:

    Carbon Dioxide (CO2): 95.32%
    Temperature: + 1° F, ( -17.2° C) to -178° F (-107° C)
    Atmospheric pressure: 6 to 10 millibars

  17. gnarf says:

    @curiousgeorge
    If you consider a column of the atmosphere in a stable state, with thermodynamics, at the top you have 3K temperature, and you will see that the gradient of pressure implies a gradient of temperature.

  18. MattN says:

    Funny. My brother-in-law brought up Venus the other day. “Why is it so hot there if not because of all the CO2?” My response was, “Are you kidding me with this?”

    “Group Think” just doesn’t adequately decribe it. I really simply cannot figure out how they get this stuff in their brain.

  19. SidViscous says:

    “Sorry, I must be missing something. I’ve dealt with high pressure gases for many years, and while a cylinder will heat as it is filled to say 3000 psi, it quickly cools. It does not stay hot. So there must be something else on Venus – volcanic activity perhaps is part of it – that is at work there.”

    But what is the temp of the ambient air around the cylinder. Your filled bottle has somewhere to transefer the heat too. Where is Venus’ heat sink to spill all that heat into?

  20. Curiousgeorge

    What keeps the earth warm? The sun. Without the sun, the Earth and Venus would be close to absolute zero.

    Now, why is it -40 degrees on top of Mt. Everest? They get lots of sunshine up there and it is the same latitude as Saudi Arabia.

  21. D. King says:

    Thanks Steve.

    92 atmospheres @ 14.7 psi per, is 1352.4psi (Earth)
    @33 ft. per atmosphere that’s about 3036ft (ocean).
    Ballpark SCUBA numbers!

  22. Duster says:

    If you really want to feel confused check out Nasif Nahle’s site: http://biocab.org/Induced_Emission.html. Professor Nahle seems to say that there is no “green house effect,” partly because none of the common models take thermodynamics into account properly. He argues, provided I follow his logic and mathematics correctly, that the thermal capacity of the atmosphere, being orders of magnitude less than the land and more importantly the oceans, cannot add any significant amount of heat to the climate. Instead, the land and ocean during the night damp atmospheric cooling by warming the air immediately above these important thermal masses. According to Nahle, the atmosphere’s primary climatic effect, mainly through convection, carries warmed air away from thermal masses warming it outward and upward to where it radiates away from the planet. This matches discussions on real greenhouse (transparent windows with plants inside) effects, which point out that a true green maintains a warmer environment than the surroundings by limiting convection. Energy loss through longwave radiation is not significant. Consequently the primary heat loss in a greenhouse is through conduction, and glass is a poor conductor.

    Reading Nahle one might get the idea that any explanation of climate that admits to a “greenhouse effect” might be making assumptions that are contrary to the laws of thermodynamics. Not being a climatologist, physicist or engineer, I would really like to see this discussed.

  23. This whole Venus thing goes back the E. Velekofski (sp?) in the 1950’s. Segan, like many others had some rather strange ideas. This one he picked up from Velekofski from one of his books. He wrote several (can’t be sure of the titles). I did try to read them and found his understanding of geology completely screwed up. So I judged his astronomy was little better. Like many strange people he was not completely, wrong just mostly so. Segan is much the same. Some of his stuff is okay and some not so good. When you get down to the facts we know so little about Venus that making any kind of comparison to Earth is rather foolish. Then if we did not have foolish people we would not need the term. Appeals to authority will never go away, let us hope the choice of that authority is a wise one in the future. (It won’t be.)

  24. CRS, Dr.P.H.

    No doubt the Venusian clouds create a barrier to IR. But they are 30 km above the ground surface. Most wavelengths of IR have almost nothing blocking them in the lower 30 km of the atmosphere.

  25. Cam_S says:

    I attended a talk by Andrew Weaver, and this was one of his big selling points of CO2 causing the Earth to get warmer. Venus is hotter than the Earth, because it’s atmosphere is mostly CO2. Not because it is closer to the sun.

    If I remember my basic physics: energy absorbed is an inverse square to the distance from the source. Mercury has no atmosphere, and I’ll bet it’s sunny side is a lot hotter than Venus.

  26. HankHenry says:

    The critical pressure of CO2 is 7,380 kPa. The critical temperature is 30 C. In those supercritical fluid conditions it’s hard to say whether Venus has an atmosphere or an ocean. Pointing to Venus as a model demonstating something about earth is an exercise in lulling the mind into a belief that it understands something that it has a hard time even imagining.

  27. MKELLY says:

    PV=nRT. Venus is hot because of the pressure. I also maintain that some of the supposed 33 C temperature increase due to GHG is really caused by the pressure of our atmosphere. All the gases in our atmosphere would still be gases at the -18 C used as the temperature based on black body radiation. I maintain that the atmospheric pressure should bring us up to 0 C leaving only 15 C for greenhouse effect. Besides Wien Law says the absorbtion line at 15 mirco for CO2 is a temperature of 200K and that will not heat up anything.

  28. Enneagram says:

    What the hell happened at 12.5 kilometers? Each probe went haywire as it passed through a height of about 12 kilometers, or 7.5 miles, above the surface. The temperature and pressure sensors sent back crazy numbers, power surged throughout the probes, and some instruments stopped functioning entirely.” The NASA report found that “the sensors that failed at almost the same time were made of different materials and their electronics were isolated from each other.” Furthermore, some of the strange readings “can best be explained if the probe became covered with a plasma of charged particles.”
    http://www.thunderbolts.info/tpod/2005/arch05/050207electrifiedvenus.htm

  29. hunter says:

    this is an interesting take, but what maintains the temperature?

  30. Zeke says:

    Just because you don’t understand something doesn’t make it wrong… There is a wealth of literature on Venus’ atmospheric dynamics. A good starting point is here: http://www.nature.com/nature/journal/v226/n5250/abs/2261037a0.html

    Also, Carl Sagan smoking pot is a bit of a cheap shot :P

  31. Dr T G Watkins says:

    Excellent post and some interesting links.
    Looking forward to the EPA hearings; not one prominent UK politician has expressed any doubts re. AGW.
    Nearly 44,000,000 hits ! The message must be getting through and a tipping point will come.

  32. Smokey says:

    Zeke says:
    May 6, 2010 at 12:36 pm:

    “…Carl Sagan smoking pot is a bit of a cheap shot :P”

    And what is your opinion of all the ad-hom comments about Viscount Monckton? Are they cheap shots too?

  33. Zeke

    There is a wealth of literature about catastrophic global warming. The weight of the literature is no more interesting than the weight of the duck in the Holy Grail.

    And no, scientists should not be taking drugs.

  34. The Ghost Of Big Jim Cooley says:

    Anthony – have you seen this?!? http://www.telegraph.co.uk/earth/earthnews/7686079/Climate-change-deniers-accused-of-McCarthyism.html

    REPLY: I can’t respond to every crazy journalist out there, and Louise Gray is certainly a victim of retarded thinking. -A

  35. Troels Halken says:

    Why does Venus have a much more dense atmosphere than Earth?

  36. GeoFlynx says:

    This article, more than most, is and example of how blind belief can distort physics almost beyond recognition. Perhaps something stronger that “pot” is at work!

  37. HankHenry

    The Russians have landed spacecraft on Venus and there is no ocean. Just rock.

  38. Curiousgeorge says:

    @ SidViscous says:
    May 6, 2010 at 12:14 pm

    …………………But what is the temp of the ambient air around the cylinder. Your filled bottle has somewhere to transefer the heat too. Where is Venus’ heat sink to spill all that heat into?

    That doesn’t compute. Let the cylinder stabilize at ambient. Then put it in a perfectly insulated container. It will not reheat due simply to pressure. It will stay at whatever temp it was when placed in the container.

  39. stumpy says:

    There is a bigger issues with Venus many wont be aware off, not that long ago scientists thought venus would be a similar temperature to earth. Then a young upstart geologist came along and suggested that Venus would actually be around 450 degrees due to geothermal venting. He was laughed away of course, daring to question concensus, but later on when they actually measured the temperature they found he was almost spot on! This caused a problem for the “experts” so they came up with a compromise, it was called the “green house effect”, rather than accept the geothermal heating scenario they invented a new one so no-one had to be wrong. They all accepted it and shut their mouths. Of course it never actually fitted, as Steve points out, plus the temperature day and night are constant and the poles and the equator the same. This does support geothermal heat, and the atmospheric mass also explains the high air temps better. I am sure no-one really understands Venus, we dont understand earth yet!

    It merely demonstrates that the greenhouse effect when applied to other plants doesnt work, NASA recently found it didnt quite work for Mars either when they tried modelling its climate. Atmospheric pressure is the key and it determines global temperature, its very reliable for predicting weather and temperature change over height changes, we should be looking at changes in atmospheric pressure as well as the atmospheric composition of the atmosphere. Venus merely highlihts the frailty of the “greenhouse” holy cow. It was invented to explain an observation and fortunetly came within a few degrees of observation, but fails any kind of testing when applied to alternative atmospheres!

  40. stephen richards says:

    Or Boyles law PV=RT where P=pressure and R is a constant

    Therefore, p increases T increases proportionally;

    p=9000 times more T = 9000 times more. voilà.
    P= 1 atmos @ 15.9°C (the earth) P = 92 atmos @ 92*15.9=1462°c

    obviously pressure is not the only factor in creating venus’ temperature but you can see where the difference in T comes from.

  41. Bob H. says:

    A lot of years (about 30) ago I took a thermodynamics class. In it we learned that when you increase temperature without increasing the volume, pressure increases. When you increase pressure without increasing the volume, temperature increases.

    This is basic thermodynamics. If we want to make Venus more like Earth, we need to export to Venus some sun-loving, CO2 munching bacteria to turn CO2 into some solid carbon compound. This would eventually decrease the atmospheric pressure and thus reduce the temperature. In fact, if we really want to do geoengineering, Venus would be a good place to practice (until we get it right).

  42. geronimo says:

    Do you know Steve I’d already figured that out, but in the opposite direction, I was trying to figure out why Mars with almost the same atmosphere in terms of CO2 as Venus was cold compared to Venus, and indeed the Earth. I figured it was because the atmospheric pressure was very low, I never connected it to Venus where it’s the opposite.

  43. PJF says:

    “What keeps the earth warm? The sun. Without the sun, the Earth and Venus would be close to absolute zero.”

    Assume you mean surface temps here (both would remain internally hot for a long time without the sun). In the case of Venus it is quite likely that the surface temperature would be hot too, at least some of the time.

    Venus’ atmosphere comes from volcanic outgassing, and Venus is a very different geological animal to Earth. It has no water so there are no tectonic plates. Instead of releasing heat gradually as does Earth, Venus is thought to occasionally “boil over”, where the whole surface completely melts. With the thick atmosphere, a high surface temperature would remain in the absence of solar heat.

    In the outer solar system where the sun’s heat is minimal, the massively thick atmospheres of the giant planets are heated primarily from within and would remain almost intact if the sun was switched off.

  44. Troels Halken

    Venus does not have any limestone, so they have much less CO2 sequestered in rock. Because of this, their atmosphere is much more dense than earth.

    My point is that it is the partial pressure of CO2 (much more than the IR absorption of CO2) which keeps Venus so hot. The implications for earth are completely different, because we have oceans which form limestone, particularly at warmer temperatures.

  45. pat says:

    Venus is extremely volcanic.

  46. stephen richards

    The ideal gas law isn’t quite so simple as you are thinking. As the pressure increases, the volume decreases. In an ideal gas they would exactly balance each other out. But no gases are ideal, so they warm under pressure.

  47. PJF

    Heat flow from inside the earth is much smaller than the energy received from the sun.

  48. Enneagram says:

    What Steve Goddard is trying to tell us is that greenhouse effect will never explain Venus temperature. Would you cook your meals using it?

  49. agimarc says:

    Dumb question: Given that it is hotter on the surface of Venus than the surface of Earth because of the mass of the atmosphere of Venus and the fact that it is closer to the sun and receives more energy than Earth on a daily basis, how did all that mass get into the atmosphere?

    I am familiar with the suggestion written earlier in this thread that Venus started off with liquid oceans that were eventually evaporated, disassociated into hydrogen and oxygen and the hydrogen driven off; and then the carbon dioxide in the rocks baked out to form the atmosphere.

    Given that both planets were formed in the same general region of the solar system accretion disk, does this mean that Earth also has about that same amount of carbon dioxide locked up in the rocks (not to jack up temperatures due to greenhouse, but to increase the total mass of the atmosphere)?

  50. Enneagram says:

    Zeke: Obviously you are NOT our skeptic friend Zeke the Sneak. Don’t you have any creativity as to invent another name but to copy one of ours?

  51. Cam_S

    The amount of solar energy entering Venus atmosphere is about the same as earth, because of the extra cloud cover. Venus reflects most of the sunshine it receives, which is why it sometimes appears so bright

  52. tommy says:

    I also bet the slow rotation speed would also contribitute to the high temps.

  53. Archonix says:

    Curiousgeorge says:
    May 6, 2010 at 12:48 pm

    That doesn’t compute. Let the cylinder stabilize at ambient. Then put it in a perfectly insulated container. It will not reheat due simply to pressure. It will stay at whatever temp it was when placed in the container.

    He didn’t say that. He said that the heat in the cylinder would be taken away by the air surrounding it. The cylinder model of Venus is one where the cylinder is already in a perfect insulator when it is filled with case.

    What happens when you let the gas out of that cylinder at a high rate? Bet it gets pretty cold, yeah? Same effect in reverse.

  54. SidViscous says:

    “That doesn’t compute. Let the cylinder stabilize at ambient. Then put it in a perfectly insulated container. It will not reheat due simply to pressure. It will stay at whatever temp it was when placed in the container.”

    ??????

    Okay sure, point granted. Yes, if we allowed Venus to cool giving it a sink to dump it’s heat into it would not re-warm, absent some outside influence, by pressure alone.

    But what would happen if you filled your cylinder inside of a perfectly insulated conatainer. Would it still cool off?

  55. Onion says:

    I don’t understand the physics but I do think this article is wrong, because Genus being warm because of a greenhouse effect is backed by physicists, not merely an urban legend.

    So the question becomes, where is this article wrong? I don’t understand the physics to know how physicists propose the greenhouse effect works on Venus, but I can observe this:

    -If Venus was that hot because of pressure, then surely Jupiter should be alight in comparison. Jupiter does generate heat, but far too little compared to how warmer Venus is and Jupiter generates it through contraction.

    -Sunlight might not reach the surface, but if nevertheless passes through thick greenhouse gases before being absorbed in the atmosphere, there would still be a strong greenhouse effect.

    -I am not aware that high pressure on the sea floor is proposed to generate heat.

    Anyway those are my initial thoughts on where this article may be wrong.

  56. PJP says:

    The references to Boyle’s and Charles’ law are not correct here.
    In both cases they describe changes that take place when one of the parameters change.

    In the case of Boye’s law it shows the relationship between volume and pressure WHEN TEMPERATURE IS HELD CONSTANT.

    Avogardro’s law is more appropriate, which is basically:

    (P1.V1)/(T1.n1) = (P2.V2)/(T2.n2)

    P = pressure
    T = temp (K)
    V = volume
    n = amount of substance

    This shows that as you increase the pressure of a fixed quantity of gas its temperature increases and its volume decreases.

    You know this from blowing up tires = as the air compresses, it gets warm.
    Does the air in your tires STAY hot? (Answer – no).

    But that doesn’t mean that it STAYS warm. Just because a gas is compressed doesn’t mean its hot forever. That would equivalent to perpetual motion.

    This is the principle of a heat pump and air conditioner.

    Something with a thick atmosphere is not forcibly hot at the surface just because of pressure.

  57. Stephen Goldstein says:

    “So why is Venus hot? Because it has an extremely high atmospheric pressure. The atmospheric pressure on Venus is 92X greater than earth. Temperatures in Earth’s atmosphere warm over 80C going from 20 kPa (altitude 15km) to 100 kPa (sea level.) That is why mountains are much colder than the deserts which lie at their base.”

    Hmmm. I know that’s a popular view but I’m not so sure . . . .

    Indeed, if one compresses or decompresses a quantity of a gas the temperature will rise or fall to reflect the “work” done on on that quantity (for compression) or the work that it does on its surroundings (for expansion).

    But that’s not what’s happening here, is it? We’re not actually moving air from the top of Mt. Everest to the lower parts of Death Valley, doing the mechanical work to heat it up, are we?

    Say I connect a SUBA diver’s air tank to a compressor and “fill” the tank with compressed air. I ask how come the tank is warm and you reply “because it has an extremely high pressure.” Okay, but I come back in an hour, the gauge still reads 3000psi but the tank is no longer warm. How come? The gas is still at an extremely high pressure.

    Just guessing here but I think that the pressure differential, Earth vs Venus, is not a complete explanation.

    Comment?

  58. Onion says:

    The why isn’t Jupiter that hot?

  59. This argument seems quite wrong to me. Pressure and temperature are independent variables — both can be high, both can be low, one can be high and the other low, etc. The temperature of a planet is determined by its energy balance: in the long run, solar energy absorbed must equal long-wave radiation going out. (I am aware that this is a substantial simplification, but it captures the main truth about terrestrial planets.)

    Sunlight is almost twice as intense at the orbit of Venus, but because Venus is more than twice as reflective as the Earth (due to the clouds), it actually absorbs slightly less radiation per square meter. Yet the surface of Venus is hot — we know this by direct spacecraft measurement — so that surface must be radiating long-wave radiation upward like crazy — about 40 times the amount that Earth’s surface radiates. Yet the radiation to space at the top of the atmosphere is only 2% of this. As far as I can see, the ONLY way to explain this is that the atmosphere of Venus strongly absorbs IR. That’s the greenhouse effect, isn’t it?

    How Venus got to be in such a state is another (and very interesting) question. But surely there can’t be much doubt that the present high surface temperature is due to a present very strong greenhouse effect?

    Postscript: I am a physicist, and though my specialty is not atmospheric physics, I do know a thing or two about thermodynamics. I believe that anyone who is cautious and skeptical about AGW is obliged to be equally cautious and skeptical about stuff on the other side. The present argument doesn’t just cut it, in my view.

  60. Hu McCulloch says:

    Very interesting points, Steve. Your point about pressure sounds very plausible, so it will be interesting to see if someone can find a flaw in it.

    It does seem to me that your point that there will be no GHG effect there because incoming radiation can’t reach the surface is weak — The incoming radiation that doesn’t get reflected must get absorbed somewhere, if only by the upper atmosphere. This layer then should act like the radiative “surface” of the planet, and should radiate long IR back into the outer atmosphere where it generates a GHG effect.

    However, it would then seem that the equilibrium temperature of this layer would behave like the surface of an ordinary planet with this distance from the sun, albedo, and upper atmosphere. From that point down, then, temperatures would increase with pressure as you describe, leaving the actual surface temperatures much higher than the “radiative surface” temperatures. (I’m just musing here — an actual physicist should check in on this.)

    It would take a lot more than one doubling of the exisiting level of CO2 to get earth’s CO2 surface partial pressures up to those of Venus!

  61. Fitzy says:

    We grew up to COSMOS on TV.
    Sagan was good at flights of the imagination, even then, Post Normal was trying to lure us with its Siren song.
    Apart from the measurable facts of Venus, its atmospheric properties and temperature, and the known Laws of Thermodynamics, what do we have?
    We have a puzzle, missing a lot of pieces, periodically assembled into a shape, that the public never gets to see scientists label a theory as….”We Think…x,y,z…”
    Thats the bit that drives me crazy, the sudden shift in discussions in private where words like….”we assume, we currently think, the data currently shows, it appears…” transitioning to the printed word as….”Venus is a perfect example of run away green house effect.”
    I blame the French school of Management, which excludes the function of uncertatiny in managers, it filtered into everything in the late 60’s and 70’s, and permeated the mindset of the western man. Now we must all be experts, all the time, if we are uncertain, we keep it to ourselves, because confidence is a component of competence, and we must always have an answer ready. Uncertainty, promotes a lack of confidence, low confidence impacts the bottom line. Cha-Ching $$$.
    Add to that the Human tendancy to seek group approval, and we have the perfect mess of nodding and smiling, and concensus, and approval for policies sake.
    You want to know why Venus is as it is? First ask how Holy has our confidence in the KNOWNS become, is it assailable? Shouldn’t it be?

  62. ShrNfr says:

    And what else about pressure broadening of molecular absorption lines is not understood?

  63. KPO says:

    OT but might be something for another post.
    If you are using the Yahoo browser you’ll probably have seen the latest from the “we’re all going to die” MSM hysteria.
    “Now the bad news: The ozone layer has also thinned over the North Pole. This thinning is predicted to continue for the next 15 years due to weather-related phenomena that scientists still cannot fully explain, according to the same UN report. And, repairing the ozone hole over the South Pole will take longer than previously expected, and won’t finish until between 2060 and 2075. Scientists now understand that the size of the ozone hole varies dramatically from year to year, which complicates attempts to accurately predict the hole’s future size.
    Interestingly, recent studies have shown that the size of the ozone hole affects the global temperature. Closing the ozone hole actually speeds up the melting of the polar ice caps, according to a 2009 study from Scientific Committee on Antarctic Research.
    So even though environmentally friendly laws have successfully reversed the trend of ozone depletion, the lingering effects of aerosol use, and the link between the ozone hole and global warming, virtually ensure that this problem will persist until the end of the century.”
    Thus endith today’s reading according to ….. ah hell, there just so many!!!!

  64. sonicfrog says:

    Funny thing about the Sagan Venus conundrum… that put me on the path to AGW skepticism. I had the pleasure of seeing him in person for a 2 hour lecture in 1992. He presented a lot of his “Cosmos” stuff, and then turn his presentation to global warming , Venus, and CO2. That was the weakest part of Sagan’s presentation. He didn’t cover the great differences between the two planets, atmosphere composition, distance from sun, etc, that make Venus and Earth a poor comparison. At the time, the press was using the Venus analogy to promote AGW, yet, no one would raise the same questions, since, well, it was Sagan after all, everyone was GaGa over him, and who would be so foolish to question Sagan.

    Don’t get me wrong, I love Carl Sagan. Will always be a great admirer of him and his work. I just though that he purposely over-emphasized the weak Venus / Earth correlation to increase the fears and concerns of AGW, a concept he strongly championed. I believe his convictions to save the planet over-rode his common sense.

  65. Onion

    The ocean is made of water, which is a liquid. Unlike gases, liquids are not very compressible, so they do not heat much under pressure.

  66. ShrNfr says:

    To Onion: Jupiter actually emits more energy than it receives from the sun. To expand on my comment previous. The Pauli exclusion principal prevents fermions from being in the same state in the same place. Also leptons. Bosons are a different matter. As you increase pressure on any gas you are forcing more and more fermions into a smaller and smaller volume. The spectral line of absorption/emission of that gas will get wider and wider because the gas objects have to be in a different state than the others. At 60 bars of pressure, CO2 on Venus has a barn door absorption spectrum. At a pressure of a couple of millibars on Mars it’s a razor edge. The earth is approximately 1 bar (the standard atmosphere is 1013 millibars at sea level).

  67. tommy

    Temperatures on Venus are same on the day side and the night side, so at this point in Venus history the rotation speed is probably not a big factor.

  68. tarpon says:

    I think you need to start our discovery of Venus way back in geologic time. Two points to consider, Venus has no magnetic field of significance and therefore no real magnetosphere. Second at the distance it is from the sun, with no magnetosphere to shield it’s atmosphere, all but the heaviest of molecules would have long since been blown away by the solar wind.

    No one seems to know when Venus went magnetically dead, we may never know.

    All that is left of Venus’ atmosphere is what we now see, with no way to determine the complete picture of how it arrived at what is left. Without understanding that, comparisons make little sense. We face similar problems on Earth, don’t we.

  69. geronimo

    Excellent point about Mars.

  70. jorgekafkazar says:

    Denis Hopkins says: “…My understanding is that this [flat earth] was a myth put about by Washin(g)ton Irvine in the 19th century…”

    As a descendant of the Irving clan, I should like to point out that the author you refer to was Washington Irving. There are, on the other hand, no fewer than 145 ways to spell “Irving,” so Irvine is close enough for jazz, hand grenades, astrophysics, and climatology.

  71. Enneagram says:

    Sagan said that marijuana helped him write some of his books.
    The trouble of Marijuana (Pot) is that cannabinoid chemicals resemble almost exactly that of the female hormone (estrogen).
    These results indicate that there are some metabolic interactions between cannabinoid and steroid metabolism and that the constituents showing estrogen-like activity exist in marijuana
    http://www.ncbi.nlm.nih.gov/pubmed/15588936
    So GWRs. sneak out from the closet!

  72. Peter Pan says:

    stephen richards says:
    May 6, 2010 at 12:51 pm

    Or Boyles law PV=RT where P=pressure and R is a constant

    ============================================

    I do believe the greenhouse effect occurred Venus since pressure alone may not completely contribute the temperature increase.

    The reason is:

    On the Venus, temperature increases 400 C at 90 atmos of CO2, that is to say every atmos of CO2 contributes 400/90=4.4 C forcing.

    Since on the Earth, the CO2 pressure is 0.004 atmos (398ppm), the CO2 caused greenhouse effect is about 4.4 X 0.004 = 0.018 C.

    Here we completely recognize CO2 as a greenhouse gas, it indeed causes greenhouse effect on the Venus’ temperature but did insignificantly on the Earth’s because the difference between the concentrations of CO2 in both planetary atmospheres.

  73. TallDave says:

    I was confused where the heat from pressure came from, this helped:

    http://en.wikipedia.org/wiki/Adiabatic_process

  74. kwik says:

    I cant say I follow this idea that its the pressure that keeps Venus warm.

    If you have
    -A big cylinder with a piston at one end, filled with CO2 at one athmosphere, and it is very well insulated.
    -Then compress the Co2 to a very high pressure.

    Okay, now we all know about PV=RKT, so it becomes very hot.

    Now leave it alone for, say, 100 000 years.
    I think we can safely assume this heat would leak out? Sloooowly?

    And that very little heat comes in, from the sun?

    Finally it will reach ambient temperature? Yes?

    The only explanation that sounds reasonable to me, is that someone put a very hot entity inside the cylinder, leaking heat. (Like, a vulcano-entity)

    But then again, I dont know much about Venus. Just philosphying a bit.

  75. hunter says:

    Venus is not volcanic like the Earth or Io is volcanic.
    Something about this pressure = temp explanation does not fit correctly, with all due respect.
    Clearly the energy reaching Venus is going into something, except for that which is reflected.
    But the heat content of the atmosphere, at the massive levels on Venus, means it is much higher, no?

  76. Enneagram says:

    Consensus accepted post normal science can’t explain it. Holy Nasa neither. Only HE who explains how the interior of the earth reaches 2 million degrees can explain it.
    Be highly praised our nefarious prophet!

  77. ShrNfr

    Good point about pressure broadening of spectral lines.

    One more reason why pressure is the problem, not atmospheric composition – and why the Venus analogy doesn’t work on earth.

  78. Peter Pan

    The relationship between pressure and lapse temperature is exponential, not linear. Please look at the Y-axis on the left side.
    http://upload.wikimedia.org/wikipedia/commons/1/12/795px-Emagram.gif

  79. Enneagram says:

    Wait! Has anybody seen if there on Venus cows live?….you know, all that cow farting can provoke such an elevated temperature. Gotto send some texan cowboys up there!
    EPA should issue a ban on all venusian gases!. Big business ahead for Cap&Trade.

  80. Mike McMillan says:

    I did some back of the envelope figgerin’ about Venus here a year or two back. I don’t recall the numbers, but using the adiabatic lapse rate formula, I ran our N2,O2 atmosphere down to 90 atm, and got about a 100 degrees hotter than Venus. I ran Venus’ CO2 atmosphere up to 1 atm, and got around 20 or 30 degrees warmer than Earth, despite being so much closer to the sun.
    NASA has a different adiabatic rate for Venus, however.
    http://atmos.nmsu.edu/education_and_outreach/encyclopedia/adiabatic_lapse_rate.htm
    which didn’t seem to fit from the lapse rate equation.

    We don’t have a runaway greenhouse effect anywhere in the solar system, despite what dead tv personalities said.

  81. Hans Erren says:

    I’m not buying it, did you read any scientific literature at all?
    Bullock, Mark A.; Grinspoon, David H. (March 2001). “The Recent Evolution of Climate on Venus”. Icarus 150 (1): 19–37. doi:10.1006/icar.2000.6570.

    Check for more:
    http://plutoportal.net/~bullock/
    http://plutoportal.net/~bullock/Homedocs/SciAm99.pdf

    BTW The CO2 spectrum is completely saturated in the infrared at 90 atm.
    http://members.casema.nl/errenwijlens/co2/lambertvenus.gif

  82. HankHenry says:

    Steve, my question is still whether when that russian spacecraft is at the bottom of an ocean or an atmosphere. Since the CO2 there is neither gas nor liquid but supercritical fluid, I’m not sure how you say. Remember that our space capsule, Liberty Bell Seven landed on the bottom of an ocean – like the Venera spacecraft. The difference was that Liberty Bell made a short bobble at a liquid gas phase boundary while Gus Grissom panicked and flooded the thing. Sure, light doesn’t penetrate but I am quite confident there was just rock where that space capsule landed at the bottom of the ocean. What do you suppose the density of CO2 is at the surface of Venus? I don’t know, but I suspect that it is much closer (on a percentage basis) to the density of liquid water than the density of air at sea level.

  83. Cold Lynx says:

    Even the greenhouse effect based on “common knowledge” for our earth is fundamentally misunderstood.
    Imagine a atmosphere completely without any greenhouse gas and clouds.
    That atmosphere would still be heated and cooled by our sun.
    Heated by energy from the surface of the earth. Cooled by? Yes the same surface.
    You can heat the entire atmosphere column from the bottom but not cool it from the bottom. It is a fluid where cooler air is denser. A cooling from the bottom is not efficient and THAT cause a greenhouse effect. The atmosphere will have a higher temperature than average surface temperature. Of course with consideration for the lapse rate in height.
    If You then add greenhouse gases in this inert atmosphere is the cooling of the atmosphere enhanced…..

  84. r says:

    How did we get here?
    With this kind of logic:

    If a witch floats, she must be made of wood…
    and what do you do with wood?
    Burn it!

    If Venus has 90% CO2 and is hot…
    and Earth has .035% CO2?

    It must mean APGW!

    My apologies Carl Sagen, loved your show anyway.

  85. timheyes says:

    @stevengoddard

    Despite your explanations involving non-ideal gases, I still don’t find the pressure argument convincing. Apart from that the debunking of the runaway greenhouse effect is very good.

    If I compress a set volume of air in a bicycle pump I can feel it get warmer. This is essentially the conversion of the molecular kinetic energy into sensible heat as a result of the decrease in entropy of the system. But as others have commented above, that heat dissipates out of the system quite rapidly. In order for this to be the mechanism of heating the Venusian atmosphere, there needs to be a constant cycling of (high level) low pressure gas down to the (lower level) high pressure atmosphere. The corollary to this thermal release in downward moving gas is that there needs to be upward moving gas to maintain the cycle.

    This upward moving gas will expand as it rises, drawing the necessary energy from the surrounding gas and cooling it. I’m not sure that this has been demonstrated and, to be fair, you haven’t claimed any of this – it’s just implied by the physics I’ve assumed to be going on.

    What you seem to be discussing in some your responses is the specific heat capacity of the gases which will increase with pressure. However, this relates to the themal capacity of the gas, not the thermogenic ability of the gas which is what is implied by your responses.

    I like most of what you’re postulating, but maybe you can discuss the temperature question so more. I don’t think the analogy of a tall mountain stacks up. Pressure is a component in the thermal capacity of air at altitude but I’m struggling to see it as a thermogenic component.

  86. Johnny D says:

    “The effects of increasing CO2 decay logarithmically. Each doubling of CO2 increases temperatures by 2-3C. ”

    Hang on here — so the climate sensitivity really *is* 2-3 degrees C? From everything I’ve seen at WUWT, I thought CO2 didn’t affect the climate. Or that increased CO2 followed increased temperature. Huh.

  87. Chad Woodburn says:

    I have two questions. Not being a scientist, I am well aware that my two questions might be silly, but I’d really like to know the answers.

    1. Why, if CO2 keeps certain wavelengths of radiative heat inside our atmosphere (creating a positive feedback) does it not also keep an equal amount from coming into the atmosphere in the first place (creating a negative feedback like clouds)?

    2. It is my understanding that CO2 only traps radiation within a narrow spectrum of radiation. While measurements of the total heat coming into the atmosphere from the sun are measured in total watts per meter squared, does the composition of that radiation vary? If the amount of radiation that can be trapped by CO2 varies as much as the solar dynamics vary (active sun, passive sun, solar wind, cooling stars, etc.), do the models track for that in making their calculations for heat trapping by CO2 and the rest of the variations in global temperature?

  88. Hans Erren

    I made the point that it is the pressure, not the concentration of CO2 that is important. You seem to be agreeing with me, without realizing it.

  89. Peter Pearson says:

    In defense of HankHenry’s reference to an “ocean”, I believe he was talking about an ocean of CO2, not of water; and he made the interesting point that since the pressure and temperature at Venus’s surface exceed the critical pressure and temperature of CO2, it is just as valid to call it liquid as gas.

  90. HankHenry,

    The density of the atmosphere of Venus is 65. kg/m3 which is about one fifteenth that of water.
    http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html

  91. Anders L. says:

    “Even worse, if earth’s atmosphere had almost no water (like Venus) temperatures would be much colder – like the Arctic. ”

    And if earth’s atmosphere had no CO2, we would indeed be in that very state, since the earth would be a ball of ice.

    In the case of Venus, if one presumes that Venus is a terrestrial planet and not a very small star, there is no other explanation for the surface temperature than the greenhouse effect, since greenhouse gases are the only gases capable of trapping heat. And naturally a very dense greenhouse atmosphere traps more heat than a very thin greenhouse atmosphere.

  92. Johnny D

    I have written a number of articles here discussing the greenhouse effect and the relationship of CO2 to temperature. Perhaps your preconceived notions about WUWT are not correct?

  93. Timothy Ray Erney says:

    @Zeke
    Mentioning Carl Sagans cannabis use is not a cheap shot or ad hom attack of any sort. It’s just simply stating facts according to Sagans biographer and others who knew him.

    Biographer: Sagan Smoked Marijuana

    In the essay, Sagan said marijuana inspired some of his intellectual work.
    “I can remember one occasion, taking a shower with my wife while high, in which I had an idea on the origins and invalidities of racism in terms of gaussian distribution curves,” wrote the former Cornell University professor. “I wrote the curves in soap on the shower wall, and went to write the idea down.
    Sagan also wrote that pot enhanced his experience of food, particularly potatoes, music and sex.
    Grinspoon, Sagan’s closest friend for 30 years, said Sagan’s marijuana use is evidence against the notion that marijuana makes people less ambitious.
    “He was certainly highly motivated to work, to contribute,” said Grinspoon, a psychiatry professor at Harvard University.
    Grinspoon is an advocate of decriminalizing marijuana.
    Ann Druyan, Sagan’s former wife, is a director of the National Organization for the Reform of Marijuana Laws. The nonprofit group promotes legalization of marijuana.

    Many people, like myself, treat a variety of medical conditions, like glaucoma, with cannabis. Check out a list of well known people that have/do use cannabis here at Very Important Potheads. Note that Al Gore is on the list. Actually the current and previous US presidents are on the list. Clinton should be listed but he’s in denial although Hillary makes the cut. The “founding fathers” of the USA were big time hemp farmers and pretty much stoners too.

    “Make the most of the Indian hemp seed, and sow it everywhere!” -George Washington

  94. David L. Hagen says:

    R. Gates
    Your ad hominem attack on Lord Monckton evidences the vacuity of your position. It appears you have neither scientific basis nor argument to address the substance of Monckton’s evidence and logic. For further evidence see:
    Climate Change Reconsidered

    By far the greatest immediate danger is the peaking of light oil and urgent need to provide alternative fuels to keep from a massive global deep depression. See:
    World Liquid Fuels Supply, slide 8, in Meeting the World’s Demand for Liquid Fuels, G. Sweetnam, EIA, AEO2009.
    World Oil Exports [00] Introduction Luis de Sousa
    See discussion etc at The Oil Drum.

    The most serious danger from “Climate Change” enthusiasts is that they divert the global community’s attention from the critical issue of the peaking of light oil and urgent need to develop alternatives on a war time footing.

  95. Warren in Minnesota says:

    The following values are from the NASA fact sheets as referenced from Steve Goddard’s link to “Composition of Venus Atmosphere”. This may help to explain the high pressure of Venus.

    The comparison of the masses of the atmospheres:
    Venus= ~4.8X10^20kg
    Earth= 5.1X10^18kg
    Mars= ~2.5X10^16kg

    The comparison of the surface pressure of the atmoshperes:
    Venus=92 bars
    Earth=1.014 bars or 1014 mb
    Mars=0.0087 to 0.0040 bars depending on season or 8.7 to 4.0 mb.

  96. George E. Smith says:

    “”” Robert says:
    May 6, 2010 at 12:04 pm
    As far as i understood it would take two things to turn Earth into a seccond Venus, and that is enough time, and about twice the amount of energy from the Sun.

    And this all to start building up the atmospheric pressure which needs a lot of time, more energy means more watervapour, more watervapour means higher pressure wich in result in an atmosphere wich is beter suited to hold an higher temperature. “””

    Well where did you get the idea that water vapor increases the density of the atmosphere. H2O has a molecular weight of 18 versus 28 for Nitrogen or 32 for oxygen. So water vapor is way less dense than the rest of the atmosphere. CO2 on the other hand has a molecular weight of 44 which is more than double what H2O is.

    Seems to me that on earth approaching storms are signalled by a pressure drop; not a pressure increase; not that I am suggesting that is simply due to the amount of moisture in storms.

    does it not occur to anybody that Water alone, in the earth atmosphere forms clouds in its liquid and solid phases; and clouds always cool the surface in the shadow zone; by reflecting sunlight back into space (albedo) and blocking further sunlight from the ground due to the optical density of the cloud.
    It was reported, that Professor Stephen Schneider of Stanford; the apparent inventor of Climate sensitivity, and the myth of a lgarithmic surface temperature connection to CO2 abundance; in his criticism of the recent “Climategate” book by Meteorologist Brian Sussman; in which Schneider is reported to have dismissed Sussman as “misfiring on all cylinders” and pooh poohed Sussman’s statement that H2O was the principal cause of greenhouse warming on earth; not CO2.

    Scneider is reported to have said that H2O is a very weak GHG whereas CO2 is a strong GHG, and that counts for more than sheer abundance.
    So question (1) is; if H2O is a weak GHG compared to CO2; then what is all this crap about H2O being a feedback factor that amplifies CO2 caused warming. We know that more warming of the oceans leads to the escape or lack of take up of CO2 in the oceans; so one could argue that is a positive feedback factor of CO2 cause and effect. Of course any H2O warming of the oceans would lead to the same escape of CO2.
    But actually there is very little warming of the oceans due to either CO2 or H2O greenhouse effect; because that long wave Infrared radiation from the warmed atmosphere; whether CO2 or H2O caused, simply warms the top few microns of the surface, and leads mainly to evaporation of more water; along with massive Latent heat cooling of the surface.
    Neither one of these things is a “feedback”. Both simply reflect a change in the system parameters from one state to a different state based on some other change.

    For example, if you have a mass hanging from a spring, with gravity acting on it to stretch the spring; and you increase that amount of mass, the spring will start to stretcvh further, and that plus the spring compliance will set up an increasing counter force to try and stop the spring from stretching further.
    Climatologists would therefore call that a NEGATIVE feedback. The stretching of the spring sets up an opposing force to stop the spring from stretching. Balderdash ! The system is simply readjusting itself from one stanle state to a different state that too is stable so long as the increased mass remains in place.

    Same thing with the ocean; if you change its temperature; the equlibrium distribution of both H2O and CO2 in the atmosphere in contact with the surface; will change in accordance with Henry’s Law, in the case of the CO2, and the Clausius-Clapeyron Equation in the case of the H2O vapor. Neither one of these adjustments is a FEEDBACK; and furthermore neither one could care less what it was that caused the ocean surface temperature to change.

    but back to Schneider’s rather silly statement that H2O is a weak GHG compared to CO2. Does he dispute the general validity of those absorption spectra for CO2 and H2O that Steve posted above ? Is it not true that H2O absorbs much more of the LWIR energy spectrum than CO2 does; not to mention the absorption of incoming Solar radiation ; where H2O has a very significant absorption (which warms the atmosphere) but CO2 does not (it has some; but nowhere near what water has (molecule for molecule)).

    You can’t have it both ways; you can’t proclaim H2O to be a feedback effect that amplifies a weak CO2 atmosphereic warming; and then turn around and call H2O a weak GHG compared to CO2. What’s more both of them are equally permanent constituents of the atmosphere, and H2O virtually always exceeds CO2 even over the most arid of deserts.

    There’s one more Venus/Earth CO2 discrepancy, that you should throw into your mix Steve.
    Earth mean surface temperature is 288 K which corresponds to a BB radiation spectrum peaking at 10.1 microns. CO2 affects this spectrum mostly due to the 15 micron absorption band of CO2. The next higher energy CO2 band at around 4 microns has little effect on earth since it is less than half of the 10.1 micron peak LWIR spectrum peak; so somewhat less than 1% of theat earth emission acts on the CO2 4 micron line. On the other hand 4 microns is also 8 times the peak of the solar spectrum; so less than 1% of the solar spectrum energy is present beyong that 4 micron line; so the CO2 4 micron line has negligible influence on eather solar insolation or outgoing LWIR.

    Now Venus has a surface temperature of 485 deg C (I’ll use you figure Steve); so that is 758 Kelvins compared to Earth’s 288.

    So the surface BB spectrum emission from the surface of Venus would be expected to lie at 288/758 x 10.1 microns; whchi is 3.84 microns.

    So the earth inactive 4 micron CO2 line is the principal active line on Venus; whereas the 15 micron bending mode line is at 3.9 times the wavelength of the Venus surface emission; and only about 6-7% of the Venus surface emission lies at 15 microns or longer.

    For Earth to go Venus, due to CO2, the temperature would have to somehow travel through a region where the CO2 absorptance was less than 10% of the peak LWIR emission, and somehow get hot enough to activate the Venus 4 micron line of CO2.

    Ain’t gonna happen; no way; well no way under current general earth orbiat and othe major conditions. Anthropogenics isn’t going to do it.

    How about those clouds on Venus Steve; they certainly aren’t H2O; and how could they be CO2 at those temperatures. Aren’t they due to some sulphurous component of the Venus atmosphere?

  97. Mike McMillan says:

    A couple additional points. The radiation chart atop this page shows black, blue, and lavender black-body curves for earth at roughly our min to max temperature. Venus’ curve will be shifted significantly left due to the 400+ degree hotter surface. That affects the CO2 absorption, shifting from the fat band up to the narrower bands.

    The clouds may be transparent to some regions of IR. However, the very depth of the cloud cover could negate that, and produce effects of its own that alter the adiabatic lapse rate. Without weather, Venus should have a much simpler atmospheric model, but one very different due to its composition.

    Both Venus and Mars have CO2 atmospheres, but at opposite extremes to what Earth is used to. I don’t see how either of them can be useful to the AGW case.

  98. Rob says:

    On the comparison of compressing gas in a cylindar to Venus: Space is cold and for a planet drifting in space, can act as a heat. Greenhouse gases are your insulation. They stop some solar radiation from being radiating back into space, hence insulating the planet. There is still some penetration into this thick atmosphere by solar radiation. Whether or not it reaches the surface is irrelevant. The question is, whether there is enough of a greenhouse gas blanket above the penetration level to trap some of that heat and re-emit it back into the atmosphere. The surface, with a hot atmosphere above it, would certaininly get hot.

    The pressure-temperature analysis is for the static condition of Venus today, NOT Venus developing through the evolution of the solar system, which is what the runaway greenhouse model addresses.

    Besides watching a Nova special, no research was presented on what goes into the Venus runaway greenhouse idea. COnsidering the author’s insistance on refusing to take scientists statements about other scientists theories at face value, I am inclined to ask the author to go back and do his homework.

  99. Jim Barker says:

    Just a thought, but wouldn’t the atmosphere around Venus, thick clouds and all, act like a very good insulator and keep the temp very stable? What little leakage occurred would be made up by the 30% not reflected.

  100. harrywr2 says:

    I thought Venus was hot because of SO2 clouds.

  101. SidViscous says:

    To those trying to make a comparison to Jupiter and asking why it’s not hot.

    Who is saying htat it’s not hot. the upper atmospher may be cool, but deeper in, where the pressure is higher, it is extremely warm and toasty.

  102. Al Gore says:

    Zeke said:
    “May 6, 2010 at 12:36 pm

    Just because you don’t understand something doesn’t make it wrong… There is a wealth of literature on Venus’ atmospheric dynamics. A good starting point is here: http://www.nature.com/nature/journal/v226/n5250/abs/2261037a0.html

    Also, Carl Sagan smoking pot is a bit of a cheap shot :P”

    Zeke – I clicked the link, and it’s nothing but a list of references of papers from the ’50s and ’60s, which support the runaway GH theory. You have clearly done nothing to argue its case, and nothing to address the points made in this post – which we would welcome here, as most of us are all for constructive debate. Lazy, lazy post.

  103. rbateman says:

    How did Venus get such a dense atmosphere? It heated up over time to the point where all of it’s Carbon, Oxygen and Sulfur volatilized. No magnetic field means it lost it’s Hydrogen early on.
    Why didn’t Earth do that?
    It has life which aids in sequestering the elements that would lead to a denser atmosphere. a magnetic field which keeps the Solar wind from blowing away the lighter elements, and vulcanism to keep it regenerated.
    Mars froze out because it has no magnetic field and no vulcanism.
    The question is: Why does Venus still have vulcanism?

  104. patagonico says:

    A layman’s question:

    The greenhouse effect of the CO2 does not depend on his percentage in the atmosphere (96,5% in Venus, but 95,3% in Mars) . Alone this is true if the volume of the atmosphere is constant

    The greenhouse effect depends on the absolute number of molecules that exist in the atmosphere

    In mars it is said that the greenhouse effect of the CO2 does not have relevancy because his atmosphere is very thin

    But:
    Land: atmospheric pressure: 90 kPa %CO2 0,038 %
    Mars: atmospheric pressure 0,6 kPa %CO2 95 %

    If for art of magic they were eliminating all the rest gases and we were remaining with the CO2 we would have a pressure of
    Land: 0,03 kPa
    Mars: 0,57 kPa

    Then, or I have been wrong in some point or the question arises: Why there is only a weak greehouse effect in Mars?

  105. kramer says:

    I think the 3rd poster (Curiousgeorge ) has a good point.

  106. MattB says:

    An interesting corolary to this line of thinking though is that besides the raw heat associated with burning fossil fuels that act should to some degree also increase the pressure of the earths atmosphere (due to adding gas mass) which by this argument again gives some credence to actions of man causing an increase in global temps, just again not leading back to the runaway greenhouse effect that is being thrust upon us.

  107. Rob says:

    I also disagree that the comparison of the oft stated
    “each doubling of CO2 concentration would increase temperatures by 2-3 degrees” as applied to earth is comparable to what one would expect on Venus. Volume must be as important as concentration. I am not familiar with the volume of Venus’ atmosphere as compared to Earth’s, but I think you’ve established that the atmosphere is thicker.

    If you consider a model in which one atmosphere is wrapped in a second atmosphere, where the concentration of CO2 in each is allowed to vary, there is no mixing between the 2 atmospheres, and solar radiation can penetrate both atmospheres, then by simply using the concentration approach, your total temperature increase would be double that of the single atmosphere model as you applied in your analysis. However, combine those 2 atmospehres together, and via the concentration approach, you halve your temperature affect.

    For comparisons on earth, we know the size of our atmosphere, but you can’t go applying earth concentration approximations to places with different sizes of atmosphere.

    (For the record, I am a geologist who does not believe in significant AGW, but did get my phd at Lamont Doherty Earth Observatory, which does tow the party line in favor of AGW)

  108. Phil M. says:

    Wow.

    No longer content with doubting earthly science, this group is now reinventing the field of astrophysics? I’m better off asking a sleepy 5 year old for a scientific opinion.

    This website is hysterical. Keep ‘em coming Steve.

  109. John Trigge says:

    For those using the filling of a gas cylinder example and the consequent cooling due to conduction/convection to the surrounding atmosphere:

    Where does the heat from compression go when the entire planet is, effectively, the ‘cylinder’? Everywhere is at the same temperature, hence cooling cannot occur.

  110. Vuk etc. says:

    Venus’ day (243d) is about 20 Earth’s days longer than Venus’ year (224d). Odd that, but it means that surface being irradiated for that long reaches high temperature (closer to the sun too), and being covered in dense volcanic gasses, acting as a thick blanket, unable to cool during night. Simple as that.

  111. Ian L. McQueen says:

    Steve-

    Interesting article. But I wonder why the pressure is so high. Is the atmosphere of Venus so much thicker than that of Earth? My calculus is a bit weak, but I think that there would have to be a much thicker atmosphere than 30-40 km (and is that from surface to the edge of space?). I believe that the size of Venus is about the same as that of Earth, so the force of gravity should be comparable.
    Furthermore…..if the temperature of Venus (presumably in the atmosphere near the surface) is 485°C, and the atmosphere is nearly all CO2, and less energy is absorbed from the sun than on Earth, why does the atmosphere not just radiate away its energy to space?
    I don’t see the logic of high pressure = high temperature. It could be thus following an adiabatic compression, but if the heat could escape (as by radiation), the temperature would drop, the same as happens on Earth as heat is lost from compressed gas in a cylinder (for example). It is impossible to insulate the gas perfectly.
    Comments / explanation welcome!! An inquiring mind wants to know.

    IanM

  112. timheyes

    Ever hiked down the Grand Canyon? Same weather, same sunshine, similar rocks, same everything – except temperatures at the bottom are much warmer.

    Hot gases rise only if the vertical temperature gradient is greater than the lapse rate. I’ve seen some very hot days in Houston with almost no air circulation.

  113. Jim Barker

    The amount of radiative energy leaving Venus is (nearly) identical to the amount it receives.

  114. PJF says:

    “Heat flow from inside the earth is much smaller than the energy received from the sun.”

    Thanks for that, but I feel the need to point out that I didn’t say otherwise.

    This article:
    http://www.datasync.com/~rsf1/vel/1918vpt.htm
    uses measured and inferred Venusian temperature and pressure profiles (to make an unrelated point). Interestingly, it shows that temperatures on Venus at a height where the pressure matches that of the Earth’s surface are also a fairly close match, differing in tens of degrees rather than hundreds. Not much of a “runaway greenhouse effect” there despite the >95% CO2.

    Following the link back to the original authors behind the temperature and pressure profiles:
    http://www-star.stanford.edu/projects/mgs/profile.html
    reveals something astonishing. They not only say that the high surface temperature of Venus is due to the “runaway greenhouse effect”, they say that the high pressure is due to the “runaway greenhouse effect!” This does show that scientists operating outside of their specialist areas can be remarkably dim.

  115. Dr A Burns says:

    Jupiter has a temperature hotter than Earth’s … with no CO2, just H and He … and a high pressure.

    http://www.ilovemycarbondioxide.com/pdf/Rethinking_the_greenhouse_effect.pdf

  116. Anders L.

    I live along the Front Range in Colorado. Two days ago we had downslope winds which warmed the night time temperatures up by 30 degrees. It had nothing to do with the greenhouse effect, and everything to do with compression of atmospheric gases at the higher pressures found at lower elevations. Look up “Chinook” for reference.

    Clouds also block radiation. You don’t need greenhouse gases to impede IR.

  117. joshua corning says:

    One should note that at the altitude at which Venus’s atmospheric pressure is equal to Earth’s atmospheric pressure at sea level that the temperatures are the same. This is despite the fact that the air on Venus is 96% CO2.

  118. Louis Hissink says:

    Steve omitted one pertinent fact – Sagan put bthe Venus greenhouse effect to counter Velikovsky’s deduction from historical data that Venus had to be hot as it appeared to be a young planet.

    Venus’ surface is radiating heat, from what I can gather from the known probe data, so Velikovsky’s deduction seems correct, Venus is hot because it was recently formed. Well that is what our ancestors reckoned.

    This statement will cause hyperventilation among the mainstream geological types as well as the astronomers, but that’s science.

  119. Dennis Wingo says:

    I really HATE that graph of the incoming and outgoing radiation from globalwarming art. It tends to make people think that the amount of incoming and outgoing temps are equivalent. If you actually scaled that correctly you would see that the solar IR is a very significant fraction, of the outgoing thermal radiation during the day.

    The left hand scale of spectral intensity does not accurately represent what is going on.

  120. Dennis Wingo says:

    So why is Venus hot? Because it has an extremely high atmospheric pressure. The atmospheric pressure on Venus is 92X greater than earth. Temperatures in Earth’s atmosphere warm over 80C going from 20 kPa (altitude 15km) to 100 kPa (sea level.) That is why mountains are much colder than the deserts which lie at their base.

    The spectral absorption characteristics of CO2 are also pressure dependent. If you have an atmosphere that much more dense than the Earth, the “wings” of the absorption bands are much wider and taller.

  121. Dave McK says:

    Even more significant about water is the phase change.
    Do the calculations- you will find that in a volume of atmosphere containing 1% water vapor and 500ppm CO2, the heat transported from surface to space by the water is 50,000 times more than the CO2 can do. If it gets Cirrus, multiply times 5+.
    Earth is a has a heat pump and the atmopheric profile is one of a refrigerant.
    Water vapor is the lightest gas of the major constituents of the air and it rises inexorably, carrying the heat of vaporization with it.
    Anybody can understand that improving the heat capacity of the working gas of a heat pump just makes it do a better job – it reduces the rate of flow required to maintain equilibrium.
    When a cloud comes over, you have shade. CO2 does nothing.
    When a cloud parks over the tomatoes at night, you have no frost. CO2 does nothing.
    The only thing CO2 does is present a straw man that draws all the attention while they dilate your colon for cap & tax.
    You have to stop debating this and run these people off. They’ve already learned that ‘no’ means yes because it’s all talk and no consequences. Look how Mann was defended by those who will bear his babies.
    We are still losing and will continue to lose until this topic no longer gets top billing and removal of the mystics is finally understood to be the ONLY thing that matters.

  122. sHx says:

    No need to hark back to Carl Sagan. Here is what James Hansen says in his recent book:

    After the ice is gone, would Earth proceed to the Venus syndrome, a runaway greenhouse effect that would destroy all life on the planet, perhaps permanently? While that is difficult to say based on present information, I’ve come to conclude that if we burn all reserves of oil, gas, and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty.

    IMHO, it was a terrible, terrible mistake to put James Hansen, a Venus specialist, in charge of an institution researching the Earth’s climate way back in early the 80s. Hansen, it seems, re-imagined Earth climate system in Venusian terms. His obsession with CO2 and runaway greenhouse effect originates from his early expertise in Venusian atmosphere. This is a mere speculation, but I don’t think we would have this runaway AGW scare had a Venus specialist not been in charge of NASA GISS.

  123. kuhnkat says:

    If Venus is hot because of the atmospheric pressure, Jupiter, Saturn, Neptune, and Uranu should be warmer shouldn’t they??

    Venus is hot because it is either younger than the consensus claims, or had a relatively recent catastrophic impact.

    They have found that Mercury has more atmosphere and is hotter than it should be based on their consensus science also. I don’t think atmospheric pressure enters into it there either.

  124. feet2thefire says:

    @ Duster says: May 6, 2010 at 12:19 pm

    If you really want to feel confused check out Nasif Nahle’s site: http://biocab.org/Induced_Emission.html. Professor Nahle seems to say that there is no “green house effect,” partly because none of the common models take thermodynamics into account properly. . . According to Nahle, the atmosphere’s primary climatic effect, mainly through convection, carries warmed air away from thermal masses warming it outward and upward to where it radiates away from the planet. This matches discussions on real greenhouse (transparent windows with plants inside) effects, which point out that a true green maintains a warmer environment than the surroundings by limiting convection.

    This agrees with the conclusions of Gerhard Gerlich (2007) Falsi cation Of
    The Atmospheric CO2 Greenhouse Eff ects Within The Frame Of Physics
    of the Institut für Mathematische Physik in Braunschweig, Germany. It is 114 pages and refutes, from a Physicist’s point of view, the concept just as Nahle asserts: It is the hindrance of convection which heats the greenhouse, not radiation.

    The math and the laws of physics Gerlich goes into are over my head, so I can’t myself claim to know one way or another.

    But I’ve been waiting to post this link for a LONG time, because Sagan was wrong, and I wanted to have a venue for directing people to it. See my next comment somewhere below…

  125. Mike Lorrey says:

    Great article.
    For those asking about Earth’s pressure increasing in the future, that won’t happen. In fact, when Earth was young, the atmosphere was about 50 times as dense as it is at present. Largely made up of CO2. The sun was about 40% dimmer than at present.

    Where did all that atmosphere go? Into the rocks. The marble, limestone, and other carbonates that make up large portions of our continental plates were created by life forms sequestering that CO2 in the atmosphere as rock, as well as acidic rainfall that reacted with volcanic, igneous, and sedimentary rocks to create carbonates. All that CO2 is permanently sequestered there. A smaller amount of that former CO2 is sequestered in coal, oil, and natural gas deposits as well as methane hydrate deposits under the sea bottoms. When we burn fossil fuels, we free up that CO2 to be resequestered as more permanent rock by corals as well as acid rain weathering rocks.

    The Ice Ages we’ve experienced in the last several million years are a harbinger of permanent end of life on Earth. The interglacials have only been temporary interludes that enabled life to extract more CO2 from the landscape and sequester more of it as rock. Until and unless there is a major volcanic intrusion into fossil fuel deposits (for instance, an eruption of Yellowstone caldera intruding into coal and oil shale deposits elsewhere in Wyoming), the only force putting sequestered CO2 back into the atmosphere to keep life going on Earth is mankind.

  126. phlogiston says:

    rbateman says:
    May 6, 2010 at 2:42 pm
    How did Venus get such a dense atmosphere? It heated up over time to the point where all of it’s Carbon, Oxygen and Sulfur volatilized. No magnetic field means it lost it’s Hydrogen early on.
    Why didn’t Earth do that?
    It has life which aids in sequestering the elements that would lead to a denser atmosphere. a magnetic field which keeps the Solar wind from blowing away the lighter elements, and vulcanism to keep it regenerated.
    Mars froze out because it has no magnetic field and no vulcanism.
    The question is: Why does Venus still have vulcanism?

    r, doesn’t distance from the sun have something to do with temps on Venus and Mars?

  127. kuhnkat says:

    How did such poor science come to be common knowledge??

    Ask our Venus probe modeler and physicist, who is in charge of GISS and thinks coal trains are the same as Holocaust Trains in the Third Reich, James Hansen!!!

    HAHAHAHAHAHAHAHAHAHAHAHAHAHA

  128. wsbriggs says:

    Dennis Wingo says:
    May 6, 2010 at 3:22 pm
    “The spectral absorption characteristics of CO2 are also pressure dependent. If you have an atmosphere that much more dense than the Earth, the “wings” of the absorption bands are much wider and taller.”

    So Dennis, how about a little quantitative information, how much wider, how much taller? If you integrate the curve, do you really get a lot of area, or maybe just a slight spreading, but these are the tails of the absorption bands, and so how much matters a lot.

    Sounds like more PNS to me.

  129. PJF says:

    “…Venus is hot because it was recently formed.”

    Despite my earlier linking to a Velikovsky fan page, I don’t think the science shows he was correct. It would be more accurate to say that Venus is hot because its *surface* was recently formed (in geological timescales). Surface cratering (or lack thereof)indicates a very young surface. Due to the lack of tectonic activity (which allows gradual heat loss on Earth) the planet is believed to have been entirely molten within the last five hundred million years.

  130. pft says:

    “PJF says:

    May 6, 2010 at 12:08 pm
    It would be interesting to know what the atmospheric temperature on Venus is at the height equivalent to one Earth atmospheric pressure.”

    One commenter on another thread at some other time had said it was within 1-2 deg C of Earths temperature. Sounded like he knew what he was ralking about, and it makes sense.

    Heck, even the temperature of the earth at increasing depth and higher pressure increases, it reaches over 100 deg C where water boils at 300 deg C, so obviously at a pressure of 92 atmospheres it’s going to be hot. CO2 does make it hotter though, since I would expect some mixing of the atmosphere from top to bottom

    For some reason, deep ocean temperatures 2.5-5 miles deep is only 3 deg C and does not increase. But who knows, if NASA and their scientists can lie (distort) about the cause of the temperature on Venus surface, maybe this is not true as well. Maybe that’s the corrected temperature after adjusting for pressure, like they do with the atmosphere where the potential temperature (corrected for lower pressure and lapse rate) is much higher than the actual temperature (down to -100 deg C)

  131. solarguy says:

    Yes, To compare the surface temperature of Venus to the Surface temperature of Jupiter you would have to go down about 57000km (trough Jupiter’s “Atmosphere” to reach the mostly solid/liquid surface at which point the temperature is as high as 24000K. A good deal warmer than Venus and a bit more pressure too.

  132. JAE says:

    Hmmm, aren’t you now agreeing that the atmospheric pressure explains why the Earth’s temperature averages about 16 C, rather than -18? I thought that conventional wisdom says that the greenhouse effect is the reason.

  133. Joe says:

    Core size of Venus would have a great deal to do with magnetic field and speed of rotation. No core like the moon is no more rotation. Small core on a big planet would slow faster with the frictional load.

  134. Hey Skipper says:

    stevengoddard:

    Good article.

    This substantiates it.

    The Venusian atmospheric temperature at the 1000 mb level (about 50 km above the surface) is right around 100 deg F.

    Which, considering how much closer Venus is to the sun, is scarcely any different from the Earth’s temperature at sea level.

  135. Warren in Minnesota says:

    Ian L. McQueen says:
    May 6, 2010 at 3:00 pm
    Steve-
    Interesting article. But I wonder why the pressure is so high.

    * * * * * * * * * * * * * *

    I also wondered why the pressure is so high. I found that the mass of the atmosphere of Venus is larger than that of the Earth by a factor of 100. Venus has about ~4.8X10^20kg whereas the Earth has about 5.1X10^18kg. The compression of the gas would be higher with more mass and gravitational attraction, thus the higher pressure. Similarly, the atmosphere of Earth has more mass than the Mars by a factor of 100. Again Earth has about 5.1X10^18kg whereas Mars has about ~2.5X10^16kg. With less compression on Mars, its pressure would be less than the Earth’s pressure.

    Warren

  136. Gail Combs says:

    Chad Woodburn says:
    May 6, 2010 at 2:12 pm

    I have two questions. Not being a scientist, I am well aware that my two questions might be silly, but I’d really like to know the answers.

    1. Why, if CO2 keeps certain wavelengths of radiative heat inside our atmosphere (creating a positive feedback) does it not also keep an equal amount from coming into the atmosphere in the first place (creating a negative feedback like clouds)?

    2. It is my understanding that CO2 only traps radiation within a narrow spectrum of radiation. While measurements of the total heat coming into the atmosphere from the sun are measured in total watts per meter squared, does the composition of that radiation vary? If the amount of radiation that can be trapped by CO2 varies as much as the solar dynamics vary (active sun, passive sun, solar wind, cooling stars, etc.), do the models track for that in making their calculations for heat trapping by CO2 and the rest of the variations in global temperature?
    ________________________________________________________________________

    Take a look at the graph in the post. The red curve is the incoming solar radiation and the blue curve is the energy bouncing off the earth’s surface as transmitted by the atmosphere. The purple, blue and black lines are the radiation transmitted from the earth into space; they are calculated using a blackbox assumption based on temperature. The 3 lines represent 3 different temperatures from 210–310 K (–63 to +37 °C) due to the variation of the surface and atmospheric temperature over the earth. The blue area is what escapes into space. Next look at the gray curves. The third one down is CO2. The absorption bands are not in the solar energy curve area except for one. Also note by looking at the top curve that ALL the energy bouncing off the earth’s surface has already been absorbed in the CO2 absorption bands. (that is the logrithmic thingy Steve is talking about) There is a bit of room left at 2um but that is in the sun’s part of the spectra. Adding CO2 is not going to do a darn thing.

    One look at that graph convinced me (a chemist) this was nothing but a political money making scheme. If the CO2 already in the atmosphere has already absorbed all the radiation adding more CO2 just isn’t going to matter much. There is a convoluted explanation about one molecule re-radiating and the additional molecules absorbing the same energy a second and third time. However think about it. The actual curve shows the energy is not getting transmitted from the atmosphere at those wavelengths at all. How can more CO2 effect that blue curve???

    It is not quite as simple as that. Here is one explanation http://www.udel.edu/Geography/DeLiberty/Geog474/geog474_energy_interact.html

    And the other side of the debate: http://landshape.org/dokuwiki/doku.php?id=introduction

    Hope that helps.

  137. JAE says:

    I tried to comment, but no show. Try again:

    “So why is Venus hot? Because it has an extremely high atmospheric pressure. The atmospheric pressure on Venus is 92X greater than earth. Temperatures in Earth’s atmosphere warm over 80C going from 20 kPa (altitude 15km) to 100 kPa (sea level.) That is why mountains are much colder than the deserts which lie at their base.”

    Hmmm, are you saying that the reason the Earth’s avg. temp. is something like 17 C, instead of -18 is because of atmospheric pressure? The experts keep telling me that the difference is due to the greenhouse effect!

  138. Onion says:

    Could the pressure be an effect of the heat rather than the heat being caused by the temperature?

    With regards to Jupiter, wikipedia says: ” The amount of heat produced inside the planet is nearly equal to the total solar radiation it receives.[26] This additional heat radiation is generated by the Kelvin-Helmholtz mechanism through adiabatic contraction. This process results in the planet shrinking by about 2 cm each year.[27] When it was first formed, Jupiter was much hotter and was about twice its current diameter”

    There’s no mention of pressure itself generating heat, only absorbed solar radiation and heat generated through the planet shrinking.

  139. Steve Fitzpatrick says:

    Steve Goddard,

    Great post.

    Every small debunking of nonsensical horse**** helps.

  140. Steve Fitzpatrick says:

    So te ultimate solution to CAGW is to liquify a bunch of the Earth’s atmosphere and lower the atmospheric pressure!

  141. Eric Flesch says:

    Pressure and temperature are dependent only in a constrained adiabatic system. For black box systems like planets, temperature is independent of pressure because heat is freely exchanged. Venus’s albedo likely pertains more to visible light than heat; I expect the opaque atmosphere absorbs most impinged solar heat. Venus receives 2x the solar radiation intensity as Earth, and its temperature (K) is about 3x; the excess 50% probably retained by atmospheric opacity. It just takes the heat a bit longer to escape. Superpressurized CO2 may play a big role in that, but Earth has nothing like that, and never can.

  142. George Turner says:

    The temperature profile on Venus stays very close to the adiabatic lapse rate of CO2, which has nothing to do with IR radiation, just the coefficient of specific heat and constant pressure. In Carl Sagan’s 1967 paper on the surface temperature of Venus, prior to any measurments of it, he got it right to within 50C or so just based on the cloud top temperature and the depth of the atmosphere. He also showed that the surface temperature would be hotter if the atmosphere was nitrogen instead of CO2, due to the differing coefficient of specific heat at constant pressure.

  143. Onion says:

    The EPA Endangerment Finding Comment Response contains a relevant comment on this question about pressure:

    Comment (3-49):
    A commenter (2210.1) states that Venus is not an example of the greenhouse effect but is merely warmer because it is closer to the sun. Another commenter (2210.5) attributes Venus’ warmth to higher atmospheric pressure because compression causes temperature increases (for example, this occurs when inflating a bicycle tire, due to the proportional relationship between pressure and temperature represented in the ideal gas law, pV=nRT, i.e., pressure times volume equals amount of gas times temperature times a constant), and that a 95% CO2 atmosphere is actually cooler than a 100% biatomic atmosphere would be.

    Response (3-49):
    Venus is warmer than the Earth both because of the greenhouse effect and because of its distance to the sun; in contrast, Mercury is cooler than Venus despite being even closer to the sun. Were Venus’ atmosphere to be transparent to radiation, then the surface temperature of Venus would be determined only by the blackbody radiation of the surface, and the pressure of the atmosphere would not change this equilibrium temperature. There is a large body of literature on Venus’ climate; one example is Bullock and Grinspoon (2001)—all of which show that CO2 is a significant contributor to the planet’s warmth. Because volume is not held constant, it is not appropriate to use the ideal gas law to determine the temperature on the surface of Venus based only on knowledge about its pressure. Therefore, the scientific literature shows clearly that the temperature of Venus is an example of a greenhouse effect, in contrast to the assertion by the commenters.”

  144. Willis Eschenbach says:

    Almost exactly ten years ago, Dr. Hartwig Volz made what I think is the best analysis of this on the late and greatly missed John Daly’s website. His analysis is here. By and large it agrees with what Steve Goddard says, only with more detail, more math, and a curious twist.

    The twist is that on the surface of Venus, CO2 is no longer a gas but a “supercritical fluid”, which behaves very differently than a gas.

    In any case, another excellent post, Steve.

  145. feet2thefire says:

    Dennis Nikols says: May 6, 2010 at 12:20 pm

    This whole Venus thing goes back the E. Velekofski (sp?) in the 1950′s. Segan, like many others had some rather strange ideas. This one he picked up from Velekofski from one of his books. He wrote several (can’t be sure of the titles). I did try to read them and found his understanding of geology completely screwed up. So I judged his astronomy was little better. Like many strange people he was not completely, wrong just mostly so. Segan is much the same. Some of his stuff is okay and some not so good. When you get down to the facts we know so little about Venus that making any kind of comparison to Earth is rather foolish.

    We know them as Sagan and Velikovsky.

    In Worlds In Collision (1950), Velikovsky asserted that the surface temperature of Venus would be found to be between 800F and 900F. Velikovsky set off such a absolutely thunderous reaction among astronomers that they threatened the publishers, Macmillan, which published many school textbooks, with being blackballed if they didn’t cease and desist. Macmillan capitulated, even though the book was #1 on the best sellers list. Doubleday took over the publishing.

    Be it known that the consensus (ever had of that term?) in 1950 was that Venus’ surface temperature was approximately 200F-300F. It was one of the reasons the astronomers were so furious with Velikovsky.

    While I completely disagree with Velikovsky’s mechanism, a few of his observations and piecing of facts have subsequently been seen to hold water. But I disagree with the scientists and their reaction even more than I disagree with Velikovsky.

    A latecomer to the brouhaha was Carl Sagan. When in 1962 the NASA Mariner probe flew by Venus and determined that the surface temperature was approximately 428C (802F), the LAST thing the astronomers were going to do was admit that Velikovsky (whose book, combined with the UFO furor of the late 1940s and early 1950s, started the Hollywood era of catastrophes from space) was correct. They had to come up with an explanation, and they had to do it NOW.

    Along came Sagan and his runaway greenhouse speculation.

    It is a constant of scientists that when they run across something they can’t explain – but they can’t deny, either – they throw out a speculation and then turn on their heels and exit, stage right, leaving everyone to assume that, since the scientist has now spoken, the issue is settled.

    The world as assumed ever since that since Lord Sagan hath spoken, that what came from out his mouth must be true. The runaway greenhouse effect went down in the records as THE truth about Venus. Hell, they needed SOMETHING. Otherwise they would have to have admitted that Velikovsky might have been right – which would mean that they were wrong. Heaven forbid.

    It was similar to the period in the early 1800s when scientists finally could put the beliefs in Noah’s Flood to rest. Noah’s Flood – the last bastion of religion which science had not been able to bury – had all the evidence going for it. All round, everywhere, there was well-documented evidence of a great catastrophe – striated rocks; overturned layering of the earth; erratic boulders on top of the Alps and other high peaks; foothills made up almost entirely of mammoth; elephant, hippopotamus and rhinoceros bones (in the Arctic Ocean), caves filled with the shattered bones (100%, BTW) of every sort of animals, both prey and predator. Then along came Agassiz and Lyell and then Darwin, to provide a framework that allowed for Ice Ages and seemingly limitless eons for the changes that had appeared to Cuvier and his predecessors as diluvian, meaning flood-caused. The Bible was overthrown by geologic ages.

    But then 100 years later, along came Velikovsky, whose efforts threatened to let the beast of the Bible back into the discussion. And even though Velikovsky’s work was related to accounts in religious writings, it had nothing religious about it. But they couldn’t let even a hint (deny the decline) that there was anything but slow Uniformitarianism and Darwin’s survival of the fittest. So Velikovsky had to be destroyed in 1950 – even as the world was listening to him. And then in 1962, Velikovsky had to be dstroyed again. He had to be trumped by scientists, so that he couldn’t claim that manna hadn’t fallen from the sky (a literal claim in Worlds In Collision). That was WAY too close to bringing religion back.

    Sagan’s speculative runaway greenhouse effect saved the day. The scientists could turn on their heel, exit left, and leave everyone assuming that St Carl had saved the day.

    It was left to another decade and one James Hansen to really put the greenhouse effect – the one that hadn’t YET runaway, BUT THAT MIGHT! – together with Arrhenius’s CO2 concern (at a time when it was aerosols in the form of coal dust that was the real issue) and VOILA! BE SCARED! BE VERY SCARED!

    Sagan took a 96.5% CO2 Venus atmosphere, and he made assumptions. That became a dogma.

    Then that dogma was taken by Hansen to apply to Earth’s atmosphere, which was only 0.3% CO2 – 320 times less – and created another dogma. We had dogma-squared, and without any science behind it. The greenhouse mechanism was assumed to be real, because SAGAN said it was real.

    I’ve been screaming about this for three decades now. I am SO happy to see someone else questioning it.

    Velikovksy WAS right, but for the wrong reasons.

    Sagan was WRONG, but – in his mind – for the right reasons.

    Hansen was WRONG, and for the wrong reasons.

    P.S. Velikovsky’s other main book, Earth In Upheaval delineates MUCH that argues against Uniformitarianism. So did Comet Shoemaker-Levy’s impacts on Jupiter in 1994. Only after that did science wake up to the real possibility of catastrophic events in the time of man – which was Velikovky’s main point in the first place. Since 1994, not one nouveau-catastrophist has credited any of their plagiarized concepts to their father, Immanuel Velikosky. To do so would be to admit that the consensus was wrong for the last half century. But it would also give religion a foot in the door – and well, that will never do…

    If Velikovsky was right, what chance would Ice Ages and limitless eons have? Who would stop our schools from teaching all kinds of non-Darwinian things? What would happen to the consensus?

  146. chris y says:

    re- kuhnkat says:
    May 6, 2010 at 3:32 pm

    “If Venus is hot because of the atmospheric pressure, Jupiter, Saturn, Neptune, and Uranu should be warmer shouldn’t they??”

    Jupiter is blazin’ hot. Some info on Jupiter-
    top of atmosphere is at -145 C
    50 km thick layer of clouds, followed by 21000 km of H2, He, transitioning to liquid, followed by 40,000 km of metallic liquid H2, followed by possible solid rocky core (surface).
    Surface pressure of several million atmospheres.
    Surface temperature estimated at 24,000 – 30,000 C. Nowhere near the Gorian crustal Earth temperature of a few million degrees (C, F, K, R, take your pick), but still pretty hot.

    Adiabatic lapse rate of Jovian atmosphere is about 2 C/km.
    Earth is 6 – 10 C/km.
    Venus is 10 C/km.
    Mars is 4.5 C/km.

    Steve Goddard is simply repeating the standard lapse rate calculation, given for adiabatic case as Gamma=g/Cp, where g is gravitational constant and Cp is the specific heat of the atmosphere.

    If you want a runaway Greenhouse here on Earth, you need to somehow boost the atmospheric pressure by a factor of 20 or more. Good luck with that.

    Its simply stunning that Venusian expert Hansen continues to spout runaway Greenhouse drivel due to anthro emissions as being remotely possible here on Earth.

  147. Zeke the Sneak says:

    “The next problem is that the albedo of Venus is very high, due to the 100% cloud cover. At least 65% of the sunshine received by Venus is immediately reflected back into space.”

    It is not hard to find figures that say more like 80% of the sunshine is reflected into space. That leaves 20% of the sunshine to get in and raise temperatures to the melting point of lead!

    I am inclined to go with the much higher albedo than S. Goddard has cautiously cited. For one thing, Venus is the 3rd brightest object in the sky after the Sun and Moon, with its greatest magnitude being 4.6.

    Hard to believe that twinkling beauty is a place where you would be fried, poisoned, squashed and corroded. I suppose there could be a lesson in there somewhere, but it isn’t the “runaway greenhouse effect”!

  148. Onion says:

    The EPA say: “Were Venus’ atmosphere to be transparent to radiation, then the surface temperature of Venus would be determined only by the blackbody radiation of the surface, and the pressure of the atmosphere would not change this equilibrium temperature. There is a large body of literature on Venus’ climate; one example is Bullock and Grinspoon (2001)—all of which show that CO2 is a significant contributor to the planet’s warmth. “

  149. Gail Combs says:

    sHx says:
    May 6, 2010 at 3:26 pm
    “…..Hansen, it seems, re-imagined Earth climate system in Venusian terms. His obsession with CO2 and runaway greenhouse effect originates from his early expertise in Venusian atmosphere. This is a mere speculation, but I don’t think we would have this runaway AGW scare had a Venus specialist not been in charge of NASA GISS.”
    _______________________________________________________________________

    CAGW comes from the first Earth Summit and Maurice Strong in 1972. As Elaine Dewar wrote in Toronto’s Saturday Night magazine:

    “It is instructive to read Strong’s 1972 Stockholm speech and compare it with the issues of Earth Summit 1992. Strong warned urgently about global warming, the devastation of forests, the loss of biodiversity, polluted oceans, the population time bomb. Then as now, he invited to the conference the brand-new environmental NGOs [non-governmental organizations]: he gave them money to come; they were invited to raise hell at home. After Stockholm, environment issues became part of the administrative framework in Canada, the U.S., Britain, and Europe.”
    http://www.mail-archive.com/ctrl@listserv.aol.com/msg106963.html

    Strong is a member of the Club of Rome.
    Club of Rome Document, 1991, “The First Global Revolution” p. 71,75 1993
    – Richard Haass,

    “The common enemy of humanity is man.
    In searching for a new enemy to unite us, we came up
    with the idea that pollution, the threat of global warming,
    water shortages, famine and the like would fit the bill. All these
    dangers are caused by human intervention, and it is only through
    changed attitudes and behavior that they can be overcome.
    The real enemy then, is humanity itself.”

    Strong is a trustee of the Rockefeller Foundation and worked for the Rockefellers in Saudi Arabia when he first started out. Even David Rockefeller had the gall to admit they are trying to wreck the USA. He writes in the Rockefeller autobiography “Memoirs” on page 405, “For more than a century ideological extremists at either end of the political spectrum have seized upon well-publicized incidents… to attack the Rockefeller family for the inordinate influence they claim we wield over American political and economic institutions. Some even believe we are part of a secret cabal working against the best interests of the United States, characterizing my family and me as “internationalists and of conspiring with others around the world … If that’s the charge, I stand guilty, and I am proud of it.”

    There is plenty of evidence that CAGW and the anti-nuclear movements were orchestrated for political and monetary motives. Both Strong and the Rockefellers are heavily into oil and did not want nuclear as a competitor in the 1970’s

  150. Z says:

    One of the things overlooked is that Venus has an opaque atmosphere. That means that energy can only be radiated from the very edge of the atmosphere, unlike Earth, where a photon can fire out from just about anywhere from the surface upwards. That makes the effective surface area of Earth (and Mars) very large, and the effective surface area of Venus very small in comparison.

    Combine this with the increased albedo of Venus – recognising that the whiter a surface, the less it radiates – and you can see that Venus probably has a hard time dumping heat, especially in comparison to Earth and Mars.

    A little bit of geothermal energy probably goes a long way there – I’m not surprised the surface periodically melts.

  151. Mike Ewing says:

    I think Venus and earth have nothing in common. Youve gotta ask the why with the thick atmosphere of venus, vrs earth. And water is the obvious difference… which enables chemical reactions that lock co2 from the core outta the atmosphere. So venus would have been of similar composition at its birth, with its location in the solar system, but the main difference that i can see that would result in the H2O being stripped would be the absence of a magnetic field on venus, the result i suppose of its slow rotation/long days… which would have meant that the solar winds would have stripped the atmosphere/planet of lighter gases.

    If earth had all the co2 in its atmosphere today that had been vented from its core since its birth, id wager it would also have a dense atmosphere. And be a tad warmer than it is now;-)

    And it dosnt matter if the shortwave dosnt reach the surface, if its absorbed in the atmosphere, it will still cause a greenhouse effect.

  152. Curiousgeorge says:

    @ kramer says:
    May 6, 2010 at 2:46 pm

    I think the 3rd poster (Curiousgeorge ) has a good point.

    Well, thanks; but the point was merely to get people thinking a bit. I know full well that Venus does not behave as a cylinder does. It has sources of energy, including tidal effects, possibly some internal radiation, etc. as well as solar heating & volcanism that effectively keep those gas molecules moving and therefore keep the energy level up. And that’s really what we’re talking about here – energy.

    It’s theorized that Titan has liquid water under it’s miles of ice due to heating from the tidal effects of Jupiter, so Solar tidal effects may not be an insignificant factor on Venus, especially given it’s slow rotation.

  153. Leon Brozyna says:

    Stunningly obvious.
    Stunningly simple.
    And stunningly ignored.

  154. Savante says:

    You might want to make a calculation of “radiation transmitted by the atmosphere” on Venus (as shown above for Earth); You will be surprised by what you see. There is essentially as much water (absolute) on Venus as on earth (yes it is a smaller fraction of the atmosphere, but the atmosphere is ~100 times more massive); in addition, the much higher pressures broaden the IR transitions (both for water and CO2) producing a very thick greenhouse. The presence of sulfur dioxide and sulfuric acid add additional opacity.

  155. Philip Mulholland says:

    Congratulations Steve.
    Now ask this really interesting question:
    At what temperature does Calcium Carbonate thermally disassociate into Carbon Dioxide and Calcium Oxide? Notice that this temperature is way above the surface temperature of Venus and so limestone would be a thermally stable rock, even on Venus. (OK, I know, but not chemically stable in the presence of the sulphuric acid in the Venusian atmosphere).
    The real point is this. It is not possible for the carbon dioxide sequestered in the limestone rocks of Earth to be naturally released into our atmosphere by thermal dissociation of limestone (except of course in a cement works). In order to load our atmosphere with the equivalent mass of Carbon Dioxide gas seen on Venus, all of the limestone on Earth would have to be destroyed.
    You are right Steve. For the Earth, runaway carbon dioxide greenhouse is a complete fiction.

  156. bubbagyro says:

    It is 9000 KPa on earth. Deep under the mantle. I wonder if it is cool there?

  157. Mike says:

    As Rob above explained you are looking only at the present conditions and not how Venus’s atmosphere evolved. The Wikipedia article you cite does explain this.

    “Studies have suggested that several billion years ago Venus’s atmosphere was much more like Earth’s than it is now, and that there were probably substantial quantities of liquid water on the surface, but a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere. [34]”

    http://en.wikipedia.org/wiki/Venus#Atmosphere_and_climate

    The reference is to one paper that uses a one-dimensional model and requires a subscription. Does anyone have a better reference for the evolution of the Venusian atmosphere? It may be that the high temps caused even more CO2 to go into the atmosphere and increase the density. Anyone know?

  158. rbateman says:

    phlogiston says:
    May 6, 2010 at 3:35 pm

    The distance from the Sun has to do how much energy reaches a planet.
    What happens from there is the subject.
    Magnetic field vs how much early Solar Wind scouring has taken place. Mass counts as radioactive material decay can internally heat a planet. Have a look at the density of and mass of the inner planets.

  159. Bill Illis says:

    The greenhouse effect is not the only thing that makes objects hot in the universe.

    Gravitation compression causes Jupiter’s core to be 24,000K, Earth’s core to be over 6,000K, and for the stars to initiate main sequence nuclear fusion, temperatures have to increase to 10 million Kelvin (no greenhouse effect involved in that).

    Furthermore, some of the hottest places on Earth are the depressions below sea level. The Dead Sea for example is about 5C to 7C warmer than the temperatures above the rift valley (a higher rate than would be expected from the lapse rate alone at 2C to 4C).

    Obviously, it is not as easy as just “pressure”. The deep ocean has a temperature close to 1.0C despite the very high pressure in the deep ocean but that is because water is denser as it get colder. The hottest temperatures in the Earth system are, in fact, at the very top of the atmosphere in the Thermosphere because it is subject to so much EM radiation from the Sun and the magnetic field (and the fact that it is so thin, temperature starts to mean less and less).

    If you look at the lapse rate of Mars, Earth, Venus and the Sun, it has a logarithmic relationship to temperature with higher lapse rates occuring as the temperature increases but it is logarithmic.

    Generally, I think pressure and, in effect, the work being done by gravity, has not been taken into account in global warming theory and someone needs to put it back in.

  160. Mike Ewing says:

    Savante says:
    “There is essentially as much water (absolute) on Venus as on earth”

    Are you sure about this…..i take it this isnt counting H2SO4 as water… can you cite a source please?

  161. Nick Stokes says:

    “No such place exists, but if it did – it would be extremely hot, like Venus.”
    No, it wouldn’t, not without a greenhouse effect. A surface at 700K emits about 12,000 W/m2. Incoming sunlight, averaged over surface area, on Venus is about 400 W/m2. If the atmosphere is transparent to thermal IR, that 12,000 W/m2 would just go out to space and sunlight couldn’t possibly balance it. The surface would cool.

    What does balance it, of course, is thermal IR emitted from the atmosphere itself. But that can only happen with some GHG effect.

    The adiabatic transport effect can explain a temperature difference. But it can’t provide that source of radiant heat. All it means is that TOA would be correspondingly colder.

    “The way a greenhouse effect works is by shortwave radiation warming the ground, and greenhouse gases impeding the return of long wave radiation to space.”
    It doesn’t have to involve the ground. It only requires that heat passes through a layer of gas at a frequency to which the gas is relatively transparent, and is part-blocked from returning at lower thermal IR frequency. It doesn’t matter whether the absorption and reemission happens at the ground or at a lower level of the atmosphere.

  162. artwest says:

    OT:
    I was watching UK Channel Four’s Alternative Election Night programme and they brought on trendy, all-over-telly-at-the-moment, Prof. Brian Cox and asked him what we SHOULD be worried about. He had a list of five things and as I was expecting the obligatory CAGW, probably as No.1 “threat”, I frankly zoned out a bit, but shockingly, amongst super volcanoes, plagues and asteroids, I don’t think there was a single mention of global warming. Even when he came to his No 1, human stupidity, I didn’t hear anything about AGW.

    Did my ears deceive me? Anyone else catch this? Doesn’t he realise that even the fact of not mentioning AGW will cause him to be banished to the wilderness – or is he a closet sceptic?
    Surely if he was any kind of believer, AGW would be in his top 5 threats to humanity?

    I know it sounds like a minor point but, given the non-stop gushing about AGW on British TV this was genuinely a surprise.

  163. kuhnkat says:

    Onion,

    CO2 has a very narrow bandwidth for absorption of IR radiation. Unlike the earth with oxygen, ozone, water vapor, and a couple other high efficiency radiation absorbers that are wide band, the CO2 atmosphere of Venus is like stretching a few reflective strings over a wide open window to try and reflect back the energy.

  164. HankHenry says:

    Steve,

    Thanks and that would mean that while CO2 on Venus is a fifteenth the density of water, air on earth (at 1.2 kg/m3) is only about one *fiftieth* the density of CO2 on Venus. I wonder if you’d call movement of something that heavy – a wind or a current. I also wonder what convective processes would be like on Venus.

  165. kuhnkat says:

    Savante,

    “…adds additional opacity.”

    Opacity means BLOCKED. Doesn’t mean reradiated in all directions which is the so called Greenhouse theory.

    Like earth there is still the issue as to whether a cooler atmosphere CAN heat a hotter surface!!!!!!!!

    How high is the tropopause on Venus again??

    How much water vapor is actually below the tropopause??

    By the way, there is no confirmation of actual water only hydroxyl.

  166. If there was a lot of heat coming out of the interior of Venus, it would be detectable as a radiative imbalance at the exterior of the atmosphere. Has anyone heard of this? I haven’t.

  167. CodeTech says:

    I had to explain this to a few people while working with turbos, so let me try to throw some plain English explanations into the mix.

    When you compress ambient air with a turbocharger, it gets hot. Really hot. Most people simply use the logic that the turbo is hot (driven by exhaust gas), therefore it heats the air. This isn’t even remotely close, since the air isn’t in contact with the blades nearly long enough to heat it much. What is happening is that all of the energy that was already in the air is now packed into a smaller space, thus there is more energy in the same space, thus it is warmer.

    And by warmer, I mean really warmer, hundreds of degrees. This is why turbo cars use an intercooler, a mini radiator that lets the compressed air radiate much of that heat before it gets into the engine.

    The post above about compressing air into a bottle heating it but then later it’s cool? The simple reason is that the energy has radiated away. If you compress air into a thermally isolated chamber it will remain warmer (don’t try a Thermos, they can’t take much pressure… voice of experience).

    As we all know, the atmosphere of Earth holds only a tiny fraction of the energy that the oceans do. The exact same is true of the Venusian atmosphere: it is under a higher pressure and therefore CAN hold more energy. So it does. And it gets that energy from the local star. Who knows how long it has taken to reach its current equilibrium? Are there Venusian Climatologists right now worried about 10K temperature variations over the last century?

    Ironically, we use the stereotype of Mars being red, angry, male, and Venus being gentle, mellow, female. In actuality Mars is cold, barren, dull, and Venus is hot, roiling, active.

  168. Nick Stokes

    You set up a straw man using a selectively edited quote. Very naughty of you.

    What I wrote was :

    9000 kPa atmospheric pressure would occur on earth at an altitude many miles below sea level.  No such place exists, but if it did – it would be extremely hot, like Venus.

  169. Earth’s atmosphere has 1,000 times the concentration of water as Venus. Venus has only 90 times as much atmosphere. That means that earth has 10 times as much water stored in the atmosphere as Venus, plus a massive buffer of excess water in the oceans.

  170. MattN says:

    Kenneth Chang of the NY Times and I had an email exchange last year and this very subject was thrown out there. This is lifted word for word from one of his responses to me:

    “Let’s turn the question around: what would convince you that the climate is warming? I’m guessing that actual temperature data from other parts of the world (and images of shrinking glaciers and stuff like that) are not convincing data to you, either. The policy questions don’t hinge much on Antarctica. I guess I also don’t understand how you could be so certain that CO2 emissions could a priori never cause warming. The fundamental basic physics of carbon dioxide says it should. And for clear proof that CO2 in sufficient quantities can cause global warming, there’s Venus.”

    This guy is the “science” reporter for the Times….

  171. PJF says:

    “It’s theorized that Titan has liquid water under it’s miles of ice due to heating from the tidal effects of Jupiter…”

    I doubt there are any such theories. Titan orbits Saturn.

    Interestingly, Titan has a surface atmospheric pressure 60% greater than Earth’s and the temperature is minus 178C. Other Saturnian moons with no atmosphere at all have average temperatures only about ten degrees colder. Without a heat source (internal or external), atmospheric pressure contributes little in and of itself.

  172. Brian G Valentine says:

    SO2 produced on the surface reacts with water vapor to form sulfuric acid (droplets) stabilized to boiling by the catalyst (dust) in the Venusian atmosphere, and that reaction produced quite a bit of heat?

    Note that the martian atmosphere of 95-99% CO2 (at 3-5 mm Hg pressure) does not contribute to the heat of Mars at all. The size of the planet and the heat capacity of Martian soil account completely for the diurnal change in temp of up to 250K.

    Carl Sagan had way to many conversations with extraterrestrials. I think they were responsible for a lot of his bad judgment

  173. jcrabb says:

    I guess the high pressure at the bottom of the Ocean explains why it is so hot down there…

  174. Brego says:

    Re: Dave McK says @ May 6, 2010 at 3:23 pm

    You get it. Good on you!

  175. DougB says:

    Hi Steven
    If the atmosphere were to behave as an ideal gas the pressure cannot determine the long-term temperature. The atmospheric pressure at the planet surface would be determined by the total weight of the atmosphere divided by the total area of the planet. If the atmosphere is losing more heat by radiation than it receives from all sources (the sun plus any flow from a hot interior) then the atmosphere will cool. As it cools it will contract so that its volume decreases. The high pressure does not determine the temperature. Temperature decreases with altitude in the troposphere of a planetary atmosphere because heat is being radiated more from a higher level so a negative temperature gradient is established. I rather fear that your article will give the CAGW alarmists an avenue to attack us.
    Kind regards, DougB

  176. Pamela Gray says:

    Alright guys, this redhead is hyperventilating cuz we are just about to start the fishing season and I don’t have the rod I want! I just bought (well, last month) a very nice baitcasting reel and am looking for a shorter, flexible baitcasting rod so that I can fish along a brushy tree lined river. I am not fond of spinners as they snap the line back when I want to stop the line at the other side of the bank (which is where the trout I want ALWAYS are, right?). I want a flexible rod that takes 4 to 8 lb test that is less than 7 feet and preferably 6’6″. Got any ideas where I can find such a rod without going to #%*$ Venus????

  177. Smokey says:

    Just for general interest, here is a graphic description of the total amount of water in the oceans and air in the atmosphere compared with the planet. [Water on left, air on right.]

  178. u.k.(us) says:

    20 minutes till sunset in Chicago, then Venus will be very bright in the West/Northwest. Conditions on Venus are being extrapolated? with our conditions?
    We live here, and can’t figure it out.
    3.4 billion years of asteroids, volcanos, continental drift and ice ages.
    The results (not obliterated), are still being discovered/studied.
    The next 1000 years, will be a “blink of an eye” in Earth’s geologic history.
    P.S. Don’t tell Al Gore. Lest his head explode.

    I know, you know, but had to say it.

  179. Brian says:

    Here is the part that still confuses me. Looking at the Radiation Transmitted by the Atmosphere chart. At the Wavelenghs that CO2 absorbs radiation, no radiation escapes the earth. How does adding more CO2 decrease the outgoing radiation more that it does.

    It is like an assembly like with multicolored M&M going down it. If one person is removing red M&Ms. Lots of red M&Ms get through. With each added person, fewer get through. At some point, the odds of a red M&M getting through is very small.

    Is there any measured data that says some of the radiation in CO2 absorbing wavelengths are actually getting through? If not, how can increasing CO2 levels capture more outgoing radiation?

  180. Mike Ewing says:

    Pamela Gray

    It sounds like they would be ideal candidates for the nickel or copper head spinners… You use a short high velocity spinner launching “rod”(also known as a rifle in some countries) and place the spinner just above offending fish… then you just require a net to scoop them out, or wait down stream at an eddie that catches em… hope this cures yah hyperventilating. (also is ideal to use for spot light aided night fishing)

  181. Willis Eschenbach says:

    Nick Stokes says:
    May 6, 2010 at 5:23 pm

    “No such place exists, but if it did – it would be extremely hot, like Venus.”
    No, it wouldn’t, not without a greenhouse effect. A surface at 700K emits about 12,000 W/m2. Incoming sunlight, averaged over surface area, on Venus is about 400 W/m2. If the atmosphere is transparent to thermal IR, that 12,000 W/m2 would just go out to space and sunlight couldn’t possibly balance it. The surface would cool. …

    Nick, I’d be interested in your comments on the Volz piece I referenced above.

  182. Derek B says:

    Both explanations, “it’s the CO2″ and “it’s the pressure”, are too glib in themselves. As pointed out in a previous post, high temperatures result in a thick atmosphere.
    The present Venusian climate is stable, despite the combination of high albedo and high temperature. The interesting question is how did it get this way?
    According to explanations I’ve seen, it is believed that Venus used to have a lot of water; that at some point the Sun’s heat baked a lot of CO2 out of the rocks; that the combination of CO2 and water vapour drove up the temperatures; and that although subsequent dissociation of the water lost its hydrogen into space, the thick atmosphere is enough to sustain the present balance.
    If that is correct, it stills represent a feasible scenario for Earth’s future – indeed, rather likely when the sun eventually gets hot enough or large enough.
    One way to challenge that explanation would be to show our models do not match its present energy balance. Do they? I don’t know, but that does not appear to be a claim being made in this blog.

  183. Robert of Ottawa says:

    PJF, this link shows the temp/pressure profile of the Venusian atmosphere. Note that around 1 Earth atmosphere of pressure, the atmospheric pressure is roughly the same as the Earth’s.

    http://www.datasync.com/~rsf1/vel/1918vpt.htm

  184. davidmhoffer says:

    Zeke says:
    May 6, 2010 at 12:36 pm
    Also, Carl Sagan smoking pot is a bit of a cheap shot :P>>

    Surely you jest.
    It was clearly a pot shot.

  185. JAE says:

    Bill Illis @5:22
    “Generally, I think pressure and, in effect, the work being done by gravity, has not been taken into account in global warming theory and someone needs to put it back in.”

    Right on. I am so sick of seeing all these discussions that focus on only one variable, like radiation.

    Those folks who keep saying that AGW is “proven” with basic physics need to explain some anomalies, and it is my experience that they are reluctant to do that. For example, please provide a K&T-style “radiation equilibrium diagram” for Fiji! I guess Neoscience allows folks to totally ignore empirical evidence.

  186. Nick Stokes says:

    Steven G, May 6, 2010 at 5:44 pm
    I don’t believe I did misquote you, but anyway the issue is there. High temps create a huge IR flux, and something has to block that, otherwise losses will far exceed the energy supply. The adiabatic effect can’t create a large heat flux.

  187. Tsk Tsk says:

    Stephen Goldstein says:
    May 6, 2010 at 1:18 pm

    “…Say I connect a SUBA diver’s air tank to a compressor and “fill” the tank with compressed air. I ask how come the tank is warm and you reply “because it has an extremely high pressure.” Okay, but I come back in an hour, the gauge still reads 3000psi but the tank is no longer warm. How come? The gas is still at an extremely high pressure…”

    Because the cylinder won’t be at 3000psi when you come back. The ideal gas law still applies: PV=nRT. You haven’t changed V (entire cylinder). You haven’t changed n (amount of stuff, i.e. moles). You haven’t changed R (material properties of the stuff). You have changed T (lower) and so you have changed P. Having filled SCUBA tanks at my dad’s shop lo’ the many years ago I can attest to this. Tanks were filled in a bath of water to draw the heat of compression off as quickly as possible and were only considered full when they measured 3000psi (or 2400 depending on whether they were aluminum or steel) and were only moderately warm to the touch. If we hadn’t done that we would have had some pissed off customers who didn’t get the full amount of air they’d paid for.

    Having said that I’m in the camp that the application of the ideal gas law doesn’t explain Venus. Take away the sun or perhaps its own vulcanism and Venus would have to cool through radiation to the local background, i.e. ~4K, and the pressure of its atmosphere would not maintain its temperature indefinitely, nor would the pressure or volume remain constant.

  188. Robert of Ottawa says:

    PJF, I think about the P-T -H profiles of atmosphers a lot.

    Let’s start at the basic. Without external energy inputs, all planetary atmospheres will ultimately form a crust on the surface of the planet and have zero height.

    With external energy input, that crust will evaporate and form an atmosphere. The P-T-H characteristics of that atmosphere are defined primarily, I believe, by three things:

    1. The ratio of the mass of the atmosphere to the mass of the planet
    2. The radiative energy budget, which must equalise at the “top” of the atmosphere.
    3. The thermodynamic requirement for all parts of the atmosphere to have the same total energy – thus we must consider the sum of gravitational and thermal energy.

  189. Pamela Gray says:

    No, no, no!!! I’m not talking about a lure spinner. I am taking about the rod. A baitcasting rod has a trigger on it (a place for parts of your hand so you can use other parts to slow down the line as you land that fat worm just where you want it). A spinning rod doesn’t have this thorn like feature under the rod. But most baitcasting rods are made for bass fishing (a fat heavy fish) and are usually made for 8+ pound test weight (think log size girthy rod, not twig size skinny rod). I want an ultralight baitcasting rod (twig size skinny and flexible) with the trigger and I want it to be short (less than 7 ft), not the usual length for such a rod. I want to use 4 to 8 lb test. Any baitcasting rod I have found is too long and too telephone pole stiff for trout.

    See???? I am hyperventilating again!!!!! Come on you guys!! You’re GUYS! You should know this stuff!!!!

  190. Smokey says:

    Thanks, Willis, for that interesting link. John Daly had a post up the thread showing why the Earth and Venus can’t be compared:

    Venus rotates backwards, ever so slowly. A day on Venus is almost like a year here. I don’t know what such a slow rotation would have on a planet’s climate, but I wouldn’t like to be on the daylight side.

    Venus also has no magnetic field, so it gets the full brunt of corpuscular bombardment from the sun, a secondary energy input.

    Venus has no large tilt angle and therefore little precession. This would prevent any Venusian equivalent of our “ice ages” (speaking very relatively of course)

    Whether geothermal activity is a significant source of heat on Venus I cannot answer. On Earth geological fission is certainly an important factor

    The topography of Venus was shown by satellite radar sweep to have vast lava flows etc. So geothermal activity is a possible real factor here and may go part of the way to explain the high temperature (465°C)

    In short, an astronaut landing on Venus would find himself asphyxiated by the carbon dioxide atmosphere, burned to a crisp by the searing heat, poisoned by the acid rain, and crushed by the super-dense atmosphere. That’s why goddesses are best viewed at a distance :-)

    The Venus atmosphere has 90 bar, mostly sulfur acid and CO2 and is by no means comparable to Earth.

    Chick, I hope that your original assumption that it was 1 bar is not the same assumption being made by others who are quick to compare Earth with Venus. It’s well known in Astronomy that Venus has a super-dense atmosphere of almost pure CO2. The atmospheric pressure there is 90 times ours. Since we only have 0.036% CO2 [<--- written in 2000], whereas Venus has 98% CO2 in an atmosphere with 90 times our pressure, that means Venus has 2,500 times our density of CO2, or 5.5 times our CO2 for every extra degree of temperature.

    I don’t think Venus can possibly be used as a surrogate comparison with Earth. The baseline parameters are so horrendously different to make all such comparisons meaningless.

    And PJF responds @5:56 pm to this comment:

    “It’s theorized that Titan has liquid water under it’s miles of ice due to heating from the tidal effects of Jupiter…”

    with:

    “”I doubt there are any such theories. Titan orbits Saturn.””

    Actually, Titan has immense quantities of hydrocarbons.
    [source]

  191. JAE says:

    Nick:

    ““No such place exists, but if it did – it would be extremely hot, like Venus.”
    No, it wouldn’t, not without a greenhouse effect. A surface at 700K emits about 12,000 W/m2. Incoming sunlight, averaged over surface area, on Venus is about 400 W/m2. If the atmosphere is transparent to thermal IR, that 12,000 W/m2 would just go out to space and sunlight couldn’t possibly balance it. The surface would cool. …”

    Nick, I’m still waiting for an “equilibrium radiation balance diagram” for Fiji (K&T play around with an “average,” which means absolutely nothing when radiation varies as T^4–it means nothing for a real “spot” on Earth).

    Now, in that comfortable clime of Fiji, there is adequate radiation JUST from the water to “explain” the air temperature year-around. The damn Sun just keeps heating the water up each day. The “backradiation” is not needed, and, indeed, if it were employed in the diagram, it would make the temperatures so high that the Fiji People would be fried. The GHG effect is an apparition, methinks. Can you explain this anomaly?

    I await your diagram.

  192. Curiousgeorge says:

    Sorry, I meant Europa. Brain freeze. :)

  193. Smokey

    There is essentially no difference in surface temperature between the day and night sides of Venus.

  194. Ric Werme says:

    Here are a couple other links when we covered this 2 1/2 months ago at
    http://wattsupwiththat.com/2010/02/22/bill-oreilly-hosts-bill-nye-the-science-guy-and-accu-weathers-joe-bastardi-in-fox-news-debate/#comment-325845

    Julian Braggins (01:37:34) :


    A search for Venus temperature at 1 bar will bring up a figure comparable with Earth’s taking into consideration insolation at that distance, and lod, alternatively, taking dry air lapse rate and increasing depth of troposphere on Earth to that of Venus it comes out to 756K°, very close again, with no extra CO2 involved, ie. CO2 greenhouse is negligible.

    Ah, very good. I was going to say that too, but figured I’d see if someone else did already. The WUWT readership seems to be big enough so I don’t have to read everything any more to make sure my point of view or factoid gets heard. Maybe I can break my addiction to WUWT now!

    Links to Venus atmospheric profiles:
    http://www.esa.int/esaSC/SEM5A373R8F_index_1.html
    http://www.datasync.com/~rsf1/vel/1918vpt.htm

    Warning: the second one is a bit weird. Okay, more than a bit weird. However, the graphs are easy to read.

  195. Dave says:

    Misconception Number 1: That CO2 forcing is logarithmic at very high concentrations.

    Reality: At very low concentrations CO2 forcing is linear. It becomes logarithmic when saturation of the central absorption line is reached, and increased forcing depends on the wings of the lines (and pressure broadening). However, as concentrations continue to increase, minor absorption lines become sufficiently important in comparison to the wings of the major lines that the increased absorption of CO2 is mostly dependent on the minor lines, and the forcing of CO2 increases linearly with concentration again.

    Misconception 2: Lack of Energy Balance thinking.

    Two examples have been presented: 1: Titan, despite high pressures, is very cold. A similar thought experiment would be what would happen to Venus if we turned the Sun off – I hope the obvious answer would be that Venus’ temperature would quickly drop to whatever could be supported by internal tectonic/volcanic heating (which wouldn’t be much).

    2: Venus with a totally transparent atmosphere: the surface would radiate directly to space. As Nick Stokes pointed out, in such a case, in equilibrium the radiation out from the surface CANNOT be larger than the radiation the surface receives (plus any internal heating): therefore, it doesn’t matter how many atmospheres of the perfectly transparent gas there are, the surface temperature will be solely determined by that radiation.

    A simple example of GHG forcing experienced in daily life: humid nights compared to dry nights: humid nights are warm, dry nights are cold. This has nothing to do with temperature, and a lot to do with outgoing radiation and GHG absorption (in this case, water vapor). (it is even more obvious with clouds, but clouds are sufficiently different from a gas that it isn’t as clean a comparison).

    -Dave

  196. Mike says:

    I found this: “Even though a large percentage of heat radiation is reflected from the top of the clouds and never reaches the surface of the planet, the heat that does penetrate is captured by the thick cloud covering. Less than half of the infrared radiation is released back to space. the effect is to raise the temperature of the planet by a massive 500°C (900°F).” http://www.planetsalive.com/?planet=Venus&tab=B

  197. Leonard Weinstein says:

    Steve,
    Much of what you stated is right. The comment that failed was to say that the statement: “Without the greenhouse effect caused by the carbon dioxide in the atmosphere, the temperature at the surface of Venus would be quite similar to that on Earth” was completely wrong. Later you qualified this by using the statement: “if 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees”. That last statement is correct. However if there were no CO2 or clouds (or other greenhouse gasses), the average surface temperature would only be ~55 degrees C or less (depending on albedo). The lapse rate due to adiabatic expansion at altitude would still hold but the only source of atmospheric heating would then be surface conduction and convection up, which would then eventually spread through the atmosphere. This makes the first quote correct, although somewhat misleading, as your second quote is also correct.

  198. astrowright says:

    Mr. Goddard shows here how little he understands about planetology. On its face, yes, the “greenhouse effect” is not responsible for Venus’s temeperature at present. But this is complete buffoonery, akin to saying that a person lives a tax-free existence every moment he or she isn’t being handed a paycheck with taxes removed, and then going on to calculate that 99% of American citizens go untaxed 90% of the time. It is not only incorrect, but it shows a complete misunderstanding of process.

    CO2 is a heat-storing molecule. More CO2 present in a planet’s atmosphere will store more heat as shortwave radiation has a harder time escaping the planet. The “runaway” part, then, is not isolated to CO2 but involves how other consitiuents of the atmosphere respond to this initial increase in heat.

    Venus has not always had a thick atmosphere, as evidenced by by circumstantial conditions of the early solar system as well as Venus’s geologic history. In fact, it likely started out quite similar to Earth’s early atmosphere, with no free oxygen, heavy in nitrogen with a smattering of CO2 and a decent amount of water and water vapor and nearly identical surface pressure (governed by the planet’s nearly identical mass and gravity). However, Venus’s slightly closer proximity to the Sun meant that more ionizing radiation was available to disassociate the water vapor in the upper atmosphere. As a result, hydrogen was separated from oxygen by ultraviolet light and lost to space, and the free oxygen quickly bound to plentiful carbon to make CO2. In this way, all of the planet’s water started being converted to CO2. Suddenly, this “greenhouse effect” vaporized more water, which meant it was vulnerable to UV disassociatio, and yet more CO2 was created, which warmed the surface even further, vaporizing more water, which was in turn disassociated and turned to CO2…. a runaway effect. At the end, we have a Venus as we know it today – completely devoid of water with an absolutely incredible surface temperature and pressure. The hellish end-result of a runaway “greenhouse effect.”

    So, as a planetary geologist myself, I can only assume that Steve Goddard is aware of all of this and intentionally attempting to mislead his readers with this ridiculous and simultaneously well-researched farce. I can’t see how he could possibly have researched enough to produce the information he did about atmospheres and chemistry yet somehow manage to miss all information learned during the past 40 years about the history of the specific planet he alleges to describe. Either way, the production of this sort of catchy misinformation is why the US falls farther against other nations in science and innovation each year.

    If you’re really interested, read a book, not a blog, people. I can suggest quite a few if you’re interested in how planetary atmospheres really work.

  199. Smokey says:

    Steven Goddard:

    “Smokey

    There is essentially no difference in surface temperature between the day and night sides of Venus.”

    I didn’t say there was, but from Willis’ link to Dr Hartwig Volz: “Day temperature at 65 km is about 300 K, night temperature slightly below 200 K…”

    I don’t know if there’s a difference, myself. And I understand that 65 km is not the same as surface temps. Just commenting on it, that’s all.

  200. Frank from Texas says:

    I was all set to edit the Wiki, but then I saw the reference which is a Nasa Ames thing:

    Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus
    James F. Kasting
    Space Science Division 245-3, NASA Ames Research Center, Moffet Field, California 94035, USA
    Received 12 March 1987; revised 17 September 1987. Available online 26 October 2002.

    Abstract:
    A one-dimensional climate model is used to study the response of an Earth-like atmosphere to large increases in solar flux. For fully saturated, cloud-free conditions, the critical solar flux at which a runaway greenhouse occurs, that is, the oceans evaporate entirely, is found to be 1.4 times the present flux at Earth’s orbit (S0). This value is close to the flux expected at Venus’ orbit early in solar system history. It is nearly independent of the amount of CO2 present in the atmosphere, but is sensitive to the H2O absorption coefficient in the 8- to 12-μm window region. Clouds should tend to depress the surface temperature on a warm, moist planet; thus, Venus may originally have had oceans if its initial water endowment was close to that of Earth. It lost them early in its history, however, because of rapid photodissociation of water vapor followed by escape of hydrogen to space. The critical solar flux above which water is rapidly lost could be as low as 1.1S0. The surface temperature of a runaway greenhouse atmosphere containing a full ocean’s worth of water would have been in excess of 1500°K—above the solidus for silicate rocks. The presence of such a steam atmosphere during accretion may have significantly influenced the early thermal evolution of both Earth and Venus.

    I don’t know enough to have an opinion, but to take the language out of the Wikipedia entry, I’d need some points that rebut that specific source.

  201. Bob_FJ says:

    Stevengoddard,
    Thanks for your stimulating article!
    With an Average temperature: 737 K (464 C) it has left me decadaly incredulous that it could be as a sole consequence of a greenhouse effect. However, I think it has to be part of the story from the following considerations:

    1) A Soviet probe (s?) reported surprising brightness in visible light at the surface, including good quality photos. (Although there was some argument that they could not be genuine photos because of pronounced shadows around the rocks)
    2) Regardless of the source of the energy, at 737K there would be significantly greater radiation from the surface compared with Earth, (as a consequence of T to the fourth power; moving towards near infrared in the Planck curve)
    3) The CO2 at ~90 bars is not alone in high absorption capability. The PPMV of H2O at 20 is low percentage wise, but when amplified by 90 bars, that becomes significant.
    4) Although ~40% of sunlight is near infrared, this appears to be absorbed high in the atmosphere, above around 60Km, as evidenced by diurnal variations; see below. This would have the effect of reducing the T gradient between the surface and the mid or upper atmosphere, which would slow heat escape a little. (See links below in item 9)

    Other stuff:

    5) If there is an internal heat source within Venus, (like on Earth), with such a high surface T and maybe an insulation effect of very dense high specific heat CO2, the rapid fall-off of underground temperature towards the surface as seen on Earth would be less pronounced. (also no H20 oceans with evaporative cooling)
    6) One of the Soviet probes was reported to have picked-up unusual methane, part way through descent, that was suggested to have been a volcano plume.
    7) Although currently reported as dormant, there is agreement on past volcanic activity
    8) Khiel and Trenberth/IPCC have claimed that the greatest heat loss from the surface on Earth is from evapo-transpiration, which cannot occur on Venus.
    9) This study shows that the temperature in the atmosphere is a nice comfortable 20C at 54 Km. Here’s something interesting and more recent from ESA.
    10) There is even less known about Venus than there is of Earth, and I guess the dynamics in the atmosphere are largely speculative.

  202. davidmhoffer says:

    Pamela Gray
    I want an ultralight baitcasting rod (twig size skinny and flexible) with the trigger and I want it to be short (less than 7 ft), not the usual length for such a rod. I want to use 4 to 8 lb test. Any baitcasting rod I have found is too long and too telephone pole stiff for trout.>>

    My experience has been that an ultralight rod that short will frequently snap under the pressure of even a small trout, just not worth the aggrevation. Go with the length you want but in a stiffer rod. Put a thick rubber band between the leader and your rig to absorb the shock of the trout’s strike. The combination will give you the feel of a light rod in the length you are after and will stand up to a lot more punishment than the ultralight. You can even go down to about 5 feet to get the weight down and still have a very responsive set up. I know this is off topic but all that hyperventilating is messing with your CO2 blood index and we don’t want you over heating, you might be the tipping point!

  203. Nick Stokes says:

    Willis,

    Volz makes the point, correctly, that effective thermal emission to space happens at a higher level of the atmosphere, and the adiabatic heat transport (dry adiabat) would produce a surface heat increment beyond that. That’s true – the greenhouse effect on Earth works somewhat similarly.

    The dry adiabat creates a temperature difference, but is not a heat source. Consequently the actual temp is determines by some radiative balance requirement at a point where effective emission happens. On Earth, that is part surface (at ~290K, for atmospheric window frequencies), and part TOA (at ~225K, for GHG absorption.emission frequencies), and of course, some in between. The nett result is IR emission at the effective no-GHG temp of 255K, but with a warmer surface.

    So you could say that Volz is arguing for a reduced GH effect, in that some mid-layer of the atmosphere acts like our ground surface, and below that there is little nett flux, and adiabat heat amplification. The IR is still part-blocked by the atmosphere, but by clouds, not GHG.

    All true, and known – to work out what it really means, you have to identify the level of that effective layer, which Volz hasn’t done with any great precision.

    So to qualify my earlier remark – you can’t have 700K on the surface with an IR-transparent atmosphere. You could get a high temperature from cloud blocking plus adiabat, even without selective IR absorption. You can also get it from a greenhouse effect, and there’s lots of GHG for that. Both effects seem to be at work here.

    The “snowball Venus” temp, allowing for albedo, is about 390K. As with Earth, if you found that the outgoing IR spectrum corresponded to a BB that temp, you could say there was no greenhouse effect. I don’t have the information here, but I believe that, as with Earth, it is segmented into different regions of different apparent temperature.

    I don’t think the supercritical fluid issue affects the IR considerations, except maybe by increasing opacity. Volz’ notion is that nett IR flux at low levels is zero or small. It probably reduces the adiabat gradient.

  204. Ric Werme says:

    CodeTech says:
    May 6, 2010 at 5:41 pm

    I had to explain this to a few people while working with turbos, so let me try to throw some plain English explanations into the mix.

    When you compress ambient air with a turbocharger, it gets hot. Really hot. Most people simply use the logic that the turbo is hot (driven by exhaust gas), therefore it heats the air. This isn’t even remotely close, since the air isn’t in contact with the blades nearly long enough to heat it much. What is happening is that all of the energy that was already in the air is now packed into a smaller space, thus there is more energy in the same space, thus it is warmer.

    Umm, I have doubts about some of the packing existing energy idea. I use the more technical description that compressing a gas requires adding energy (force x distance) and that’s what is converted to heat. (Springs don’t heat up because they store the energy in the strain in the spring, gasses accelerate as their molecules bounce off the compressing surface.)

    You can give someone a good floor bicycle tire pump and tell them to pump up a car’s tire – that gives people a good idea of how much energy is stored in the compressed air!

  205. JAE says:

    Shucks, I guess no “radiation cartoons” for Fiji are forthcoming. It seems that the cartoons only work for “average” conditions?” What is really disconcerting is the silence on this subject. Can someone please put me in my place? LOL.

  206. gbaikie says:

    “As far as i understood it would take two things to turn Earth into a seccond Venus, and that is enough time, and about twice the amount of energy from the Sun.

    And this all to start building up the atmospheric pressure which needs a lot of time, more energy means more watervapour, more watervapour means higher pressure wich in result in an atmosphere wich is beter suited to hold an higher temperature. Once all the water in the ocean has been transformed into atmosphere the temperatures will be high enough to start the outgassing of rocks wich raises the temperature and pressure even further. Eventually Earth would look like Venus with a high pressure and CO2 rich atmosphere.”

    There isn’t enough [known] CO2 on earth.
    Water vapor can not build up unless it’s over 100 C everywhere on earth.
    There is enough carbon on earth but there isn’t enough oxygen to combine with the carbon to make say more than 4 atm of CO2.
    If you split all the water in our oceans you would have enough oxygen. Or if were to somehow get the oxygen from rock on the the Earth surface there is also more than enough oxygen. Though “somehow” getting the oxygen from the water from the ocean seems easier than getting it from the earth’s crust.

    So it’s more than two things- you also need to find or somehow make vast amounts of CO2- of the scale of roughly the mass of our oceans.

    Basically I would say it’s too late to make earth into Venus- life has irreversibly shunned us from that little piece of heaven.

  207. DocMartyn says:

    you don’t think it may have something to do with the fact that there are two phase transitions within Earths day/night temperature cycle?
    Pump heat into the Earth during the day and you convert water from liquid to gas, and increase the air pressure. At night the gaseous water is converted into liquid water, dropping pressure.

  208. Leonard Weinstein says:

    Astrowright,
    The present hot temperature of Venus is due to a combination of greenhouse gasses, clouds, and large atmospheric pressure. It would only take a relatively small fraction of greenhouse gasses at at the high surface pressure to make the radiation to space occur mainly at the outer edge of the atmosphere. The upper atmosphere temperature is determined by how much energy is absorbed by the atmosphere, surface, and clouds, and increases downward due to the adiabatic pressure increase effect. Even if there were only 1% CO2 and 99% Nitrogen, there would be little difference in surface temperature from the present. If there were 100% Nitrogen, the surface would be closer to Earth temperature (but with a hot side and cold side due to slow rotation). The thermal capacity of the CO2 is not important, its absorption of long wave radiation is.

  209. JAE says:

    Goddard: If you are gonna make this kind of post, I think you owe me an answer for my comment at : May 6, 2010 at 3:58 pm:

    Just what is your take on the “greenhouse effect?”

  210. Bob_FJ

    There is no question that absorption of IR by greenhouse gases elevates the temperature on Venus. My point is that it doesn’t explain the very high temperatures, and particularly on the dark side of the planet.

  211. DesertYote says:

    I have been waiting for the appropriate time to post this NASA link. You have to read to near the end for the AGW propaganda. There is a slight change from the last time I looked at this (a week or so ago.) One of the byline authors name has been removed, probably the source of the moonbattery. It was for someone at that Arctic Ice Institute thingy of NASAs ( can’t remember the exact name). What she was doing writing up a piece about Venus is anyone’s guess. The NASA editors must have thought it looked suspicious, so removed her name.

    http://www.nasa.gov/topics/solarsystem/features/magellan20100408.html

  212. hunter says:

    astrowright,
    Please finish the excellent explanation of Venus and go on to explain that we on Earth are no where close to even being able to cause a similar fate on our home world.

  213. Ted Annonson says:

    Atmospheres are NOT static. It is constantly mixed by vertical and horizontal air currents, so that the energy content of one mole(6.023X10^23 molecules of gas) at 10,000 feet altitude is ~= to the energy content of one mole of atmosphere at sea level. When compressed the gas does not gain energy; the molecules merely strike each other more frequently, so the measured temperature goes up. No gain or loss of energy. These air currents also prevent the heavier molecules from drifting down so that we have a well mixed atmosphere at most levels.
    Since Venus atmosphere is also well mixed, it too must have air currents to mix the air in both content and and molecular energy, so adiobatic warming will take place.

  214. Alan McIntire says:

    I question the extra atmosphere pressure as a reason for highVenus temps.
    p1v1/t1 = p2v2/t2. plug in p1, v1, t1 =1, and you get
    1*1/1 now put in a p2 of 90, a v2 of 1/90, and a t2 of 1, you still get 1. Nfr above got it right when he mentioned spectrum broadening. For more on that, look up “Voigt Profile”

  215. DesertYote says:

    Ric Werme
    May 6, 2010 at 7:37 pm

    You are goofy wrong. PVT, its simple physics, the basic gas laws, sheesh! Don’t they teach simple science in school any more? No wonder the greenies can promote their nonsense.

  216. Squidly says:

    Jonas N says:
    May 6, 2010 at 11:56 am
    Thanks Steve, interesting post! And if correct and reasonalble, it baffles me that noone else has noted this before …

    This simply cannot be! Other people must have hade similar thoughts and estimates.

    Actually Jonas, I had come to the same conclusions as cited in this post quite a long time ago while arguing about this with my father. Interestingly, after a considerable amount of Internet research, I have found a plethora of information across the web on this subject. Quite a large volume of information, even information gained from NASA websites, corroborates precisely what Steve has written here.

    If you do a little research and gather the FACTS about Venus, and then apply a little dose of Occam’s razor:

    1) “when you have two competing theories that make exactly the same predictions, the simpler one is the better.”
    – or –
    2) “Scientists must use the simplest means of arriving at their results and exclude everything not perceived by the senses.”

    The only plausible conclusion is again, precisely what Steve has illustrated here. Just do a little bit of “real” research and you will find this for yourself. It is undeniable.

    – Cheers

  217. gbaikie says:

    “If I remember my basic physics: energy absorbed is an inverse square to the distance from the source. Mercury has no atmosphere, and I’ll bet it’s sunny side is a lot hotter than Venus.”

    It isn’t.

    Mercury:
    Maximum surface temperature: 427°C
    Minimum surface temperature -173°C
    Venus:
    Mean surface temperature 482°C
    http://www.solarviews.com/eng/homepage.htm

    So Venus is hotter and has a higher average temperature [whatever that means].

    Of course you comparing apples to oranges. On Mercury the temperature is the surface temperature and venus is temperature is air temperature- though the Venus air would warm the ground to that temperature.

    If Venus had an airless moon, obviously it’s surface temperature would be cooler than Mercury. If you gave Mercury a 1 atm of atmosphere [of whatever gas] you would get a lot of wind. The wind would so vicious it’s would beyond the minds of humans to grasp. And I suppose it would hotter, though the dust would make it quite dark on the ground.

  218. R. Gates says:

    While you’re all debating what is keeping Venus so warm, here on Earth, Arctic sea ice is now below the levels of both 2008 & 2009 for this same date according to JAXA…

  219. Leonard Weinstein says:

    Steve Goddard,
    My previous comments are not clear enough. The lapse rate (drop in atmospheric temperature with increasing altitude) due to the very high surface pressure on Venus would exist with a greenhouse atmosphere or one totally transparent to both incoming light and outgoing long wave radiation. The greenhouse gas as you pointed out does only cause a few degree effect directly. However, without a greenhouse gas, the surface is where the outgoing radiation has to match the energy of the incoming that was absorbed, and thus this is where the surface temperature is determined. In that case, the lapse rate results in the atmosphere getting very cold as altitude increases. If there is any reasonable amount of greenhouse gas, the location of much of the source of radiation to space moves up in the atmosphere. Even less than 1% CO2 in Venus’s atmosphere results in almost all of the radiated energy to space occurring at very high altitude. Now the added temperature from the CO2 is still small, but the location of the temperature is very high altitude, and the increasing temperature (adiabatic compression) as you go lower still holds. It is the movement of the location of the source of radiation to space from the ground to high altitude along with high pressure that makes the surface hot on Venus, and this is not a runaway effect but straight Physics given the present conditions.

  220. Willis Eschenbach says:

    astrowright says:
    May 6, 2010 at 7:18 pm (Edit)

    … Venus has not always had a thick atmosphere, as evidenced by by circumstantial conditions of the early solar system as well as Venus’s geologic history. In fact, it likely started out quite similar to Earth’s early atmosphere, with no free oxygen, heavy in nitrogen with a smattering of CO2 and a decent amount of water and water vapor and nearly identical surface pressure (governed by the planet’s nearly identical mass and gravity). However, Venus’s slightly closer proximity to the Sun meant that more ionizing radiation was available to disassociate the water vapor in the upper atmosphere. As a result, hydrogen was separated from oxygen by ultraviolet light and lost to space, and the free oxygen quickly bound to plentiful carbon to make CO2. In this way, all of the planet’s water started being converted to CO2. Suddenly, this “greenhouse effect” vaporized more water, which meant it was vulnerable to UV disassociatio, and yet more CO2 was created, which warmed the surface even further, vaporizing more water, which was in turn disassociated and turned to CO2…. a runaway effect. At the end, we have a Venus as we know it today – completely devoid of water with an absolutely incredible surface temperature and pressure. The hellish end-result of a runaway “greenhouse effect.”

    Astrowright, a fascinating post. A few questions:

    1. You say that in the early days, the atmosphere of Venus was similar to that of the early earth, mostly nitrogen. What evidence is there for that?

    2. At present, the atmosphere of Venus contains very little nitrogen (~ 3.5%). What happened to all the early nitrogen?

    3. You say that the cause for what you call the “runaway greenhouse effect” is the stronger ionizing radiation at the the top of the Venusian atmosphere. If that is the case, wouldn’t a much more accurate term be the “runaway ionization effect”, and as such, be something that could never happen on earth?

    4. You say that the ionizing radiation at the very top of the atmosphere dissociated the water vapor and that the “free oxygen quickly bound to plentiful carbon to make CO2″. Why would carbon be plentiful at the very top of the atmosphere? And why would the oxygen not reform as O2?

    5. Why is there still water vapor in the Venusian atmosphere (20 ppmv)? What has prevented the ionization of the last of the water?

    Many thanks,

    w.

  221. bgcamroux says:

    A wonderful and thorough analysis, I cannot find anything in here to disagree with. I think it safe to say that probably 99.999% of the population is quite happy to accept things blindly, simply because a well-known personality says it is so. This is why the Hawkings of the world must be very careful about what they say.

  222. Ted Annonson says:

    PS
    Before the readings of the Venus probes became erratic the pressure/temperature readings were well within normal adiabatic paramaters.

  223. Mike Ewing says:

    astrowright says:
    CO2 is a heat-storing molecule. More CO2 present in a planet’s atmosphere will store more heat as shortwave radiation has a harder time escaping the planet.

    Typo there, yah mean long wave radiation o course.

    “However, Venus’s slightly closer proximity to the Sun meant that more ionizing radiation was available to disassociate the water vapor in the upper atmosphere.”

    And obviously the water vapor on mars suffered a similar fate, so wouldnt the lack of a magnetic field be more of a candidate over location? Considering mars is further from the sun than us. And initially wouldn’t the water vapor feedback, disassociation theory have resulted in an ozone layer? As well with corresponding albedo feedback’s from increased cloud cover from the increased GHG forcings? (id imagine we arnt going to fare to well when our core cools, and our atmosphere gets blasted by plasma. )

    End o the day, it is speculation, i see there was a paper printed recently that challenged the traditional early earth faint sun paradox/high atmospheric co2 compensating, with a theory, backed with evidence that atmospheric co2 was low, that cloud cover at the time was greatly reduced, as a result of the absence of life, that it self was responsible for the nuclei creation for cloud formation through biological processes. So if this paper stands up to time, it would also bring into question, whether life it self could be a factor.

    I dont think there is anything wrong with the open discussion of competing idea’s, even if i dont agree with them.

  224. Squidly says:

    PJF says:
    May 6, 2010 at 12:52 pm

    Venus’ atmosphere comes from volcanic outgassing, and Venus is a very different geological animal to Earth. It has no water so there are no tectonic plates. Instead of releasing heat gradually as does Earth, Venus is thought to occasionally “boil over”, where the whole surface completely melts. With the thick atmosphere, a high surface temperature would remain in the absence of solar heat.

    Also, I have not heard anyone here mention the fact that Venus has not magnetosphere either. It has NO magnetic shielding from the sun as we do. Any idea how hot Earth might be without a magnetosphere?

  225. Michael R says:

    In this way, all of the planet’s water started being converted to CO2. Suddenly, this “greenhouse effect” vaporized more water, which meant it was vulnerable to UV disassociatio, and yet more CO2 was created, which warmed the surface even further, vaporizing more water, which was in turn disassociated and turned to CO2…. a runaway effect.

    Unfortunately, what you have declared so adamantly as fact is, by it’s very nature, what is under dispute currently. In fact, what you have described is, in effect, what the whole argument of global warming is and consequently, people who do not agree that we understand fully the processes by which this plant achieves its temperature balance, are even less than willing to accept that you (or anyone else) can then ascribe said theory – with another planet altogether – and expect to be 100% correct.

    I note you were particularly blunt with your critisms and so shall I – I can only assume that the complete lack of uncertainty relating to process we know only partially how they work and arrogance in assuming you do was a result of your Planetary Geology degree being …. honorary?

  226. D. King says:

    Pamela Gray says:
    May 6, 2010 at 6:57 pm

    Wrap your own rod, that’s what I do.
    Read about blanks here.
    http://www.onorods.com/calhist.htm

    Steve,
    What a great post.
    You got everyone thinking. Bravo!

  227. Mike Ewing says:

    Willis Eschenbach says:
    5. Why is there still water vapor in the Venusian atmosphere (20 ppmv)? What has prevented the ionization of the last of the water?

    If the stripping of the water vapor was due lack o magnetic field, and solar winds, the water vapor in the atmosphere would be the result of the resultant thicker atmosphere becoming charged, and acting as a magnetic field itself . And the later vented H2O not being stripped. As id imagine would also be the case with astrowrights hypothesis.

    Just thought id throw it out there;-)

  228. Squidly says:

    Ahhh, Mike, you beat me with a “magnetosphere” topic reply … a good reply and a topic of Venus I would be interested in learning more about.

  229. DesertYote says:

    astrowright
    May 6, 2010 at 7:18 pm

    One big difference between the Earth and Venus; the Earth has a whopping big atmosphere stripping moon!

  230. JustAddWater says:

    @ Duster May 6, 2010 at 12:19 pm & Feet2thefire

    The problem I have with Professor Nasif Nahle’s work was put forward on another blog (unknown poster), quote:

    “This suggests that the atmosphere transers no photons to the surface of the Earth at night. This is not the case, as the flux of longwave radiation from the atmosphere has been measured, and even occurs during the polar night (the months of darkness the occur at the poles each winter). See http://journals.ametsoc.org/doi/full/10.1175/JCLI3525.1

    It’s perfectly reasonable to state that at night the surface cools by radiation – that’s true. But if there were no back radiation from the atmosphere, it would cool faster at night! This is not a takedown of AGW – it’s attempting to take down the very notion of a greenhouse effect! (Well, as far as I can tell anyway). “

  231. Pamela Gray says:

    Sea ice is within 1 SD of the mean. All predictable due to weather. Moving on.

    Venus versus Mars. Sounds like a WWF fight. The winner must battle Earth for the belt. Will there be chairs involved?

  232. Amino Acids in Meteorites says:

    The high temperatures there can be almost completely explained by atmospheric pressure – not composition. If 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees.

    Troll scratches head….. doesn’t know where to turn…… watches ‘An Inconvenient Truth’….. goes to bed happy….. dreams of dead polar bears and cannibal grandpas….

  233. DesertYote says:

    Pamela Gray
    May 6, 2010 at 9:00 pm

    Would that be the Asteroid Belt?

  234. Amino Acids in Meteorites says:

    Pamela Gray says:
    May 6, 2010 at 6:57 pm

    Can I have your number Pam? hehe

  235. Lon Hocker says:

    As many folks have pointed out, your analysis is thoroughly flawed. Some sunlight gets in, but the IR is trapped by the extremely pressure broadened infrared absorption lines. I’m sorry, but the Venus greenhouse effect is real.

  236. James says:

    This is all over my head, but I’ll point out something anyway:

    1) CO2 only absorbs radiation at certain wavelengths. Those wavelengths belong to black bodies below 50 deg C and above 300 deg C. It doesn’t absorb anything in-between.

    2) Earth has very few places – outside of the upper atmosphere – at those temperatures, so very little radiation is produced by the earth that is absorbed by CO2.

    3) Venus has lots of things at those temperature – including mostly the atmosphere, so CO2 is much more relevant to Venus than to earth.

    James

  237. James says:

    Oops – in previous comment, I meant CO2 obsorbs energy from black bodies below -50 deg C. Not 50C. My bad.

    James

  238. Jeremy says:

    astrowright says:
    May 6, 2010 at 7:18 pm (Edit)

    … Venus has not always had a thick atmosphere, as evidenced by by circumstantial conditions of the early solar system as well as Venus’s geologic history.

    And how much of Venus’ geologic history do we have an evidence for? My understanding was that for decades we had about exactly 1 picture of the surface, and only recently have we revealed the entire planet surface through long-range-radar studies. Exactly what evidence on our radar maps and single picture tell us that the atmosphere used to be thin?

  239. Robert says:

    About the nitrogen in the atmosphere in venus, its 3.5% of 4.8 × 10^20 kg. On earth its 78.08% of 5 × 10^18 kg.

    So guess what, there is even more nitrogen in the atmosphere of Venus then there is in the atmosphere of Earth. In fact there is about 4 times more nitrogen on Venus compared to Earth so i guess it is still there if both atmosphere started out equally, the better question would be, where is our nitrogen?

    As for water still being a trace element in the Venusian atmosphere, it has a lot of sulfuric acid and hydrogen sulfide. Carbon Dioxide will split into Carbon Monoxide and Oxygen under UV light, Oxygen reacts with Sulphur to form Sulphuric Trioxide wich then combined with water will lead to Sulphuric acid.

    Volcanism (although not yet proven on Venus) could add all the needed gases into the atmosphere. On Earth watervapour is the most abundant gas that comes from vulcanos. That could well be the source for the water on Venus, not much but enough.

  240. Lon Hocker

    This article is pointing out that it is pressure, rather than composition which causes Venus to be hot.

    You responded with a statement saying that I am wrong, because it is pressure that makes Venus hot.

    You might want to think that line of argument through a little bit.

  241. Ric Werme says:

    DesertYote says:
    May 6, 2010 at 8:17 pm

    Ric Werme
    May 6, 2010 at 7:37 pm

    You are goofy wrong. PVT, its simple physics, the basic gas laws, sheesh! Don’t they teach simple science in school any more? No wonder the greenies can promote their
    nonsense.

    I am quite aware of the gas laws, thank you, physics was my favorite high school course in 1967/68. Laws say what, they don’t say why. Compress a gas, the temperature goes up. Temperature is a measure of kinetic energy, so something has accelerated the gas molecules. Why is that goofy?

    I like physics because it explains how the natural world works. The derivation and meaning behind the equations of motion, gravity, etc are more important to understanding the world than slavishly plugging in numbers into equations.

    You might want to check out my web site, I don’t think you’ll find much AGW support there.

  242. Phil. says:

    Pamela Gray says:
    May 6, 2010 at 6:57 pm
    No, no, no!!! I’m not talking about a lure spinner. I am taking about the rod. A baitcasting rod has a trigger on it (a place for parts of your hand so you can use other parts to slow down the line as you land that fat worm just where you want it). A spinning rod doesn’t have this thorn like feature under the rod. But most baitcasting rods are made for bass fishing (a fat heavy fish) and are usually made for 8+ pound test weight (think log size girthy rod, not twig size skinny rod). I want an ultralight baitcasting rod (twig size skinny and flexible) with the trigger and I want it to be short (less than 7 ft), not the usual length for such a rod. I want to use 4 to 8 lb test. Any baitcasting rod I have found is too long and too telephone pole stiff for trout.

    See???? I am hyperventilating again!!!!! Come on you guys!! You’re GUYS! You should know this stuff!!!!

    I’d make my own, it’s easy, you can buy a baitcasting rod butt and it sounds to me like 7′ fly rod blank would work well (try Cabelas). I built myself a 9′ noodle rod for steelhead using 3lb test using a fly blank, the biggest I caught with it was 18 lb. Good luck.

  243. Lon Hocker

    One more thing. Please explain how the dark side of Venus (which is dark for months on end) manages to keep the same temperature as the other side of the planet which is light for months on end.

    If you can invent a greenhouse which stays as warm at night as it does during the day, you should get very rich.

  244. Ric Werme says:

    Lon Hocker says:
    May 6, 2010 at 9:23 pm

    As many folks have pointed out, your analysis is thoroughly flawed. Some sunlight gets in, but the IR is trapped by the extremely pressure broadened infrared absorption lines.

    And then what happens? The heated gas convects upward to a region transparent enough to radiate in wavelengths that aren’t blocked.

  245. James Sexton says:

    Carl Sagan…….up until now, the most prolific science fiction writer ever to pass his work off as science. He had a great imagination. When the Martians or Saturnians come and get us, he’ll be proven correct. Like the rest of the cast of idiots, he said “I’ve got a degree from a meaningless institution that gives me license to say whatever comes off of the top of my head and people should believe me. After all, I’ve got a degree in…..lunacy.”

  246. michael hammer says:

    Sorry Steve, while I am very much a skeptic of AGW I have to disagree with your analysis. You make a mistake early on in the analysis. Doubling of CO2 relates to doubling the partial pressure or if you like the number of molecules per square meter of surface area. On earth the partial pressure is about 350e-6 of 1 atmosphere. On venus it is close to all of 92 atmospheres or about 250,000 times greater. At that sort of pressure there is absolutely massive pressure broadening so that CO2 absorbs almost everywhere. Thus it retains a very large amount of heat pushing the temperature up very considerably. But there is worse. CO2 also has very strong absorption bands at 2 and 4 microns which will also be massively pressure broadened. As the surface heats up, more and more of the emission moves to shorter wavelengths (look at planks distribution curve) where it is also intercepted by these other lines.

    This is a totally different situation to that existant on Earth. The Earth is too cold to emit signifcantly at 2 and 4 microns. The logarithmic law is a good approximation at Earth conditions where CO2 absorbs only a small part of the surface emission but cannot be extrapolated to a change as large as a quarter of a million times increase. The broadening becomes so extreme it occupies the entire spectrum.

    It is really nonsensical to try and draw parallels between 0.0003 atmospheres and 92 atmospheres.

    One thing I would say however is that it is also ridiculous to talk about run away green house effect. The term runaway implies positive feeedback causing an unstable escalating effect often called a tipping point. The situation on Venus is nothing of the kind. You might as well say that plugging a radiator into the wall socket causes runaway heating causing it to glow red hot. Certainly it glows red hot but there is nothing runaway about it. Its simply the equilibrium point that results from the power input and cooling available. Its the same on Venus. If one were to decrease the amount of CO2 in the atmosphere the temperature would come down progressively, there would not be any tipping point.

  247. Savant says:

    “Earth’s atmosphere has 1,000 times the concentration of water as Venus. Venus has only 90 times as much atmosphere. That means that earth has 10 times as much water stored in the atmosphere as Venus, plus a massive buffer of excess water in the oceans.”

    Steve, you mean “mixing ratio” not “concentration”. On Earth, H2O is ~0.5% or less of the column (though of course it can be much higher in the boundary layer). This is relatively similar to the amount thought to be present in the atmosphere of Venus. The high pressure of CO2, however, makes the water significantly more opaque due to pressure broadening of the IR transitions. I encourage you to do the radiative calculation — it isn’t so hard and there are some nice tools available (try modtran).

    Your argument about the lapse rate is largely correct, but as others have commented, the question is at what altitude does the OLR = absorbed solar. In the venus atmosphere this is at high altitude; it is the very efficient greenhouse that allows the surface to be cooked. If the venus atmosphere was transparent to IR (e.g. made of N2 for example) the surface would be very cold, no matter how dense the atmosphere was.

  248. Robert says:

    Oh why do we think that there has been a lot of water on Venus in the past? Isotopes, the ratio between Deuterium and Hydrogen on Venus is much higher than it is on Earth.

  249. Dennis Wingo says:

    So Dennis, how about a little quantitative information, how much wider, how much taller? If you integrate the curve, do you really get a lot of area, or maybe just a slight spreading, but these are the tails of the absorption bands, and so how much matters a lot.

    The detailed information on this is from the textbook “The Quantum Theory of Light” by Loudon, page 84-91. I have the 1968 version of the textbook. The equations for line broadening of CO2 are both temperature and pressure dependent.

  250. Willis Eschenbach says:

    stevengoddard says:
    May 6, 2010 at 9:52 pm

    Lon Hocker

    One more thing. Please explain how the dark side of Venus (which is dark for months on end) manages to keep the same temperature as the other side of the planet which is light for months on end.

    If you can invent a greenhouse which stays as warm at night as it does during the day, you should get very rich.

    Well, according to the usual font of misinformation (Wikipedia),

    The atmosphere of Venus is in a state of vigorous circulation and super-rotation.[5] The whole atmosphere circles the planet in just four Earth days, much faster than Venus’ sideral day of 243 days. The winds supporting super-rotation blow as fast as 100 m/s (~220 mph).[5] On the other hand, the wind speed becomes increasingly slower as the elevation from the surface decreases, with the breeze barely reaching the speed of 10 km/h on the surface[6]. Near the poles are anticyclonic structures called polar vortexes. Each vortex is double-eyed and shows a characteristic S-shaped pattern of clouds.[7]

    I’d suspect that would be sufficient to come close to equalizing the temperature on the two sides, but what do I know? I was born yesterday …

  251. Savant

    If you dug the Grand Canyon down to a depth of 30 miles below sea level, what would be the temperature there?

  252. michael hammer

    If you dug the Grand Canyon down to a depth of 30 miles below sea level, what would be the temperature there?

  253. I’m fascinated by some people here who are implying that a test tube full of oxygen would have to be close to absolute zero, because it is not a greenhouse gas.

  254. Ric Werme says:

    James Sexton says:
    May 6, 2010 at 9:56 pm

    Carl Sagan…….up until now, the most prolific science fiction writer ever to pass his work off as science. He had a great imagination.

    While there were a couple good things in Cosmos (the Samurai crabs of the coast of Japan, for one), his stupid dandelion starship (likely made of star-stuff) was one of billions and billions of shortcomings.

    I bought my first color TV in 1974 to watch Jacob Bronowski’s The Ascent of Man, a vastly superior series, IMHO. Okay, not-so-humble-opinion.

    The existence of crystals proves the existence of atoms. The mud at Auschwitz.
    http://www.museum.tv/eotvsection.php?entrycode=ascentofman

  255. Jon-Anders Grannes says:

    I agree totaly that atmosphere density/pressure is the key driver for climate on planets.
    As I hypothised earlier when we discussed(in the end of comments)
    http://wattsupwiththat.com/2010/04/07/faint-sun-paradox-explained-by-stanford-greenhouse-effect-not-involved/

    As such I really really have problems accepting that the Earths atmosphere is warmed up by an “greenhouse effect”?
    When we can explane this better if we use the words “isolation/insulation effect” and the “thickness”(“air”pressure on the surface of the planet) .
    And the composition of the atmosphere, water, metan, co2 etc. etc. can also have some effect?
    A thicker atmosphere means that less energy is needed to warm it up and that the energy stays longer or use longer time to escape the atmosphere.

    As it is with houses that are better isolated/insulated in cold weather.

    Who made up this idea that Earths atmosphere has a “greenhouse effect”?
    When it is totally wrong and misguiding?
    Radical environmentalist? Again?

  256. Nick Stokes says:

    Steven G:
    “some people here who are implying that a test tube full of oxygen would have to be close to absolute zero, because it is not a greenhouse gas.”
    Where on Earth do you get that from? Oxygen neither emits nor absorbs IR, so that’s neutral on temperature. It is held at ambient temperature by thermal conduction and convection, which has nothing to do with GHG status.

  257. Dave says:

    A test tube full of oxygen, suspended in space so it isn’t getting any convective or conductive heat transfer, would be pretty darn cold.

    (note you’d have to prevent ozone formation and there would be some energy absorption of very high energy photons even with a diatomic gas so it wouldn’t be quite absolute zero, but… darn cold, yes).

    ps. “pressure broadened absorption lines” is not “lapse rate” so perhaps you want to try rereading Lon Hocker’s statement? And in an atmosphere with slow radiative heat loss and lots of atmospheric circulation, I don’t see why you are so hung up on a warm night-side.

    Two questions for you, Steve Goddard: if the Sun were turned off, what would the temperature of Venus be? And, if you had a black planet with an atmosphere that was transparent to all radiation, how could the surface of the planet be any warmer than the blackbody temperature as defined by the incoming solar radiation, regardless of how much atmosphere the planet had?

    -Dave

  258. CodeTech says:

    Ric Werme,

    As I explained, I was throwing plain English into the mix. At the very least, what I wrote about turbos helps explain to those who are not familiar with the more technical aspects of gases. Judging by some of the comments on this thread there are quite a few people who want to understand but don’t have the background.

    After all, one of the appeals of WUWT is that it is more accessible than CA to the average reader.

  259. Phil. says:

    Brian says:
    May 6, 2010 at 6:27 pm
    Here is the part that still confuses me. Looking at the Radiation Transmitted by the Atmosphere chart. At the Wavelenghs that CO2 absorbs radiation, no radiation escapes the earth. How does adding more CO2 decrease the outgoing radiation more that it does.

    That’s because it’s a cr*p graph that doesn’t represent what it purports to (it’s used all over the internet though). Here’s a detail of part of the CO2 absorption spectrum at both the conditions of Mars and Earth (under venusian conditions it would fill in and look more like that cartoon).
    http://i302.photobucket.com/albums/nn107/Sprintstar400/Mars-Earth.gif

  260. Jon-Anders Grannes says:

    “A thicker atmosphere means that less energy is needed to warm it up and that the energy stays longer or use longer time to escape the atmosphere.”

    Should be:
    A thicker atmosphere means better isolation/insulation and that less star/Sun energy is needed to warm it up because this energy use longer time to escape the atmosphere again(Stays longer in the better isolated/insulated atmosphere).

  261. Gilbert says:

    Not that this explanation has no merit at all, but I’m appalled that the water cycle is constantly overlooked. The earth’s climate is dominated by a giant air conditioner, which constantly moves heat from the surface to higher altitude. I suspect the earth would be much, much hotter if there were no water.

  262. R John says:

    As a chemist, it is interesting that soooo many people cite things like the ideal gas law. No gas is “ideal” – they all begin to fail under low temperatures and – wait for it – high pressures. Ever heard of the van der Waals equation?

    One thing the trolls cite is that a compressed gas will lose its temperature over time. That is true on earth as heat always flows from hot to cold objects (the surrounding uncompressed air). However, one of the fundamental principle’s of a gas is that it’s collisions are ELASTIC. Energy In to a Collision = Energy Out of a Collision. Thus, a constantly compressed gas will ALWAYS remain warmer. This is why gas molecules do not continually slow down (like billiard balls on a frictionless table) until the liquefy.

    I await the troll responses…

  263. Bryan says:

    geronimo

    ……Do you know Steve I’d already figured that out, but in the opposite direction, I was trying to figure out why Mars with almost the same atmosphere in terms of CO2…..

    Professor Bryan Cox discussed Mars in his recent excellent TV series “The Solar System”.
    He came to the conclusion that Mars had lost almost all of its geothermal activity.
    This has led to the present climate.
    At one time Mars had much more geothermal activity and liquids produced huge “Grand Canyon” like features on Mars.
    One feature throughout the series was his emphasis on geothermal activity.
    In the whole series of about 6 episodes his only reference to the “greenhouse effect” was given in one sentence .

  264. gbaikie says:

    “2. At present, the atmosphere of Venus contains very little nitrogen (~ 3.5%). What happened to all the early nitrogen?”

    Venus has about 90 atm- or about 90 times earth’s atmosphere.
    So if Venus has 3.5 % nitrogen, it has 2 times or more as much nitrogen as Earth’s atmosphere.
    Same goes for the low percentage of water in Venus’ atmosphere- because it’s such a huge atmosphere, it’s quite a bit of water. Though not anywhere near the amount on Earth, but perhaps near the amount on Mars- a small ocean or very large lake worth.

  265. Robert C says:

    You are correct that Venus does not have any Greenhouse Effect at the surface. However, you are wrong to use that drawing showing the spectra of IR absorption because, while it is useful at 1 atm, it is completely wrong at 92 atm. At that pressure, CO2 is totally opaque to longwave IR (due to bandwidth broadening) with 99.99% being absorbed within one foot of the surface at most important frequencies. (A few frequency bands require about 200 meters to absorb 99.99%.) Your discussion of logarithmic decrease with concentration only applies to a narrow band around a selected frequency. A different (and highly complex) set of equations applies to the analysis in a wide band of frequencies. And another set of equations is needed at high pressure.

    Thus, your association of temperature with atmospheric pressure is wrong. The correct association is that the atmosphere becomes IR opaque at those pressures. If the atmosphere was Nitrogen, then it would remain transparent and the surface would be cold.

    As for Sagan – he was correct to assume a runaway Greenhouse effect when it was believed that the atmospheric pressure on Venus was maybe two times the pressure on the Earth. However, once probes landed on the surface that theory was shown to not be necessary or correct.

  266. Julian Braggins says:

    Steve Goddard,
    I thought that Velikovski’s prediction of the cooling of Venus and its confirmation was well known,
    this is one ref. that confirms that it is emitting more heat than it receives,
    http://www.agu.org/pubs/crossref/1992/91JA02444.shtml
    Thank goodness you are doing something to refute the ‘ runaway greenhouse’ myth of Venus, and I would like to point out to others that the churning of the atmosphere restores the adiabatic lapse rate constantly both here and on Venus, a reliable guide to temperatures where I live at 1000mtrs at the same latitude as Sydney, 9°C below their forecast, absent strong winds.
    A profile of temp. pressure of Venus is shown here, indicating that at a similar pressure, our temperatures are remarkably similar taking into account insolation and the different properties of CO2 at saturation and high pressure. http://nova.stanford.edu/projects/mgs/images/t3213.gif

  267. Couple of points:
    1. Venus is about half the distance of earth from the sun. It surely follows that it receives four times the radiative energy (inverse square law).

    2. It may be a bombshell to state this, but the ‘radiation trap’ hypothesis to explain a glasshouse warming invented by Fouier, Tyndall and Arrhenius is wrong.

    A. The Wood experiment of 1909 killed it completely. He showed that short wavelength radiation is not transformed into long wavelength by the ground nor does a glasshouse warm by feedback of radiation from the glass – it is purely due to conduction of heat from the ground to the air above, convection which recirculates the air which cannot escape through the glass roof. If the glass WERE really radiating IR to further warm either the air or the ground it would have to be itself warmer than the ground – basic laws of thermodynamics. Next time you park your car/automobile
    in the sun, feel the dashboard then the windscreen/windshield. Which is warmer?
    A recent experiment using a laser beam (0.7Wm) onto a thermometer showed no change in temperature. http://www.greenhouse.geologist-1101.net//
    Similarly unless the air above the ground containing ‘greenhouse gases’ were always warmer than the ground, it cannot heat the ground. Reality is that the atmosphere is always cooler than the ground.
    The earth’s atmosphere keeps us warm simply by the gases absorbing heat by conduction and convection – as Cp/Cv is more or less the same for all gases it does not matter what those gases are (except H2O which undergoes changes of state) – slowly losing that heat overnight.

    B. NASA released a report recently of the temperature fluctuations of the surface of the moon. Just like the earth it too shows a ‘greenhouse’ temperature elevation of 40K about the theoretical surface temperature. In other words neither the earth nor the moon (nor Venus) is kept warmer by any greenhouse effect.
    http://www.climaterealists.com/attachments/database/RadiativeNonEquilibrium_BHermalyn_Final.pdf

  268. Keith Minto says:

    With Earth having water in a dynamic state as gas, liquid and ice, this must be part of the engine that creates the climate system here( I know this is simplified). The tropical part of this system starts out producing vertical convection at the equator, turning horizontal and distributing heat to the poles.
    There is nothing that I can see that can produce any phase change on Venus that in any way resembles the water phase change on Earth, nothing to produce vertical convection and convective heat distribution. This lack of vertical convective energy may be responsible for the ‘layered’ wind pattern on Venus that seems to be maintaining the dark side heat content.

  269. Richard Briscoe says:

    Good article. Just one slip. “9000 kPa atmospheric pressure would occur on earth at an altitude many miles below sea level.”
    In the oceans, pressure increases by one bar – the equivalent of sea-level atmospheric pressure – for approximately every 10 metres, or 30 feet, of depth. A simple calculation shows that the pressure will exceed 92 times atmospheric pressure at less than one kilometre depth, or just over half a mile.

  270. HelmutU says:

    Excellent post. Venus is for me the cpnvincing example that CO2 has no influence on the temperature in the atmosphere. In addition: when the atmosphere of Venus would consist mostly of a two atomic gas like nitrogen then the temperature would be 200 °C higher as it is now.

  271. michael hammer says:

    Steven; I hear what you are saying and I do not want to say that the pressure and depth of the atmosphere is irrelevant but not in the way you think. Green house gases absorb because they have a resonance in a molecular bond. When a photon with the same frequency as the bond resonance commes along it can be absorbed with the energy going into exciting the resonance. This energy is then dissipated to other moelcules through collisions. As the gas pressure increases there are more collisions between molecules. Some of these collisions momentarily upset the resonance somewhat changing its resonant frequency and thereby allowing it to absorb a photon of a slightly different frequency if one comes along at just the right time – this is pressure broadening. On top of that, the resonance lines plotted with respect to frequency (or wavelength) do not have infinitely steep sides. Rather they are somehwat like a gaussian curve. As the amount of gas in the path increases, wavelengths out in the wings where the absorption was very small start to show sigificant absorption and this again leads to line broadening (this is what gives rise to the logarithmic relationship). These are exceptionally well understood aspects of spectroscopy which are beyond dispute. Denying them does not advance the sceptical cause.

    The impact of line broadening is very interesting. Lets take a very stylised example (one that is clearly much more simple than reality but it shows the point) Imagine the surface of the planet can emit to space at say 50 wavelengths and it emits equally at all wavelengths (yes I know very over simplified but it shows the point). It emits 50 watts so 1 watt at each wavelength. Now you place over it a green house gas which prevents it from emiting to space at say 5 of those wavelengths. For equilibrium the planet still has to emit 50 watts but now it can only emit at 45 wavelengths so it has to emit 1.11 watts at each wavelength. To emit more at each wavelength it has to get hotter. OK the GHG line broadens so that it now blocks 10 wavelengths. Now the planet can only emit at 40 wavelengths so it emits 1.25 watts/wavelength and gets yet hotter in a reasonably close to linear fashion. But what happens when 40 wavelengths are blocked and further broadening cuts that down to 45 wavelengths? For the same reduction of 5 wavelengths the energy at each of the remaining wavelengths has to double. That is one of the reasons why one cannot extrapolate from the situation on Earth to Venus.

    So one may ask, what happens when all 50 wavelengths are blocked? Does the temperature go to infinity? No, because other mechanisms come into play. The heat travels up the atmospheric column via conduction and convection eventually heating the outer layer of the atmosphere which radiates the energy to space. The point is that the heat has to have a thermal gradient driving it up the atmospheric column and as a result, the thicker the atmosphere the longer the thermal gradient and the greater the temperature difference between surface and top of atmosphere. Since the top of the atmosphere is dictated by the energy radiated to space if this does not change neither does the top of the atmosphere temperature and all the increase is via heating of the surface. So in that sense the much thicker atmosphere does contribute very much to the surface temperature but only becuase the CO2 has blocked virtually all surface emission directly to space.

    This is of course very much simplified, both radiation and convection processes occur on Earth. This is one of my objections to the Kiehl and Trenberth model. They claim something like 2/3 of the direct radiation is blocked and must travel via convection yet the data from the interferometer abord the Nimbus satellite clearly shows that the direct radiation from surface to space is much larger – more like 2/3 than 1/3.

    If the atmosphere on Venus was all nitrogen with no GHG I think you would find the planet was not all that much warmer than earth despite the deep atmosphere and the closer proximity to the sun.

    Your point that a vessel of oxygen would have to be close to absolute zero because it is not a GHG is not quite accurate. Oxygen does not have any absorption lines in the thermal infrared which means it is also not capable of emiting in the thermal infra red. As a result its temperature will not be determined by thermal infrared radiative processes (more by conduction and convection). I am not sure but from memory it does have some emission lines in the microwave region so it can both absorb and emit in that wavelength region.

  272. dr.bill says:

    This comment isn’t about Venus, but a there is a lot of misinformation, erroneous Physics, and random nonsense being presented in many of the comments on this thread. Perhaps Moonbat’s Trolls are out in force. In any case, it would take forever to sort out some of the errors or misdirections, but I was gratified to see George E. Smith setting a few things straight, and I will add one comment on a matter that I think is important to understand. To wit:

    Re-distribution of energy in the atmosphere is largely carried out by convection processes, and an analysis of such processes, in and of themselves, leads to the conclusion that the top of the troposphere should be about 70°C cooler than the surface of the Earth, which is indeed the observed situation.

    It isn’t that the pressure gradient warms the bottom. It is that the surface (initially warmed by the Sun) heats the lowest layer of air by contact. This layer then starts to rise. As it does so, it performs work on the cooler air through which it pushes its way while rising. The rising mass of air is itself cooled as it expands while rising, but will keep rising as long as it is a bit warmer than the air it encounters. Energy is thus transferred from the surface to the atmosphere above, and makes it warmer than it would be, while simultaneously cooling the surface. The overall effect, however, is a vertical temperature gradient (a lapse rate) with the top cooler than the bottom.

    There are times and places where this process does not operate. In such cases, there can be Chinooks, Foehn winds, and various kinds of down-flowing air masses, but they are all short-lived events, and not the dominant effect.

    The fact that we have an atmosphere in the first place, and the fact that the Earth spins on its axis, then allows redistribution of energy in a lateral sense. This minimizes the day/night variation, and we thus do not thave the boiling day and freezing night conditions that would otherwise be present.

    The process mechanism itself sets a value for the lapse rate, which can be calculated from first principles. The simplest case is with dry air expanding adiabatically as it rises, giving a lapse rate of just under 10°C/km. The exact expression is (Mg/R)(γ-1)/γ, where γ is the adiabatic exponent, M is the molar mass of air, g is the acceleration of gravity, and R is the usual gas constant. If humidity is added to the air, the same process takes place, but leads to a smaller lapse rate, depending on the amount of water vapour present. The “global average” is generally taken to be 6.5°C/km, and at any given time and geographical location, the actual value will be somewhere in this range.

    In summary then, on Earth, the pressure gradient does not warm the surface. The surface warms the atmosphere by a convective re-distribution of energy that is facilitated by the pressure gradient. Without this process, the surface would be much hotter than it is.

    /dr.bill

  273. D. Patterson says:

    astrowright says:
    May 6, 2010 at 7:18 pm
    Mr. Goddard shows here how little he understands about planetology. On its face, yes, the “greenhouse effect” is not responsible for Venus’s temeperature at present. But this is complete buffoonery[....]

    Venus has not always had a thick atmosphere, as evidenced by by circumstantial conditions of the early solar system as well as Venus’s geologic history. In fact, it likely started out quite similar to Earth’s early atmosphere, with no free oxygen, heavy in nitrogen with a smattering of CO2 and a decent amount of water and water vapor and nearly identical surface pressure (governed by the planet’s nearly identical mass and gravity). [....]

    Those statements are utter nonsense. The Earth and Venus have had radically different origins and development of compositions as evidenced by the existence of the Moon (Luna) in orbit with the Earth. /The Earth’s first atmosphere was overwhelmingly dominated by Hydrogen and Helium as was most likely true of Venus. As the Sun’s solar winds stripped the inner planets of this first atmosphere of of Hydrogen and Helium during its T-Tauri phase, Venus, Earth, and Mars were left their second atmospheres dominated by percentages of carbon dioxide greater than more than something around 96% Carbon dioxide with methane, ammonia, Nitrogen and other gases. The second atmosphere of Earth was massive enough to produce surface pressures of far more than 150 atmospheres, much like what is found on Venus at the present time. Unlike Venus, however, the Earth was most likely smaller than present until a collision with a Mars size planet sometimes dubbed as Theia. The collision increased the mass and size of the Earth, radically changed the mass and composition of the planetary core, mantle, crust, and atmosphere. Much of the massive second atmosphere was ejected into the solar wind and swept away to the outer solar system. Much of the lighter crustal mass of Theia and the Earth were incorporated into the Moon, while much of Theia’s iron core was incorporated into the Earth. The much lesser mass of the post-collision Earth was still many atmospheres greater than at present and overwhelmingly dominated by Carbon dioxide. The Moon’s atmosphere was lost to space, and the Earth’s massive atmosphere was also greatly reduced by further losses to space before the geomagnetic core became effective in producing a magnetosphere obstructing the solar wind. Yet, the much reduced atmosphere continued to be composed of Carbon dioxide by overwhelming percentages until the biosphere began to sequester Carbon dioxide in the the lithosphere by biological activity. Venus most certainly did not experience these dramatic events and consequent changes. The Earth most certainly was not comparable in size to Venus at its origin. The Earth’s atmosphere was nearly all Carbon dioxide and massive like that of Venus until the biosphere removed the Carbon dioxide from the Earth’s atmosphere.

    Gravity is the source of the energy which keeps any substance hotter at greater atmospheric, hydrospheric, and lithospheric pressures. Sunlight certainly does not keep the Earth’s mantle and core in a molten condition, but gravity and radioactivity do so. Without the events which greatly reduced the Earth’s atmospheric mass and then stabilizing it against further losses, the Earth would have eithr remained to massive and hot to precipitate its Hydrogen monoxide (water) into a hydrosphere or it would have lost the water to space by heat, dissociation, and solar winds in much the way we see occuring in varied circumstances on Venus and Mars.

    I want to know when the EPA is going to recognize the dangers of greenhouse warming posed by the unregulated emissions of the world’s far most effective greenhouse gas, Dihydrogen monoxide, from pollution sources such as Hydrogen fueled automotive vehicles, power plants, and so forth.

  274. Scipio says:

    I’m wondering; doesn’t an equivalent volume (column) of water exert more pressure than the atmosphere and if it does why then are our oceans not 600 degrees C at one mile deep? I believe the thermocline for the deep oceans show increased cooling for increasing depth but the pressure is increasing proportionately too. If pressure is the driving factor for atmospheric heating shouldn’t the same be true for oceans and lakes?

  275. D. Patterson says:

    Correction:
    The much lesser mass of the [post-collision Earth] Earth’s post-collision atmosphere was still many atmospheres greater than at present and overwhelmingly dominated by Carbon dioxide.

  276. Ryan says:

    I am sorry but the analysis is wrong. You are assuming that CO2 is an ideal gas, when no gas is in fact ideal. What happens to a gas under pressure is that it tends to get hot, but if it cannot stay hot (because the heat is being taken away elsewhere) then it stops being a gas altogether. In other words, it liquifies (or in the case of CO2 solidifies directly). This is not taken into account at all by the gas equations, because they assume ideal gasses in isolation from external factors.

    So what would happen on Venus if there was a lot of pressure but no solar heating? The CO2 would not be hot enough to stay a gas and would solidify, just as it does on many small moons in the outer solar system. Clearly it would not then be an ideal gas at all.

    Gasses exist purely because they already have some energy within them that causes the molecules in the gas to vibrate. If that energy is allowed to transfer to space, then the temperature of the gas would drop and the gas would in fact cease to be a gas.

    So, there is a gaseous atmosphere around Venus purely because a lot of energy is being absorbed from an external source, mostly from the sun. The planet doesn’t rotate very fast so heating from gravitational tidal forces is minimal. Heating from internal fission would likely be the same as the earth, except that the lack of a magnetic field suggests that there isn’t a lot going on insider Venus. So it is most likely that the planets temperature is most likely to be due to its thick insulating blanket of CO2. It is not a “runaway” effect because the planet’s CO2 and temperature is quite stable and predicatable.

    However, this has almost nothing to do with planet Earth where the density of CO2 is so low it is more or less negligible and where the planet’s surface is within a powerful cycle dominated by the evaporation and precipitation of H20 close to the planets surface, and where internal fission and gravitational tidal forces generate substantial internal heating.

  277. Merrick says:

    Shrnfr,

    Your comments on pressure broadening are naïve Yes, pressure broadening exists. But for one, the effect isn’t as large as you make it out to be and even if it were pressure broadening doesn’t effect the integrated oscillator strength of the molecule. For exampIe, if the unbroadened spectral featrue of interest were 100 kHz wide and the peak extinction coefficient were 1000 mol^-1 cm^-1 then if it were pressure broadened to 1000 MHz the peak extinction coefficient would be reduced to 100 mol^-1 cm^-1. Of course, you’d have to have a spectrometer with much higher resolution than 100 kHz to see this. The point is, the area under the curve, which is the actual measure of total light absorbed, is identical in the pressure broadened and unbroadened cases.
    In the case where the absorption itself is highly saturated (like on Venus) broadening will some impact, but since the absorption is saturated, and since the spacing between ro-vibrational lines in the CO2 absorption peak of interest are already more closely spaced than the other homogeous broadening contributors (like Doppler) the only real impact that pressure broadening can have is on the outer edges of the envelope where it probably can’t contribute more than a percent vs. unpressure broadened.

  278. michael hammer

    Thanks for the explanation. I didn’t make any attempt in the article to explain the reasons why gas temperature increases with pressure – the article simply points out the correlation. Earth’s atmosphere would also be very hot, if it (at current composition) was much thicker.

  279. Nathan says:

    The question Steven Goddard should be asking is “Who squished the Venutian atmosphere?”

    Therein lies the answer to your conundrum

  280. Ryan

    I most certainly am not assuming that the atmosphere is an ideal gas. If it were, it would follow an isotherm when the pressure increased, and the temperature would not rise.

  281. Richard Briscoe

    I’m not talking about ocean pressure. I’m talking about atmospheric pressure. Death Valley and the Dead Sea are below sea level. Both are very hot places. Mt. Everest is at the same latitude as Saudi Arabia, and averages about -40 degrees.

  282. TomVonk says:

    The thesis is not correct .

    1)
    T and P are linked by the equation of state but don’t give any information about the energy dynamics .
    In thermal equilibrium high pressures don’t cause high temperatures and high temperatures don’t cause high pressures !
    Temperature being an average energy , its value is only determined by energy in and energy out regardless of the pressure .
    The pressure adapts then accordingly following the state equation .
    As Venus has a high mass of the atmosphere , it would have a high pressure in ANY case , regardless of the temperature .

    2)
    Let’s debunk fast the geothermal heat hypothesis .
    We know that Venus radiates around 10 000 W/m² .
    Let’s suppose that this energy is provided by solidifying lava .
    How much lava do we need to generate 10 000 W/m² ?
    You write 10 000 x S (Venus surface) = m (mass of the solidified lava per second) . L (latent heat of solidification) .
    You can use L = 4.10^5 J/kg and density = 3000 kg/m^3 .
    You will find that if whole Venus was initially molten , it would solidify by emitting
    10 000 W/m² in some 2.10^11 seconds what is 7600 years !
    So clearly it is not the lava that makes Venus emit 10 000 W/m² during billions of years .

    3)
    Let’s also debunk for the umptieth time the absurdity that I keep reading over and over that CO2 traps/stores heat .
    It does nothing such and never did !
    In equilibrium and we always consider equilibriums in these matters , CO2 emits exactly the same amount of radiation as it absorbs . It traps nothing and stores nothing , it only transmits .
    Another a bit more “sophisticated” absurdity is that CO2 heats the atmosphere by collisions .
    It certainly does nothing such because it does 2 things – it heats the atmosphere by collisions and it also cools it by collisions . By definition of equilibrium both (cooling and heating) are exactly equal .

    4)
    So now we are still left with the question how can Venus surface emit 10 000 W/m² and be in equilibrium ?
    The only physical answer is that something is giving it also 10 000 W/m² and we excluded lava .
    This something is not the Sun either because it doesn’t give enough .
    So that leaves only the atmosphere which acts by convection and radiation .
    Clouds , gases , particles , sulphuric acid , winds it’s all that .
    Convecting and radiating (little phase change here) .
    Does the CO2 “backradiation” play a role ? Surely .
    How much ? Nobody knows but the computers make believe that they do .

  283. Philip Foster

    Venus is 0.723 AU from the sun, not 0.5. 0.723^2 = 0.522729
    http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html

    Venus Earth Ratio (Venus/Earth)
    Semimajor axis (106 km) 108.21 149.60 0.723

  284. Interesting in the comments seeing claims that my explanations of the causes of the warming are incorrect. I didn’t make any attempt to explain causes, rather I simply pointed out the correlation between pressure and temperature.

    Sort of like how rumours and their attributions spread.

  285. Julian Braggins

    I didn’t see anything in that AGU abstract implying that Venus is losing substantial heat from it’s interior. Please explain.

  286. Willis,

    Thanks. Much appreciated.

  287. Stephen Wilde says:

    Scipio

    May 2010 3.41 am

    The density of water attenuates incoming solar energy to near zero well before it gets to the bottom. Furthermore convection within the water and evaporation at the top draw energy back upward. Thus oceans of water are not affected by pressure in the same way as the atmosphere.

    As regards the main point of this article I said this back in July 2008:

    “The atmosphere of Venus is very dense so the surface is much hotter than it otherwise would be. That of Mars is very thin so the surface is only a little hotter than it otherwise would be. The Earth is a special case because I would argue that the oceans should be regarded as a form of atmosphere in much the same way as the air because both air and oceans have heat storing properties. In effect Earth’s ‘atmosphere’ is in two parts for heat storing purposes and water is the primary player in both components.”

    and this :

    “CO2 and other trace gases are too small a proportion of the atmosphere to make a significant difference to overall atmospheric density even if their volumes were to be multiplied many times over. This problem for warmists is greatly enhanced if one considers the much more dense oceans as part of the planetary atmosphere for heat storage purposes.”

    from this article:

    http://climaterealists.com/index.php?id=1562&linkbox=true&position=4

    I always thought it was common knowledge that Venus was hot because of atmospheric density and not any so called greenhouse effect. Somewhere during the last 50 years that basic knowledge seems to have been overlain by nonsense.

  288. Nick Stokes says:

    stevengoddard says:May 7, 2010 at 4:36 am
    “I most certainly am not assuming that the atmosphere is an ideal gas. If it were, it would follow an isotherm when the pressure increased, and the temperature would not rise.

    Quite wrong. Some of what you’ve said about the adiabatic lapse rate is right, but it’s ideal gas theory.

    An ideal gas under adiabatic compression follows the relation T~P^q, where q=1-1/gamma, gamma=1.4 for bimolecular. Definitely not isothermal.

  289. kwik says:

    Scipio says:
    May 7, 2010 at 3:41 am

    Scipio, isnt this related to the fact that water is “incompressible”. It doesnt compress (much) under pressure. While a gas is compressible. So when you compress a gas, the distance between mocelules becomes smaller.

  290. Merrick

    Thanks for the explanation about spectral broadening. Much appreciated.

  291. Regarding Venus’ distance : I stand corrected – sorry for that error.

    I stand by the rest of my posting.

  292. Ric Werme says:

    CodeTech says:
    May 6, 2010 at 11:41 pm
    Ric Werme,

    As I explained, I was throwing plain English into the mix. At the very least, what I wrote about turbos helps explain to those who are not familiar with the more technical aspects of gases. Judging by some of the comments on this thread there are quite a few people who want to understand but don’t have the background.
    After all, one of the appeals of WUWT is that it is more accessible than CA to the average reader.

    In these respects we fully agree. I’m getting the sense that the overall quality of comments here has declined in the last few months. That’s not necessarily a bad thing, as it means more people are finding WUWT and are here learning the skeptics’ understanding of “real” climate. While WUWT certainly should not strive to become a big version of ClimateAudit, it certainly should present interesting and relevant information.

    Your notes about the temperature increase in turbochargers is something people here should understand (along with compression in diesel engines becoming hot enough to ignite fuel), even if I come along and question your description of increased energy density or if someone calls my added work as the source of the energy as goofy wrong.

    In comments to this post, it’s unfortunate that Steve didn’t mention lapse rates, that could have deflected a whole bunch of comments that temperature is related just to pressure. (It is in ye olde perfect insulation and lack of conduction, radiation, etc. that is important in physics class but rarely exists outside of mental experiments.) The lapse rate concept is critical to understanding what’s going on and that convection is an important part of moving heat upward.

    The recent post referring to 95°F wet bulb temperatures makes it clear that people don’t understand the concepts behind wet bulb and dew point temperatures. That’s one reason why I began to challenge all the claims that people regularly experience that environment.

    I’m not sure how WUWT, you, or I should respond. Blogs are fine for issues of the day, but I prefer freestanding web pages for describing facts. I’m not real fond of Wikis that are open to anyone, so I’m tempted to write new web pages for describing my understanding of various phenomena. I already have several but not so many on climate issues. I’m not sure how they’d work into the discussion here and I certainly don’t have time to keep up with all of posts and comments here. BTW, in http://wermenh.com/2016.html about the movie The Day after Tomorrow I note how downdrafts brought stratospheric air down to the surface so quickly it didn’t have time to heat up. Compared to that movie, we’re doing pretty well.

    Or I could go in a completely different direction and decide to “graduate” to ClimateAudit and Chiefio. I’ll be at http://www.heartland.org/events/2010Chicago/index.html and I want to talk about such stuff, time permitting.

  293. Oscar Bajner says:

    @Smokey – I have never understood the point of that http://i224.photobucket.com/albums/dd137/gorebot/WaterAirvolume.jpg graphic. I get that they want to show water volume is tiny relative to the planet, but the relative volume of the air depends on the pressure. If they compared mass it would make more sense.

    @Pamela Gray – Real GUYS don’t fish — they hunt ;)

  294. Pamela Gray says:

    stevengoddard! I know! I know! It’s one gaztillion frillian! That’s true cuz I heard Vice President Gore say it.

  295. Ric,

    The diagram in the article shows various wet and dry lapse rates.
    http://en.wikipedia.org/wiki/File:Emagram.GIF

    Some people will argue, no matter how obviously correct a concept is. Temperatures increase at lower elevations, and decrease at higher elevations.

  296. Merrick says:

    stevengoddard wrote:

    “Merrick

    Thanks for the explanation about spectral broadening. Much appreciated.”

    Of course I mistyped – sent that in using my blackberry while getting ready this morning. The second width should have been 1000 kHz or 1 MHz. As type, 1000 MHz makes the statement incorrect. The upshot is: if the peak is broadened by a factor, x, then the average absorption is decreased by that same factor, x, such that the area under the absorption feature remains contant. The absorption strength is simply spread out over a larger portion of the spectrum. No more or no less photons get absorbed per molecule.
    In situations where the absorption is very weak (very low concentrations) the broadening effect is exactly cancelled out by the lower absorption strength. In situations where the absorption is extremely saturated (extremely high concentrations) the impact is only at the edges of the large absorption feature. In intermediate cases (like on Earth) the impact is at is greatest. So relatively to Earth, this has a lesser impact on Venus.

  297. Alan McIntire says:

    Hey Anthony, ask Michael Hammer to post one or more articles here. He’s a spectrosopist who knows what he’s talking about. He posted several informative articles on Jennifer Marohasy’s blog.

  298. 1DandyTroll says:

    One thing I don’t get with supposedly rational and objective people is the inherent jumping of the bridge mentality of jumping through a zillion hoops just to prove an obvious ridiculous claim.

    Is it because it was writ in pedia and is supposedly verified by NASA? If that’s the case then it’s the most daft thing ever since NASA didn’t change their stuff until after the greenies went ape shit on pedia pages with their crap.

    But of course something has to be true just because it has been assumed to be true, especially if it has been assumed to be true for so long.

    This article is on par with what NASA should’ve kept, especially on their pages that are directed at kids, instead of boiling the venutians like lead with their pot-logic.

  299. Luboš Motl says:

    Dear Steve,

    I apologize but your statement that only the pressure matters is silly, and you haven’t provided us with any evidence. You make “back of the envelope” estimates, and then you pretend the results to be accurate at “tenths of a degree”. Moreover, you neglect – and claim to be zero about – many physical effects, the greenhouse effect in particular, but you never give any evidence that it is legitimate to neglect them. Because it’s not.

    I am going to write an article to debunk you.

    Best wishes
    Lubos

  300. Luboš Motl

    Huh? You might want to read the article a little more carefully before trying to “debunk” it. You must have missed the table in the article showing how temperature increases with each doubling of CO2.

    Where do you see a claim of accuracy to tenths of a degree?

    9000 kPa atmospheric pressure would occur on earth at an altitude many miles below sea level.  No such place exists, but if it did – it would be extremely hot, like Venus. A back of the envelope estimate – temperatures on earth increase by about 80C going from 20 to 100 kPa, so at 9,000 kPa we would expect temperatures to be in the ballpark  of :

    20C + ln(9000/(100-20)) *80C = 400C

  301. Luboš Motl says:

    Oh, I see, the sentence says “few tens”, not “few tenths”. I take it back. I actually agree with this estimate.

  302. Ryan says:

    @Stevengoddard: You said this “The high temperatures there can be almost completely explained by atmospheric pressure – not composition.”

    In other words, you say that the gas pressure above Venus is what causes the higher temperature. What I am telling you is that you are 180 degrees facing the wrong direction. Gases only become gases because they have heat energy applied. Therefore the CO2 is only a gas because there is heat from the sun (or elsewhere if you prefer). Therefore the pressure is a function of the applied temperature not the other way around.

  303. Enneagram says:

    Philip Foster:
    B. NASA released a report recently of the temperature fluctuations of the surface of the moon. Just like the earth it too shows a ‘greenhouse’ temperature elevation of 40K about the theoretical surface temperature. In other words neither the earth nor the moon (nor Venus) is kept warmer by any greenhouse effect
    This is why there must be a change of paradigm: No one dares even to utter a single word against “consensus”: OK! then, the moon is made from cheese and comets are made of icecream.
    Is that what you want?…but be careful, common people is now realizing that New Age Scientists did a lot of “mistakes”, and if, based on wrong bedwetters science, someone menaces to radically change their way of life, they will react by not believing in them anymore and politicians will adapt rapidly to this new environment (as they smartly and intelligently respond to “market”) and the outcome may be as tragic as leaving all bedwetter babies to starve (No more “milk” babies!) and that would be bad,bad news.
    And…there is an additional justification: In harder economic times as these, Post Normal Science’ s precautionary principle will make them choose “to cut all unnecesary expenses”.

  304. D. Patterson says:

    Ryan says:
    May 7, 2010 at 8:20 am

    So, are we to understand you mean to imply that a brown dwarf and a proto-planet have and maintain atmospheres in the absence of a parent star only by heating from radioactive decay and none from gravitational kinetic energy?

  305. klem says:

    ” I am embarrassed to admit that I blindly accepted it for decades.”

    Man it’s nice to hear a smart scientifically literate person admit this, I don’t feel so bad. I too blindly accepted this. What I have also noticed is the phrase ‘runaway greenhouse’ implies that at one time, C02 levels were lower than today and that they somehow uncontrollably rose to comprise 95% of the atomosphere. And if we aren’t careful, we could cause the same thing to happen here. I have never seen evidence to suggest that venus ever had lower C02 levels than they are today. My understanding is that Venus has always had high CO2 in the atmosphere. Do we have evidence for low CO2 in the past and what was that CO2 concentration?

  306. Eneagram

    re NASA report. Not quite sure of what you are saying? The moon data shows the 40K elevation exactly like the earth does. What this means is that the theoretical baseline (calculated – clearly wrongly – from the Stefan-Boltzmann law of BBR) by ‘warmists’ is just wrong. Ie there is no greenhouse effect at all – either on the earth or on the moon or anywhere. CO2 has nothing whatever to do with warming the atmosphere. Which is what most of us knew anyway.

  307. Luboš Motl

    Got ya. I thought about changing the wording of that sentence to avoid confusion. Guess I should have done that.

  308. beng says:

    ******
    PJP says:
    May 6, 2010 at 1:17 pm

    The references to Boyle’s and Charles’ law are not correct here.
    In both cases they describe changes that take place when one of the parameters change.

    In the case of Boye’s law it shows the relationship between volume and pressure WHEN TEMPERATURE IS HELD CONSTANT.

    Avogardro’s law is more appropriate, which is basically:

    (P1.V1)/(T1.n1) = (P2.V2)/(T2.n2)

    P = pressure
    T = temp (K)
    V = volume
    n = amount of substance

    This shows that as you increase the pressure of a fixed quantity of gas its temperature increases and its volume decreases.

    You know this from blowing up tires = as the air compresses, it gets warm.
    Does the air in your tires STAY hot? (Answer – no).

    But that doesn’t mean that it STAYS warm. Just because a gas is compressed doesn’t mean its hot forever. That would equivalent to perpetual motion.

    This is the principle of a heat pump and air conditioner.

    Something with a thick atmosphere is not forcibly hot at the surface just because of pressure.
    ******

    PJP is correct. The act of increasing/decreasing pressure does produce heat/cold, but only from the amount of work input. Once compression or expansion stops, work stops, and the heat or cold will dissipate to ambient. A static atmosphere (like a planetary atmosphere) doesn’t produce any heat from compression, any more than a close-valved 2000 psi air-cylinder would. On Earth, localized compressional heating does indeed take place — Chinook winds or under strong high-pressure systems of descending air. But since the total mass of atmosphere doesn’t change, an equal amount of rising, expansion & cooling has to occur somewhere else to balance it. The net effect, temp wise, is zero. Yes, there is work going on in the atmosphere like blowing winds, air-compression, etc, and no work process is 100% efficient, so some waste heat is produced from this, but I’m certain this amount is insignificant.

    But pressure does influence the GHG effect. An imaginary Venus with 100 earth atmospheres but only 390 ppm CO2 (like earth) would still produce considerably more GHG effect than on earth ’cause the CO2 partial-pressure would be 100x that of earth.

    It’d be nice if we could measure the spectral properties of the Venusian atmosphere thru its entire depth. It seems to me that Venus has few ways to cool its surface — almost complete opacity above from the dense air and sulfurous clouds, and from what I’ve read, little air movement or convection at the surface. Any geologic heat from below would be “trapped” at the surface & lower air. Eventually over billions of yrs it would get mighty warm under there….

  309. michael hammer,

    So what you are saying is that the high temperatures on Venus are the result of high pressure. I could have sworn that was the point of this article.

  310. James F. Evans says:

    The Venus so-called “greenhouse” effect started all this AGW bull.

    Jim Hansen spread this erroneous idea.

    Such is the limited amount of knowledge that this supposed Venus effect could ever be taken seriously.

    Yet, it was taken seriously by many people.

    This is a classic example where the scientists were wrong — and for many years maintained the fallacy — the thin “lab coat” line.

    Indeed, some scientists still do maintain this idea — never admit you are wrong, just fade from the conference circuit and pass away from the picture.

    Such is often the process of change in scientific circles.

    Well, I tell you that kind of hide-bound process isn’t acceptable anymore.

  311. Luboš Motl says:

    Yes, I confirm the conclusions – that the greenhouse effect on Venus is just in dozens of degrees – independently, with many details about the lapse rates etc. clarified here:

    http://motls.blogspot.com/2010/05/hyperventilating-on-venus.html

    Thanks to Steve Goddard for pointing this interesting fact out, and sorry for my original criticism. I was selectively led to the independence of the composition statement, and both of us misread “tens” as “tenths” because we’re much more used to “tenths” than “tens” when degrees are discussed.

    Cheers
    LM

  312. Zeke the Sneak says:

    The 900 deg temps, the thick atmosphere, the dearth of craters, and its comet like tail (in dark mode) are all unique to Venus as a rocky body in our solar system. Perhaps it is not as old and does not have the same history as the other planets?

    The runaway greenhouse effect and the periodic catastrophic resurfacing of the planet then would not be necessary theories in that case.

  313. Phil. says:

    stevengoddard says:
    May 7, 2010 at 9:06 am
    michael hammer,

    So what you are saying is that the high temperatures on Venus are the result of high pressure. I could have sworn that was the point of this article.

    The high temperatures on Venus are the result of the high IR opacity of the atmosphere, due to CO2 and other gases such as SO2. The high opacity is the result of spectral broadening due to high pressure, high temperature and high concentration. Below is a figure showing a portion of the CO2 transmittance under the atmospheric conditions of Mars and Earth, the increased opacity on Earth is clearly seen, under the atmospheric conditions on Venus the transmittance is zero for that part of the spectrum indicating greatly increased opacity. The result of visible transparency and IR opacity gives rise to the ‘Greenhouse effect’.

    http://i302.photobucket.com/albums/nn107/Sprintstar400/Mars-Earth.gif

  314. Jeremy says:

    There is one thing that hasn’t been mentioned here yet (afaik, I’ve read a lot but not all of the responses). Temperature is not a direct measurement of energy (heat) content, it is related to content through the specific heat (lambda) of the substance. This is why it takes less energy to bring ice to its melting point than it does to bring water to it’s boiling point. It’s because the greater degrees of freedom in liquid water vs ice means liquid h20 can store more kinetic energy before the temperature goes up. Perversely for water, when it becomes a gas it’s specific heat drops below it’s liquid phase. This means it takes less energy to make the same mass of water (as steam) go from 101C to 102C than it takes to go from 98 to 99C (as a liquid).

    I couldn’t easily find any references/plots/data depicting what happens to the specific heat of gasses at Venus pressures, but I certainly do not believe it is static or within our human-weatherman-feeling of how our own atmosphere behaves. Does anyone have any information on this? I’d tend to believe specific heat would increase quite a bit, meaning the total ability of Venus’ lower atmosphere to store energy as heat would more resemble Earth’s oceans than it’s atmosphere.

  315. Lon Hocker says:

    Yes, it’s a lot more than pressure broadening. At one atmosphere the 4.3u symmetrical stretch of CO2 has an absorption length of 2 millimeters! The high pressure and temperature means that even transitions that are extremely weak will have absorption lengths that are tiny fractions of the atmospheric depths. It will radiate basically as a black body from the upper atmosphere, so there will be no pressure inversions, and consequently no convection cells.
    Sorry, the greenhouse effect for Venus is real.

  316. Richard M says:

    A thought experiment. Let’s create a fictional planet with no external source of energy. Drop in an atmosphere like that of Venus. Gravity would start bouncing all those little molecules around. Heat would be generated. However, eventually the heat would be dissipated to space by radiation. The molecules would slowly but surely fall to the surface where the gravitation energy would be transferred to the underlying surface. No more energy to heat the atmosphere. Eventually all the molecules would lie harmlessly on the surface.

    Could someone explain what is wrong with this scenario.

    If not, haven’t I just proven that the energy from the atmospheric pressure cannot, in and of itself, be the sole cause of the temperature of Venus?

    Therefore, the energy comes from somewhere else. OK, we add the Sun and it gets the molecules moving again. However, the total heat energy should be exactly equal to what is provided by the Sun. If there is anything extra then it seems to me that must comes from something else, ie GHGs.

  317. beng

    What you are implying is that the temperature is the same in Death Valley and on Mt. Everest.

  318. JAE says:

    stevengoddard says:
    May 7, 2010 at 9:06 am:

    “So what you are saying is that the high temperatures on Venus are the result of high pressure. I could have sworn that was the point of this article.”

    I don’t think the temperature is actually a RESULT of the high pressure; but the temperature is necessary to sustain the high pressure. Then the question goes back to “what sustains the temperature?” Is it a “greenhouse effect,” a “heat storage effect” or some combination. One cannot deny that the greenhouse gases absorb/emit IR. But since no empirical evidence seems to be available to demonstrate the greenhouse effect, one can only speculate about the impact of it. I happen to agree with those that accept the notion of greenhouse gas radiation, but think that convection overwhelms the effect. Otherwise, it should be a hell of a lot hotter in humid areas. In the end, perhaps the warmness of the Earth is due to storage of heat by water (mostly), and by the atmosphere.

    Back to my Fiji question which nobody wants to touch: the water there is plenty warm to explain virtually all of the air temperature, without impacts from the copious amounts of greenhouse gases (water vapor) there. If you add the radiation from the water surface to any guestimate of “backradiation” from the air, it would have to be a hell of a lot hotter than the usual max. of about 33 C.

  319. CodeTech says:

    Ryan, are you taking into account the sheer quantity of material available to become gaseous? For example, Mercury. What material exists to become gaseous and create an atmosphere? If Pluto were closer to the sun, what would its atmosphere be like? (those familiar with Science Fiction might recall an old story about someone’s rocket exhaust igniting Pluto while landing on it…)

    What counts is equilibrium. Venus clearly has it, Earth obviously has it. Minor changes in gaseous content do not push an atmosphere far away from equilibrium, especially if it has been there for hundreds of millions or billions of years.

    Ryan says:
    May 7, 2010 at 8:20 am
    @Stevengoddard: You said this “The high temperatures there can be almost completely explained by atmospheric pressure – not composition.”

    In other words, you say that the gas pressure above Venus is what causes the higher temperature. What I am telling you is that you are 180 degrees facing the wrong direction. Gases only become gases because they have heat energy applied. Therefore the CO2 is only a gas because there is heat from the sun (or elsewhere if you prefer). Therefore the pressure is a function of the applied temperature not the other way around.

    You say the pressure is a function of the applied temperature. However, the pressure is due to how much material is gaseous. If it was cooler then perhaps more of the CO2 would be stored in rocks rather than floating around the atmosphere. But it’s not cooler. Overall, higher pressure = higher volume of material = higher ability to contain energy.

  320. Vincent says:

    Steven Goddard:

    “michael hammer,

    So what you are saying is that the high temperatures on Venus are the result of high pressure. I could have sworn that was the point of this article.”
    ===========

    I think Michael is saying that high pressure leads to spectral broadening which enhances the greenhouse effect. But I thought your thesis is that pressure alone is responsible for the high temperatures, not spectral broadening. To help clarify this point, would you say that your thesis applies equally if Venus’s atmosphere consisted of nitrogen instead of CO2? If your answer is yes, then the greenhouse effect does not enter into the picture, and this is definately not the same as what Michael has just said.

  321. Robert C says:

    Remember, it is not just the pressure, but also the mixing ratio.
    * On Earth – 350 ppm at 1 atm
    * On Venus – 965,000 ppm at 92 atm
    Pressure broadening removes the spectral fine structure, but has a minimal effect on the band widths. The increase in the total number of molecules is what makes the absorption bands so wide that the Venusian atmosphere becomes IR opaque. On Earth, the amount of CO2 in the atmosphere is about 12 feet thick, on Venus, it is 312 miles thick (at 1 atm, at 92 atm it is thinner and denser).

  322. Phil. says:

    Luboš Motl says:
    May 7, 2010 at 9:27 am
    Yes, I confirm the conclusions – that the greenhouse effect on Venus is just in dozens of degrees – independently, with many details about the lapse rates etc. clarified here:

    Yes Lubos, but as usual you jump into something where you have little knowledge and get it wrong. Strong absorbing lines vary as the square root of the concentration ratio, which certainly applies to Venus. “A little knowledge is a dangerous thing”

  323. Lon Hocker

    So what you are saying is the high temperatures on Venus are due to high atmospheric pressure. I could have sworn that was the point of this article.

  324. Al Cooper says:

    Centrifugal force would have an effect on atmospheric pressure.
    One rotation as slow as Venus has will not produce much reduction
    in pressure.

  325. Vincent

    About half of this article is devoted to the greenhouse effect, que no?

  326. feet2thefire says:

    @ gbaikie says: May 7, 2010 at 1:23 am

    Venus has about 90 atm- or about 90 times earth’s atmosphere.
    So if Venus has 3.5 % nitrogen, it has 2 times or more as much nitrogen as Earth’s atmosphere.
    Same goes for the low percentage of water in Venus’ atmosphere- because it’s such a huge atmosphere, it’s quite a bit of water.

    Which means that Venus’ 96.5% CO2 content is a freaking LOT of CO2. 96.5% x 90 atm = about 86 times CO2 as much as the entire composition (all elements) of Earth’s atmosphere. Would that be close to correct?

  327. Joel Shore says:

    Steven Goddard says:

    beng

    What you are implying is that the temperature is the same in Death Valley and on Mt. Everest.

    No. He is not saying that at all. What do you guys say about correlation not equaling causation? The fact that both the pressure and the temperature are higher in Death Valley than on the top of Mt. Everest does not imply that the higher pressure is causing the higher temperature. In the earth’s thermosphere the temperature becomes even higher than at the earth’s surface ( http://envam1.env.uea.ac.uk/images/tprofile.jpg ) and yet the pressure is down by a factor of more than a million!

    No matter how you slice it, you can’t have a surface temperature as high as Venus’s is in the absence of an IR-absorbing atmosphere. It would radiate way more than it absorbs and rapidly cool down. It really is as simple as that.

  328. Pofarmer says:

    In the earth’s thermosphere the temperature becomes even higher than at the earth’s surface ( http://envam1.env.uea.ac.uk/images/tprofile.jpg ) and yet the pressure is down by a factor of more than a million!

    Isn’t the deal there that the molecules are so far apart you essentially have no transfer between molecules?

  329. Onion says:

    To summarize what I have gathered from comments so far:

    -Atmospheric pressure cannot in itself generate heat. If Venus’s atmosphere consisted of only nitrogen at the same pressure and temperature, it would not be able to sustain that temperature and would cool down hundreds of degrees.

    -The best (and only) explaination for why Venus is so much hotter than would be expected from the amount of solar radiation it absorbs, is the greenhouse effect.

    So I consider the articles claim “The greenhouse effect can not be the cause of the high temperatures on Venus” to be completely wrong.

  330. Joel Shore

    Do you think it is a perpetual coincidence that it is much warmer at the bottom of the Grand Canyon than at the top?

    About half of this article is devoted to the greenhouse effect.

  331. Venus has very little water in it’s atmosphere relative to earth – about one tenth as much.

    0.00002 H2O * 90 = 0.0018

  332. kwik says:

    A very interesting post, this.

    Steven Goddard,

    I hope you understand that many of us hasnt been at school for…well, for myself it is
    30 years ago this year. Difficult to accept, even for myself.

    Anyway, in the mean time one has been into other thinks than thermodynamics.

    Further up here Stephen Wilde led me to his article here;
    http://climaterealists.com/index.php?id=1562&linkbox=true&position=4

    Which is the same issue as you say in your post.
    Thanks to both of you for refreshing my schooldays teaching.

    hehe.

  333. Phil.

    What would be the temperature of a hypothetical place on earth, which was at low enough elevation to have 9,000 kPa atmospheric pressure? Kind of warm perhaps?

  334. Dave says:

    Once again, your little table of logarithmic CO2 temperature effects is WRONG WRONG WRONG. The logarithmic approximation is only applicable for a small range of concentrations (including the concentrations that are relevant for Earth). Venus is WAY outside this range, and the effect of CO2 becomes much closer to linear again.

    Let me try another way of explaining why you need CO2 for a warm Venus. The lapse rate only works up to the tropopause. The height of the tropopause is, in part, determined by the optical thickness of the atmosphere. If you remove most of the CO2, the optical thickness drops, the tropopause drops, and therefore if the lapse rate stays fairly constant and the temperature of the tropopause is fairly constant, the surface temperature must drop.

    Again, pressure alone does nothing. You need an external energy source (the sun). You need an IR-absorbent atmosphere (CO2 or H2O). You need to be in the troposphere. Then, and only then, can you start using pressure as a short-hand approach to calculating temperature.

    I’m sure there must be good textbooks that cover Venusian atmospheres out there somewhere. I’d suggest going and finding one and actually studying it, rather than continuing to putter around with your erroneous “blog science”. 99% of the time, the consensus science is fairly close to reality, and way less than 1% of the time are there no fatal misconceptions when someone’s back-of-the-envelope calculation differs from consensus science. This is another example of those times when fatal misconceptions creep in…

    -Dave

  335. Enneagram says:

    Onion : Next time you heat your coffee in your microwave remember Venus.

  336. OceanTwo says:

    Dave says:
    May 7, 2010 at 12:17 pm

    Once again, your little table of logarithmic CO2 temperature effects is WRONG WRONG WRONG. The logarithmic approximation is only applicable for a small range of concentrations (including the concentrations that are relevant for Earth). Venus is WAY outside this range, and the effect of CO2 becomes much closer to linear again. …

    Huh. Interesting….why don’t you show us that graph. Are you implying there’s a ‘tipping point’? If not, then you might just be correct – as you go along an exponential curve, it does, indeed appear to be linear, but this linear approximation has a tiny scaling factor.

  337. Dave

    I suggested replacing 90% of the CO2 with N2 (not 100%.) At 10% CO2, you are already way, way up in the linear range.

    Please read the article more carefully.

    If 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees.

  338. OceanTwo says:

    Holey moley! I cannot believe anyone could say the following with a straight face! This must be a party trick or something, designed to figure out how much people have had to drink.

    Onion says:
    May 7, 2010 at 12:00 pm

    To summarize what I have gathered from comments so far:

    -Atmospheric pressure cannot in itself generate heat. If Venus’s atmosphere consisted of only nitrogen at the same pressure and temperature, it would not be able to sustain that temperature and would cool down hundreds of degrees.

    -The best (and only) explaination for why Venus is so much hotter than would be expected from the amount of solar radiation it absorbs, is the greenhouse effect.

    So I consider the articles claim “The greenhouse effect can not be the cause of the high temperatures on Venus” to be completely wrong.

  339. Dave

    Also, my table of logarithmic CO2 temperature effects was for Earth, not Venus. If Earth somehow hit 100% CO2, temperatures would only increase by about 25-35C.

  340. kadaka (KD Knoebel) says:

    Alright, I think I can word the general “layman’s explanation” of this.

    Let’s look at a certain amount of gas molecules, which have a certain amount of energy. If it helps, think of them in a perfect balloon that can contain them, be any size, but the material puts no pressure on the gas.

    We’ll start with them being surrounded by a low pressure. So the molecules are nice and spread out at a certain temperature, where “temperature” can be thought of here as a reading of how much energy is in a fixed volume. Now we raise the pressure around those gas molecules. That amount of molecules will then squish down to a smaller volume at that higher pressure. The same amount of energy is there but in a smaller volume, thus the temperature will be higher. The process is reversible, of course, reduce the surrounding pressure and the volume goes up while the temperature goes down.

    On Earth, sunlight warms the surface. The high pressure gas absorbs the heat, then moves higher in the atmosphere. The pressure gets lower, the gas expands, gets cooler. It was heated while compressed, and now gives off heat that goes off into space.

    On Venus, sunlight doesn’t make it to the surface. The heating is done up high, at lower pressure. Circulation forces the gas downwards, where it is compressed and thus at a higher temperature. It gives off whatever heat it can at the surface, then it circulates upwards to continue the cycle.

    Something that makes Venus so confusing is how such circulation is not a natural pattern of convection, where hot gas rises, cools off, then sinks back down to take in a fresh batch of heat. A driven system is indicated, as heated gas is being lowered into the atmosphere and compressed. Where could the energy driving this system be coming from?

    For one thing, we can already see that Venus has a lot of energy in its circulation patterns, far more than in a normal atmospheric system like with Earth, as can be noted in this section of the Wikipedia “Atmosphere of Venus” entry. (Anyone got a better source?) Thus already there is an indication there possibly is another source of energy than solar.

    As to what it could possibly be, well… When doing atmospheric models, things get simplified, certain “big picture” elements get overlooked. For example, planetary rotation. The pressure at the surface of Venus is 90 times that of Earth. At such densities, there is far more atmospheric drag against the surface than is found on Earth. Now look at the rotation period of Venus, seen best at the chart at the bottom of the linked source. Venus rotates very slowly, it has the slowest rotation period in the solar system. Two possibilities for this spring to mind. One, Venus could have had a rather odd formation and ended up having such a slow rotation at the start. Two, something has caused it to drastically slow down. Atmospheric drag over a long time could do it. That would represent an enormous input of energy into the atmospheric system, that could drive a cycle of compressing heated air while driving it down to the surface.

    Does work exist that shows the slow rotation period is due to something else? Does anyone know of any atmospheric modeling of Venus where the energy input of such atmospheric drag has been considered? Has the possible energy gain from drag been shown to be insignificant, without resorting to claiming “it must be insignificant since CO2 and the greenhouse effect provides enough energy”? Inquiring minds want to know.

  341. Phil. says:

    OceanTwo says:
    May 7, 2010 at 12:32 pm
    Dave says:
    May 7, 2010 at 12:17 pm

    Once again, your little table of logarithmic CO2 temperature effects is WRONG WRONG WRONG. The logarithmic approximation is only applicable for a small range of concentrations (including the concentrations that are relevant for Earth). Venus is WAY outside this range, and the effect of CO2 becomes much closer to linear again. …

    Huh. Interesting….why don’t you show us that graph. Are you implying there’s a ‘tipping point’? If not, then you might just be correct – as you go along an exponential curve, it does, indeed appear to be linear, but this linear approximation has a tiny scaling factor.

    Here’s what the graph shape looks like, the first portion is for weak absorbers and is ~linear, the middle portion is ~log, and the final portion is ~square root.

    http://spiff.rit.edu/classes/phys440/lectures/curve/gcurve.jpg

  342. MaxL says:

    The concepts of atmospheric thermodynamics are not always intuitively obvious. In fact it is generally not taught until the final year of undergraduate or the graduate level at university. One of the books that I “grew up” with is Atmospheric Thermodynamics by Iribarne and Godson. You do need a pretty solid background in math and physics for this book.

  343. jeff brown says:

    Steve, I believe you clearly said:

    So why is Venus hot? Because it has an extremely high atmospheric pressure. The atmospheric pressure on Venus is 92X greater than earth. Temperatures in Earth’s atmosphere warm over 80C going from 20 kPa (altitude 15km) to 100 kPa (sea level.) That is why mountains are much colder than the deserts which lie at their base.

    Thus, you claimed Venus is hot because of it’s high atmospheric pressure. Many posts here have proved that conclusion to be incorrect. Why not admit you made a false statement?

  344. OceanTwo says:

    Richard M says:
    May 7, 2010 at 9:58 am

    A thought experiment. Let’s create a fictional planet with no external source of energy. Drop in an atmosphere like that of Venus. Gravity would start bouncing all those little molecules around. Heat would be generated. However, eventually the heat would be dissipated to space by radiation. The molecules would slowly but surely fall to the surface where the gravitation energy would be transferred to the underlying surface. No more energy to heat the atmosphere. Eventually all the molecules would lie harmlessly on the surface.

    Harmlessly? Then what happens? As more and more molecules ‘fall’ to the surface on this supposedly ‘dead’ planet isn’t it’s mass going to increase? As it’s mass increases doesn’t this mass exert a (gravitational) force on all those molecules? When you impart a force onto molecules, what happens?

  345. 1DandyTroll says:

    @Joel Shore

    ‘In the earth’s thermosphere the temperature becomes even higher than at the earth’s surface ( http://envam1.env.uea.ac.uk/images/tprofile.jpg ) and yet the pressure is down by a factor of more than a million!
    No matter how you slice it, you can’t have a surface temperature as high as Venus’s is in the absence of an IR-absorbing atmosphere. It would radiate way more than it absorbs and rapidly cool down. It really is as simple as that.’

    Actually you can. It doesn’t matter the atmosphere if you don’t add pressure, with one pressure you’re left to the planet core, and the planets behavior in its orbit, and the amount of sun light/radiation the planet receives. Our moon has virtually zero atmosphere, and zero atmospheric pressure, yet reaches about 190 f in the sun, which is about the mean for Mercury which has trace atmosphere at best, virtually no co2 at all or nitrogen or water vapor or pressure, but it is a whole lot closer to the sun though. Venus, for all its weird ass behavior in its sneaky orbit, has everything, yet co2 only comes at third place when it comes to temperature but then only as part of the collective thing that is its planetary greenhouse effect, first comes pressure, second solar radiation.

    The thermosphere can reach like 1500 degrees C, yet a person would freeze to death at 0C if he was waiting to get boiled to death, assuming of course he had oxygen to last. :p

  346. Paul Jackson says:

    Troels Halken says: May 6, 2010 at 12:45 pm
    Why does Venus have a much more dense atmosphere than Earth?

    Well for starters Venus’s atmosphere is made out of much heavier gases, it has a Mean molecular weight: 43.45 g/mole where Earth’s atmosphere has a Mean molecular weight: 28.97 g/mole so it weighs 1.49 times as much under the same pressure and temperatures conditions.

  347. kadaka (KD Knoebel) says:

    Note that I expect my previous post to get shot down from where I start proposing how the Venusian heating could be working. After all, “of course” such possibilities must have been considered before.

    However, it’s hard to find anything else but the CO2 and greenhouse “noise” regarding Venus. I should learn some good information in the debunking of my proposed system. I will also learn something if it is not soundly debunked. ;)

  348. beng says:

    ******
    stevengoddard says:
    May 7, 2010 at 10:05 am

    beng

    What you are implying is that the temperature is the same in Death Valley and on Mt. Everest.
    *******

    No, not at all. The atmosphere is mostly heated at the bottom by the warm, irradiated surface — water or land. That’s why it’s warmer down there, not because of pressure. If you took earth into deep, cold intergalactic space, the solid surface and air at all elevations/pressures would chill down to the background ambient temp — and there’d be no lapse rate. This is assuming the air didn’t liquefy and there was no internal heat, of course.

  349. Lon Hocker says:

    stevengoddard says:
    May 7, 2010 at 10:53 am
    Lon Hocker

    “So what you are saying is the high temperatures on Venus are due to high atmospheric pressure. I could have sworn that was the point of this article.”

    Pressure alone wouldn’t accomplish anything. It needs CO2 or some other IR active molecule in a high concentration in combination with the high pressure to reach Venus’ extreme state. Swap in Ar, N2 or O2, and the atmosphere would be transparent, and Venus would cool off quickly. It even would have convection cells, and could support Willis’ thermostat.

  350. Stephen Wilde says:

    I see some confusion here.

    The pressure at a planetary surface is a function of gravity and atmospheric density.

    The atmosphere of Venus is extremely dense compared to those of Earth or Mars. It is that density combined with the gravity of Venus that dictates both pressure and temperature.

    The temperature will be higher for the same quantity of CO2 than for say Nitrogen because of their different molecular weights and thus their contributions to total atmospheric density.

    Steve Goddard has just used the term pressure as meaning the composite effect of gravity and atmospheric density at the surface. It is true that the higher the pressure at a planetary surface then the higher also will be the temperature given a constant solar input.

    Hence the differences between Venus, Earth and Mars with the greenhouse effect idea being a mere unnecessary distraction.

    Extra GHGs will only affect temperaure if they also affect total density enough to make the difference noticeable. The amount of CO2 in Earth’s air is so small that it could never have a measurable effect on total atmospheric density from anything humans could ever achieve.

  351. Phil. says:

    Stephen Wilde says:
    May 7, 2010 at 1:40 pm
    I see some confusion here.

    The pressure at a planetary surface is a function of gravity and atmospheric density.

    The atmosphere of Venus is extremely dense compared to those of Earth or Mars. It is that density combined with the gravity of Venus that dictates both pressure and temperature.

    The temperature will be higher for the same quantity of CO2 than for say Nitrogen because of their different molecular weights and thus their contributions to total atmospheric density.

    Steve Goddard has just used the term pressure as meaning the composite effect of gravity and atmospheric density at the surface. It is true that the higher the pressure at a planetary surface then the higher also will be the temperature given a constant solar input.

    Only if the atmosphere has IR opacity that depends on pressure, i.e. a greenhouse atmosphere. For an atmosphere of nitrogen the pressure will have no effect.

    Hence the differences between Venus, Earth and Mars with the greenhouse effect idea being a mere unnecessary distraction.

    No it is the essential feature!

    Extra GHGs will only affect temperaure if they also affect total density enough to make the difference noticeable. The amount of CO2 in Earth’s air is so small that it could never have a measurable effect on total atmospheric density from anything humans could ever achieve.

    No, it has nothing to do with density.

  352. Roger Clague says:

    Scientists must always try the simplest explanations first. This principal is called Occams Razor. Physics comes before chemistry.

    The gas law PV = nRT is difficult to visualise. Many find it hard to accept that an increase in pressure leads to increases in temperature.

    The chemistry of CO2 absorption depends on its being made up of two elements. It is easy to visualise.

    Mrs Thatcher was a chemistry graduate and popularized the CO2 theory of surface temperatures in her 1988 speech to the Royal Society.

  353. beng

    The top of the Grand Canyon receives just as much solar radiation as the bottom of the Grand Canyon, yet it tends to be 20-30 degrees F cooler.

    How does that fit into your theory “The atmosphere is mostly heated at the bottom by the warm, irradiated surface…That’s why it’s warmer down there, not because of pressure. “

  354. omnologos says:

    Nice to see I am not the only one with questions about Venus. Does anybody mind if I claim precedence on this idea?

    This is the first of four Omniclimate blogs on the topic, from 2008. And this is the original blog from Aug 2007.

  355. Lon Hocker says:

    stevengoddard says:
    May 7, 2010 at 2:07 pm
    beng

    The top of the Grand Canyon receives just as much solar radiation as the bottom of the Grand Canyon, yet it tends to be 20-30 degrees F cooler.

    How does that fit into your theory “The atmosphere is mostly heated at the bottom by the warm, irradiated surface…That’s why it’s warmer down there, not because of pressure. “

    There are breezes at the top of the canyon due to convection cells pulling away hot air and replacing it with cool air. Not much in the way of breezes at the bottom of the canyon as I remember. Also fewer steradians of cool sky to radiate into.

    Please Steve, this article is awash with problems, give up on the CPR.

  356. Richard M says:

    OceanTwo says:
    May 7, 2010 at 1:08 pm
    ======================
    Richard M says:
    May 7, 2010 at 9:58 am

    A thought experiment. Let’s create a fictional planet with no external source of energy. Drop in an atmosphere like that of Venus. Gravity would start bouncing all those little molecules around. Heat would be generated. However, eventually the heat would be dissipated to space by radiation. The molecules would slowly but surely fall to the surface where the gravitation energy would be transferred to the underlying surface. No more energy to heat the atmosphere. Eventually all the molecules would lie harmlessly on the surface.
    =========================
    Harmlessly? Then what happens? As more and more molecules ‘fall’ to the surface on this supposedly ‘dead’ planet isn’t it’s mass going to increase? As it’s mass increases doesn’t this mass exert a (gravitational) force on all those molecules? When you impart a force onto molecules, what happens?
    —————————————–

    What happens is the force of gravity from the extra molecules is mostly directed at the internal structure of the planet. It would necessarily be warmed slightly. Assuming this heat reaches the surface you might see occasional motion of the molecules. Would this be enough to keep the entire atmosphere in motion?

    I venture it takes a lot more energy to keep the atmosphere in motion. Now, there are other possible sources. However, I just don’t see these as sufficient as the energy provided would radiate away quickly. It seems to me you would have a dead planet.

    My point still stands, it seems that the heat due to the motion of the atmosphere is not enough to prevent the atmosphere from eventually going dormant. Keep in mind this only a starting point for what happens next.

  357. Nick Stokes says:

    ” beng says:
    May 7, 2010 at 1:30 pm”

    Beng, I think you and Steven each have half the story there. Some people are saying that somehow pressure causes high temperature. That’s wrong – a cylinder of compressed oxygen will generally be at ambient temperature.

    What is true is that a layer of air in motion tends to a temperature gradient – the dry adiabat. The motion causes compression and rarefaction, which pumps heat downwards. The theoretical gradient is g/c, where g=9.8 m/s2, and c is specific heat of air at constant pressure.

    That makes it work like a battery, which has a voltage difference, say 1.5V, from end to end. That doesn’t mean that the pointy end is at high or low voltage, only that there is a difference. The actual voltage depends on what it is connected to.

    So 1 km of dry air in motion will have about a 10C difference, bottom to top. Then, as you say, if the temperature is fixed by heat absorbed and radiated at the bottom, it will be warm there, and cooler as you go up. In winter, there is less sunlight, so it’s cooler at the bottom, and again, drops off at the same rate from there as you go up.

  358. Ammonite says:

    The engineers and sicentists from the European Space Agency that designed the Venus Express spacecraft have my utmost admiration. Think about their task. They had escape a delicate payload from Earth’s gravity well, aim it at Venus and trasmit data successfully from such a hostile environment. It is an astonishing achievement realised in 2009.

    Does it seem a little odd to anyone that their scientists have not considered atmostpheric pressure and its relation to temperature??

    To quote the European Space Agency’s web site (and note Venus has a very high albedo (reflectivity)):

    “On the global scale, Venus’s climate is strongly driven by the most powerful greenhouse effect found in the Solar System. The greenhouse agents sustaining it are water vapour, carbon dioxide and sulphuric acid aerosols.

    About 80% of the incoming solar radiation is reflected back to space by the cloud layer, about 10% is absorbed by the atmosphere and only 10% manages to get through it and heat the surface. However, the thermal radiation emitted by the surface gets trapped by the same atmosphere. The result is an amazing 500 °C difference between the surface and cloud-top temperatures.”

  359. astrowright says:

    Michael R says:
    May 6, 2010 at 8:44 pm

    “Unfortunately, what you have declared so adamantly as fact is, by it’s very nature, what is under dispute currently. In fact, what you have described is, in effect, what the whole argument of global warming is and consequently, people who do not agree that we understand fully the processes by which this plant achieves its temperature balance, are even less than willing to accept that you (or anyone else) can then ascribe said theory – with another planet altogether – and expect to be 100% correct.

    I note you were particularly blunt with your critisms and so shall I – I can only assume that the complete lack of uncertainty relating to process we know only partially how they work and arrogance in assuming you do was a result of your Planetary Geology degree being …. honorary?”

    Michael,

    I was blunt because of the pointlessness and cyclical nature of arguments about global warming, and particularly comparative planetology, on the blogosphere. To your point, no, the process I pointed out is not in dispute. The fact that you and others unfamiliar with the field continue to dispute it does not reflect a corresponding dispute amongst those who have actually spent significant time studying planets. And with the honorary degree swipe to your credit, I’ll say up front that this is why scientists are usually not involved in the discussion. It usually winds up being a waste of time because those who are ignorant of the facts and details end up believing what they want to anyway. If it offends you to discover that someone knows more than you do, my friend, then no one can help you.

    To the point:
    1) Upper-atmospheric disassociation of H2O is the only viable model anyone has thought of that can replicate Venus’s current conditions, unless you believe that there was a mysterious asymmetry in the composition of the solar nebula during condensation. If you’ve got a better model, then fire away. If not, keep your honorary degrees to yourself.

    2) To point out how silly this entire conversation is, let’s also talk about the 900-lb gorilla in the room: Hydrogen Sulfide, which composes a sizeable ~2 ppm of the atmosphere and is also an incredibly effective (and perhaps dominant) “greenhouse gas.” Sulfuric acid cloud layers between 45 and 75 km altitude (because there the temperature is cool enough for H2S to condense into droplets) act as terribly effective re-radiating layers, such that – yes – Venus can be hotter on the surface with only a fraction of the insolation because, due to the cloud cover (as mentioned above), Venus does receive less solar energy than Earth does. This is just one example of why the conversation here is crippled before we start – most of the participants aren’t familiar (no offense) with the basics.

    3) You also seem to misunderstand something critical here – I was talking about Venus at its distance from the sun, not Earth. Nothing about this “theory” is being asribed from Earth to Venus, as you say. This is basic chemistry worked out from scratch under specific planetary conditions. So, for you to extrapolate that I believe the Earth’s “greenhouse effect” is the same is erroneous, and secondly, to say that I’ve just described the whole “global warming” argument show show little you understand about it. Earth’s “global warming” argument involves planetary feedback mechanisms not even in play on Venus, including the formation of limestones and dolostones (the Earth’s natural CO2-removal mechanism,) oceanic density current temperature-regulation mechanisms, and micrometeorology that people are only starting to describe. I do believe that Earth’s atmosphere at present is much more dynamic than Venus’s (though Venus’s is more impressive to us). If you were to ask me about the threat of “global warming” on Earth, I suspect you would be surprised by my answer. In fact, I did a blog interview on climate change a couple of months back, which I think you would find enlightening. Link: http://jordanspeak.wordpress.com/2010/02/21/an-interview-on-climate-change/

    If we’re going to talk about climate change, that’s one thing. If we’re going to drift into comparative planetology, that’s something entirely different, and come prepared.

  360. Lon Hocker

    The reason why the rim of the canyon is much cooler than the bottom has nothing to do with “breezes.” You can travel anywhere along the 200 mile long 7,000 foot elevation Mogollon Rim in Arizona, and experience approximately the same temperature, 20-30 degrees cooler than the bottom of the Grand Canyon or the Sonoran Desert. Wind conditions have nothing to do with it.

    I’m sorry that you don’t understand. Don’t hike up Mt. Everest in shorts though to display your lack of understanding.

  361. jeff brown

    Have a look at this graph.
    http://en.wikipedia.org/wiki/File:Emagram.GIF
    It shows very clearly the relationship between temperature and atmospheric pressure on earth. The fact that you don’t understand something does not make it untrue.

    If you don’t accept the relationship between atmospheric pressure and temperature, then book your next ski vacation in Yuma, Az instead of Aspen. They have nice mountains there too.

  362. astrowright says:

    Willis Eschenbach says:
    May 6, 2010 at 8:31 pm

    Willis, thanks for your post, and I’ll do my best with each of your questions:

    “1. You say that in the early days, the atmosphere of Venus was similar to that of the early earth, mostly nitrogen. What evidence is there for that?”

    -As far as direct evidence is concerned, not much, yet. We don’t have a time machine, our landers melt before long, and direct observations are related to re-worked areas of Venus’s crust and what minerals we can infer (their exact crystal structure is a function of their formation temperature). However, as far as circumstantial evidence goes, there’s TONS. First, the average distribution of chemical elements we see in condensing stellar nebula across the galaxy is fairly uniform, so it would be quite unlikely that Venus simply started out very differently (i.e., we’ve NEVER seen globular asymmetries). Second, what differences we do see between the planets is a predictable function of which minerals would cool and crystallize out first as the stellar nebula began to cool around the young Sun, (which is how we can tell that a given meteorite on Earth came from Mars and not Venus, for example.) – For the geologists amongst us, this tends to follow a loose version of Bowen’s Reaction Series, (and also explains why all of the “rocky” planets are close to the sun, and all of the “gas giant” planets are past 3 AUs from the sun.) It’s geochemistry. And, since Venus does follow this predictable geochemical pattern, it’s even less likely that Venus would be deficient in a single molecule, like H2O.

    “2. At present, the atmosphere of Venus contains very little nitrogen (~ 3.5%). What happened to all the early nitrogen?”

    Two things – One, I was generalizing when I described the atmosphere in my earlier post, so I wasn’t implying that there was 80% nitrogen or anything. Just a significant amount. Two, the nitrogen is all still there, it’s just been overwhelmed by CO2. Imagine if we took all water on Earth and spontaneously turned it into CO2 – well, our atmosphere would be far, far denser than it is now. We haven’t contributed any new nitrogen, so the percentage of nitrogen in the atmosphere would have plummeted.

    “3. You say that the cause for what you call the “runaway greenhouse effect” is the stronger ionizing radiation at the the top of the Venusian atmosphere. If that is the case, wouldn’t a much more accurate term be the “runaway ionization effect”, and as such, be something that could never happen on earth?”

    Good question. For starters, the “greenhouse effect” was never absolutely literal to begin with – greenhouses don’t work like atmospheres – it’s a general term. But having said that, yes, emphasizing the ionization would make it more accurate. However, this ionization effect IS already happening on Earth. A very tiny fraction of the water vapor that makes it to the upper atmosphere is separated and is lost to space. However, water tends to cool, condense, and return to the lower atmosphere before it gets there, so we’ve “trapped” the water here in a way that Venus couldn’t. The very concern is that slight increases in the atmospheric temperature with a “greenhouse gas” might send more water to the upper atmosphere – and any we lose, we lose forever. Hydrogen by itself is too speedy for Earth’s gravity to hang on to. However, ask me if I think we’re anywhere close to that here on Earth? Nope. Human beings’ effects are on the scale of a large volcano, which the Earth has plenty of mechanisms to mitigate.

    “4. You say that the ionizing radiation at the very top of the atmosphere dissociated the water vapor and that the “free oxygen quickly bound to plentiful carbon to make CO2″. Why would carbon be plentiful at the very top of the atmosphere? And why would the oxygen not reform as O2?”

    This is where the devil is in the details. Carbon is plentiful as CO2 and other compounds in the atmosphere, which is twice as effective at holding oxygen, but oxygen could also easily form up as diatomic oxygen. Think on a bigger scale, though. For starters, free oxygen could have been lost to space during disassociation. Also, there are other chemicals in play in the atmosphere: hydrogen sulfide can snap up free oxygen to make sulfuric acid (H2SO4), which we see. However, imagine also the O2 concentration going up slightly in a general sense, which would eventually be cycled through the atmopshere and brought into contact with the planet surface, where chemical erosion occurs. There’s lots of evidence of oxidation on the surface – lots of O2 ended up there, and plenty of carbon to bond with.

    “5. Why is there still water vapor in the Venusian atmosphere (20 ppmv)? What has prevented the ionization of the last of the water?”

    Essentially, the atmosphere itself has prevented all water from being lost. That would require all water vapor getting to the upper atmosphere, and there’s plenty of atmosphere to shield it from UV these days. However, if Venus ever had a shallow ocean, (which the isotopic composition of the hydrogen we see in the Venusian atmosphere supports,) it’s been long evaporated, fried, and lost to space.

    Hope this helped to answer some of your questions, but as I said earlier, this barely scratches the surface about the discussions/research people are having/performing about Venus’s geologic history – it’s an awesome field of study!

  363. kadaka

    Nice explanation!

  364. barefootgirl says:

    Time to chime in for a moment…

    Here on Earth temperatures are warmer than they would be w/out a greenhouse effect. In the past (and in most college books), the warming was estimated to be 33C, as it’s obtained as the difference between the globally observed surface air temperature (Ts) of 15C and the radiative equilibrium temperature of Earth (Te) of -18C, and represents the longwave radiation effect of the atmosphere. Te is computed from the Earth’s radiation balance with the observed planetary albedo of 0.3 [Trenberth et al., 2009].
    The warming effect of our atmosphere trace gases (i.e. Co2, H2O, O3, NO2) on the Earth’s surface temperature is quantitatively computed as the temperature difference with and without these gases in the atmosphere.
    In reality Te should be recomputed by considering clouds so that the planetary albedo of 0.3 is replaced by the combined reflectance of the atmosphere and the surface, which would be 0.14. Doing so would show there is a 20C difference between Ts and Te. Note Ts is caused by the atmospheric radiation effect (primarily from GHGs and clouds) and surface sensible and latent heat fluxes due to fluid motions in the atmosphere. W/out these heat fluxes the differences between Te and Ts would be larger.

    Seems to me we should frame the discussion about Venus in a similar framework

  365. What would happen to atmospheric pressure if the sun turned off?

    PV = nRT

    If T dropped to zero, then P would also drop to zero. It is the sun which provides the energy that keeps the molecules moving, and keeps the pressure up.

  366. Phil. says:

    stevengoddard says:
    May 7, 2010 at 2:07 pm
    beng

    The top of the Grand Canyon receives just as much solar radiation as the bottom of the Grand Canyon, yet it tends to be 20-30 degrees F cooler.

    How does that fit into your theory “The atmosphere is mostly heated at the bottom by the warm, irradiated surface…That’s why it’s warmer down there, not because of pressure. “

    The lapse rate just sets the stable temperature gradient, it has nothing to do with setting the temperature of the planet. All you have done (and Motl) is transfer the problem to the tropopause. The temperature is set by the radiation balance, the gradient by the adiabatic lapse rate. If there are condensible species in the atmosphere then it’s the ‘wet’ lapse rate that applies (H2O on earth, H2SO4 probably on Venus).

  367. Ric Werme says:

    Ryan says:
    May 7, 2010 at 8:20 am

    @Stevengoddard: You said this “The high temperatures there can be almost completely explained by atmospheric pressure – not composition.”

    In other words, you say that the gas pressure above Venus is what causes the higher temperature. What I am telling you is that you are 180 degrees facing the wrong direction. Gases only become gases because they have heat energy applied. Therefore the CO2 is only a gas because there is heat from the sun (or elsewhere if you prefer). Therefore the pressure is a function of the applied temperature not the other way around.

    On your last sentence, that applies to a container of gas. In a planetary atmosphere, the pressure is mostly due to the weight of the column of air above the barometer. Move up, the pressure goes down. Light a fire, a little air moves up (convection) and the barometer reads the same. Get a large whirlpool of air driven by temperature differences and the planet’s rotation (i.e. a storm) and the pressure goes down a little bit. On Earth, sea level pressure only varies between about 960 and 1060 millibars except for small scale heat engines called hurricanes, but note the pressure changes there have little to do with surface temperature.

    As for “In other words, you say that the gas pressure above Venus is what causes the higher temperature. What I am telling you is that you are 180 degrees facing the wrong direction,” I’m not sure how that would read -180° facing the right direction. Hike to the top of your favorite mountain, take a bagful of air and stick it in a bag made of a perfect insulator, hike with it down to the valley. The air will be warmer, all in accordance with the (nearly) ideal gas law.

    Do the same sort of thing on Venus – start from a point where the atmosphere is radiating out to space, refill your bag, and take it down to the surface. Being an ideal bag, it won’t melt, but the air/CO2 inside will be mighty hot. If the heating at the planet’s surface is greater than the outgoing radiation, then convection will mix the atmosphere and you’ll get a nice adiabatic lapse from ground to tropopause.

  368. Bob_FJ says:

    Bill Illis Reur May 6, 2010 at 5:22 pm:

    “…Generally, I think pressure and, in effect, the work being done by gravity, has not been taken into account in global warming theory and someone needs to put it back in.”

    And, in response:
    JAE Reur May 6, 2010 at 6:43 pm:

    Right on. I am so sick of seeing all these discussions that focus on only one variable, like radiation.

    I strongly agree with these sentiments. It is beyond me that in extremely complex systems some people try to pick out a single cause!

    There have been a host of comments here asserting that the GH effect is THE cause of the high T. However, I don’t think that a single such asserter has commented on an important issue in Steven’s article, which is the extremely long day together with claimed uniformity of diurnal T. NASA gives the diurnal temperature difference as zero, last updated 2005. The ESA reiterated this in 2006.

    The puzzle is of course that if there is a significant GH effect, then how does it work during the months of darkness!
    According to the ESA, the dynamics of the atmosphere are really weird, (at least with the scant data available), and not well understood. It seems to me that these strange dynamics may somehow “mix” the GH heating across to the dark side, but it also suggests to me that the GH effect is relatively minor.

    Here is an interesting extract speculation
    from an ESA article:
    “…The ‘temperature inversion’, as the layer of warm air is called, was detected in several stellar occultations performed on the night-time side of the planet. The only thing that can heat the atmosphere here is when pockets of gas sink back down into the denser atmosphere. The increased air pressure squeezes the pockets, raising the temperature of the gas inside (similar to what happens when you activate a bicycle pump)…”

    Here is an extract concerning winds from another ESA article:
    The lower atmosphere of Venus has a dramatic and peculiar behaviour. At the level of the cloud tops, the atmosphere rotates at a formidable velocity, with wind speeds up to 360 kilometres per hour. [Elsewhere; four days to circumnavigate]
    The speed of the winds then progressively decreases to almost zero at the planet surface, where it becomes a gentle breeze, only able to raise dust. What mechanisms cause this ‘zonal super-rotation’?
    Furthermore, two enormous vortices, with very complex shapes and behaviours, rotate vertically over the poles, recycling the atmosphere downwards. The vortex at the north pole, the only one previously observed in some detail, has a peculiar double ‘eye’ shape, surrounded by a collar of cool air. It completes a full rotation in only three Earth days.
    How are the super-rotation and the polar vortices linked? How does the global atmospheric circulation on Venus work? No model is able to simulate so far the dynamics of the atmosphere of Venus as too few data are available.

  369. michael hammer says:

    Steven 9:06. No you are misquoting me. I claim that the green house effect on Venus is real. In fact it very significantly blocks (almost eliminates) radiation from the surface of the planet to space. Given that, the heat must escape to the top of the atmosphere (where it can be radiated) by conduction and convection. Once you rely on that process the thickness of the atmosphere does matter. Vincent 10:40 has noted this.

    Alan McIntire at 6:54 Alan I would very much like to post some articles on wattsupwtihthat but I do not know of any way of emailing them to Antony. I did request an email conact address via a message in the tips and notes section of the website but got no reply. There are some interesting issues. It seems to me that some of the Nimbus data is in conflict with “established wisdom”. Two issues in particular, one that the emissivity of ice and snow in the thermal infrared is close to1 and secondly that the stratosphere is well mixed. These may sound esoteric and of limited interest but infact they have serious impact on the AGW issues. I admit I could be wrong but it would be very interesting to debate this on the blog. The thermal infra red emissivity issue is particularly interesting because if true it means that soot in ice covered regions leads to negative feedback not positive feeedback and will cool the region. Also by the way the same Nimbus data shows extremely clearly that the direct impact of the green house effect is to cool the poles not warm them.

  370. Ric Werme says:

    stevengoddard says:
    May 7, 2010 at 6:39 am

    Ric,

    The diagram in the article shows various wet and dry lapse rates.
    http://en.wikipedia.org/wiki/File:Emagram.GIF

    I saw it up at the top. I didn’t bother to click on it to read it better, it was just a blank Skew-T chart. You would have saved a lot of arguing if you had used just a real sounding from Venus like I linked to above and six weeks ago. Being a Terran Skew-T chart, it has wet adiabats cluttering up what you want to show, and all the scales simply don’t apply to Venus without more scaling and redrawing than I can do off-hand.

    If you expected people unfamiliar with atmospheric lapse rates to glance at the graph paper and understand how it applies to Earth, you’re sadly mistaken. The introduction to Skew-T plotting http://airsnrt.jpl.nasa.gov/SkewT_info.html needs 9 pages to print and much of that doesn’t even apply to Venus. Besides the lack of water vapor, I suspect the atmosphere is very well mixed and inversions, CAPE, and all that good Terran meteorology stuff on the graph paper just muddies the issue.

    You description of the Venusian lapse rate just didn’t work. Apparently it’s too late to fix it now, attempts get lost in the 373 comments so far.

    Some people will argue, no matter how obviously correct a concept is. Temperatures increase at lower elevations, and decrease at higher elevations.

    Is this directed to me? I wouldn’t call it obvious – we frequently have winter mornings in New Hampshire where the top of Mt Washington (6288′) is warmer than the valley. However, those conditions likely don’t apply on Venus. Perhaps they do given the long nights, but in daytime conditions once the inversion dissipates/evaporates/whatever it does when the surface warms up then air mixes up and down as easily as it moves from side to side and follows the dry adiabatic lapse rate on the chart up to the clouds and the wet adiabatic lapse rate up to the top of the mixed air.

    Guess I’ll go see how Lubos did with his article.

  371. michael hammer

    No one is misquoting you. You attributed the high temperatures on Venus to an effect caused by high pressure. Your words:

    On venus it is close to all of 92 atmospheres or about 250,000 times greater. At that sort of pressure there is absolutely massive pressure broadening so that CO2 absorbs almost everywhere. Thus it retains a very large amount of heat pushing the temperature up very considerably.

    Everything else kept the same, without the high pressure, Venus would be cooler than earth due to the lack of water vapour.

  372. beng says:

    ******
    stevengoddard says:
    May 7, 2010 at 2:07 pm

    beng

    The top of the Grand Canyon receives just as much solar radiation as the bottom of the Grand Canyon, yet it tends to be 20-30 degrees F cooler.

    How does that fit into your theory “The atmosphere is mostly heated at the bottom by the warm, irradiated surface…That’s why it’s warmer down there, not because of pressure. “
    ******

    It’s a good question. I think I’m right about this, but not sure how to explain it, since I’m just an old power-plant engineer.

    I like to think in terms of insulation. Qualitatively, there’s alot of similarity w/GHG effects. In a layer of insulation, there’s a similar “temp lapse rate” across its thickness from the hot/cold pipe temps to ambient temps. This is why falling stratospheric temps could suggest increasing GHG effects — just like adding more insulation on a hot pipe makes the outside insulation surface feel less & less hot, gradually approaching ambient temp as more insulation is added.

    In this simplistic (but qualitatively correct) view, the top of Grand Canyon has less insulating atmosphere above it (including GHGs), and so loses more heat via IR radiation to the sky than lower elevations (notice how the sky gets darker blue as you gain elevation, eventually becoming black). The average temp is less, despite the same solar input.

  373. Ric,

    Lapse rates on Venus (10.468 K/km) are very similar to Earth (9.760 K/km.)
    http://atmos.nmsu.edu/education_and_outreach/encyclopedia/adiabatic_lapse_rate.htm

    I’m sorry that you are confused.

  374. Phil.

    Venus and Earth have very similar energy budgets, which are set by TSI and albedo at the TOA.

    The difference is that Venus has a very thick (high pressure) atmosphere. If you dug an open pit 30 miles deep in the earth, the air temperature would be comparable to Venus.

  375. astrowright says:

    Re: stevengoddard says:
    May 7, 2010 at 4:29 pm

    “What would happen to atmospheric pressure if the sun turned off?

    PV = nRT

    If T dropped to zero, then P would also drop to zero. It is the sun which provides the energy that keeps the molecules moving, and keeps the pressure up.”

    1) This ignores all heat from a planet’s core and any subsequent tectonics and volcanism that may result, and it in addition also ignores energy released due to radioactive decay.

    2) Your statement is actually backwards in a practical sense. In most planetary atmospheres, higher temperature = lower pressure because the atmosphere is free to expand.

    3) If what you said were true in a blanket sense, then the moon Titan, which is nearly 10 times farther away from the Sun than the Earth, should have almost no atmosphere. Instead, Titan has an atmospheric pressure identical to Earth. It is the cold that keeps the pressure up on Titan, not the heat, because the atmosphere has contracted.

    Every planetary environment must be specifically considered because each is unique from the others.

  376. Keith Minto says:

    In Canberra, I live at 800m and due to cool air pooling at night it will be 2-3degC warmer that the valley/ airport where the temperature readings are taken at
    500m. Day temperatures are similar.

    To discuss cooler temperatures with altitude, I might start with my concern about the difference between reading air and radiative readings.
    What are you reading with radiative ? reflected energy from a radiative body, so on the moon is there any difference between lunar valleys and peaks? I think not, a hot rock heated by the sun is really the same in a valley or on a mountain top.

    On a rocky planet with an atmosphere there is, in still air, the adiabatic lapse rate.
    But what is being measured in a temperature reading of atmosphere? molecular collisions with a sensor, given that the the sensor is cooler than surrounding air when the temperature is rising and the reverse applies in cooling temperatures. In cooling the sensor is back radiating the energy received by air molecular collisions, so it lags slightly the true reading. Now at ground level the air is denser and there will be more collisions and limited sensor back radiation ‘cooling’, but at altitude with less dense air there are less collisions and more chance of sensor back radiation. So the temperature at altitude is lower as the sensor has greater freedom to give back collision energy. At altitude the collisions would also be fewer and less energetic. Perhaps to measure correctly at altitude we need to surround the sensor in a pressurised box matching the pressure at ground level and then compare readings. The ‘collisions’ would be similar and you would be measuring the energy level difference which would be a more accurate measure of temperature difference, assuming still air.
    Really the intimate contact of a free flowing liquid with a sensor is the most accurate indication of the temperature of the fluid. Anything measured in air, thick (but not liquid) or rarefied, is influenced by the molecular collision rate and will give a spurious result.
    Is this a reasonable argument?

  377. Willis Eschenbach says:

    michael hammer says:
    May 7, 2010 at 5:02 pm

    … There are some interesting issues. It seems to me that some of the Nimbus data is in conflict with “established wisdom”. Two issues in particular, one that the emissivity of ice and snow in the thermal infrared is close to1 and secondly that the stratosphere is well mixed.

    My bible on these matters, “The Climate Near The Ground” (first published back in the day when people actually measured things) gives the emissivity of fresh snow in the 9-12 micron region as 0.986.

    There’s an excellent library of emissivity values here. It says inter alia:

    Water, ice, and snow generally have a high emissivity, 0.94 to 0.99, across the thermal infrared region. Snow is unusual in that it has a high reflectance in the solar (visible) region where most of the downwelling energy is during the day, and a very high emissivity in the thermal region.

    Note that these are measured values from actual samples.

    Emissivity of carbon seems to range from 0.8 to 0.95, depending on the exact form. The main effect of black carbon on snow/ice is the huge difference between the albedo of the two. Toss some wood ashes out on the snow, wait a day or so, and you’ll see what I mean.

    We now return you to your regularly scheduled programming … Venus.

    To me, the key to the Venus temperature is the clouds. High clouds surround the planet. When you have that, most of the IR will be radiated from up high, and the lapse rate will guarantee a warmer surface. How much warmer? Depends on the elevation of the clouds, which for Venus is very high (on the order of 75 km). Given high IR absorbing clouds, the composition of the lower atmosphere is not so important.

  378. Doug Jones says:

    I do thermodynamic calculations almost every day- engine cycles (often various flavors of Brayton and Rankine cycle), heat transfer in regeneratively cooled rocket engines, things of that sort. I use the PV=nRT relation routinely, and I see a lot misunderstanding of it in this post and these comments. I’ll try to help, please bear with me.

    For instance, turning off the sun and cooling the Earth’s atmosphere would NOT change the sea level pressure… only the scale height would change, as the density increased with lower temperatures. Pressures at higher altitudes would drop proportional to the altitude and the temperature ratio, as the colder, denser atmosphere “fell” to lower altitudes. Finally, as the surface temperature approached 90K, the boiling point of LOX, the air would start to rain out, and finally the sea level pressure would drop. On a uniform spherical earth, the pressure at the bottom of the liquid air ocean would still be 101 kilopascals, with the same 10 metric tons of air on top of each square meter.

    Back to Venus, though. Just below the cloud tops, the atmosphere is effectively opaque, scattering or absorbing almost all sunlight so that very little reaches the surface to heat it. The crucial altitude is the one where the air is opaque in thermal IR wavelengths- at around 60-70 km this is where the radiation budget balances at about 240K. Below this altitude, absorption of solar heat drives convective heat transfer, and the temperature gradient is can be no greater than the dry adiabatic lapse rate… which is really just the ideal gas law with a geopotential term added .

    So you see, the temperature at the top of the troposphere is similar to that on Earth, but there’s a lot more air below that point, mostly at the dry lapse rate. Why at that rate? The _conduction_ through any air is very low, so if there is even a tiny heat flux toward the surface, the lower layers will heat up until the gradient reaches the convective limit (the dry lapse rate). This is what makes a troposphere a troposphere, and for almost any heat flux across a large range, will display the dry adiabatic lapse rate unless there is enough of a condensible component to drop it to the wet adiabatic lapse rate. On Venus, that species is sulfuric acid, oh joy, and sure enough, the lapse rate is diminished in the cloud layers. http://en.wikipedia.org/wiki/Venus%27_atmosphere

    So yes, on Venus as on Earth, CO2 is not the critical component controlling the temperatures, it is the cloud- and rain-making component that matters. On Earth, water, on Venus, sulfuric acid.

  379. Keith Minto,

    This JPL publication has a good graph on page 12 showing the inversion effect you see at night in Canberra.
    http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/13139/1/01-1749.pdf

    Below 2,000 feet, there is a temperature inversion. Otherwise, temperatures decrease linearly about 10C per 4,000 ft elevation.

  380. astrowright

    Heat escaping from the interior of the Earth is very small compared to heat received from the Sun.

    Higher temperature and pressure almost always go together. Mountains have cold, low pressure air. Lower elevations have warm, high pressure air. That is why people ski at high elevations where the air is thin, and why people in Colorado take vacations in Hawaii.

  381. Ric Werme says:

    michael hammer says:
    May 7, 2010 at 5:02 pm

    > Alan McIntire at 6:54 Alan I would very much like to post some articles on wattsupwtihthat but I do not know of any way of emailing them to Antony.

    Anthony’s official “public” Email address is info (at sign) surfacestations.org,
    http://www.surfacestations.org/contact.htm

    I have another, that I think is the “good” one that I’ve come across twice, but Anthony hasn’t given it to me, so I won’t share it and haven’t used it. I expect to see him in Chicago in a couple weeks.

    BTW, thanks for your post on spectral broadening, etc. I’ve been meaning to hunt down more about that for the last year or two. I have a question – once a CO2 molecule absorbs a photon, how long does it take before it reradiates it, and how long does it take before it bangs into an air molecule and transfers energy in the collision? Both in high altitude (say 10 mb) and low (1000 mb) conditions.

  382. Doug Jones

    Molecules would stop moving at absolute zero, so there would be no pressure. Pressure is caused by movement of molecules.

    Of course, you can’t have gases as you approach absolute zero.

  383. Reed Coray says:

    This discussion of Venus and the relationship between atmospheric pressure and planetary surface/atmosphere temperatures has prompted me to describe and seek solutions to three “simplified planetary-like” atmospheric scenarios. The solutions to these scenarios may provide insight into the thermal effects of atmospheric greenhouse gases on planets devoid of water. Specifically, if solutions can be generated, we should at least start to quantitatively understand the phenomenon of Co2 IR “energy capture”–a term often used, but not well understood, in the AGW discussion.

    All three scenarios use the same model of the planetary surface, but they differ in their atmosphere models. For each model, I seek quantitative characterizations of the temperature/pressure properties of the models. I don’t have the knowledge to provide answers to those questions; but given the responses to Mr. Goddard’s blog, I thought readers of this blog might be able to provide those answers.

    Planetary Surface Model:
    Suppose in the vacuum of space and “infinitely far removed” from all other celestial bodies, we have a thin spherical “shell” that from every perspective possesses spherical symmetry about the center of the sphere. Assume (a) the shell mass is equal to the mass of the Earth, (b) the shell outside radius is the average of the Earth’s polar and equatorial radii, (c) the shell thickness is small compared to its radius, (d) the shell is diathermic (i.e., a perfect conductor of heat) and (e) when in the presence of a vacuum, both the inner and outer shell surfaces are “black body” radiators. The shell center of mass is at rest with respect to inertial space, and the shell is NOT rotating. At time zero, the temperature of the shell is below the freezing points of carbon dioxide (CO2), Oxygen (O2) and Nitrogen (O2). Within the walls of the shell we have an energy source that generates heat at a rate such that if the vacuum of space exists everywhere outside the shell, when the outgoing rate of black body radiated energy equals the rate of internal energy generation, the surface of the shell will be at a uniform temperature of 290 K.

    First Atmosphere Model:
    Over the outside surface of the shell we symmetrically distribute (a) a mass of Oxygen (O2) equal to the mass of Oxygen in the Earth’s atmosphere, and (b) a mass of Nitrogen (N2) equal to the mass of Nitrogen in the Earth’s atmosphere. All masses are distributed at the temperature of the shell surface at time zero–i.e., they are distributed as solids. We observe the shell and its “atmosphere” as time progresses. The heat generated in the shell walls will warm the shell surface, first melting and then vaporizing the Oxygen and Nitrogen. Heat will be transfered away from the shell surface via both conduction and radiation. Symmetry arguments preclude heat transfer via convection. The shell surface, the Oxygen and the Nitrogen will all conduct and radiate heat. Portions of that radiated energy will be absorbed by the shell surface and the atmospheric gases, and portions of the radiated energy will “escape” into space. When the total energy per unit time “escaping” into space is equal to the rate at which energy is generated within the walls of the shell, the shell/atmosphere system will have reached steady state and macroscopic changes will cease. Steady-state conditions will include (a) a temperature for the surface of the shell, (b) a temperature profile as a function of distance above the surface of the shell, and (c) partial pressure profiles for Oxygen and Nitrogen as a function of distance above the surface of the shell.

    Second Atmosphere Model
    Same as the First Atmosphere Model at time zero except that along with Oxygen and Nitrogen we symmetrically distribute a mass of Carbon Dioxide (CO2) equal to the mass of CO2 in the Earth’s atmosphere. As with the First Atmosphere Model, we are interested in the steady-state (a) surface temperature, (b) temperature profile as a function of distance above the shell surface, and (c) partial pressure profiles as a function of distance above the shell surface.

    Third Atmosphere Model
    Same as the Second Atmosphere Model at time zero except that we symmetrically distribute an additional mass of CO2 equal to 1% of the CO2 mass of the Second Atmosphere Model. As with the First and Second Atmosphere Models, we are interested in the steady-state (a) surface temperature, (b) temperature profile as a function of distance above the shell surface, and (c) partial pressure profiles as a function of distance above the shell surface.

    For the above three scenarios, quantitative solutions for the shell surface temperature and atmospheric temperature profiles should help us better understand the phenomenon of “CO2 IR energy trapping”.

  384. Phil. says:

    Ric Werme says:
    May 7, 2010 at 7:41 pm
    I have a question – once a CO2 molecule absorbs a photon, how long does it take before it reradiates it, and how long does it take before it bangs into an air molecule and transfers energy in the collision? Both in high altitude (say 10 mb) and low (1000 mb) conditions.

    Collision rates are approximately 10/nsec at atmospheric pressure, it will take a number of collisions to deactivate the excited state. The mean radiation lifetime for CO2 is orders of magnitudes higher.

  385. kuhnkat says:

    Nick Stokes,

    “No, it wouldn’t, not without a greenhouse effect. A surface at 700K emits about 12,000 W/m2. Incoming sunlight, averaged over surface area, on Venus is about 400 W/m2. If the atmosphere is transparent to thermal IR, that 12,000 W/m2 would just go out to space and sunlight couldn’t possibly balance it. The surface would cool.

    This is based on assumptions that you and other scientists have made about the origin of Venus. IF Venus is young the internal heat of the planet will easily keep the surface at high temps with no help from anything for a time. Please prove your assumption that Venus is about 4 billion years old or that it did not have a rather large collision in the recent past that raised the temp and resurfaced it.

    “What does balance it, of course, is thermal IR emitted from the atmosphere itself. But that can only happen with some GHG effect.

    The adiabatic transport effect can explain a temperature difference. But it can’t provide that source of radiant heat. All it means is that TOA would be correspondingly colder.

    “The way a greenhouse effect works is by shortwave radiation warming the ground, and greenhouse gases impeding the return of long wave radiation to space.”
    It doesn’t have to involve the ground. It only requires that heat passes through a layer of gas at a frequency to which the gas is relatively transparent, and is part-blocked from returning at lower thermal IR frequency. It doesn’t matter whether the absorption and reemission happens at the ground or at a lower level of the atmosphere.”

    Nick, Venus emits more energy than it receives in SW. Your argument is a non-sequitur.

    “So to qualify my earlier remark – you can’t have 700K on the surface with an IR-transparent atmosphere. You could get a high temperature from cloud blocking plus adiabat, even without selective IR absorption. You can also get it from a greenhouse effect, and there’s lots of GHG for that. Both effects seem to be at work here.”

    CO2 only covers very narrow bands even here on earth. What other GHG’s are there to cover all the rest of the bandwidth of IR?? Do you think the little OH found in the atmosphere on Venus will replace the water vapor function seen here on earth?? By the way, why do you think there is ANY water vapor on Venus again?? Got any explanation for the continuous hurricane force winds, the radar reflectivity of the peaks, the interesting anomalies at both poles?? Why do you argue from IGNORANCE??

    “Beng, I think you and Steven each have half the story there. Some people are saying that somehow pressure causes high temperature. That’s wrong – a cylinder of compressed oxygen will generally be at ambient temperature.”

    Only AFTER it has radiated the heat due to compression to the environment. Now, if the cylinder is partially filled with liquid air, THEN it might never be at higher than local temps. Of course, the heat from liquifying the air was radiated elsewhere.

    Nick, for a guy who can pull out formulas when it suits your argument, you write some awfully stupid things at times!! When are you going to grow a pair and admit you are trying to shore up CRAP!!!

  386. Bryan H. says:

    So when I was a child, and before years of engineering education my childhood heros were: Asimov, Feynman, and Tesla.

    The people I thought were the biggest idiots? Sagan, Hawking, and Ford.

    I still stand by those choices I made as a child.

  387. Ric Werme says:

    stevengoddard says:
    May 7, 2010 at 7:41 pm
    Doug Jones

    Molecules would stop moving at absolute zero, so there would be no pressure. Pressure is caused by movement of molecules.
    Of course, you can’t have gases as you approach absolute zero.

    Pressure is merely force per unit area and comes from more than just gases.

    I used to work in an old woolen mill converted to building computer systems. There were a number of signs around listing the maximum floor loading in pounds per square foot, typically 50 lbs/ft^2. Surprisingly, none of us ever fell through the floor, even if we stood on one foot, but I digress.

    So, if we simply cooled our shoes to 0.0 Kelvins we would have been even safer!
    Cool!

  388. CRS, Dr.P.H. says:

    …can we all at least agree that the likelihood of Earth experiencing a Venus-like runaway greenhouse effect is essentially zero?

    Well, unless Earth develops clouds of sulfuric acid and a surface pressure of 93 bar, anyway!

  389. Ric Werme

    Unless you are gas suspended in the atmosphere, the analogy isn’t going to work. The pressure from your shoes to the floor is caused by gravity. Gas pressure on the other hand is caused by movement of molecules.

  390. kuhnkat

    Not much SW radiation is absorbed by the atmosphere, particularly the lower atmosphere. Almost all of it that comes through the clouds warms the ground.
    http://www.globalwarmingart.com/images/7/7c/Atmospheric_Transmission.png

  391. jcrabb says:

    Once pressure has stabilised it doesn’t create heat, so how can this be warming the atmosphere of Venus?

  392. Robert of Ottawa

    PJF, this link shows the temp/pressure profile of the Venusian atmosphere. Note that around 1 Earth atmosphere of pressure, the atmospheric pressure is roughly the same as the Earth’s.

    http://www.datasync.com/~rsf1/vel/1918vpt.htm

    Look again. The second graph has Venus’s pressure = Earth’s sea level pressure at 49.5km and at that altitude, the first graph has temperature at about 350K (76C).

    There are several fundamental flaws in this whole argument. One is that PV=nRT applies in a closed system. If the planet is able to radiate to space, you don’t have a closed system, so the temperature will drop until energy in = energy out. Also, you cannot equate conditions on Earth to those on Venus with a much higher CO_2 concentration. The logarithmic relationship between CO_2 concentration and warming breaks down at around 10%. Pressure broadening is well understood by planetary atmosphere scientists, and the very high temperatures of Venus cannot be explained without it. Mars with a very different scenario, very low pressure, is also accurately modelled by the same theory. As are Earth’s major climate swings, including extremes such as a snowball earth.

    If you have a better theory, work it through in detail and let’s see it. This is all a little too hand-wavy for my liking, not least since it doesn’t work through the physics or explain how it fits observations better than the existing theory. Wishful thinking and putting down the aspects of a theory you disagree with to pot smoking is a pretty sloppy way of doing science to say the least.

  393. Julian Braggins says:

    Steve Goddard,
    Sorry if my cite about Venus cooling wasn’t the right one, here are a couple that explain it though.

    http://www.science-frontiers.com/sf014/sf014p03.htm

    “The second law of thermodynamics is a general principle, which places constraints upon the direction of heat transfer. To maintain the high surface temperature of Venus there should be no net flow of heat through the atmosphere. However, when the Pioneer Venus probes looked at the amount of radiant energy passing through the atmosphere, each one found more energy being radiated up from the lower atmosphere than enters it as sunlight. And, if this were not enough, the night probe site was shown to be about 2K warmer than it was at the day probe site. The Russian probes, Vega 1 and 2, also “recorded a pronounced upward radiation flux.” These findings simply show that Venus’ surface is hot and still cooling.”

    http://www.holoscience.com/news.php?article=9aqt6cz5

    “Probably the most damning for the greenhouse theory is the data from all of the US and Russian probes showing that the thermal gradient of the atmosphere is from base to cloud tops, i.e. the heat source is at the bottom, not outside. In short, the claims that have been made publicly notwithstanding, the planet is not in thermal equilibrium. According to the probe data, the emitted surface infrared flux is 40 times more than enters as sunlight. About 2 percent of the heat at the surface can be attributed to solar input. Overall, Venus emits 15 percent more energy than it receives from the sun, implying a heat output 10,000 times greater than Earth’s. Although Venus rotates 243 times more slowly than Earth (58-day dark period), nightside temperatures are slightly higher than on the day side–contradicting the notion that the sun is the heat source. Rigorous mathematical modeling by the thermodynamicist George R. Talbott showed that given an incandescent state 3,500 years ago as the recent-origin theory proposes, the cooling curve over that period yields a temperature today exactly as observed.”

  394. Nick Stokes says:

    KK
    “Nick, Venus emits more energy than it receives in SW.”
    You need to provide some evidence for that. I’ve pointed out the huge disparity between IR leaving the surface (>12000 W/m2), and that leaving TOA. It’s actually nearly 2 orders of magnitude – Venus only absorbs and reemits as IR about 164 W/m2, because of its high albedo. If you really want to claim Venus emits that much more than it receives, there should be much evidence. If not, then something is absorbing the surface IR.

  395. michael hammer says:

    Willis at 7:04. Your comments about the emissivity of snow is exactly what I also have found and yes it has been determined by experiment (I read the articles). Thus I strongly suspect that the data is correct however creates an apparent paradox, maybe you can explain it.

    If one looks at the Nimbus 3 plots of thermal infrared emission from earth to space over the antarctic the plot shows an equivalent black body temperature of 180K in the atmospheric window. Now there is no place in the antarctic that is as cold as 180K, even the high plateau is at about 220k. There is also no place in the atmosphere that is as cold as 180K, so how can the emission be so low? The only explanation I can come up with is that Nimbus is looking at a surface significantly hotter than 180K – (somewhere between 220K and 250K depending on which portion of the Antarctic it is looking at) but a surface with a low emissivity. For a 220K surface to look like a 180K black body it would need to have an emissivity of around 0.45. One cannot explain the situation by claiming that the black body curves overlayed over the Nimbus data are simply wrong because there is to much internal consistency. For example, the equivalent black body temp at the CO2 line is 215K which is consistent with the temperatures over the meditteranean and over the Sahara and these match the tropopause temperature (in that lies another very interesting paradox but thats another subject) which I would expect. Further, the emission at the CO2 line is higher than the emission from the atmopsheric window yet the surafce is warmer than the tropopause (we know by the way that the CO2 emissivity is 1 since it is a deep column of gas) . Then again the black body temperatures for both the meditteranean and the Sahara in the atmospheric window pretty well match surface temperatures which is again what one would expect. I could go on – the Nimbus data with overlays is internally consistent and matches reality on several points so it also would seem to be correct. Yet the emissivity of snow and the Nimbus data seem to be in conflict, how come?

    This is far from a trivial point because if the emissivity were low in the thermal infrared then covering the surface with soot would raise both emissivities. However when one calculates the energy gain from absorbed sunlight versus the energy loss from thermal emission to space above the arctic circle the latter dominates considerably. If one raises the emissivity for both visible and thermal infra red energy it turns out the increase in energy loss is greater than the increase in energy gain and the net impact is additional cooling not warming. Hence negative not positive feedback. Your experiment about throwing wood ash on snow and observing what happens is not relevant unless it is done in the Arctic or Antarctic because at more benign latitudes the solar energy is so much higher. Please respond, I would be very interested in your thoughts on this issue.

    Rich Werne thanks for the public email address I will attempt to use it.

  396. jcrabb

    The atmosphere doesn’t “create heat.” Heat is continuously introduced from outside the atmospheric system – i.e. the Sun.

  397. Julian Braggins

    Excellent links! Thanks much for the information.

  398. Hans Erren says:

    stevengoddard says: May 6, 2010 at 2:12 pm
    “@Hans Erren
    I made the point that it is the pressure, not the concentration of CO2 that is important. You seem to be agreeing with me, without realizing it.”

    Steve,

    Sure I do realise it’s the adiabatic heating downward from the venusian cloudtops (the effective photosphere) that make the surface of Venus hot, but as you can read in Bullock and Greenspoon, even without clouds the effective photosphere would be sitting far above the solid surface due to the complete CO2 saturation of the infrared spectrum.
    The effective photosphere height for Venus is at 20 mBar pressure whereas on earth it is at 500 mbar. And that difference is due to the effect of CO2 infrared saturation.

    http://pds-atmospheres.nmsu.edu/education_and_outreach/encyclopedia/atmospheric_parameters.htm

  399. Hans Erren

    I understand what you are saying. My point is that the reason CO2 saturates the infrared spectrum on Venus is because of the high pressure. Without the high pressure, it wouldn’t happen.

  400. CRS, Dr.P.H.

    Good point. Despite the apparent disagreements about details, I don’t see anyone arguing that the greenhouse effect can be responsible for the high temperatures on Venus.

  401. carrot eater says:

    stevengoddard says:
    May 8, 2010 at 5:09 am

    “The atmosphere doesn’t “create heat.” Heat is continuously introduced from outside the atmospheric system – i.e. the Sun.”

    So where is the sun, in your little hypothesis?

  402. Sense and Science says:

    What is Governing the Temperature of Earth?

    The surface of Planet Earth is heated by the incident shortwave electromagnetic radiation from the sun. In order to balance the temperature of the earth, most of this incident radiation energy is, contrary to the assumption made in the AGW hypothesis, removed from the surface by convective cooling by a flowing atmosphere and by evaporation (removal of latent heat) from the surfaces of the seas, lakes and moist soil; and by transpiration of plants. Consequently, the lower atmosphere, is heated by convective heat transfer from the surface of Earth; by release of latent heat during condensation of water vapour (formation of clouds) and; to a small extent, by thermalisation of excited GHG molecules. The so heated air parcels increase in volume (reduce their density) and rise towards higher altitudes, while their temperature reduce along the lapse rate function. The rising warm air is replaced by cooler air, thus maintaining a continuous convective churning/stirring of the atmosphere that we call wind.

    In the upper part of the troposphere and in the stratosphere, IR energy can more efficiently be emitted towards space to achieve the required radiation balance of Earth’s. That is, the estimated effective radiation balance temperature for the earth, 18°C, is established in the upper portion of troposphere and in the stratosphere and not at the surface of the earth, as anticipated by IPCC and the AGW proponents.

    The bottom portion of the troposphere and thereby also the surface of the earth, exhibit an average temperature of +15°C. This is approximately 33 K higher than what can be estimated based on the radiative balance with space. This temperature increase is the direct result of the presence of an atmosphere, with its given mass, within the gravitational field of the earth (see contributions by Jelbring and Thieme below). The atmosphere (the air), with its mass, is attracted towards the surface of the earth by the gravitational field. Most of this atmospheric mass will thus reside close the surface of the earth where it is compressed to a higher pressure (on average 1.013 bar) and obtains thus a higher temperature.

    Correspondingly, the atmosphere becomes thinner (less compression and thus lower pressure) and cooler, the higher the altitude is. This pressure and temperature distribution is governed by a restricted thermodynamic equilibrium, so-called adiabatic condition. Such a condition prevails when the size of the air parcels is large in comparison to the length scales for heat conduction and diffusion during the time interval pertaining to the state change. Adiabatic changes in temperature thus occur due to changes in pressure of a gas while not adding or removing any heat from or to the surrounding. This entails that the total energy content in an air parcel with a given mass remains constant when it moves vertically, that is, the sum of potential and thermal energy remains constant, independent of the altitude.

    The (vertical) circulation of the air is a continuous process that is driven by the dynamics of the planetary atmosphere. At high altitude (high potential energy), a parcel of air of given mass has a large volume and low temperature (low thermal energy). When brought to lower altitudes (low potential energy and high thermal energy) it becomes compressed and thus heated. Again, the temperature of the air parcel will be governed the lapse rate function, which is a consequence of the prevailing thermodynamic equilibrium under adiabatic conditions.

    The mathematical description of this mechanism has been called the adiabatic model of atmospheric temperature (see the paper by Chilingar, Khilyuk and Sorokhtin below) and can closely (within 0.1%) describe the long-term average temperature distribution as function of altitude in the troposphere. The normal atmospheric pressure (1.013 bar) near the surface of the earth will bring the air temperature to around +15°C, or delta-T_Earth=33K higher than the temperature determined from the radiation balance between incident (short-wave) radiation from the sun and outgoing (long-wave) radiation from the upper part of the atmosphere towards space.

    The cyclic heat input from the sun (over day and night; seasonal variations at different latitudes, etc.) provides the driving forces behind the continuously circulating atmosphere and its vertical transport of heat from the surface of the earth to higher altitudes, where heat balance can be established by long-wave radiation towards space. Well proven, basic physics considerations (radiation balance and adiabatic compression) therefore directly explain the observed temperature of Earth’s atmosphere, without the need to revert to obscure and unverified greenhouse effects from greenhouse gases.

    The Hothouse Venus:

    Planet Venus, with its CO2 rich atmosphere (96.5% CO2) has a very high surface temperature, in the order of 462°C (735 K). This high surface temperature is often claimed to be the result of a runaway greenhouse effect due to the high CO2 concentration, evaporation of the surface water and subsequent rise of the levels of other GHGs. This, of course, sounds plausible in the ears of the AGW proponents, who want to scare the inhabitants of Planet Earth that similar dramatic temperature increases (beyond the tipping point) may develop also here, if we do not take appropriate measures to curb the emission of GHGs.

    There exists, however, a physically well-founded, explanation for the high surface temperature on planet Venus, namely the adiabatic model of atmospheric temperature (see paper by Chilingar, Khilyuk and Sorokhtin below), mentioned above. Not only is the concentration of CO2 much higher at Venus than on Earth, but also the atmospheric pressure at the surface of Venus is much higher, approximately 90 bar. While the gravitational effects on the mass of the (dynamic) planetary atmosphere heats the bottom of the atmosphere and the surface of Earth by delta-T_Earth=33K above the effective temperature expected from radiation balance alone, the same effect on Venus heats its surface by delta-T_Venus=507K above its effective radiation balance temperature, which is 45°C (228 K). The adiabatic model of atmospheric temperature also well describes the temperature of the Venusian atmosphere as function of altitude, within 1%. Again, there is no need to revert to an (unverified) runaway greenhouse effect to explain the high surface temperature of Venus. Plain, well established, physics suffices. Consequently, the (runaway) greenhouse effect does not exist.

    Suggested Reading:
    • H.R. Jelbring. The Greenhouse Effect as a Function of Atmospheric Mass, Energy & Environment, Volume 14, Number 2 – 3, May 2003, pp. 351-356, http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
    • Hans Jelbring, Politics and the Greenhouse Effect, http://www.tech-know.eu/NISubmission/pdf/Politics_and_the_Greenhouse_Effect.pdf
    • Heinz Thieme, The Thermodynamic Atmosphere Effect – explained stepwise, http://freenet-homepage.de/klima/atmoseffect.htm
    • L. F. Khilyuk, G.V. Chilingar, On global forces of nature driving the Earth’s climate. Are humans involved? Environmental Geology, Volume 50, Number 6 / August, 2006, pp. 899-910, http://www.springerlink.com/content/t341350850360302/ (behind pay-wall)
    • G.V. Chilingar, L.F. Khilyuk, O. G. Sorokhtin. Cooling of Atmosphere Due to CO2 Emission. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Volume 30, Issue 1, January 2008, pages 1 9
    http://www.mitosyfraudes.org/Calen9/Chillingar_Atm_Cooling_due_to_CO2.pdf

  403. carrot eater

    The sun warms the atmosphere, causing it to convect. This is not a “little hypothesis.” It is basic physics.

  404. Ric Werme says:

    Julian Braggins says:
    May 8, 2010 at 12:31 am

    http://www.holoscience.com/news.php?article=9aqt6cz5

    I followed that link. Nearly at the bottom I read much to my amazement:

    On the Venusian surface, nitrogen molecules are converted to carbon monoxide molecules by a catalytic surface nuclear reaction in the presence of red-hot iron. The brilliant French chemist, Louis Kervran, when investigating carbon monoxide poisoning of welders, discovered this surprising nuclear transformation.

    I had never heard of this character, even when I was actively following cold fusion (which still hasn’t gone away!) I couldn’t finish the rest of the article, but did spend a little time reading about all the marvelous biological transmutations that somehow have escaped my notice. Chemtrails are more believable….

  405. Ric Werme says:

    Sense and Science wrote May 8, 2010 at 7:20 am …

    Very good post, thank you for taking the time to write it.

  406. Lon Hocker says:

    Thank you “Sense and Science, and Steve for explaining why temperature changes with altitude. Sorry I was so slow in picking it up. There’s a detail I’m not sure I get, though.

    At some point there is a balance between solar heating and radiation out. On the moon, that would be the surface, since there is no atmosphere to make things complex. I would imagine that on Venus it would be the altitude where the atmosphere is essentially opaque to IR. You start there and can calculate temperatures up and down from there. Change all the atmosphere on Venus to Argon (or N2 or any other IR transparent gas), and the altitude would be the surface, so you would see a vastly cooler surface. It would appear that there really is a greenhouse effect after all, and that sets the starting point for the temperature model.

    Is this right, or am I missing something?

  407. CRS, Dr.P.H. says:

    stevengoddard says:
    May 8, 2010 at 6:05 am
    CRS, Dr.P.H.

    Good point. Despite the apparent disagreements about details, I don’t see anyone arguing that the greenhouse effect can be responsible for the high temperatures on Venus.
    ——-
    REPLY: Thanks, Steve! I don’t know the origin of that urban legend (Earth is at risk of a “Venus GH Effect,” perhaps Karl Sagan as noted above, but I do recall reading about it in the early 1970’s.

    It surprises me that serious scientists are still hyperventilating over that scenario for Earth! Comparing two planets to one another in that fashion is just pure, simple folly.

    BTW, I once considered writing a sci-fi novel about the terra-forming of Venus! You’d want to use green sulfur-bacteria like C. Chlorobium limicola forma thiosulfatophilum, and you’d have to add water to the planet. Several decent-sized comets would do it.

  408. Roger Clague says:

    Great post by Sense and Science. I especially recommend the reference

    Heinz Thieme, The Thermodynamic Atmosphere Effect – explained stepwise, http://freenet-homepage.de/klima/atmoseffect.htm

    All basic physics and no mention of CO2.

    It should be re-posted as a headliner.

  409. Stephen Wilde says:

    Lon Hocker

    May 8 2010 11.08 am.

    All you are missing is that the phenomenon you describe is nothing like a greenhouse.

    It’s just the natural consequence of gravity and total atmospheric density just as Steve says. Those two features are what sets both pressure and temperature at the surface.

    Composition dictates density and thus temperature but the same density can arise from an infinite number of compositional variations. To change the surface temperature one must have a significant change in total atmosphere density. More human CO2 could never do that for the Earth.

    Density describes the total molecular weight (mass) for the planetary atmosphere however it is composed. Each molecule present whether it is in the form of a gas or solid particulates has it’s own mass and that mass dictates the amount of energy it is capable of absorbing from incoming photons before re radiating.

    CO2 molecules have more mass than Nitrogen molecules and so carry more heat energy but what matters for setting the base surface temperature is the total density of the atmosphere under the influence of gravity. A pure Nitrogen atmosphere will have a very low density and so will be much cooler than a pure CO2 atmosphere.

    On Venus there are many sulphuric acid clouds. They add greatly to total atmospheric density and so contribute greatly to the temperature of Venus.

    The rate at which energy is shifted away from the surface by convection and other processes is a seperate issue.

    A unique feature of water is that the phase changes from water to ice and water to vapour and back again are so powerful in shifting energy away that they seem capable of neutralising even changes in temperature that would otherwise arise from changes in the density of the air above the oceans.

    For that reason I have proposed elswhere that we should regard Earth’s oceans as an integral part of the atmosphere for energy processing purposes with the air above being powerless to change the equilibrium set by the ocean surfaces combined with solar energy input.

    One can call the warming effect of gravity and density a greenhouse effect but it is not what is normally meant by the term and that is what Steve is gently pointing out (Ithink).

  410. Andrew W says:

    stevengoddard says:
    May 7, 2010 at 10:38 pm

    “…Gas pressure on the other hand is caused by movement of molecules.”

    But the pressure at the surface equals the weight of the gas above, halve the temperature ,the surface pressure remains the same, liquefy it or freeze it, and the pressure at the surface still remains the same. It’s only when the gas is confined in a vessel that pressure increases with temperature, heat the atmosphere of a planet and it expands.

  411. Andrew W says:

    CRS, Dr.P.H. says:
    May 8, 2010 at 11:48 am

    It surprises me that serious scientists are still hyperventilating over that scenario for Earth! [Venus type runaway GH]

    Are they? Name one.

  412. Robert Hafer says:

    Supercritical CO2 is neither a liquid nor a gas. It’s a separate state of matter. It can become a gas without vaporization and a liquid without condensation. It has chemical properties unique to that state.
    An atmosphere composed of a supercritical fluid must surely be unique in our solar system and may have little relation to any other atmosphere.

  413. Lon Hocker says:

    Steven Wilde
    All you are missing is that the phenomenon you describe is nothing like a greenhouse.

    You didn’t address the question I had. Let me repeat it:
    “At some point there is a balance between solar heating and radiation out. On the moon, that would be the surface, since there is no atmosphere to make things complex. I would imagine that on Venus it would be the altitude where the atmosphere is essentially opaque to IR. You start there and can calculate temperatures up and down from there. Change all the atmosphere on Venus to Argon (or N2 or any other IR transparent gas), and the altitude would be the surface, so you would see a vastly cooler surface. It would appear that there really is a greenhouse effect after all, and that sets the starting point for the temperature model.”

    It would appear, since the energy balance isn’t at the surface on Venus, but way up in the atmosphere, that something is holding the heat in. This is usually called the greenhouse effect. If you can find a flaw in this argument, please let me know.
    Thanks

  414. Andrew W says:

    Steve Goddard in post “I bought off on the “runaway greenhouse” idea on Venus for several decades (without smoking pot) and only very recently have come to understand that the theory is beyond absurd.”

    Sounds to me like you were happy to accept what is an established theory, only to reject it when it became ideologically inconvenient.

  415. Stephen Wilde says:

    “But the pressure at the surface equals the weight of the gas above, halve the temperature ,the surface pressure remains the same, liquefy it or freeze it, and the pressure at the surface still remains the same. It’s only when the gas is confined in a vessel that pressure increases with temperature, heat the atmosphere of a planet and it expands.”

    How would you propose to halve the temperature without altering gravity and density ?

    If the gas were to liquify or freeze how would you prevent it from dropping out of the atmosphere thereby reducing density, temperature and pressure ?

    The atmosphere is to some extent confined in a vessel, namely gravity. Weaken the gravity and the enclosure grows to reduce both pressure and temperature. Strengthen the gravity and the enclosure shrinks to increase both pressure and temperature.

    One has to assume a constant energy flow from outside however.

    If the external energy source changes within ‘reasonable’ parameters then expansion or contraction of the atmosphere will result but temperature and pressure at the surface remains the same.

    If the external energy source ceases altogether the constituents of the atmosphere will change state and fall to the ground reducing density, pressure and temperature.

    If the external energy source becomes far more active then molecules will be stripped away to space reducing density, pressure and temperature.

  416. Andrew W says:

    Stephen Wilde, the pressure at the surface will remain the same whatever state the matter above it is in, only by changing gravity or the amount of matter above the surface will the pressure change.

  417. CRS, Dr.P.H. says:

    Andrew W says:
    May 8, 2010 at 12:52 pm
    CRS, Dr.P.H. says:
    May 8, 2010 at 11:48 am

    It surprises me that serious scientists are still hyperventilating over that scenario for Earth! [Venus type runaway GH]

    Are they? Name one.
    ——
    REPLY:

    http://www.sjsu.edu/faculty/watkins/GWvenus.htm

    “The planet Venus is often cited as an example of a runaway greenhouse effect and used to alarm people about the effect of increasing levels of CO2 in the Earth’s atmosphere. This material is to put matters in perspective.”

    and:

    “Ian Pearson, the UK minister for science and innovation, said: “Understanding the influencing factors of global warming on Venus could help us in mitigating the threat here on Earth.”
    http://news.bbc.co.uk/2/hi/7117303.stm

    (Pearson has a Ph.D in Industrial and Business Studies, University of Warwick, MA)
    —–
    You don’t have to look very hard to see that AGW proponents still try to draw a direct (and scary) comparison between the climates of Venus and future climate of Earth.

  418. Stephen Wilde says:

    Lon Hocker:

    “It would appear, since the energy balance isn’t at the surface on Venus, but way up in the atmosphere, that something is holding the heat in. This is usually called the greenhouse effect. If you can find a flaw in this argument, please let me know.”

    Gravity prevents the atmosphere from escaping to space. The density of the atmosphere dictates how much energy the constituents can hold before re radiating again. It doesn’t matter where the point of radiative balance lies.

    You can call it a greenhouse effect if you wish (annoyingly many do) but that’s a misleading description because it suggests something akin to the huge heating effect caused by restraining convection within a glass structure. It’s nothing like that. It’s just a slowing down of energy through the system and unless one increases density there will be no additional slowing down. CO2 is far too small a component of Earth’s atmosphere for any conceivable increase from human activity to measurably affect total atmospheric density.

    Even if it could do so the oceans neutralise the effect of any minor changes of density in the air via the far greater influence of what I have called ‘The Hot Water Bottle Effect’.

    http://climaterealists.com/index.php?id=1487&linkbox=true&position=3

    It’s not just the air that has that gravity/density effect in slowing down the passage of energy through the system. The oceans possess it too to a far greater degree.

    In fact one could say that the level at which the equilibrium temperature is set for the Earth is actually the ocean surface. The mistake people make is regarding the radiative balance in the air alone as all important. It isn’t. The ocean surfaces control the availability of energy to travel up through the air above. The ocean proposes and the air is merely it’s servant.

  419. Stephen Wilde says:

    “Andrew W says:
    May 8, 2010 at 1:39 pm
    Stephen Wilde, the pressure at the surface will remain the same whatever state the matter above it is in, only by changing gravity or the amount of matter above the surface will the pressure change.”

    Re read my post especially:

    How would you propose to halve the temperature without altering gravity and density ?

    If the gas were to liquify or freeze how would you prevent it from dropping out of the atmosphere thereby reducing density, temperature and pressure ?

  420. Stephen Wilde says:

    Please note that all my comments here relate only to the basic equilibrium temperature of a planetary atmosphere as a whole.

    There are lots of mechanisms arising from internal system variability that operate to vary that base temperature over time.

    Anyway the basic point made by Steve Goddard is perfectly correct.

  421. Andrew W says:

    Steve Goddard said “If 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees.”

    Yep, but others have commented, replace all of the GH gases with non GH gases and the surface temperature would plummet to that of a black body.

    When we talk about the runaway GH effect on Venus we’re also talking about the process that created the atmosphere that that planet now has.

    The CO2 now in the Venusian atmosphere came from the O in H2O and the C baked out of the planets surface by the temperature that resulted from the GH effect of the water vapour that, further from the sun, would have been a Venusian ocean.

  422. Stephen Wilde says:

    Andrew W
    May 8, 2010 at 2:22 pm

    “Steve Goddard said “If 90% of the CO2 in Venus atmosphere was replaced by Nitrogen, it would change temperatures there by only a few tens of degrees.”

    I’d guess he is right. So much of the density of the Venusian atmosphere is comprised of other gunk such as sulphuric acid clouds that removing 90% of the CO2 wouldn’t make much difference even if you didn’t bother to replace it with anything.

    “The CO2 now in the Venusian atmosphere came from the O in H2O and the C baked out of the planets surface by the temperature that resulted from the GH effect of the water vapour that, further from the sun, would have been a Venusian ocean.”

    Quite so. If Venus had retained water oceans like ours the hydrological cycle would have stripped out all that gunk and the density of the atmosphere would have been far lower with a much reduced Venusian temperature.

    In other words we have nothing to fear until our oceans boil dry and perversely the AGW crowd say the oceans will get bigger !!

    Go figure.

  423. CRS, Dr.P.H. says:

    Andrew W, no less than King of the Warmists, NASA Scientist James Hansen, promotes the “Earth will turn into Venus” concept!

    Here’s a 2008 presentation paper: http://www.mediafire.com/?trm9gnmznde

    Page 22 of 39, Dr. Hansen says:

    “The Venus syndrome is the greatest threat to the planet, to humanity’s continued existence.”

    Good enough for ya? What is this guy THINKING??

  424. Andrew W says:

    CRS, Dr.P.H.

    So you can’t name a “serious scientist” making such a claim, Pearson certainly does not claim Earth faces a Venus type runaway GH effect, just that some insights might be gained by studying Venus, and a Ph.D in Industrial and Business Studies doesn’t even make him a scientist.

  425. michael hammer says:

    Steven at 6 am

    you stated
    “I understand what you are saying. My point is that the reason CO2 saturates the infrared spectrum on Venus is because of the high pressure. Without the high pressure, it wouldn’t happen.”

    Steven, one of the problems with the warmists is that they have become ideologically committed to a theory to the point that they cannot let go even in the face of very significant contrary evidence. Please don’t make the same mistake. Your comment above distorts what several people have been saying on this blog, me included. The reason CO2 saturates the infra red spectrum is because there is such a huge amount of it in the atmosphere of Venus. The pressure is a consequence of the amount of CO2 present. If Venus had the same pressure but it was all due to nitrogen rather than CO2 the temperature would be far lower. If it was mainly due to nitrogen with a trace of CO2 it would also be lower.

    I agree that a dense deep atmosphere predisposes to higher surface temperatures as you claim but you are going further and claiming that this is the entire, or at least the principle, reason for the very high surface temperature on Venus. The reality is that GHG effect from CO2 is a major factor. The massively broadened absorption bands of CO2 block radiation to space which means the surface can only lose heat through convection/conduction and that requires a more or less constant temperature
    gradient as others have pointed out. However, don’t lose sight of the fact that the energy has to be lost by conduction/convection because of the massive greenhouse effect from CO2.

    If Earth had to rely totally on conduction/convection in order to lose energy even with our current atmospheric pressure, the temperature on Earth would be very significantly higher. It is not because a large portion of the energy is lost by direct radiation to space in the atmospheric window. Having said that, any comparison between Earth and Venus is pointless because to bring about a Venus type situation you would have to convert essntially all the oxygen on the planet to CO2 and we would all be dead from lack of oxygen. Such a situation could not come about by any conceivable level of burning of fossil fuels so the comparison is irrelevant.

    Robert Hafer at 12:55 “Supercritical CO2 is neither a liquid nor a gas. It’s a separate state of matter.” Sorry Robert but this is rubbish. supercritical CO2 is simply a liquid like any other liquid. Pressure temperature phase transition diagrams were a strighforward part of 1st year uni chemistry at least when I did it. What you may not realise is that the same situation exists in all refrigerators and air conditioners. The gas is not CO2 because the transitions occur at incoveniently high pressures. Instead they use hydro fluro chlorocarbons(HFC’s) (used to use freon before the greenies). This is compressed until it liquifies. When it does so the latent heat of condensation is released and disposed of to the environment via a radiator and fan. The liquid is then pumped into the room, the pressure allowed to drop at which time the liquid evaporate again. As it evaporates it absorbs the latent heat of evaporation which of course extracts heat from the room cooling it. The gas then returns to the compressor and the cycle repeats. You can do exactly the same thing with water if you pick the pressure and temperature regime accordingly. At low enough pressure the boiling point of water can fall so low that it is below 0C and water can transition straight from ice to water vapour missing the liquid phase. It called sublimation and by the way it occurs in all frost free freezers not because the pressure is so low but because the water vapour pressure is so low.

  426. CRS, Dr.P.H. says:

    Andrew W says:
    May 8, 2010 at 2:38 pm
    CRS, Dr.P.H.

    So you can’t name a “serious scientist” making such a claim, Pearson certainly does not claim Earth faces a Venus type runaway GH effect, just that some insights might be gained by studying Venus, and a Ph.D in Industrial and Business Studies doesn’t even make him a scientist.
    —–
    REPLY: Download and read Hansen’s paper.
    Queen takes pawn, checkmate.

    http://www.mediafire.com/?trm9gnmznde

  427. Andrew W says:

    Good point CRS, Dr.P.H.
    I’d point out that Hansen is talking about burning all the coal on the planet to lift CO2 concentrations to ~ 4000ppm. That’s not going to happen.

    Hansen also once used geometric progression to argue that a sea level rise way above the IPCC forecasts was possible, on another forum I said that he was using a “bloody stupid” argument, as he is in this case.

  428. Stephen Wilde says:

    Michael Hammer said:

    “If Venus had the same pressure but it was all due to nitrogen rather than CO2 the temperature would be far lower. If it was mainly due to nitrogen with a trace of CO2 it would also be lower.”

    Is that right ?

    Surely the temperature in a Nitrogen atmosphere with the same number of molecules as the CO2 atmosphere would have both a lower pressure AND a lower temperature because the mass of Nitrogen molecules is so much less than the mass of CO2 molecules ?

    To get the same pressure from a Nitrogen atmosphere you would need a vastly greater quantity of Nitrogen and if you achieved the same pressure by such means then you would get the same temperature too.

  429. Bob_FJ says:

    Stevengoddard & ALL: Here is an authoritative extract from the ESA, (my bold), so let’s examine it, particularly as to why Venus has a uniform average temperature everywhere. (over117 earth days, and see link below)

    “…[1] On Venus there are no day and night variations of the surface temperature. The heat is globally ‘trapped’ under the carbon-dioxide atmosphere, with pressure 90 times higher than on Earth.
    [2] Instead, the main temperature variation is due to topography. Just like on Earth, mountain tops are colder, whereas the lowlands are warmer. The ‘only’ difference is that on Venus ‘cold’ means 447º Celsius, while ‘warm’ means 477º Celsius. Such high temperatures are caused by the strongest greenhouse effect found in the Solar System…”

    [1a] When facing the sun, she is said to receive at the surface about 10% of sunlight. Whether this is a midday or total facing area average, or the effects of scattering, I don’t know, but whatever, the surface receives SOME solar energy. This energy amount must be lost back to space because the planet is apparently in thermal equilibrium. The fundamental process for this should be convection and conduction. Additionally, since infrared photography etc of the surface has been accomplished there is at least one window for some infrared to directly escape to space.

    [1b] At nightime she no longer receives any solar energy, but has capability to lose heat in the same way as on the daylight side, over a period 117 times longer than on Earth. What is more, because the upper atmosphere is no longer heated by solar infrared, (~40% of sunlight), the temperature gradient of the atmosphere should increase, inferring increased conductive/convective cooling. Yet, there is no change in surface temperature! Such a condition would require an impossible perfect insulation layer, and no geothermal energy, but clearly, this is not the case.

    [2] This part of the extract supports Steven’s hypothesis, but see also my comment above concerning the strange and unexplained dynamics of the atmosphere, according to the ESA. (that may have an astonishing “mixing” effect).

  430. Bob_FJ says:

    In my post of a few minutes ago, I forgot to ask if anyone still believes that the high surface temperature is the consequence of a greenhouse effect, despite the authoritative assertions of NASA and ESA etc?

  431. CRS, Dr.P.H. says:

    Andrew W, Hansen actually goes quite far and extrapolates to burning all coal, and then tar sands etc.

    p. 24/39: Hansen says “In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect. If we also burn the tar sands and tar shale (a.k.a. oil shale), I think it is a dead certainty. ”

    He’s quite extreme in his position on “runaway” GH effect, perhaps because he studied the atmosphere of Venus at the beginning of his career.

    Ya know, we wouldn’t be in such a position if the Democrats/greens hadn’t kept killing off nuclear power! Clinton admin killed the amazing, inherently safe sodium-cooled “fast” reactor design from Argonne Labs, and Obama admin put the final nail into the coffin by shuttering Yucca Mountain forever. Not many fuel choices left.

  432. ianpp says:

    First of all I am just a simple construction worker that has read all the comments on this issue.
    Now I am more confussed. so I have some questions?
    If CO2 blocks IR why is the surface so warm but the upper atmostshere cooler? (where is the hot spot)
    Why is it a bit warmer on the darkside of Venus. Night lasts 50+days? (even a super CO2 blanket can’t make it warmer)
    Shouldn’t we be comparing the heat content, not the temp. I rather put my hand into dry air at 100c than water at 100c.
    Thanks Ian
    NLBMN – UHK
    (No Letters Behind My Name -University of Hard Knocks)

  433. Robert Hafer says:

    michael hammer
    A supercritical fluid is not “a liquid like any other”. Please see http://en.wikipedia.org/wiki/Supercritical_fluid
    for a brief background. A supercritical fluid occurs past where the liquid/gas phase boundary ends. It has some gas properties, some of liquid and some unique. It will not conform to the Ideal Gas Law but it will compress, in most cases.

  434. They threw Venus probes data out!


    Another black mark in science

    Velikovsky’s Comet Venus
    http://thunderbolts.info/tpod/2010/arch10/100312cometvenus.htm

  435. George E. Smith says:

    http://www.templeforkflyrods.com/products/conventional.html

    “”” Pamela Gray says:
    May 6, 2010 at 6:57 pm
    No, no, no!!! I’m not talking about a lure spinner. I am taking about the rod. A baitcasting rod has a trigger on it (a place for parts of your hand so you can use other parts to slow down the line as you land that fat worm just where you want it). A spinning rod doesn’t have this thorn like feature under the rod. But most baitcasting rods are made for bass fishing (a fat heavy fish) and are usually made for 8+ pound test weight (think log size girthy rod, not twig size skinny rod). I want an ultralight baitcasting rod (twig size skinny and flexible) with the trigger and I want it to be short (less than 7 ft), not the usual length for such a rod. I want to use 4 to 8 lb test. Any baitcasting rod I have found is too long and too telephone pole stiff for trout.

    See???? I am hyperventilating again!!!!! Come on you guys!! You’re GUYS! You should know this stuff!!!! “””

    Pamela dear, hyperventilating Redheads are something else; ain’t they !

    So check out the link to TFO above; as in Temple Fork Outfitters. I’ll bet they have exactly the rod you are looking for. They are an all America Texas outfit of very nice folks. All their rods are designed in America, and built exclusively for them in South Korea.
    Go to that link and check customer service, so you can e-mail them. Ask for either Jim Shulin, or Rick Pope who is the President; and tell them that I sent you there; and I bet they can take care of your needs; so you can quit that hyperventilating.

    My son happened to buy the very first TFO rod ever sold on the West Coast; and we have been using almost nothing else since.

    Lifetime guarantee; if you break it they will replace it, for just the shipping cost. I’ve got more of them than I know what to do with; and the only one I have ever broken, I blew up in my back yard by hanging 14 pounds of salmon trolling balls on it while it was sitting up on an A-frame ladder. Well you wouldn’t be doing that with your trout rod; but they make good affordable stuff.
    Don’t forget to tell them I sent you, so they’ll know to take care of you.
    And no I don’t get anything out of it, besides contemplating you hyperventilating.
    George

  436. Jon-Anders Grannes says:

    What is happening here?

    My 2 last comments have been removed?

    For what reason?

    And what makes this a scientific site?

  437. Gail Combs says:

    Jon-Anders Grannes says:
    May 12, 2010 at 9:12 am

    What is happening here?

    My 2 last comments have been removed?
    _______________________________________________________________
    Both your other comments are there. This blog gets a lot of comments on several articles so there is a lag time. Please remember the moderators are all volunteers not paid employees.

  438. Joey Joe Joe Jr. Shabedeaux says:

    You know where else the pressure is extremely high? The bottom of the ocean. Hey, it even receives next to no sunlight, just like Venus’ surface! I bet it’s extremely hot down there!

  439. Adam R. says:

    @Jonas N says:
    May 6, 2010 at 11:56 am
    … if correct and reasonalble, it baffles me that noone else has noted this before …

    As well it should.

    This simply cannot be! Other people must have hade similar thoughts and estimates.

    Bingo.

  440. jay says:

    Ben Schumacher

    “As far as I can see, the ONLY way to explain this is that the atmosphere of Venus strongly absorbs IR. ”

    The problem with your interpretation is this: IF the clouds are absorbing all this energy where is it going? The clouds themselves would radiate and become part of the radiating surface, shedding a huge amount of energy back into space because the clouds themselves are not behind a green house layer.

    Basically you cannot have an average surface temperature (in this case clouds are a portion of the ‘surface) MORE than the black body temperature. Hot surface temps, EVEN AT NIGHT simply don’t make sense without another energy source.

    The pressure argument here is irrelevant, though. Pressure does not cause heat (compressing uncompressed gas concentrates heat, which is eventually shed).

  441. Bob_FJ says:

    jay Reur May 13, 2010 at 9:45 am

    The pressure argument here is irrelevant, though. Pressure does not cause heat (compressing uncompressed gas concentrates heat, which is eventually shed).

    But with bottom heating, (very hot surface), convection takes place and there is constantly descending gas, which is recompressed

    Joey Joe Joe Jr. Shabedeaux Reur May 12, 2010 at 10:00 am

    You know where else the pressure is extremely high? The bottom of the ocean. Hey, it even receives next to no sunlight, just like Venus’ surface! I bet it’s extremely hot down there!

    Water is incompressible, unlike a gas.
    Try it out with the bicycle pump analogy.

  442. Robert Pavlis says:

    The usual IR absorption model of CO2 to explain a hot Venus is, like many other explanations, overly simplistic. Although Venus has an high albedo, most of the solar radiation that is absorbed certainly is by the Venusian atmosphere, thus the upper atmosphere above the subsolar point MUST BE WARMER than farther away where CO2 without anything above it is radiating into space. This causes increased scale height above the subsolar point, and will result in a general flow in the upper atmosphere away from this area, and gases will rise from the lower atmosphere as a result. Away from the subsolar point where the scale height is much lower, upper atmosphere components must descend, and undergo adiabatic compression, heating them according to the adiabatic gas equations. p1v1**gamma=p2v**gamma. This will heat the descending air like the compression phase in a diesel engine.

    Radiative transfer is very slow with all the CO2, and thermal inertia from the huge mass of atmosphere keeps surface temperatures fairly constant even through the very very long Venusian night. It is not true that temperatures are constant on the surface, by the way, though the variation is slight.

  443. Bob_FJ says:

    Robert Pavlis Reur May 16, 2010 at 5:52 am

    Radiative transfer is very slow with all the CO2, and thermal inertia from the huge mass of atmosphere keeps surface temperatures fairly constant even through the very very long Venusian night. It is not true that temperatures are constant on the surface, by the way, though the variation is slight.

    Yes, but there are some small windows allowing direct radiation to space, and conduction-convection-advection is arguably probably the greatest HEAT transfer process from the surface. Also, although the atmospheric mass near the surface, (as distinct from weight), is ~102 times greater than Earth, the sidereal nighttime is ~122 times longer than earth

    Concerning your other comments on airflow; has it been observed that way?

    You may also find the following of relevance:

    The unexpected temperature profile of Venus’s atmosphere
    http://www.esa.int/SPECIALS/Venus_Express/SEM5A373R8F_0.html#subhead3
    New map hints at Venus’ wet, volcanic past
    http://asimov.esrin.esa.int/SPECIALS/Venus_Express/SEMUQCLXOWF_1.html
    EXTRACT: The map [of the southern hemisphere] is centred at the South Pole. The measured temperatures range from 442°C (or 715K), red to 422°C (or 695K) blue; higher temperatures correspond to lower altitudes, while lower temperature correspond to higher altitudes.

    However, I have great difficulty in accepting the ESA claim that there is no variation in average T. See my comment on the other Venus thread:
    http://wattsupwiththat.com/2010/05/08/venus-envy/#comment-389606

  444. nick c says:

    From the article:
    “So why is Venus hot? Because it has an extremely high atmospheric pressure. The atmospheric pressure on Venus is 92X greater than earth.”

    Your refutation of the runaway greenhouse is excellent. But you have failed to explain the heat of Venus. The pressure explanation does not stand up to scrutiny. If that were the case the deep oceans of Earth should be warmer than the surface. A better explanation is that Venus is not in thermal equilibrium. It is emitting heat from the interior of the planet. That is, Venus is cooling having a recent history, being a new member of the solar system. This hypothesis should be testable, if it is so, then Venus’ temperature should be measurably decreasing as observations continue.

    Nick

  445. omnologos says:

    Nick – didn’t know that the ocean would behave like a gas. Some big discovery you’ve made!

    ps Venus doesn’t have to be a “new member of the solar system”. All it needs is a catastrophe big enough to melt its surface, tilt its axis and remove huge quantities of angular momentum, around 500 million years ago

  446. Much later than everyone else.. a new article on Science of Doom:
    Venusian Mysteries

  447. Enneagram says:
    May 6, 2010 at 12:33 pm

    What the hell happened at 12.5 kilometers? Each probe went haywire as it passed through a height of about 12 kilometers, or 7.5 miles, above the surface. The temperature and pressure sensors sent back crazy numbers, power surged throughout the probes, and some instruments stopped functioning entirely.” The NASA report found that “the sensors that failed at almost the same time were made of different materials and their electronics were isolated from each other.” Furthermore, some of the strange readings “can best be explained if the probe became covered with a plasma of charged particles.”
    http://www.thunderbolts.info/tpod/2005/arch05/050207electrifiedvenus.htm

    Each of our probes were nice and round with no sharp points sticking out of them.
    This allowed them to become charged with static electricity with no way to bleed the charge off. I figure that at 12 .5 kilometers from the planet’s surface the potential difference between the charged probes and the surface became great enough for a lightning bolt to jump between the probes and the surface. Kerzot!

    The Russian landers, by contrast, had all the gadgets in the world hanging off them with plenty of places for corona discharges to occur. They probably hissed all the way to the surface.

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