Goddard’s Folly

As many of you are already aware, Steve Goddard contributed a post to WUWT about the planet Venus. The theme was that the extreme temperatures on our neighbor planet aren’t due to the greenhouse effect, but due to the extremely high pressure of the Venusian atmosphere. He followed it up with another post in order to add “a few ideas which should make the concepts clear to almost everybody.”


I’ll leave that to others to dissect Goddard’s arguments. But I couldn’t resist the temptation to highlight a statement Goddard makes early in his 2nd post:


If there were no Sun (or other external energy source) atmospheric temperature would approach absolute zero. As a result there would be almost no atmospheric pressure on any planet -> PV = nRT.

Yes, folks, this is how well Goddard understands atmospheric behavior. His posts say a lot about the level of scientific understanding of Watts and his contributors.

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382 responses to “Goddard’s Folly

  1. So what is the atmospheric pressure when all the components of the atmosphere are condensed and frozen on the planet’s surface?

  2. At least he didn’t claim that Venus was hot because of a massive collision a billion years ago or because of internal heating…..

    • Brian, Goddard himself may not have claimed that, but check out some of the commenters:

      Louis Hissink says:
      May 6, 2010 at 3:11 pm
      Velikovsky’s deduction seems correct, Venus is hot because it was recently formed. [...]
      This statement will cause hyperventilation among the mainstream geological types as well as the astronomers, but that’s science.

      kuhnkat says:
      May 6, 2010 at 3:32 pm
      Venus is hot because it is either younger than the consensus claims, or had a relatively recent catastrophic impact.

      kuhnkat says:
      May 7, 2010 at 8:30 pm
      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.

      • J – I know that there are people out there who think like Hissink and kuhnkat (I had one visit my blog and make this claim), but dang.

        The math necessary to debunk this isn’t even hard to find – it took me an hour or so to dig up the equations, and most of that was figuring out the right search terms for Professor Google. The calculations took maybe 10 minutes. Maybe.

  3. arch stanton

    I guess I missed class the day they taught the formula that makes mass temperature dependent…

    Is that part of special relativity?

  4. So he’s saying Jupiter is hotter than Venus?

  5. I think my comment about Goddard’s post in the “Open Thread” here was the first one to bring news of the latest Watts/Goddard debacle to the outside world.

    It’s fascinating to scan through the comment thread there and see how many people are convinced by Goddard’s deeply confused ideas.

    For the life of me I can’t understand why somebody more intelligent on the skeptic side doesn’t warn Watts that it’s not just his own blog’s reputation that suffers every time he posts one of these howlers. It really makes the whole “skeptic” blogosphere look stupid.

  6. Could be pretty substantial for hydrogen and helium. The main point, of course, is that he’s not applying PV = nRT correctly. DP: If you think this is about phase transitions, why use PV = nRT?

  7. Goddard’s argument is obviously silly but it’s educational to try to understand why. Trying to puzzle this out, I think his fundamental error is to assume that (in the absence of condensation/evaporation) the dry lapse rate of the gas will always control the environmental (i.e., actual) lapse rate when in reality this will happen only in the case where there is convection present.

    The environmental lapse rate can be anything so long as it’s less than the dry lapse rate as then the atmosphere is stable – there’s no convection. When there’s no convection there will also be little conduction so radiation is the primary mover of energy up or down through the atmosphere and therefore any greenhouse effects are very important.

    This is something which has been in the back of my mind to ask for a while: is this the reason why on Earth the troposphere is convective but the stratosphere is not?

    • Gavin's Pussycat

      Yes. The heat cannot escape radiatively from the ground, so it is transported upward convectively, establishing the adiabatic gradient. At the tropopause, radiation can escape to space and temperature stops dropping (higher up it starts rising again, due to ozone etc.)

    • Ed,

      I think you’ve got that a bit mixed up. The lapse rate is smaller on Venus, Earth and Mars than the dry adiabatic lapse rate because there is convection going on, due to there being condensible substances in the atmosphere (on Earth, water).

      • Indeed, condensation is important in Earth’s atmosphere. I suspect it’s less important on Mars and have no idea for Venus. However, that’s beside the main point: the contrast between the lapse rate resulting from temperature change with expansion and compression of the convected atmosphere (whether wet or dry) and the lapse rate resulting from absorption and radiation of long-wave radiation.

  8. He’s assuming volume would stay constant which I’m sure is absolutely what would happen.

  9. I’m really confused by his argument.

    Doesn’t it break any grey/blackbody laws? After all, radiation is proportional to T^4, right? So if the pressure causes the heating, then the gas would radiate more.

    If there were no greenhouse gases, the heat would escape and the atmosphere would cool. In terms of his argument, both V and T would decrease.

  10. Ed – yes, the tropopause (boundary between troposphere and stratosphere) is the key point that relates greenhouse gas concentrations to the atmospheric temperature profile. As long as you have enough input sunlight and GHG’s in your atmosphere to cause a non-convective temperature gradient greater than the (humid or dry) adiabatic lapse rate, convective instabilities force the gradient to be reduced to that lapse rate. That holds true throughout the lower atmosphere (while the sun shines), but as pressure and GHG concentrations decrease with altitude it ceases to be true at the tropopause. And that is also roughly forced to be the point at which incoming and outgoing radiation are in balance (as convective heat flow through the tropopause is close to zero). So tropopause temperature is roughly fixed by incoming solar energy, and it is that height of the tropopause above the surface that determines the “thickness” of the atmosphere and therefore the degree to which surface temperatures are increased by the lapse rate.

    What Goddard fails to recognize is that the very definition of atmospheric “thickness” he relies on for his argument is one dependent on GHG concentrations. Fewer GHG’s, even with the exact same mass of atmosphere, means a lower tropopause and cooler surface.

  11. If there were no Sun (or other external energy source) atmospheric temperature would approach absolute zero. As a result there would be almost no atmospheric pressure on any planet -> PV = nRT.

    This is not so much wrong (which it is), but is a misstatement and confusion of term. Take a comet, for example. At the outermost part of its orbit, when it is extremely distant from the sun, it has no “atmosphere” because the gasses and water vapor etc. are frozen solid. So by definition, it cannot have “atmospheric pressure” or “atmospheric temperature” — there is no atmosphere. Everything is frozen solid.

    Planets or moons, of sufficient size, can have independent internal energy sources. First is the heat retained in the core or mantle from formation, coupled with the heat from ongoing natural radioactive decay in the rocks of the mantle and core, and lastly tidal forces, for example, on Jupiter’s moon Io.

    The massive and widespread volcanism on Io is believed due to tidal forces exerted from Jupiter’s gravity, coupled with internal heat from natural radioactivity. The heat energy contribution from solar radiation on Io is negligible as compared to tidal forces, which one can see by the extremely “dead” and inactive surface of Ganymede, which solely due to its size, gets a lot more sunlight than does Io, and should theoretically be “warmer.”

    • Patrick 027

      The ignoring of non-solar heating, while an error, is not really the ‘big error’ here – Unless emission is limited to relatively long wavelengths, there is significant nonlinearity, such that a flux that can be ignored when equilibrium T absent a greenhouse effect is 255 can become important at much lower temperatures. The approximation of zero geothermal and tidal heating is at least for Earth and I’d guess all the inner planets is a rather good approximation for a range of temperatures; it fails for sufficiently low temperatures; for some purposes we might not really be interested in the most realistic version of what happens at such low temperatures, but just on what changes in solar heating would do.

      (The big error of course is that p (pressure) is approximately conserved if atmospheric mass is conserved, provided that most of that mass is within a short vertical distance relative to planetary radius.)

      The size of a planet does not, in a direct way, affect equilibrium temperature (absent geothermal and tidal heating). A larger area both absorbs more solar radiation and emits more radiation. The exception would be that if a planet is not very large compared to the thickness of the atmosphere, significantly different surface areas could be involved in absorbing and emitting radiation at different frequencies – but this tends to be a very minor effect when most of the mass of the atmosphere is within a relatively thin layer).

      • Patrick 027

        … I should add that I am unaware of any such case where the differences between the effective planetary radius that absorbs solar radiation is so different from the effective planetary radius that emits radiation to space that it would be considered of first order importance. It usually isn’t even brought up as an issue so far as I know.

  12. Of all of Goddard’s arguments, his argumentum ad cannabis is undoubtedly the most convincing:

    Global warmers have been hyperventilating over CO2 on Venus, ever since Carl Sagan made popular the idea of a runaway greenhouse effect….Sagan said that marijuana helped him write some of his books.

    Horatio has read a couple books by Sagan — “The Demon Haunted World” and “The Dragons of Eden” — which were actually quite good. Sagan even got a Pulitzer for “Dragons”.

    Maybe Goddard should try it…

  13. “If there were no Sun (or other external energy source) atmospheric temperature would approach absolute zero.” Yeah whatever…. Jupiter radiates a lot more energy than it receives from the sun….

  14. dws: I think he’s making the point that if any of the terms nRT falls to zero, PV necessarily falls to zero. I think that whole direction (a sunless sky) was a pointless distraction.

    [Response: Please buy a clue. The point he was trying to make is that atmospheric pressure and temperature are proportional in planetary atmospheres because of the ideal gas law. This is truly folly, dependent on a nonexistent constant-volume condition.

    Atmospheric pressure is determined by the mass of the atmosphere and the gravity of the planet. There's no shame in being ignorant of that, but much shame in being so stupid and arrogant as to flaunt such astounding ignorance to deny climate science. But hey -- that's what Watts & Co do.]

    • Frank Ch. Eigler

      “Atmospheric pressure is determined by the mass of the atmosphere and the gravity of the planet.”

      Are you saying it’s independent of temperature?

      • Yes, that’s what he’s saying and to a very good approximation he is right.

        Increasing the temperature causes a tiny reduction in the pressure because the gas expands upwards so that more of it is further away from the centre of the planet and is therefore slightly less attracted in the gravitational field (and there’s a tiny change in the part of the weight providing a centripetal force to follow the planet’s rotation, if any). Other than those effects, the weight and, as a result, the pressure stay the same.

        In PV = nRT, increasing T increases V, not P.

      • Atmospheric pressure P isn’t a single number, is it? Isn’t it generally a function of altitude above sea level? I agree P(0) will be constant regardless of T, because the weight of the entire atmosphere is nearly constant. But won’t P(z) fall as T falls for any positive z?

      • Patrick 027

        (Re Steve):

        You could alternatively consider P(your symbol here), being P as a function of the amount of atmospheric mass remaining above. That would be approximately conserved. Different vertical coordinates besides geometric height (geopotential, pressure, potential temperature, ‘sigma’, even optical thickness itself) can be quite convenient for some purposes in atmospheric science.

  15. The pressure only “causes” heating in the sense that it boosts the power of the greenhouse effect.

    But of course that means he can claim it’s due to pressure without being technically wrong.

    He gave a figure for the scenario of 90% of the co2 being replaced with nitrogen. He didn’t given a figure for 100% of he greenhouse gases being replaced with nitrogen.

    What he’s done is made it very hard to understand exactly what he’s claiming, but the implication is strong enough to mislead the readers.

    Because he implied it and didn’t say it directly he can dodge the awkward challenges.

    Funny that.

  16. It would also seem academic, by Mr. Goddard’s hypothesis, that the temperature of Earth should rapidly decrease as one goes from its surface toward its center, away from the heating effects of solar radiation. This would mean, of course, that volcanoes spew ice cubes.

  17. Ray Ladbury

    The phrase “so bad it’s not even wrong” comes to mind.

  18. Ray Ladbury

    Goddard et al. remind me of nothing so much as the premeds taking the algebra-based physics class, who get every last bit of physics wrong on the exam, but then claim they should get partial credit for remembering to write down F=ma in a thermo problem or for using some Greek letters.

    It’s like they don’t understand that there really is a right answer.

  19. Venus is hot because she knows a good surgeon.

  20. It’s like they don’t understand that there really is a right answer.

    Thanks, Ray.

    As an undergrad, I had immense trouble with calculus, unlike algebra, because I never really “got it” in the sense that I understood the underlying intent and mechanism. Taking a calculus prelim was all memory and throwing equational darts at a dartboard and hoping for the best. It’s not like you can “argue” on behalf of an incorrect answer in basic physics. It’s not like saying you have an alternate theory as to why Ahab hunted the whale in Moby Dick.

    • Prelim! I haven’t heard that term since my days on the hill. Now if I can just get over this sudden anxiety attack/flashback over past calculus and physics prelims. Biology was just so much more fun.

      Somebody, somewhere wondered why Watts posts nonsense that undermine the credibility of his blog. I think that credibility isn’t the goal – the goal is for WUWT to be the “alternative” viewpoint. It doesn’t have to be right, it just has to show that it is open to new and revolutionary ideas. Oh, and to sow FUD.

      That’s where scientists always have a disadvantage – they have to be right all the time. The opposition throws hand grenades – they just have to be close enough. Their aim isn’t the truth, it’s to do damage.

  21. This reminds me of a common mistake my students make when weather forecasting. They will write that higher pressure makes it a warmer day and lower pressure makes it a cooler day.

    I tell them all the time that in simplest terms, air pressure measures the weight of the air above regardless of its temperature. I have them repeat:

    “A 5 pound brick taken out of the freezer weighs the same as a 5 lb brick taken out of the oven.”

    My Global Warming Blog
    Twitter: AGW_Prof
    “Global Warming Fact of the Day” Facebook Group

  22. So why aren’t y’all trying to shine some light in the comment-sphere at WUWT? At least a few people there are trying to learn something and are susceptible to scientific argument (even if Steve isn’t).

    • Ray Ladbury

      jbar,
      WUWT is not an environment conducive to logic, science or knowledge. Those seeking any of the above should avoid WUWT like the plague. We don’t know for sure that stupid is not contagious.

      • Horatio Algeranon

        “We don’t know for sure that stupid is not contagious.”

        …why so many scientists, engineers and mathematicians (including Tamino) use LaTeX.

    • I spent much time over there when I first began blogging but my time appeared to be wasted. (And posters here told me I would be wasting my time.)

      My time is better served posting at places such as this one where people are trying to learn.

      Joel Shore is my hero, BTW, for staying there and trying to make sense.

      • And Watts has banned Joel Shore now, as of the end of April.

      • Arthur – do you have a source for that? Joel has a couple of posts from May 7 in the original Venus thread.

      • Ah, good, perhaps it was just temporary. Still it shows how Watts keeps people like Joel “in line”:

        http://wattsupwiththat.com/2010/04/23/new-book-from-dr-roy-spencer/

        “REPLY: With Joel’s “so called skeptics” comment, maybe it is time for him to hit the road. Frankly I’m getting tired of him, and when he says things like that, it displays his contempt. I really don’t care for people visiting my home on the Internet that have contempt for me and the people who frequent here. If you want to engage in contempt, there’s plenty of other places for that.”

      • Thanks, Arthur. I always thought Joel was very restrained, and in that thread was certainly better behaved than his opponents.

      • Ray Ladbury

        You know, that man (micro-Watts) isn’t smart enough to get a role as a village idiot. He’d have to play the idiot’s sidekick.

        It’s a failure of our educational system. He managed to get a high school diploma without learning the most important lesson–that he’s an idiot.

  23. Douglas Watts:

    temperature+pressure increases towards core on Jupiter. The main difference is that it’s mostly light hydrogen and some helium so you need to go deeper to see higher temperatures, also it doesn’t have any real surface to begin with and that makes a huge difference.

    • Will the temperature increase with depth in Jupiter’s atmosphere continue once the (currently quite significant) emissions from the core disappear? I think it will not; the atmosphere will become isothermal.

    • Thanks for clearing that up. Gas giant planetary geology is kind of weird.

  24. Brian Anders

    jbar, Watts tends to ban people who point out flaws in his or his guests’ posts.

    He also has a somewhat creepy history of harassing commenters he doesn’t like. (E.g., looking up the email address of anonymous commenters, googling them, then referring to them by their real names….)

    • Brian Anders

      By “Watts” obviously I mean Anthony, not Douglas!

    • Watts does much more than just cyberstalk. When a poster really gets under his skin, he will try to inflict as much real-world damage as he can. Trust me.

      • You know, I’m not sure I would blame attacks on Anthony Watts specifically (though he may condone them). I think there’s a large machine at his disposal that takes on these tasks.

  25. jbar:

    So why aren’t y’all trying to shine some light in the comment-sphere at WUWT? At least a few people there are trying to learn something and are susceptible to scientific argument (even if Steve isn’t).

    I suppose it could have something to do with the fact that many if not most of us are banned there.

    • Bingo. I tried some very cordial posts at WUWT since whenever someone pointed me there to support a point, I would look for a refutation (usually Joel Shore, sometimes Phil., some others out there), but some “glitch” prevents my posts from going to moderation.

    • Nick Stokes

      I post critical comments there. And although I often get annoyed responses from Anthony, I’ve never had anything fail to appear.

      • I am banned from WUWT.

        I annoyed Anthony by asking him when he was going to get around to the followup articles he promised, after his infamous “the baselines are different” posts.

        He not only banned me, he then systematically went back and removed every post I had ever made over there – about a year’s worth.

      • I think my sin was to point out Tamino’s challenge. Watts doesn’t like to be shown to be wrong.

        Just checked – last post started, “So the change in the number of stations in the GHCN does not result in a warming trend after all. It seems that the Watts/D’Aleo/Smith claim below does not hold water…”[followed by Watts claim]

        After reading about Lee’s experience and my own experience on “American Thinker” I’ve saved copies of posts I’ve made at denial sites.

      • carrot eater

        If it matters much to you, then you can just archive the entire web page, to save what’s there or not there.

  26. t_p_hamilton

    jbar asks:”So why aren’t y’all trying to shine some light in the comment-sphere at WUWT? At least a few people there are trying to learn something and are susceptible to scientific argument (even if Steve isn’t).”

    Because they edit out critical responses. Please post this remark: “The fact that the atmospheric pressure is the same in the Sahara desert in midsummer and the Antarctic in midwinter is the same shows that surface temperature is not proportional to pressure.” Let us know how many diogeneses see the truth.

    • [quote]
      Because they edit out critical responses. Please post this remark: “The fact that the atmospheric pressure is the same in the Sahara desert in midsummer and the Antarctic in midwinter is the same shows that surface temperature is not proportional to pressure.” Let us know how many diogeneses see the truth.
      [/quote]

      But but but!!!!!

      The antarctic MUST have a higher pressure because it’s at the BOTTOM of the earth! And we all KNOW that things at the bottom are under greater pressure! Just look at the water behind the Hoover dam!!!

      Therefore it’s not perporshunal… its INVERSELY perporshunal!!!

      • The antarctic MUST have a higher pressure because it’s at the BOTTOM of the earth!

        Naw, you’re forgetting all of the CO2 that’s not in the atmosphere down there because it’s all precipitated out in those massive CO2 blizzards Goddard’s mentioned earlier.

    • I posted your remark on wattsupwiththat, and it was accepted. You can see it here. I did not warn them in advance, it was a genuine test of their openness to criticism and they seem to have passed. See:

      http://wattsupwiththat.com/2010/05/08/venus-envy/#comment-391102

  27. jbar, why on earth would any sane rational person waste time in that snake pit of pseudoscience and quakery?

    And what on earth would make you think it is a place to learn about reality, much less science?

    • Exactly. I know that Joel Shore and Nick Stokes do post there and try to inject some rationality and science but it’s futile IMO. St. Anthony’s disciples are immune to rational argument and the concept of evidence (IOW they are anything but genuinely sceptical), not to mention ignorant and incompetent.

      Casual visitors might get the impression that dissenters (from Watts’s agenda) are allowed free speech and that their small contribution shows how weak their case is. Those visitors are unaware how much those contributions are censored, both by the mods and by the dissenters themselves, who know that they must be “polite” above all else or they will be banned.

      I wonder if the net effect of Joel’s and Nick’s comments is actually negative? Has even one AGW “sceptic” been persuaded by them?

      • Ray Ladbury

        Now remind me again, what purpose does it serve to be nice to stupid?

      • TrueSceptic

        Agreed: you are allowed to do little else if you post at Watts (or McFraudit or AirHead).

        Watts used to stick to attempting to undermine the stats and the data; now he seems to host the sort of ASS craziness you used to see only in the Marohasy Bog (strangely, Jennifer didn’t censor anyone much).

  28. Lol, the pressure of the Venesian atmosphere at the surface is about 100 that of Earth…I think Goddard skipped the physics101 chapter explaining that the ideal gas law fails at such pressures.

  29. > So why aren’t y’all trying to shine some light
    > in the comment-sphere at WUWT?

    I have a friend who goes fishing only in mud puddles. No matter what bait I offer, or what tackle I provide, or how much I teach him about casting and placing it, he catches nothing good.

    Do you think I should invite him down to the lake where people catch good fish all the time?

  30. The key to this is IMHO is the response to 14. If I were to look at an upper air plot (skew-t) with stratospheric cooling it would give the impression that the atmosphere is compressing therefore increasing pressure.But if I read this right it means the atmosphere expands but pressure remains the same. Which suggest the trop gets higher.

  31. caerbannog

    OK you smarty-pants pee-atche-dees, this should learn ya something the Ideal Gas Law.

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

    The average sea level pressure is around 1013 mbar. If you live at a higher altitude the
    pressure will be less. Your barometer at 100 m above sea level will read about 12 mbar less.
    Pressure is a direct measurement of how much atmospheric mass there is above your head per
    square meter. The ideal gas law can be written PV = RT where P is the pressure (Pascal), V is
    the volume (m3), R is the gas constant (Joule/K) and T is the average temperature (over some
    days). Let us now calculate the temperature in a 1 m3 volume at any height. Hence T = P/R, T is proportional to P and P is known from observation to decrease with increasing altitude. It follows that the average T has to decrease with altitude.

    By setting both n and V to 1, we can force the density of an ideal gas to be independent of pressure. This lets us model the atmosphere as an incompressible ideal gas, which greatly simplifies the calculation of the lapse rate. Too bad none of you guys were smart enough to think of this!

  32. Paul from VA

    Hydrostatic equilibrium is more important than temperature. Hydrostatic equilibrium is the condition where the gravitational force of the layers above the current layer is equal to the pressure force of the current layer.

    The simplest calculation to do to get the sea level pressure on a planet is to assume that the bottom layer of atmosphere must support the weight of the rest of the atmosphere above it.

    Mass of earth’s atmosphere=5.1352*10^18 kg. Gravitational acceleration ~ 9.8 m/s^2 (assume constant throughout the atmosphere aka a thin atmosphere assumption)
    Force (weight of atm)= ma =5.03*10^19 kg*m/s^2

    Pressure = F/A
    Surface Area of a sphere = 4*pi*radius^2
    Radius of Earth= 6.378×10^6 m
    Pressure from my first order calculation = 9.8*10^4 Pa
    Actual pressure = 1.01*10^5 Pa

    Notice how temperature didn’t play into that calculation at all? Temperature affects the structure of the atmosphere (and possibly its total mass if you deal with messy stuff like condensation and evaporation), but to first order approximation, sea level pressure is determined solely by the planet’s radius, total mass, and atmospheric mass.

    • Paul from VA

      Okay, so I thought about this after I went home and thought about how one would then calculate the temperature of the atmosphere. It is completely independent of the surface pressure.

      Some of you probably know this already, but I’m just posting this to keep my stellar atmospheres fresh in my mind.

      So when you do an atmosphere, you have to start with a boundary condition. That’s what the above calculation does. For temperature, you have to start with a guess. For instance, one could guess an isothermal atmosphere with a temperature determined by blackbody. From the isothermal atmosphere one then determine the density and pressure profile of the atmosphere, since the density profile gets you the weight of each layer.

      That’s the simple way of doing it. To do it in all its full-blown glory, one start’s with the above calculation, and then does full radiative transfer. I.e. how much radiation is transferred between layers. What is radiated down from the sun versus what gets radiated up from the surface versus what gets radiated back down via the greenhouse effect. This is a hideous, iterative process involving partial differential equations which requires a semester long graduate course, not a comment box on a blog.

      Ironically enough, the ideal gas law is still used in that model atmosphere (and it doesn’t break down at venusian pressures), but temperature is used to determine the density, not the other way around. (although doing the radiative transfer (which depends on temperature) can change the temperature of various layers which then changes the density of the atmosphere).

  33. Wow. I’m just a first year pre-engineering major, so most of this stuff goes right over my head, but in this case I am able to follow along why Goddard is wrong.

    It’s kind of wierd how he is defending his post so rigourously in the comments. He is just digging a hole.

    • Ray Ladbury

      DnDAdict,
      Glad you are enjoying the show. Take it as a cautionary tale. Make sure you become educated and not just trained. Many professionals–be they physicists, engineers, programmers or whatever–seem to think their studies have prepared them to master complicated material at a mere glance. Learn enough about everything to realize the limits of what you know. Do that, and you’ll be a damned good engineer.

    • TrueSceptic

      Sometimes we don’t need to know an awful lot to know that an argument is just plain stupid.

      If temperature is proportional to pressure, we should all buy a few footballs and inflate them really hard. Just distribute them around the house and you have free heating for ever! For cool summer days, a few balloons should suffice. For hot water, just use filled oxygen tanks placed in your hot water system.

      (The balls, just like car/bike tyres, warm as you inflate them but that represents the energy you have put into compressing the air. The heat quickly dissipates and the ball/tyre settles at ambient temperature despite remaining above ambient pressure.)

      I’m sure someone will correct me if I’ve got this all wrong.

      • Well, if you go to the WUWT post–mind you, I’m not recommending it–you see that Goddard does talk about an ongoing process of compression, which makes it a better mystification than the static picture you describe by analogy.

        Of course in the real Venusian atmosphere, there’s also an ongoing process of expansion, which would be associated with cooling.

        As t_p hamilton pointed out on RC, it’s not as if the Venusian atmosphere as a whole were compressing, which I think we can all agree really would produce warming.

  34. Marion Delgado

    I think I see the fundamental error you’re all making – you’re leaving out the firmament!

    Like a giant clear dome around the city of Kandor, or a big pressure cooker, the firmament keeps the volume of the atmosphere from expanding.

    And the solar system is warming because of alterations in the luminiferous ether as the Sun passes through the arm of the spiral galaxy.

  35. For those of you that have seen Greenmans videos, don’t forget to vote for it.

  36. Ray Ladbury

    Increasingly, it is getting harder and harder to reject the obvious explanation for the data: These people are just flat stupid. It’s not just a lack of intelligence, but rather the sort of blinkered, pig-ignorance that can only afflict the ideologue. They are ignorant and proud…and they vote!

  37. Was there a typo in the OP title? Reads like Goddard’s Foolly.

  38. John Mason

    Cracking thread and some of the comments have had me chortling!

    I used to look into WUWT occasionally but it wasn’t doing my blood pressure much good so I quickly abandoned the practice!

  39. caerbannog

    Ray Ladbury wrote,

    They are ignorant and proud…and they vote!

    Dunno if you have seen this yet, but it certainly qualifies as a data-point in support of your thesis.

    http://pandasthumb.org/archives/2010/05/wow-just-wow-al.html

    • Ray Ladbury

      Yup, saw it. Astounding. These people simply do not live in an evidence-based world. They disdain evidence–viewing it only as a challenge to their faith.

      These people do more to damage the credibility of religion than any since the crusades. I suppose if I had any kids, I’d be really upset as to the sort of world I’m leaving them. As it is, I guess it’s just time to stock on gold, land and guns and wait for the crash.

    • The most depressing thing about that is the response of the candidate who was under attack; he apparently called the video a smear, and insisted that he is, in fact, a creationist.

  40. Chris Colose has a very well-written comment about this at his blog:

    http://chriscolose.wordpress.com/2010/05/12/goddards-world/

  41. Candidate for dumbest post in Goddard’s thread …

    I really don’t see why Mr Goddard’s ideas should be so controversial except, of course, because they question the doctrines of the AGW true believers.

    As I explained to my grandchildren just the other day, hairdryers, like Chinooks [winds, described in the snippet I cut], work on adiabatic principles, with the fan compressing and thereby heating the air, rather like the atmosphere of Venus.

    Oof. He’s never looked inside and saw the heating coils that consume most of the 1000W+ watts the hair dryer requires for operation?

    His poor grandchildren.

    He, Goddard, and a bunch of other people over there ought to learn from Carl Sagan’s example and start smoking pot.

  42. Want to know what the surface of Venus is like?

    Don’t rely on the couple of pictures Watts has posted — without attribution or explanation.

    Here are the originals, with explanations of the work done to get the colors right, and spectra taken during the descent and on the ground:
    http://www.mentallandscape.com/C_CatalogVenus.htm

    As he says, the text color there is close to the color of the light from the sky observed by the landers. It’s not the “yellow” Watts claims by referring mistakenly to the combined color filter results from the lander imagery.

    Dang, people who don’t cite sources sure mess up attempts to understand how science works.

  43. David B. Benson

    Steve // May 12, 2010 at 7:28 pm — The stratosphere is stratified, weatherless. There the pressure decreases with altitude and at the same time the temperature rises. To a first approximation, the same is true of lakes and oceans.

  44. Phil Scadden

    “…why so many scientists, engineers and mathematicians (including Tamino) use LaTeX.”

    Hey you owe me for coffee through my keyboard Horatio.

  45. Watching the Deniers

    Wow, Goddard is just like the creationists. In order to dismiss evolution, you need to dismiss the age of the earth and universe (waving away geology); in order to dismiss an old earth, you need to dismiss the age of the universe (and wave away the big bang and cosmology); in order to dismiss cosmology, you need to wave away physics

    What you end up with Russian doll of “denial”. In order to support your anti-scientific position, all science must be wrong. Each argument is nested within another dismissal of scientific theories.

  46. Check out Lubos. He says Goddard is basically correct!

  47. A foot in mouth might be more appropriate than a rather comical massive goalpost shift…

    1. Goddard last week: This is very close to what we see on Venus. The high temperatures there can be almost completely explained by atmospheric pressure – not composition.

    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.

    2. Goddard more recently: “The whole point of these articles is to demonstrate that Earth could not become like Venus, unless all the limestones dissociated. ”

    —–

    Well I guess there’s nothing to worry about.

  48. Ray Ladbury

    You know, all the lunacy going on over at “the best science blog” has me wondering. Should mainstream professional science organizations–e.g. APS, ACS, AGU, etc. maybe start to assess the job various blogs do at presenting science. Maybe it’s time for awards to blogs that actually mean something. There’s huge variability in quality–everything from the abysmal (WUWT, AIG), the mendacious (CO2″Science”, Climate Fraudit), the Deluded (Spencer’s blog) and all the way to the excellent (this effort, RC, Rabett Run, this place…). There should be some consequence for spouting utter bullshit, as well as a positive consequence for trying to get it frigging right.

  49. Kevin Stanley

    Ray, I agree. On the other hand, I suspect the people who would care what mainstream professional science organizations think are already paying attention to the blogs that try to get it frigging right, and the devotees of the utter bullshit blogs would see endorsement by APS, ACS, AGU, etc. as (further) evidence that the conspiracy has taken over these entities.

    • I don’t know. I’d probably refer to such certifications if they were available.

      I wouldn’t expect it to convert any denialists, but my conviction is that you have to play to the “neutral” readers/lurkers–maybe even the odd (true) skeptic.

  50. Ray Ladbury

    Carroteater, Camel and Kevin,
    The imprimatur of professional societies still carries a modicum of weight, and while the delusionists would see a snub by these organizations as a badge of honor, our elected officials might be more reluctant to rely on sources that did not have such an imprimatur.

    As it stands now, blog users choose who gets the awards–which leads to absurdities like Watts-up-’is-arse being named best science blog. These guys actually think they are doing science, and that there are mainstream scientists who support them. They need to be informed of how absolutely looney they are.

    BTW, Motl has responded to Chris Colose’s post with more drivel of his own. Did Motl ever take any real physics courses at Hahvahd?

  51. D Johnson // May 13, 2010 at 2:58 am | Reply

    Check out Lubos. He says Goddard is basically correct!

    Well that’s an endorsement one could well do without!
    I suppose one needs to be a string theorist to come up with the concept of a ‘nonlinear diatomic’ molecule? For some reason he thinks that CO2 and N2 have the same molar specific heat! He also neglects vibrational modes which is fine at room temperature but not at 760K on Venus (particularly for CO2). He has a tendency to jump in to areas where he has no expertise and make elementary mistakes (see above) and a ad hominem style that makes it not hard to see why he’s no longer at Harvard!

    “Recall that monatomic, spherically symmetric ideal gases have “C_V=3/2 R” (from three “linear” degrees of freedom) and “C_p=5/2 R”: the difference “C_p-C_V” can be shown to be equal to one “R” quite universally, from the first law of thermodynamics. However, complicated molecules such as CO2, N2, or N2O have three degrees of freedom for the momentum and two extra degrees of freedom for rotations (because they’re still linear, i.e. symmetric around an axis; otherwise they would have three rotational ones). That increases “C_p” to “7/2 R” for CO2 and N2.

    Fine. So CO2 and N2, treated as ideal gases, have the same molar heat. It’s probably a coincidence because Goddard apparently hasn’t paid any attention to the difference between monatomic, diatomic linear, and diatomic nonlinear gases. If he replaced CO2 by helium, it wouldn’t work. ;-)”

  52. WTF is proving the old saw that if you keep your mind completely open, people will use it as a place to dump their trash.

    It’s kind of sad, though, that they seem to have attracted so many poe/Sokal fake posts–WTF is no longer–if it ever was–a good indicator of the actual level of science incomprehension in the target audience.

    It’s become a demonstration site for how easily that audience can be fooled intentionally by fantasies. That’s the kind of information needed for the disinformation marketers, of course.

    If you can fool a majority of the voters at the midterm elections, who needs science to make your short term profits, after all?

  53. Synchronicity–got to love it.

    Just heard finance self-help guy Dave Ramsay say this:

    “Stupid has a gravitational pull.”

  54. He also does not understand the difference between time scales (weather-climate) and regional-global. Wonder whether he knows the diffence between 2D (sea ice extent) and 3D (volume).

    http://friendsofginandtonic.org/

  55. gallopingcamel

    On Earth the measured adiabatic lapse rate varies in the range 5 to 10 degrees Kelvin/km altitude. While the theoretical (dry) lapse rate is 9.7 K/km the lower numbers measured are due to the presence of variable amounts of water vapour in the troposphere.

    Turning to Venus the theoretical (dry) lapse rate is 10.5 K/km whereas the measured rate is ~7 K/km. It appears that the vapour causing the lower lapse rate is sulphuric acid as water vapour is in short supply.

    Commendably, you folks prefer peer reviewed literature so check out Soden and Held, 2000. (http://www.gfdl.noaa.gov/bibliography/related_files/annrev00.pdf)

  56. gallopingcamel // May 14, 2010 at 1:51 am | Reply

    On Earth the measured adiabatic lapse rate varies in the range 5 to 10 degrees Kelvin/km altitude. While the theoretical (dry) lapse rate is 9.7 K/km the lower numbers measured are due to the presence of variable amounts of water vapour in the troposphere.

    Turning to Venus the theoretical (dry) lapse rate is 10.5 K/km whereas the measured rate is ~7 K/km. It appears that the vapour causing the lower lapse rate is sulphuric acid as water vapour is in short supply.

    According to my calculations the lapse rate on Venus near the surface will be 7.75 (8.9/1.148 @ 750K).

  57. Julian Braggins

    Doesn’t this analysis of Polar Tropospheric temperatures and pressure support the mainly dynamic relationship between temperature and pressure?

    http://journals.ametsoc.org/doi/full/10.1175/1520-0442%282001%29014%3C3117%3ATTITPR%3E2.0.CO%3B2

    [Response: It in no way supports Goddard's truly idiotic theory.]

  58. In response to 57. It is highly possible I am wrong but what I got out of that link was the opposite. Which is the temp effected the pressure. And of course is regional and had to do with seasons.

    • Well, my unsophisticated take was that Mr. Goddard decided in advance which variable was to be “independent”–the old shell game by which one “proves” one’s postulates (metaphorically dressing them up in fake mustache and funny glasses first.)

      (Division by zero, suitably disguised, can be a great “fake mustache”–hence Tamino’s simile.)

  59. Lubos now says that “everyone was right”.

    And since he and Steve Goddard had at least two radically different versions, I guess they were doubly right.

  60. Gavin's Pussycat

    It’s kind of sad, though, that they seem to have attracted so
    many poe/Sokal fake posts-WTF is no longer-if it ever was-a good
    indicator of the actual level of science incomprehension in the
    target audience.

    Hank, you have a funny taste in things to feel bad about…

  61. GP, it’s helpful to have an undistorted sample — somewhere — of the level of comprehension in the population that we’re trying to help educate.
    http://people-press.org/report/46/the-tough-job-of-communicating-with-voters
    I do feel sad about failures to educate, anywhere, anytime.

    “Stevenson was approached by an enthusiastic woman supporter who said to him, ‘Governor, every thinking person will be voting for you.’ Stevenson replied, ‘Madam, that is not enough. I need a majority.’ http://pawprints.kashalinka.com/anecdotes/stevenson.shtml

    When a lot of convincing poes and sokals dilute the real measure, that site becomes just a circus and attracts an increasing audience and more clowns. Then we need a new site that’s being posted to in the main by honest people who really don’t understand the problem, to see where to start talking to them.

    It’s possible the faux comments there will eventually cross some threshold of outrageousness and even the passionate believers will recognize it and start asking themselves whether wanting it to be true is reason to believe it. It’s possible. Maybe.

    Just sayin’.

    I have the same concern about the reflex attacks on new people even when they come in with recognizable stuff right off the denial talking point list. Some of them are honestly in need of information even though their politics/bias/snark shows prominently. We’re seeing more older academics show up for example, who if protected from the anklebiters may come off their skeptical opening take and start reading, but if chased away by the yapdogs “on our side” are not going to take the time to think about it.

    • TrueSceptic

      It’s possible the faux comments there will eventually cross some threshold of outrageousness and even the passionate believers will recognize it and start asking themselves whether wanting it to be true is reason to believe it. It’s possible. Maybe.

      Don’t bet on it. There have been some people posting on climate-related blogs/forums for years who can’t possibly be for real, yet they are, and none of their fellow “sceptics” ever complain about them or tell them how much they are undermining the “sceptic” cause by sheer wacko absurdity.

  62. A Hank Roberts:

    “It is impossible to tell for certain the difference between genuine stupidity and a parody of stupidity.”
    —The General Case of Poe’s Law.
    “if it is impossible to tell whether something is being parodied or taken seriously, then that something is genuinely stupid.”
    —Krohn’s Corollary.”

    http://tiny.cc/20puz

    Nobody can distinguish between parody and sincere posts on WUWT , so I think Krohn’s Corollary applies.

    I don’t see how the WUWT moderators can solve this. You can filter signal from noise but not ambient random noise from added random noise. Unless you have a sense of humour, that is.

  63. Oh, I agree. But I remember Stevenson. We need a majority.

  64. My favourite line attributed to Stevenson goes something like: “If you stop telling lies about us, we’ll stop telling the truth about you.”

  65. Andy S,

    I think that was Truman.

  66. Cross-posted from RC: April NCDC numbers out; it was another record-warm month.

    http://www.ncdc.noaa.gov/sotc/?report=global&year=2010&month=4&submitted=Get+Report

    • Timothy Chase

      According to NASA GISS land and sea the last twelve months have been the warmest twelve in the instrumental record.

      Calculations here:

      NASA GISS land and sea
      http://spreadsheets.google.com/ccc?key=0Au57vongYoiAdEQwRWdLT0lRWjFhNGY3NnpKb1J1d0E&hl=en

      However this is still something of a statistical tie with ten other twelve month periods: those ending in October through December of 2005 (61.58, 61.42, 62.17), May through October of 2007 (61.33, 61.17, 62.08, 61.67, 61.25 and 60.83) and the twelve month period ending in March of 2010 (63.58).

      Please see:

      Our estimated error (2σ, 95% confidence) in comparing nearby years, such as 1998 and 2005, increases from 0.05°C in recent years to 0.1°C at the beginning of the 20th century.”

      GISS Surface Temperature Analysis
      Global Temperature Trends: 2005 Summation
      http://data.giss.nasa.gov/gistemp/2005/

      Each of these twelve month periods is within 0.05°C of the global average for May 2009 through April 2010.

      NOAA has yet to break the record it set in September 1997 through August 1998 — but I expect it to in two to four months. Hadley CRU land and sea? My guess is that it won’t happen this year.

  67. I go to WUWT to watch the spectacle of someone utterly ignorant and even less intelligent make a fool of himself and apparently be totally unaware of the fact… the blog equivalent of “car crash” TV.

    Even among the stiff competition at WUWT Goddard must get the award for “person most wrong most often” along with “person least aware of the boundless limits of their own ignorance”.

    The only physics I know is “O Level” standard (UK exam at 16 , now defunct). But even with my tiny brain and even more limited knowledge the idea that static high atmospheric pressure is enough to heat the atmosphere is clearly total and utter bullocks.

    I am waiting for his posts on a perpetual motion machine and cold fusion. Should be a laugh!

  68. “I have been thinking that I would make a proposition to my Republican friends … that if they will stop telling lies about the Democrats, we will stop telling the truth about them.”
    – Adlai E. Stevenson
    http://thinkexist.com/quotes/adlai_e._stevenson/

  69. TLM,

    you might enjoy this bit of news about the Venus Climate Orbiter… static… well not exactly. Maybe he’ll pull the next one where CD’s also get hot due friction with the air they touch ;P

    • Doug Bostrom

      I’m full of admiration for the Japanese space program (Hayabusa!) but somehow it’s annoying to me whenVenus gets a dedicated climate orbiter while back on Earth we have a dearth of orbital instrumentation suitable for general purpose climate observations. As far as I know, the only culture on Venus consists of a handful of long-cooked Russian landers.

      • Ray Ladbury

        Doug,
        This essay by Tom Bodett from the Bush era explains all:

        http://www.bodett.com/storyarchive/homeplanet.htm

        However, Global Precipitation Monitor (GPM) and ICESAT 2 are on the way, along with an OCO replacement. Some hope. At least the antennae are starting to point in the right direction again.

      • Andrew Dodds

        Doug -

        You are forgetting the Venusian VGW-Skeptics who will happily tell you that the surface of Venus is a perfectly balmy, tropical paradise, and not to listen to those alarmist types who say that their planet ‘experienced runaway global warming several billion years ago’. Admittedly it’s a bit hard to talk to people who live in heavily airconditioned bunkers several kilometers underground and refuse ever to come out..

  70. Okay, looks like I got that wrong (Truman v Stevenson). My apologies.

  71. Ray, that Tom Bodett piece is worth it!

  72. Doug Bostrom

    Ray, thanks for the pointer.

    Cultivating ignorance is ok if one does it in private, as a personal matter. Imposing ignorance on other folks is just plain rude and of course Bush was nothing if not imposing in the rudest sense of the word.

  73. Thanks for the replies, guys. As you can see by my late acknowledgement, my time is too limited.

    I appreciate Nick and Joel trying to fight the fight. I think I may try too, just not as much as them.

    I did learn something from the Venus discussion, and I too became confused about the lapse rate issue a year ago. However this time I at least convinced myself that Venus’s temp profile is set primarily by the IR opacity rather than by the lapse rate.

    I may yet give up as many of you have on debating “skeptics”. I had some hard-core crazy email acquaintances I used to debate with and most of them I don’t communicate with any more. “Hope springs eternal.”

  74. Ray Ladbury

    jbar,
    If there were any actual skeptics to debate, I’d be more than happy to do it. What I see runs the gamut scientifically illiterate ideologues to nut-job conspiracy theorists. I’m not even sure that having them on our side would be helpful.

  75. jbar, my take is that there is strong reason to counter nonsense in a basically neutral forum, as that’s where undecided people may be reached.

    On other fora, this may not apply since you’re preaching either to or against the choir–so any argumentation must be justified on other counts than the pragmatic. (Amusement, auto-pedagogy, debating challenge, need to feel superior–any number of essentially personal reasons.)

    • TrueSceptic

      Can you name any “basically neutral” forums? The only one I can think of is JREF.

      • Media websites. I hang out a CBC.CA a lot; there’s a bunch of denialist propagandizing, which I make it my business to counter. (Not alone, I hasten to add!)

    • I think there are a couple of blogs where there are regular commentators in denial – I am thinking of Chris Mooney’s blog, the Intersection, and the problems James Hrynyshyn had in his former blog, The Island of Doubt (although he seems to have tighter control of his renamed blog, Class M).

      Might be good places to advance real science.

  76. I try to at least counter bad information _attributed_to_scientists_ when it’s handwaving without citation to a source. I don’t get as irate when it’s attributed so the next reader along can look it up. Sometimes it’s still wrong — it may be a paraphrase, or a short quote out of context — and that irks me and I’ll often say something.

    But when I see people posting some belief that’s not supported by the evidence, attributed vaguely to good scientists but without citing the paper so most readers won’t be able to even know for sure where it came from or check it, that really bugs me.

    I know, being a cite-checker is as bad in ordinary conversation as being a grammarian. If it weren’t about the science and things weren’t changing so fast in bad directions, I wouldn’t care.

    And most of the people throwing crap into conversations don’t care, and don’t think there could be a problem. So they’ll say anything to interrupt and confuse attempts to teach the science and walk off whistling thinking ‘heckuva good job’ of themselves.

    “Changing baselines.” You can look it up.

    • This is true, Hank.

      However, I view each rebunking as an opportunity to present correct information (properly cited, and hopefully more compelling as a result!)

      ;-)

  77. Sagan under the influence of marijuana out thinks the WUWT crew most of the time, maybe all of the time.

    • Said what, BPL? The way comments display on the site, I couldn’t figure out what you were referring to. (Or, “to which you were referring,” if you prefer.)

  78. arch stanton

    Often attributed to him, but he was actually quoting Homer Simpson – I think it was in the same episode where Lisa invents a perpetual motion machine and Homer chastises her with “In this house we obey the laws of thermodynamics!”

  79. ROFLMAO! Sorry I missed that one…

  80. Goddard has a new WTFUWT article on Arctic ice melt. Remember, we’ve just seen the fastest 8 weeks or so of ice melt ever observed in the Arctic. Given that, Goddard’s article contains some truly stunning statements. Here are excerpts:

    “The Arctic is still running well below freezing, and as a result there just isn’t much happening”

    “The little melt which has occurred since the winter peak has been at lower latitudes, as can be seen in red in the modified NSIDC map below.”

    “Melt is proceeding very slowly.”

    “We are still about six weeks away from anything interesting happening in the Arctic. Stay tuned.”


    And then, he deposits this gem in the comments:

    ” stevengoddard says:
    May 23, 2010 at 2:05 pm

    Low concentration ice in the Arctic Basin is due to shear stresses on the ice. Temperatures are still too cold for any significant melt to be happening.”

  81. I hate to be the pedant, but got a citation for the fastest 8 weeks of ice melt? It’s escaped my notice (I’m Googling now), and I’d sure appreciate a solid source on that.

  82. The info can be found here:

    ftp://sidads.colorado.edu/DATASETS/NOAA/G02135

    While I have not checked to see whether it is the fastest eight weeks of all (the data only goes monthly, not weekly) it is certainly the fastest April to May melt on record, and there is still a week to go.

    • Thanks, David. Yes, I left out the critical qualifier ‘fastest ever for this time period.’

      According to NSIDC, 15% ice extent was just below the 1979-2000 average, going into the last week of April, and the denialosphere was trumpeting the return to ‘normal.’

      Now, a month later, 15% ice extent is below the same-date extents from 2007, and has been for closet to a week. That is ~ 2 standard deviation drop in less than a month – and Goddard claims that nothing much is happening.

  83. And obviously it cannot be the fastest eight weeks of all time: the July to August melt is pretty much always higher (one exception, although that could change as there is still a week to go) and the June to July melt is higher around half the time.

    But in any case it has still been a fast-melting time, faster than every May to June period, let alone every April to May period.

  84. Jay Pettitt

    I’ve got a soft spot for Goddard. He’s got his theories, looks stuff up, develops conclusions and publishes his ideas amongst his peer group. It’s tantalisingly close to not being an idiot.

  85. Philippe Chantreau

    Jay, you’re kidding right?

    Goddard has his “theories”, which ignore or run counter to existing science that has been verified over and over again for years. He looks stuff up, except the stuff that does not support his “theory”, like a phase diagram in the case of the CO2 snow. He develops conclusions that are not supported by any real evidence or even logical reasoning. Then throws the all pile of nonsense on a web site where he’s guaranteed a warm reception regardless how nonsensical his “theories” are, just because he says what everybody there wants to hear.

    Tantalizingly close, but no cigar.

    Pretty sad that such a large portion of the population can be fooled by the nonsense on WUWT just because it is made to look and sound “scientistical.”

    That’s where the real problem is: how can there be so many ready to believe that carbonic snow falls on Antarctica or that a hair dryer heats air by compression.

    • On the other hand …

      “publishes his ideas amongst his peer group. ”

      Is right on, you must admit!

  86. Philippe Chantreau

    OK, I missed the ice thing, so it is more obvious now that you were kidding, sorry for the rant. The denial about sea ice is pretty remarkable though. I’m still not regretting the time not spent on WUWT.

  87. I’m an “aspiring” computer scientist with about a year and a half left in my studies. I’m just starting to get into more advanced mathematics. I’m also an amateur astronomer. I just want to learn more and do not purport to know more than I really do. Hopefully I won’t embarrass myself. If I do, please forgive me! LOL!

    It seems that some are saying that pressure doesn’t have much to do with temperature. Am I wrong? When you compress a gas does it not release heat as a result? I just compared the estimated mass of Venus’ atmosphere to earth’s atmospheric mass.

    Total mass of Venus’ atmosphere: ~4.8 x 10^20 kg
    Total mass of Earth’s atmosphere: ~5.3 × 10^18 kg

    WOW! It appears that the mass of Venus’ atmosphere is some 474,000,000 Gigtons greater than the earth’s! Of course, we know that the atmospheric pressure at the surface of Venus is some 92x that of earth. I remember when the Galileo probe plunged into Jupiter’s atmosphere in 1995. The probe sent back data for about 58 minutes before the probe was destroyed. The last temperature reading from the probe was around 300 degrees F, I believe. How do you account for increase in temperature if not for the increased pressure? Just curious.

    • TrueSceptic

      See my comment.

      Just think about it. What would the world be like if pressure produced heat indefinitely?

    • Ray Ladbury

      Brent,
      Jupiter also generates a good portion of its own heat due to very slow gravitational collapse. In the case of the Sun, gravitational collapse could not explain the energy being radiated. This was and still is an argument used by creationists for a young Earth (albeit older than 6000 years).

      There is a story about the time when Hans Bethe as a graduate student was working on stellar nucleosynthesis as the energy source driving the stars. One evening, after he had gained confidence that the approach would work, he was strolling with his fiance, who remarked on how brightly the stars were shining. “Yes,” Bethe mused, “and I’m the only one who understands why they shine.”

      • Ray,
        Well, I can assure you that I believe the earth is certainly older than 6,000 years!

        I wouldn’t assume that external gravitational forces alone would account for the nuclear fusion process of the sun!

        Are you saying that you can get more energy out of the system than you’re putting into it? I know your patent will be denied if you make that claim. Maybe I’m misunderstanding you.

      • Ray Ladbury

        Brent, what I am saying is that stellar nucleosynthesis is essential to explain the energy coming out of stars, but that this was not known until the 1930s. Sorry for any confusion.

        Jupiter OTOH does derive a lot of energy internally.

      • Ray,
        No problem! I appreciate the knowledge, and it’s a very good point. I will look into it further.

    • Kevin McKinney,
      I find it “interesting” that you would link me to a rather lengthy article in support of global warming. I’m focusing on the fantastic atmospheric pressure at the surface of Venus and its effect–or lack thereof–on tropospheric temperature right now. Nor will I engage in ad hominem attacks against Goddard because he happened to forward a hypothesis that may or may not have merit within the scientific community. I find such exchanges “unhelpful.”

      I do have a contrary view regarding the often disputed Milankovitch Cycle correlation with the 100,000 year cycle of glaciation inferred in the article link you provided. There is not a convincing correlation between the 100,000 year orbital perturbation described by Milankovitch when you look at temperature alone; but, if you look at the forcing by the time rate of change in temperature; you get a beautiful correlation. Sometimes it helps to look at the obvious.

      You know what is interesting about C02 at 93 atm? It becomes a super-critical fluid!
      http://en.wikipedia.org/wiki/Supercritical_fluid

      [Response: I hope you find the insights you seek.

      I also hope it doesn't take you long to realize that Goddard's idea really is nonsense. It's not just wrong, it's ridiculous -- meaning, worthy of ridicule. It betrays an utter lack of understanding.

      This is far from the first time he's postulated truly ludicrous "theories" and grossly incompetent analysis in order to dispute man-made global warming. He has a track record; that why he attracts such ridicule.]

      • TrueSceptic

        Goddard is a dishonest incompetent who continually denies established physics (and maths, and logic).

        Why on earth would anyone take him seriously?

        If you have some great insight into the ice ages, please make it public. There are several frequencies of Milankovitch cycles and they don’t all tie in with what we know of the ice ages.

      • Brent, I’m sorry you took that link amiss. I make no secret of advocating for the mainstream view of climate science, or the fact that I see AGW as the defining crisis of our age.

        However, I pointed you to that link in good faith as an interesting article surveying the relevant science as it appeared to Ekholm back in 1901–and particularly the knots Ekholm (and most everybody else at the time) was tied up in, due to the fact that nuclear decay was just becoming known and sustained nuclear reactions had yet to be discovered at all.

        That was what we were talking about, as I recall.

      • So, Brent, do you really think some uneducated denialist twit like Goddard has really overturned a big chunk of extremely well-established physics?

        Do you not understand the examples you’ve been given?

        Since you’re taking a physics class this summer, why not bring this up during lab? Or directly to the instructor, if the summer session class is small enough?

        Even better, videotape it …

        Your post is a bit depressing, after praising you for being willing to listen and learn, you exposed yourself as being more-or-less in denial after all.

      • Phil Scadden

        Brent, you do know that milankovitch cycle correlation with global temperature is about calculating the effect of all cycles on insolation and on the distribution of this incoming energy on the planet? The pseudo-100ka cycle is interesting but I think explanations to be convincing have to make physical sense and some of hypotheses tossed up so far do. Are you developing yours into a physical theory?

      • Oh hmmm is this the same Brent who has been given his own thread at Deltoid (along with the likes of Tim Curtin, El Gordo, and other “illuminaries”).

        If so, this is a waste of time.

        Brent, true or false?

      • TrueSceptic

        Dhogaza,

        Unlikely IMO. Too many differences … unless it’s all an act.

      • dhogaza,
        I’m not agreeing or disagreeing with Goddard’s hypothesis at this point. I think I’ve made that clear. Many factors seem to be at play on Venus to explain the extremely high surface temperature at the surface. My questions are more geared to the actual forces required to create a constant temperature of 740 K at 93 atm. I’m interested in the science; and I have a lot to learn! ;-)

        Dr. Richard Lindzen stated the POSSIBLE Milankovitch correlation with the 100,000 year cycle of glaciation is stronger now than previously thought. I’m specifically referring to the elliptical “elongation” that occurs in the 100,000-year Milankovitch cycle of earth’s orbit around the sun, where perihelion and aphelion would be farther from the sun than normal.

        I realize correlation does not PROVE causality; but it is an interesting correlation!

        Hopefully, I have not “depressed” you too much. Thanks for your earlier compliment by the way. I try to keep an “open mind” when it comes to science.

        [Response: The approximately 100000-year eccentricity cycle does *not* mean that perihelion and aphelion will be farther from the sun. When eccentricity increases, aphelion is further from the sun but perihelion is closer to the sun, while their average remains the same.

        Prior to the "mid-Pleistocene transition" glacial cycles are dominated by the 41000-year obliquity and ~22000-year precessional cycles, with no hint of eccentricity cycles. After the mid-Pleistocene transition (about the last 800,000 years) the effect of obliquity and precession is still present, but in addition there's a very strong change which is *possibly* cyclic (but not surely) with period *about* 100000 years (but not precisely). Whether or not it's related to the eccentricity cycle is a subject of considerable dispute.

        The atmosphere of Venus is a fascinating topic. But Goddard's idea that the surface is so hot because of the pressure, rather than the infrared-absorbing properties of greenhouse gases, is so wrong it betrays his utter lack of understanding. IF you want to advance your understanding, you'll have to accept the reality of that.]

      • Kevin McKinney,
        The article was rather lengthy, so I perused it for the most part. I appreciate your honesty! I’ll give it another read!

      • To: dhogaza
        CC: Phil Scadden; True Sceptic

        Oh hmmm is this the same Brent who has been given his own thread at Deltoid (along with the likes of Tim Curtin, El Gordo, and other “illuminaries”).

        If so, this is a waste of time.

        Brent, true or false?

        Oh hmmm, that would be FALSE–considering I haven’t even completed my “Conceptual Physics Fundamentals” class. I WANT MY OWN THREAD! That would be cool! Although I can wax eloquent at times, only to be utterly humiliated by the likes of a Phil Scadden, who asks did I consider “effect of all cycles on insolation and on the distribution of this incoming energy?”

        OK…Phil…granted…maybe I didn’t consider all of that. You got some points there my friend! I know what you’re all thinking: frickin’ science noobs! I look kinda like Will Ferrell–act like him at times, too. Did that make any sense? :-|

  88. And just when you think Goddard’s denial has hit bottom, he starts cooking graphs, insinuates the Arctic ice melt proceeds in a linear fashion (and thus minimum extent won’t reach 0 square km before 2065, which is way before IPCC projections) and maintains 2007 wasn’t such a big deal. Amazing.

    This has to be pounded for all it’s worth. I’m a total climate science noob, but even I can see how utterly wrong and disingenuous Goddard is. Only the ultra-stupid will fail to see this.

  89. This has to be pounded for all it’s worth. I’m a total climate science noob, but even I can see how utterly wrong and disingenuous Goddard is. Only the ultra-stupid will fail to see this.

    There’s truth in this, since it appears that even the normally-stupid denizens of WUWT are seeing that he’s full of it. But there are enough of the ultra-stupid there to make the thread entertaining.

  90. It seems that some are saying that pressure doesn’t have much to do with temperature. Am I wrong? When you compress a gas does it not release heat as a result?

    And when you’re done adding energy by compressing the gas? Goddard claims that even though you stop adding energy, the compressed gas continues to get more energized. Odd, no?

    If Goddard were right, blowing up a basketball would lead to it continuing to warm after you stopped adding more air, until it finally caught fire …

    How do you account for increase in temperature if not for the increased pressure? Just curious.

    Greenhouse gasses, you may have heard of them.

  91. Ray Ladbury

    Brent,
    Have you taken a first-year physics class? The problem with the pressure argument is that for temperature to increase, one must do work on the gas–e.g compressing it against a pressure.

    But if we do work and there by raise the temperature, we increase the energy radiated by the body as the 4th power of the temperature and temperature will decrease. For a permanent increase in temperature we either have to increase the flux of energy into the body or decrease the energy escaping it. Greenhouse gasses do the latter–and that is what has hapened on Venus. Goddard is an Idjit. As Pauli would say, his argument is so bad it doesn’t even rise to the level of being wrong.

    • Hello Ray,
      It’s funny you mentioned that! I changed my electives and I’m taking “Conceptual Physics Fundamentals” this summer session. I already bought my textbook! I’ll focus on heat transfer and thermodynamics. Yes, I will have to defer to your knowledge on the subject matter. I just find Venus an interesting study in an atmosphere gone wrong.

      I’m just trying to understand the processes at work. You have a constant temperature across the surface of Venus (~860 degrees F). That’s interesting. Doesn’t matter if Venus is in the day-side or the night-side. The albedo of the cloud layer reflects about 65% of the TSI. Of course there’s the super-rotation as well. Lindzen stated that the sulfuric acid clouds can cause an increase in temperature as high as 200 degrees C. I understand that there are many factors at play and not pressure alone.

      • You’re listening, and working to educate yourself in the subject.

        That puts you a good, oh, 100 IQ points above Goddard.

  92. @Brent Allen Parish:

    “It seems that some are saying that pressure doesn’t have much to do with temperature.”

    Correct.

    I have a compressor in the back of my shop. The pressure tank stores compressed air at 400psi.

    If we start with an evacuated tank – we bleed it dry once a week for maintainance – and then fill it, the air being compressed from 1 atm to 400 psi heats up, some of that heat gets transferred to teh tank, and that tank gets damn hot.

    Yes, compressed air heats up AS IT IS BEING COMPRESSED.

    Thing is, we go home for the night, leave the tank pressurized. The heat flows from the air, to the tank, adn then radiates or is conducted away, and the air cools down. By the next morning, that tank of 400psi air is the same temperature as the shop.

    CHANGE in temperatere is a function of CHANGE in pressure, but absolute temperature is independent of absolute pressure.

    Goddard embarrasses himself – hell, he humiliates himself – by failing to understand this simple fact even when it is repeatedly pointed out to him, and then continuing to argue that he knows better than thousands of scientists.

  93. Ray Ladbury

    Goddard’s idiocy does illustrate a very important point–it’s not just energy, but energy flow, the difference between energy_in and energy_out. The micro-Watt denizens do not understand this.

  94. Philippe Chantreau

    It might be worth pointing that the air in the tank heats up while the volume remains constant.

  95. Brent
    Following up on Lee’s observation. How many aerosol containers or other pressurised containers, do you have in your home? How many are hot?

  96. Brent Alan Parish,

    One compression event could indeed heat Venus’s atmosphere significantly. The extra heat would then radiate away into space until radiative equilibrium was reestablished.

    You cannot continuously generate heat from static pressure. If you’re an astronomy student, you must have had enough physics to know the first law of thermodynamics. Goddard’s proposed source of surface heat on Venus is a perpetual motion machine of the first kind.

  97. Sorry, “Allen.” Didn’t mean to misspell your name.

  98. gallopingcamel

    Barton Paul Levenson,
    Anyone who has climbed a mountain knows that temperature falls with altitude. This effect can be quantified by measuring the “adiabatic lapse rate”.

    Planets lose energy through radiation rather than convection or conduction. Once you know the height of the effective radiative layer for a planet you can make a reasonable estimate of temperature at any height below the radiative layer if you know the adiabatic lapse rate.

  99. camel,

    The “adiabatic” lapse rate refers only to the rate in the absence of any condensible substance. On Earth, in the troposphere, you need the “saturated” lapse rate instead (6.5 K/km versus 9.8 adiabatic). Rates are also sub-adiabatic on Venus (7.7 versus 10.4) and Mars (1.8 versus 4.5).

  100. Goddard’s totally outdone himself this time.

    “The Western Snowpack is 137% of normal”

    Take a close look at how he computes that number …

    • Mike Bantom

      WTF is he doing? Besides the fact that individual sites aren’t necessarily the same in terms of snow volume regardless of the total precipitation (which he appears to ignore) how does he get Arizona at 440% of normal?

      • Rattus Norvegicus

        The chart is for water content. But yeah, given the data there this morning how the hell does he get AZ at 440% or normal?!

        Of course Mike, there’s a reason the site is called WTFUWT!

      • Rattus Norvegicus

        Of course I meant to say the the chart includes snow water equivalent. From that it would appear that Arizona is in deep trouble.

        It looks like the melt season there is pretty much over already. Up here in MT there is still a lot of snow in the mountains because of a relatively cool and wet April/May. It pretty much saved the snowpack, because up until then it was looking pretty grim in much of the state (60% – 70%) of normal.

    • OK – I’m still trying to figure out this statement: “Arizona is 446% of normal.” Is this based on the link provided? The one that has the following percentages for AZ (as of 5/26): 120, 71, 117, 118, 106, 103, 115?

      Can someone who has posting privileges there ask?

      • Oops – just saw Mike B’s post. GMTA.

      • I didn’t bother to check his sources but he’s computing his “snowpack” index by summing up the percentages per state, and dividing by the number of states.

        So, for instance, if Rhode Island had 400% snowpack and Alaska 0%, he’d be saying that overall snowpack for the two is 200% of normal.

        No area consideration at all.

        It’s hilarious.

      • I did notice that strange method of calculation. A few people on the thread have pointed out the AZ number, but Goddard doesn’t seem to have noticed. How does anyone not take a credibility hit after these blunders? Oh wait, it’s WUWT.

    • Andrew Hobbs

      Mike B and Deech56.

      Has anyone worked out yet where Watts got the data for his graph. Arizona obviously stands out since SNOTEL gives snowpack water equivalent as being between 25 and 50% of average for this state. But the results given for the other states don’t seem to match any of the data given in the URL for SNOTEL either?
      I have tried various reasonable, unreasonable and utterly stupid ways of analysing the SNOTEL data but it never matches.

      • No offense, but why would you expect it to make sense?

        It sounds like a sarcastic cheap shot, I realize, but seriously, on the rare occasions I venture into WattsWorld, I do feel that “logic and proportion have fallen sloppy dead.”

      • Andrew Hobbs

        Kevin McKinney

        No offense taken since I would agree with you entirely. I certainly don’t expect any of his arguments to make much sense. One reason I rarely visit the site.
        But it does seem a bit strange that a graph is given with simple data that is so apparently and obviously wrong to anyone who simply clicks on the link provided with the graph.
        I assume that Watts thinks his audience is so lazy, that they wouldn’t even bother looking at the link, and/or so brain dead that they couldn’t read the table of figures provided anyway.

      • And the White Knight is talking backwards…

        Andrew, several people have pointed out the Arizona error in that thread, but no explanation is forthcoming. There seems to be some exchange with GeoFlynx (off-line?), but no answer.

      • Agreed.

        Attention to (reasonable) detail is frequently not in evidence, even as obsession with the irrelevant detail is.

  101. We used to have at an aunt who’s toilet was out back in the garden. Whenever it was near full the drainage company was organized to suck the pit empty. In this case it seems all orifices are overflowing. The guy is so clueless, it requires the intelligent design of a new word.

    Per Rutgers, anomalies per May 25, 2010:

    Who’s interested in that garden window view of his?

    April North America

    Early June we learn of the May NA anomaly. Not looking good.

    • Rattus Norvegicus

      If I didn’t know better, I’d say that graph from Rutgers showed a clear declining trend. But Steve Goddard assures me that it is an upward trend, so it must be.

      • Goddardsworld (aka Wattsworld) is reminiscent of the world of Wiley Coyote and the Roadrunner, where physical laws work very differently and Coyote keeps blowing himself up and running off cliffs but never learns.

  102. Philippe Chantreau

    Shame on you guys, you made me look. I was about to count how many commenters were pointing to the inanity of averaging percentages but then I came back to my senses. And that’s the 2008 science blog of the year. Hilarious indeed. Goddard made a short appearance at John Cook’s blog to defend his idea that Arctic sea ice had recovered then left with a blanket insult when nobody would buy it. The guy is just insane.

  103. Hey, this is Steve Goddard. He probably means that CO2 snow (“dry ice”) is at 137% of normal in the western US.

    And he’s right! 137% of 0 is … 0!

  104. luminous beauty

    Something I haven’t seen mentioned, so please correct me if I’m wrong, but wouldn’t the increase in volumetric specific heat capacity at higher pressures actually repress the sensible temperature at Venus’ surface?

    Then there’s the broadening of the vibrational modes of CO2 to consider. Also.

  105. Actually, that post is by Watts, not Goddard, unless I’m missing something. The header says ” Posted on May 25, 2010 by Anthony Watts” and Goddard’s name is nowhere to be found.

    Darn, this ruins my joke about CO2 snow (see above). But it’s another data point that Watts is completely lacking in sense (not to mention basic math concepts).

    • Philippe Chantreau

      Actually, the “Western Snow Pack Update” post clearly says now that it is by Goddard. Last time I looked, 2 comments showed clearly how averaging percentages makes no sense. I could not fine either today. Surprise.

      • Weird, the May 25 post doesn’t have Goddard’s name on it, but the update does.

        I notice that according to Watts/Goddard, in just over two weeks Arizona has gone from “446% of normal” to “9% of normal”. Yikes!

        Philippe, the critical comments about averaging statewide percentages are still there in the May 25 post … just search on the word “averaging”. (Of course, the two or three sane people pointing out this problem are shouted down by a larger number who apparently see no problem averaging state-level snowpack percentages!)

      • Of course, the two or three sane people pointing out this problem are shouted down by a larger number who apparently see no problem averaging state-level snowpack percentages!

        Holy mother of Willard Scott! You’re talking about Arizona.

        “State-level snowpack percentages?” See, the mountains around Tucson won’t have any snowpack at all, because they’re too far south and too low in elevation. The San Francisco Peaks near Flagstaff, the highest points in the state, should have feet-deep snowpack this time of year. When I coached debate at the University of Arizona, we had local Tucson students who had never seen snow. But driving through Flagstaff the previous winter, it was five feet deep. Statewide averages?

        Utah has four distinct climatic zones. Three of them are desert, including the northernmost poke of the Sonoran desert, at an elevation of about 1,500 feet. The fourth is rainforest, in the High Uintah Mountains. “Statewide averages?”

        I was in a meeting once with Warren Buffett. About 50 people in the room. On average, each of us in the room was worth over $1 billion dollars. Didn’t help at bill-paying time. Statewide, of course, our average net worth was only in the tens of millions.

        Sometimes we need to pay attention to the experts. A new Darrell’s Law: Only effing idiots assume that every expert is an effing idiot.

      • Philippe Chantreau

        OK, I checked the Jun6 update. Sorry for the confusion and suggestion of suppressing comments.

      • Ed, the problem with what Watts/Goddard (?) did in the May 25 post is kind of complicated. They took individual basin-level estimates of snowpack (relative to normal) and averaged them (?) to get a state-level figure.

        Then they averaged those state-level figures and claimed that the western states were at 137% of normal snowpack. There was no weighting function, so Arizona and Idaho were counted equally in the average.

        We could probably have a lengthy discussion here about what is the right way to report snowpack data across jurisdictions with very different areas of snowpack … and in fact the “right” way might vary depending on what question you’re trying to answer. But it seems pretty clear that GoddaWatts latched on to an unambiguously wrong way of doing it.

  106. Rattus Norvegicus

    The byline is Watts’. He’s just as bad.

  107. Nice Jefferson Airplane reference there, Kevin!

    Watts is venal, too. I asked a question there yesterday, and contrary to his usual policy he let it through — with an answer that indicates he bothered to check out my ip address first, looking for dirt.

    Politics, no science. Bad politics at that.

    • That was in the CEI thread, right? I saw that creepy reply from Watts. The man has a passive-aggressive streak a mile wide. If you post something he doesn’t like he’ll use your IP address and email address to try to identify you, then make a big show of proving that he’s done it.

      • Watts really doesn’t like it when CEI is criticised or mentioned.

      • Then he shouldn’t quote them. You lie down with the former Tobacco Institute people, you get up smelling like hell. Watts doesn’t know that?

      • Watts does more than that – someday I’ll have to tell of my experience there and Watts’ cyberstalking of me. He can’t stand being shown up, and resorts to below-the-belt juvenile tactics to get “revenge”. He fights dirty. He has the maturity of a 13-year-old boy.

      • Rattus Norvegicus

        J Bowers,

        It seems as if he has made your post disappear. Did you post under you nom de blog?

      • Oh, I didn’t post at all. I’ve seen it happen there, though. It really gets his back up and he can go on about insinuations when the poster wasn’t actually insunuating anything about how he might be connected to CEI in any way.

      • Derecho64 … you should tell that story, though I doubt it would surprise us.

  108. Thanks, Ed. Gotta come ’round here to “feed your head.”

    This item just came out:

    http://www.technologyreview.com/blog/arxiv/25205/

    (Summary: the superrotation of the lower Venusian atmosphere is proposed to be energized by interaction with solar wind, via the (even faster) upper levels. A planet-wide (?) wind roar of ca. 84 dB is predicted.)

    Interesting to me is that the difference between the night and day sides of the planet was stated to be about 200 K.

    How did that not come up in the Goddard discussion–didn’t he claim the difference to be negligible? Or did I miss it?

    I do recall the point being made that the Venusian atmosphere was anything but static–and you can put exclamation points on that statement, I guess.

  109. Did I miss the discussion on ice thickness?

    At Watts’ joint, Goddard now goes on at length about the thickness of Arctic ice. He says, today, that the average thickness has been increasing.

    Help me out here, but if I melt away all the thin ice, and what’s left is thicker on average than the thin ice that melted, haven’t I increased the thickness of the ice, while at the same time reducing the total ice and coverage of the ice dramatically?

    • Robert Murphy

      “Help me out here, but if I melt away all the thin ice, and what’s left is thicker on average than the thin ice that melted, haven’t I increased the thickness of the ice, while at the same time reducing the total ice and coverage of the ice dramatically?”

      Shhhh! You’re not supposed to think so hard. :)

  110. Help me out here

    He’s pixel-counting (without taking into account projection distortion) mapped output from a model the US Navy abandoned about five years ago.

    This technique has allowed him to “prove” that the UW volume calculations, and various satellite-derived extent calculations are all “wrong”.

    • “He’s pixel-counting (without taking into account projection distortion) “

      What a numpty.

    • Rattus Norvegicus

      Oh goody, I caught that one right away. Really there is not point in paying attention to his posts. Well, except for the humor value!

      • carrot eater

        When these guys make predictions, it’s useful to take note of them.

      • Goddard has some new Arctic sea ice predictions, and encourages readers to bookmark the page and check back later.

  111. We could probably have a lengthy discussion here about what is the right way to report snowpack data across jurisdictions with very different areas of snowpack . . .

    Or we could just ask the experts who do this constantly trying to predict the flow of the Green/Colorado River system, and the Snake/Columbia. They have lots of incentive to get the figures right, since billions of dollars of commerce ride on getting it right, and since they’ve been doing it for 80 years or more and have had plenty of time to correct for mistakes they made that they know about.

    The hubris of “skeptics” makes me feel emphysemic the way it takes my breath away. Hundreds of scientists worked for a century to predict snowpack and its effects on western rivers — some clown comes along and “averages” snowpack as if he found the answer that eluded scientists for a century.

    Among other key factors on calculating snowpack is the density of the snow. There is special instrumentation to use to figure that. Six feet of light powder carries a lot less water than six feet of packed, near-ice snow. The latter snow melts a lot slower than powder.

    And it differs from the east and west slopes, and north and south slopes. There’s a helluva lot a science that goes into figuring out snowpack, the amount of water in it, and how fast it will be released. My experience has been to trust the experts, who will give a hundred qualifications on how they may be wrong, depending on the conditions.

    Unseasonably warm winters often produce larger snowpacks, and that is often a problem. If it’s warmer, it starts to melt sooner, and it melts faster. Lowlands aren’t ready for the water when it comes, and you get flooding. Then the water is gone, and you have a drought the rest of the year.

    I’ll wager Goddard didn’t grow up on a farm. Am I right?

    • Ray Ladbury

      Ed: “I’ll wager Goddard didn’t grow up on a farm. Am I right?”

      I don’t know. I mean that kind of stupidity has to be bred intentionally for years. I don’t think you’d find it nearly as refined in a wild-caught idiot.

  112. “If there were no Sun (or other external energy source) atmospheric temperature would approach absolute zero. As a result there would be almost no atmospheric pressure on any planet -> PV = nRT”

    Correct. Are people here seriously arguing that an atmosphere can even *exist* at near-absolute zero? There is no gas at that kind of temperature, so how on Earth (or Mars, or anywhere) could there be any atmospheric pressure?

    • You would undoubtedly pick up a great deal more if you were to read the thread. Some rather intelligent and quite well educated individuals give the problem some thought that I myself found rather educational.

      However, skipping to the last chapter (or would it be only the end of the first?) DP wrote a comment at May 10, 2010 at 10:43 pm, and inline to that you will find both Tamino’s physical reasoning regarding the atmosphere and his ethical reasoning for treating Goddard’s argument as the butt of a joke. However the comments that follow should further illuminate the physical principles that are involved up until Scott Mandia’s comment at May 11, 2010 at 10:00 am. But the comments after that for at least a little while continue with the ethics.

    • True Dave. Goodard is certainly implying thats the case. He often likes to throw red herrings like that out there while in midst of promoting some inane denialist proposal. Some well meaning if naive folks take the bait then generally end up on a high spin tail chasing expedition. You can’t totally blame them though. It takes discipline to leave those idiocies alone.

    • Here is the hole that Tamino finds in Goddard’s argument:

      The point he was trying to make is that atmospheric pressure and temperature are proportional in planetary atmospheres because of the ideal gas law. This is truly folly, dependent on a nonexistent constant-volume condition.

      Frank Ch. Eigler quotes Tamino as saying:

      Atmospheric pressure is determined by the mass of the atmosphere and the gravity of the planet.

      … then asks Tamino:

      Are you saying it’s independent of temperature?

      … then Ed Davies responds:

      Yes, that’s what he’s saying and to a very good approximation he is right…

      Consider this: the height of the atmosphere is quite negligible compared to the radius of the earth. The tropopause which marks the separation between the troposphere and the stratosphere has a height of only 9-17 km depending upon the latitude. Even the thermosphere only goes up to about 120 km, and atmospheric density falls off roughly as an exponential function of height so we needn’t worry too much about the exosphere. With a radius of over 6000 km we can pretty well treat the force of gravity as a constant throughout the atmosphere.

      Furthermore, if we treat the ideal gas law as a given — as Goddard does even though it isn’t — then at any given temperature the actual mass of the ideal gas atmosphere will always be the same for any given temperature above absolute zero — no matter what the temperature of the atmosphere is at any given height or more importantly for our purposes what the atmosphere’s temperature is at the earth’s surface. And as such, given a constant gravitational field which remains roughly constant throughout the atmosphere the air pressure at the surface must necessarily remain the same.

      Why? The mass of the atmosphere remains the same as it is an ideal gas that will not precipitate out, the gravitational field remains roughly constant with respect to altitude, and surface air pressure is simply the weight of the atmosphere at per unit area of the planet surface.

      So yes, to a good approximation atmospheric pressure is independent of temperature. And as Ed Davies goes on to argue it isn’t the pressure that determines the temperature or the temperature that determines the pressure — but the volume that increases in response to an increase in the temperature of the surface.

      So what is it that actually determines the temperature at the surface? Fundamentally, the principle of the conservation of energy. When the surface is in equilibrium, the rate at which energy reaches the surface will have to equal the rate at which it leaves the surface.

      If you increase the optical thickness of the atmosphere to thermal radiation this will decrease the rate at which energy is able to leave the system, but the rate at which energy enters the system will remain the same. So things have to heat up. And the hotter things get the more thermal radiation gets emitted by the surface according to where the rate of emission is proportional to T^4.

      However, the way that this will typically get calculated isn’t at the surface of the planet but at the top of the atmosphere, and one can’t assume a that the mass of the atmosphere remains constant or that all energy transport is by means of radiation. There is moist air convection, the fact that the saturation absolute humidity varies as a function of temperature, precipitation and evaporation where the mass of the atmosphere varies as the result of temperature and water vapor, etc.. And temperature will largely vary as a linear function of altitude, either according to the dry air adiabatic lapse rate or moist air adiabatic lapse rate.

      Increase the optical thickness of the atmosphere and you raise the effective height from which radiation tends to escape the atmosphere without being re-absorbed. Assuming a constant moist air adiabatic lapse rate and given the distance to the surface you can then calculate how much the temperature at the surface has to increase.
      *
      Incidentally, my avatar is derived from this:

      This infrared image of the Earth was taken on 5 March 2005 after Rosetta’s closest approach to Earth by VIRTIS from a distance of 250 000 kilometres and with a resolution of 62 kilometres per pixel.
      The image shows the distribution of CO2 bands in the Earth’s atmosphere. In the green areas the CO2 concentration is enhanced.

      CO2 bands in Earth’s atmosphere
      http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37190

      Elevated levels of carbon dioxide locally increase the optical thickness of the atmosphere, implying that radiation escapes at a higher, colder altitude — and this is what the satellite is measuring in terms of the spectra of thermal radiation then rendering in false color. But lets say that we stop emitting carbon dioxide and let the system equilibriate. Once a new equilibrium is achieved the rate at which radiation leaves the system will equal the rate at which radiation enters the system, neglecting changes in albedo, the brightness temperature of the earth as measured at a distance will return to what it was prior to the slug of carbon dioxide we put into the atmosphere.

      But this brightness temperature will be the temperature of the atmosphere at a higher altitude. And given the roughly constant lapse rate? The earth’s surface will be warmer — because you have increased the distance from the effective radiating altitude.

  113. Ray Ladbury

    Dave D.,
    Well, except that without Mr. Sun, the temperature would be the same as the inky darkness of space–about 2.7 K. He’s evidently a Big Bang denialist as well.

    • By that point, the tiny geothermal and tidal heat fluxes could actually become important…

  114. The boiling point of liquid nitrogen is about 77 K. So, below that temperature, most of the atmosphere will be gone (O2 condenses already somewhere near 90 K). At 2.7 K, I think just hydrogen and helium would be constituents of the atmosphere. Remember that the ideal gas law is just that – “ideal” – it does not predict phase change.

  115. David B. Benson

    If almost no pressure @ 2.7 K, helium is a gas:
    http://ltl.tkk.fi/research/theory/helium.html
    and so is hydrogen:
    http://www.conferences.uiuc.edu/supergrid/PDF/SG2_Schainker.pdf
    (See appendix)

  116. Hmm, Dave’s observation raises an interesting question–would there be a tenuous atmosphere of He or H2 at 2.7 K.? After all, no Sun means no solar wind stripping off light ions, and none of the ions would have escape velocity. GCR might slowly erode the atmosphere, though?

  117. David B. Benson

    Ray Ladbury // August 1, 2010 at 10:55 am — Thanks for the interest, but always David and never Dave. Dave is someone else around here.

    Sedna is warmer, 11–38 K depending on where in its orbit, but maybe it has a neon atmosphere?
    http://www.astro.umd.edu/~ssm/sedna/

  118. arch stanton

    Ah, but…Since a planet would have to have been “warm” during its formation due to collisions and compression of radioactive elements and all, could we not apply the Goddard Theory of Lapse Rate Perpetual Thermia and assume that the lower atmosphere would then remain warm in perpetuity and therefore maintain itself?

  119. I can’t stand it. I’m no great scientist, but I have flacked for politicians before, and I’ve been a reporter, and I recognize bullshit by its smell and appearance:

    Shorter Goddard: Hide the increase in temperatures, and it looks like temperatures don’t increase nearly as much.

  120. It seems there are a lot of people who don’t understand the dry adiabatic lapse rate and its relation to the ideal gas law. Perhaps changing the form of PV=nRT to P=”rho”RT might help clear up some of the confusion.

    Timothy Chase, your argument that gravity is nearly constant from surface to top of troposphere ignores that there is a difference in potential energy between objects (including molecules) at different altitudes.

    BWD

    • BigWaveDave wrote:

      Timothy Chase, your argument that gravity is nearly constant from surface to top of troposphere ignores that there is a difference in potential energy between objects (including molecules) at different altitudes.

      Dave, my argument isn’t about potential energy due to gravity being nearly constant but about the force of gravity being nearly constant. Don’t confuse the two. There is a difference.

      In principle you can hold the difference in potential energy between two points along the radius from the center of mass constant while reducing the difference in the force of gravity between those two points to something arbitrarily small. Simply by increase the distance from one point to the center of mass to something arbitrarily large and increase the mass proportional to the square of that distance.
      *
      Of course we are stuck with the earth being the size and mass that it is. So let’s look at the actual figures. The distance to space is roughly 80 km and the radius of the earth roughly 6378 km, so going from the earth’s surface to space the gravitational force is reduced by less than 2.5%.

      However, what is more relevant than the distance to space is the distance over which the density of air is decreased by a factor of e where e is roughly equal to 2.71828. This distance is roughly 7.64 km. But as a handicap to my argument let’s call that 8 km even.
      *
      Going from the surface to 8 km altitude reduces the force of gravity by less than 0.016%. And at this point you have already accounted for roughly 63% of the atmosphere’s mass. At 16 km you have accounted for 86% of the atmosphere’s mass and the gravitational force has dropped by only about 0.5%. At 24 km you have accounted for all but 6% of the mass of the atmosphere and the force of gravity has dropped by only 0.75%.

      Both Goddard and I assume that the atmosphere acts roughly in accordance with the perfect gas law. I notice that you are still counting on this approximation. That is, even though increasing the surface temperature by 10 °C will double the absolute humidity over near the ocean’s surface and likewise roughly double the water vapor content over land and at any given altitude, thus roughly doubling the water vapor content of the atmosphere.
      *
      However, given this approximation that you and I hold in common, increasing the temperature of the atmosphere at the surface will increase the height of the atmosphere where the volume of any given parcel of air will be directly proportional to the temperature. But the mass will remain roughly the same.

      Thus the pressure will remain roughly the same. And this is what I had concluded given the fact that the gravitational force is roughly constant over the distance from the earth’s surface to space.

      As I said:

      So yes, to a good approximation atmospheric pressure is independent of temperature. And as Ed Davies goes on to argue it isn’t the pressure that determines the temperature or the temperature that determines the pressure — but the volume that increases in response to an increase in the temperature of the surface.

      *
      Dave, honestly I feel sorry for Goddard. He is given a stage by Watts before a fairly large audience. A stage that he really hasn’t earned — but which no doubt feeds his ego. It must be like the kind of high that one gets from taking cocaine. Undoubtedly it is very addictive.

      But time and time again that inflated sense of ego is punctured. It bursts and as he puts it, it makes him “stoopid”. Except in my view he really isn’t stupid. He isn’t brilliant, either. But as long as he has such an inflated sense ego, thinking himself brilliant, he has no reason to learn.
      *
      And when that sense of ego bursts? The anxiety is undoubtedly intolerable. That isn’t very conducive to learning, either. And given how aweful that anxiety must be, rather than face it, rather than calmly examining why he feels it — he flees back into his addiction. Writing the next piece that appeals to his vanity.

      I don’t know whether Watts realizes it or not. I don’t know whether it would matter to him if he did. But what he is doing to Goddard — his hapless accomplice — is cruel in the extreme.

  121. BigWaveDave wrote:

    Timothy Chase, your argument that gravity is nearly constant from surface to top of troposphere ignores that there is a difference in potential energy between objects (including molecules) at different altitudes.

    Dave, my argument isn’t that potential energy due to gravity being nearly constant but about the force of gravity being is nearly constant from the from the Earth’s surface to the top of the atmosphere — and therefore air pressure at the surface will be (roughly) constant. Don’t confuse the two. There is a difference.

    But lets see how this may be derived. Pressure falls off roughly as an exponential function of altitude:

    P_h = P_0e^{-h/H};\ where P_h =\ the\ pressure\ at\ a\ given\ height\ h,
    H\ is\ the\ scale\ height\ and\ e\ is\ the\ base\ for\ the\ natural\ logarithm

    Now for a simple atmospheric model, we can pick an isothermal-barotropic approximation where air density falls off as an exponential function of height.

    So this would be:

    \rho_h =\rho_0e^{-h/H}

    … where ρ is equal to the air density. But we may ask whether an isothermal-baratropic approximation is appropriate. Baratropic assumes that air density is simply a function of air pressure. I take this to follow from our approximation of the atmosphere as a single gas obeying the perfect gas law. And isotropic? This means that we are assuming the temperature is constant with altitude.

    Now of course the temperature varies with altitude. However, it drops by only about 6.49 °K per kilometer of altitude — which is a small fraction of the 273 °K that separates us from absolute zero.

    Thus for our purposes at least we may assume a constant temperature — given how quickly air density will fall under isotropic conditions. And thus we may treat the air pressure at the surface of the Earth as something that is strictly determined by the mass of the atmosphere, the mass of the Earth and the radius of the Earth.

    Given how rapidly air density falls as a function of height we may treat r as a constant. As such we may apply Newton’s gravitational law where we treat radius as a constant.

    F=\frac{Gm_1m_2}{r^2} \ ...\ where\ F\ is\ the\ force,\ m_1\ and\ m_2\ are\ the\ masses\ of\ the\ two\ objects

    But of course the force is evenly distributed over the surface of the Earth, so given a force that is for our purposes simply a function of the atmosphere’s mass we know that pressure will be constant since pressure is simply force per unit area:

    P = F/A

    Of course increasing the temperature of the atmosphere will increase the volume and this will affect the altitude of the top of the atmosphere. However, the altitude will be negligible compared to the radius of the Earth and therefore will have a negligible affect upon the air pressure at the Earth’s surface.

  122. PS

    Anyway, the scale height is roughly 8 km for either atmospheric pressure or in the case of an isothermal-barotropic model, air density. Which means that with an isothermal-barotropic atmosphere, by 63% of the atmosphere lies below 8 km, 86% below 16 km, 98% by 32 km, and 99% by 40 km. And by 40 km. And given that the radius of the Earth is 6371 km, at 40 km altitude, the force of gravity per unit mass will have decreased by less than 1.25%. And as I said, temperature will cause the volume of the atmosphere to expand, but this will have only a negligible effect upon the air pressure at the Earth’s surface as air pressure is simply force per unit area.

    If the temperature of the atmosphere is at freezing, that is 273 °K. Doubling it (and therefore doubling the volume given the perfect gas law) brings us from 32 °F to over 500 ° F. But this will mean that instead of having 99% of the Earth’s atmosphere below 40 km we will have 99% of the Earth’s atmosphere below 80 km. And this will imply a negligible reduction in air pressure at the surface. (Goodard was expecting air pressure at the surface to increase with temperature because he was assuming that the volume would remain constant.)

    Anyway, now that you have seen some of the math you might want to re-read the comment that you were critiquing.

  123. PS PS

    Tamino — my apologies — I thought the first of my comments had disappeared as it was no longer visible to me. So I only meant to have one comment and then the PS.

  124. Timothy Chase,

    The point you seem to still be missing is that there is an energy difference due to elevation, which makes an isotropic atmosphere an unlikely and nearly impossible situation.

    Using the ideal gas law can only give the lapse rate for a still atmosphere of ideal gas, not the turbulent mixture of ideal gas and water that makes up our atmosphere.

    BWD

  125. BigWaveDave wrote:

    The point you seem to still be missing is that there is an energy difference due to elevation, which makes an isotropic atmosphere an unlikely and nearly impossible situation.

    Missing? In what way?

    What I am interested in is simply determining the extent to which atmospheric pressure at the earth’s surface is a function of temperature — for an ideal gas. We were focusing on an ideal gas — Goddard, you, me. And I am using the isothermal-baratropic atmosphere simply as an approximation.

    Atmospheric density falls off roughly as an exponential function of altitude with 63% below 8 km and 99% percent below 40 km. By 80 km the force of gravity has dropped by less than 1.25% of what it is at the surface. That means we are still talking about more than 98.75% the force of gravity at 80 km altitude as what we have at the surface of the Earth.

    Therefore even if one were to go from 32°F to 523°F (e.g., doubling the temperature relative to absolute zero) — and thereby double the volume — this would have almost no effect upon atmospheric pressure at the Earth’s surface. Dry adiabatic lapse rate, moist adiabatic lapse rate, the stratosphere’s negative lapse rate due to the absorption of ultraviolet radiation by ozone… Very little effect upon surface pressure. Assuming the mass of the atmosphere remains the same.

    I believe that’s QED.
    *
    BigWaveDave wrote:

    Using the ideal gas law can only give the lapse rate for a still atmosphere of ideal gas, not the turbulent mixture of ideal gas and water that makes up our atmosphere.

    “mixture of ideal gas and water”? What “ideal gas” are your thinking of?

    Is it composed of ideal molecules with ideal atoms? Is its molecular weight greater than nitrous oxide? And where exactly does the ideal element fit in the chart of elements? Is it before or after oxygen? Is it just down the hall from carbon or perhaps three floors up from iron?

    For something to be an actual ideal gas it would have to be a substance that never undergoes a phase transition from gas to liquid. No such animal. In fact that’s part of the reason why we call it “ideal”. When we speak of the “ideal gas law” we are speaking of an approximation that gets applied to all gases — including water vapor — but only as an approximation that works fairly well under some conditions (e.g., monoatomic gases at high temperatures and low pressures), not so well under others and begins to completely break down under still others (e.g., when vapor droplets begin to form).

    Please see:

    Sufficiently accurate measurement of pressure, temperature, volume, and amount of any gas will reveal that the ideal gas law is never obeyed exactly… At high pressures, PV is always larger than would be predicted by the ideal gas law. As the temperature decreases, deviations occur at lower pressures, and PV drops below the predicted horizontal line before rising again with pressure.

    University of Wisconsin’s Online GenChem Textbook: Deviations from the Ideal Gas Law
    http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Deviations-from-the-Ideal-Gas-Law-590.html

    *
    Look, Goddard wants to argue that the greenhouse effect is not responsible for the high temperature at the surface of Venus. Instead he wants to pin the blame for high surface temperatures on the high atmospheric pressure.

    Compress the volume of a parcel of air and the temperature of that parcel of air goes up. Sure — because you are putting energy into that parcel of air, energy that can do work, such as causing a balloon to expand when that parcel of air is permitted to expand.

    However, once you have increased the atmospheric pressure of Venus and raised the surface temperature you will increase the rate at which thermal radiation is emitted by the surface. Without something reducing the rate at which radiation is radiated into space that added heat will be lost and the surface will cool.

    On Venus that something that something is carbon dioxide. It reduces the rate at which thermal radiation is radiated into space. So even though the rate at which the surface radiates thermal radiation is much higher than the rate at which solar radiation enters the atmosphere the surface stays warm.

    Same thing that happens on Earth — although with us its more of a mix of water vapor, carbon dioxide, methane and nitrous oxide. Each has a distinct absorption spectra that leaves its mark on outgoing thermal radiation.

    You can see this here:

    http://www.globalwarmingart.com/wiki/File:Atmospheric_Transmission_png

    Likewise you can see how increasing the level of carbon dioxide reduces the transmission of thermal radiation, even in a lab:

    CO2 experiment: Iain Stewart demonstrates infrared radiation absorption by CO2
    http://www.youtube.com/watch?v=SeYfl45X1wo

    Elevated levels of carbon dioxide locally increase the optical thickness of the atmosphere, implying that radiation escapes at a higher, colder altitude.

    You can see that here:

    This infrared image of the Earth was taken on 5 March 2005 after Rosetta’s closest approach to Earth by VIRTIS from a distance of 250 000 kilometres and with a resolution of 62 kilometres per pixel.

    The image shows the distribution of CO2 bands in the Earth’s atmosphere. In the green areas the CO2 concentration is enhanced.

    CO2 bands in Earth’s atmosphere
    http://www.webcitation.org/5rgo0J0X0
    http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37190

    Increase the levels of carbon dioxide and you increase the height at which thermal radiation gets radiated into space. Given a positive lapse rate that layer is cooler than the layer from which the radiation escaped before, and therefore the rate at which radiation escapes to space is reduced.

    With radiation entering the system at the same rate as before, the principle of the conservation of energy tells you that things have to warm up. And they will keep on warming until the the rate at which energy leaves the system is the same as the rate at which energy enters the system.

    So in the long run that higher layer radiates heat at the same rate that radiation was radiated before the increase in carbon dioxide concentration. But given a roughly constant lapse rate (rate at which temperature falls with increase in altitude), the increased distance between the effective radiating layer and the surface will imply a surface that is warmer than it was before.
    *
    In any case, I have gone into this in a great deal more detail than your comments warranted — because I was writing for others who might not understand but may wish to. However, judging from your arguments by innuendo, word salads and hand-waving this is not your goal. Let me know when this changes and perhaps there will be something that I or others may be able to do for you.

  126. Timothy Chase,

    Using “the isothermal-baratropic atmosphere simply as an approximation.” might make sense, if air were a liquid.

    The candle I-R camera view snuffing with the tube full of CO2 was a pathetic set of exaggerated circumstances that apparently had no measurable effect on the gas temperature in the tube.

    As for the other 3.5 pages, you lost me with your approximation.

    BWD

    • You missed the point of the IR demo, too–the temperature of the gas was utterly irrelevant to the point (and design) of the experiment.

    • BigWaveDave wrote:

      Using “the isothermal-barotropic atmosphere simply as an approximation.” might make sense, if air were a liquid….

      As for the other 3.5 pages, you lost me with your approximation.

      I will try to keep this short and simple.

      The following is an argument as to why Goddard’s explanation of the surface temperature being due to atmospheric pressure won’t work….

      Goddard argues based on the perfect gas law that what explains the high temperature of Venus isn’t the greenhouse effect but the high pressure — given his application of the perfect gas law. I disagree. So let’s forget the isothermal-barotropic atmosphere with its somewhat realistic exponential decay in atmospheric density as a function of altitude.

      Lets make this simpler. We know that the good majority of the mass of the atmosphere is within the first 16 km. But let us imagine instead that we have the entire atmosphere at an altitude of 0 km. Now measure the weight. Now shove that atmosphere up to 80 km. Now measure the weight.

      If you calculate the change in weight as a percentage you will find that the change in weight is less than 5% — given Newton’s inverse square law. Even if we move the entire atmosphere from 0 km to 80 km the atmosphere would retain more than 95% of its weight. And as such since the surface area over which that weight is distributed will remain the same the atmospheric pressure will remain roughly the same.

      Is that unrealistic?

      You betcha! How could the entire atmosphere be at the surface to begin with? What could possibly shove it 80 km into the sky? How is the force of the weight of the atmosphere reaching the surface if there is nothing in between the atmosphere and the surface except 80 km of empty space?

      However, the extreme unreality of that scenario implies that the change in weight of the atmosphere under any realistic scenario will far less than 5% and thus that the change in atmospheric pressure will be far less. Thus under any realistic scenario the atmospheric pressure will be well within 95% of its current value. Therefore changing the temperature has very little effect upon the air pressure.
      *
      Now as I pointed out in an earlier comment, if you compress the atmosphere, increasing the air pressure, this will raise the temperature. This is because the act of compression is putting energy into the atmosphere that we know is there because removing that force results in the atmosphere expanding in a way that call do work — including pushing matter out of the way.

      But if you raise the temperature this increases the emission of thermal radiation. Without an increase in the rate at which energy enters the system (e.g., the sun) or something to reduce the rate at which energy leaves the system (e.g., greenhouse gases) the atmosphere will cool.

      So an increase in atmospheric pressure will not change the equilibrium temperature of the atmosphere. Something else has to, either by increasing the rate at which energy enters the system or decreasing the rate at which energy leaves the system.

      Notwithstanding Goddard’s invocation of the perfect gas law, the temperature of the atmosphere is roughly independent of the pressure and the pressure is roughly independent of the temperature — except insofar as raising the temperature changes the mass of the atmosphere, e.g., through the evaporation of water. Therefore if you want to explain why the temperature of Venus or the Earth differ from what you would get simply solar radiation and albedo you have to look elsewhere — at something that changes the rate at which energy leaves the system.

      • “I will try to keep this short…”

        No chance.

      • Richard C. wrote:

        “I will try to keep this short…”

        No chance.

        Richard, for me that is short. I had a philosophy professor ask for ten type-written pages once. I gave him twenty — and that was only because I shaved the margins, the spacing between the lines and used a smaller font.

    • BigWaveDave wrote:

      The candle I-R camera view snuffing with the tube full of CO2 was a pathetic set of exaggerated circumstances…

      Is it exaggerated?

      Sure — the amount of carbon dioxide in that tube is more carbon dioxide than what you will typically find in one or two meters of atmosphere. But is it comparable to what you would find in the atmospheric column — which extends 80 km straight up?

      This is presumably what Iain Stewart is trying to model inside a laboratory. And what matters in terms of absorption isn’t the actual length of the column but the optical thickness of the column — essentially, how much carbon dioxide a beam of light will run into getting from point A to point B, whether A is at one end of a two meter long plastic cylinder and B at the other — or — A is at the bottom of the atmosphere and B is at the top.

      One figure to keep in mind: for every square meter of the earth’s surface there are roughly two kilograms of anthropogenic carbon dioxide that we have put into the atmosphere. Somehow I doubt Iain Stewart had that much carbon dioxide per cross-section of tube.
      *
      BigWaveDave wrote:

      …. that apparently had no measurable effect on the gas temperature in the tube.

      The point of the experiment was simply to demonstrate that carbon dioxide absorbs thermal, infrared radiation. And when you increase the concentration of carbon dioxide you increase the absorption. Now Iain Stewart didn’t demonstrate that the carbon dioxide heats up. He didn’t prove that he was a legal resident of England, either. It wasn’t the point.

      However, if carbon dioxide is absorbing thermal radiation the energy is going somewhere. That much follows from the principle of the conservation of energy. And what do things generally do when they absorb radiation? They heat up.

      Furthermore, we know that above 20 mb of atmospheric pressure (roughly 1/1000 of the air pressure at sea level) these molecules will be undergoing roughly a million collisions over the half-life of a state of excitation. As such the molecules that absorb the photons will in all likelihood transfer the energy to neighboring molecules through collisions before they have the chance to emit a photon as the result of spontaneous decay. This is the conversion of energy into thermal energy.
      *
      Once the energy has been absorbed by greenhouse gases the possibilities are rather limited. The thermal energy may be emitted as thermal radiation by greenhouse gases at the same wavelengths that those greenhouse gases absorb radiation or it may be transferred by means of physical contact with either liquids or solids. If the energy is re-emitted by the greenhouse gases as radiation, it may either be re-absorbed by greenhouse gases, escape to space, or be absorbed by clouds, the land or water.

      But when the radiation is being re-emitted by the greenhouse gas escape to space is very unlikely unless the radiation is being re-emitted at the so-called “effective radiating height”. It may “climb the ladder” of layer upon layer of atmosphere — but at each point of re-emission it is just as likely to be re-emitted downward as upward.

      If it is absorbed by clouds, land or water it will heat them. Only then will the energy have a fair chance of being re-emitted in a “window” that is transparent to the radiation, e.g., in a spectral band that is not absorbed by greenhouse gases.

      You can get a sense for this from the link I gave earlier here:

      http://www.globalwarmingart.com/wiki/File:Atmospheric_Transmission_png

      … where according to the caption 15-30% of the thermal radiation is trasmitted from the surface directly to space, that is, without absorption and re-emission.
      *
      Even if for whatever reason you insist on setting Stewart’s experiment aside you are still left with the satellite image showing that increased levels of carbon dioxide reduce the rate at which thermal radiation leaves the atmosphere. If you reduce the rate at which thermal energy leaves the atmosphere this will result in the warming of the planet.

      This follows from the principle of the conservation of energy. Moist air convection isn’t an alternative here: it can’t get energy beyond the tropopause — at an altitude between 8 and 18 km let alone beyond the atmosphere. Realistically the only way energy is going is as radiation.

  127. Timothy Chase,

    Most surface heat gets transferred through the atmosphere by air movement, and water {in its three phases with two phase changes} that the air movement transports. More than 300 times as much heat per unit mass is needed to change ice at 273°K into vapor at 288°K; than is needed to change a unit mass of dry air (or CO2) from 273°K to 288°K

    Water also doesn’t behave like an ideal gas. It may or may not be in a heterogeneous mix. Its latent heats suppress air’s adibatic lapse rate.

    BWD

  128. Bigwavedave,
    I’m afraid you are getting lost due to Tim’s simplification–there are both wet and dry adiabatic lapse rates. That doesn’t change the basic physics though. The change in gravitational potential energy of the gas is small compared to average kinetic energy of the molecule–and that is why the atmosphere is well mixed.

  129. “ask for ten type-written pages once. I gave him twenty”

    I did the same thing on a larger scale with my final year project

  130. There seems to be some confusion here. The variation in gravitational force due to position isn’t the point . Moving the whole atmosphere to a different elevation is not the same as going to a different altitude in the same atmosphere

    Gravity creates the density distribution of molecules in the troposphere. It is like the atmosphere is being compressed from the surface side, only. It is analogous to a pile of very uniformly distributed extremely compressible spheres. At the bottom of the pile the pressure and density are high, As one works their way up the pile, fewer balls remain above, and the pressure and density diminish.

    20 mb of atmospheric pressure is roughly 1/50 of the air pressure at sea level), not 1/1000.

    The Earth, including hydrosphere and atmosphere; loses heat to space by radiation frome somewhere around the top of the troposphere.

    Most heat that leaves the Earth doesn’t follow a straight line from the surface on its way to space. (e.g. twice as much heat leaves the polar areas as they recieved.), Heat is transferred to troposphere at or near Earth’s surface by condudtion, evaporation, convection, and a fraction of outgoing radiation at wavelength or frequency bands of that are absorbed by atmospheric gases or water that get absorbed relatively neat Earth’s surface, to be transported longitudinally or up, with the rest of the warm air . A small fraction of surface heat is radiated directly to space The rest is coming from higher in the the atmosphere.

    The satellite image just shows that CO2 isn’t uniformly distributed in whatever section of atmosphere from whatever direction the image represents. Look at satellite images that show the radiating temperature distribution of Earth. Where is the correlation to CO2?

    BWD

    By the way, there is closer to 6 kg of CO2 over a square meter, out of the ~10,000+ kg of air, and about 100 kg , or so, of water. If the Earth’s surface was smootherd out with an even layer of water, there would be roughly 2,900.000 kg of water under a square meter.

    From vapor at 288°C. to ice at 273°C 100 kg of water can hold and transport three times as much heat as 10,000 kg of dry air.

    The effect of 105 ppm (vol.) CO2, representing an increase from 280 ppm to 385 ppm, reduces air’s heat capacity about 0.0016% , so to transport the same amount of heat, including the 3X contribution of latent heats in the 1% fraction of water vapor to ice, the air would have to cool from ~288.001°C verses from 288°C,. to 273°C.

    • Big Dave, I’m afraid I don’t find your last post very coherent. Most of it is non-controversial, as in “Gravity creates the density distribution of molecules in the troposphere,” or “A small fraction of surface heat is radiated directly to space The rest is coming from higher in the the atmosphere.” But these snippets, however correct they may be, don’t come together into an actual thesis–as far as I can tell just now, anyway.

      Then you go off into water vapor vs. CO2 concentrations, without any context to make your statements meaningful, and conclude with a massively irrelevant (again, as far as I can tell at least) bit about latent heat.

      Sorry, but I have little clue what you are trying to say.

  131. BW Dave,
    I have to agree, you aren’t communicating effectively–either writing or reading. What is your thesis? We know about gravity and the role it plays in atmospheric density.
    And your note about lack of uniformity of CO2 is mostly wrong. The AIM results reveal higher concentrations near sources of CO2. However, for the most part, the CO2 is remarkably well mixed in the atmosphere.

  132. Kevin McKinney,

    The contest of my last post was in general response to the several comments that referred to my previous posts, and to help clarify my earlier statements. I didn’t intend to write a thesis.

    My first two paragraphs were intended in part as a response to your statements that ended with: “However, the extreme unreality of that scenario implies that the change in weight of the atmosphere under any realistic scenario will far less than 5% and thus that the change in atmospheric pressure will be far less. Thus under any realistic scenario the atmospheric pressure will be well within 95% of its current value. Therefore changing the temperature has very little effect upon the air pressure.”, which were somehow prompted by my earlier observation: “Timothy Chase, your argument that gravity is nearly constant from surface to top of troposphere ignores that there is a difference in potential energy between objects (including molecules) at different altitudes.”, but totally missing the subject, which was potential energy.

    Please consider this hypothetical situation: Imagine an Earth clone, exactly like Earth, with the same mass distribution, motions, positions, etc. around the same sun, except totally without atmosphere but with a total albedo the same as Earth with the portion of the albedo that stems from Earth’s atmosphere suspended 25 km above the clone’s surface. Now imagine you have a giant balloon containing dry air, of the same composition and total mass as the dry portion of Earth’s atmosphere. Further imagine the pressure in the balloon is 90 mb, and the temperature is -18°C. The balloon is perfectly insulated with respect to heat and gravity, perfectly elastic, and has an exit nozzle that allows the air inside the balloon to be instantly discharged without any change in temperature or pressure, 17 km above the surface over the entire clone, allowing gravity to distribute the air. What will the air temperature be at the surface?

    Ray Ladbury;

    The CO2 non uniformity comment was in response to the satellite image that Timothy Chase linked. It does not appear uniform, and there is no reference to where on Earth the image was taken.

    My question is still this: “Look at satellite images that show the radiating temperature distribution of Earth. Where is the correlation to CO2?”.

    BWD

  133. CO2 is well mixed over several years, and by the time it reaches the upper atmosphere, not instantaneously and not at the surface where it’s emitted.

    Same for methane: http://www.fas.org/irp/imint/docs/rst/Sect16/ch4_2004207.jpg

    “The atmosphere radiates heat equivalent to 59 percent of incoming sunlight; the surface radiates only 12 percent. In other words, most solar heating happens at the surface, while most radiative cooling happens in the atmosphere.”
    http://earthobservatory.nasa.gov/Features/EnergyBalance/page4.php

  134. BWD–

    Not my words. And I still don’t know what you are trying to say. For example, what do you consider “the dry portion of Earth’s atmosphere?” And how do you “insulate with respect to gravity?”

    It sounds as if you’re basically trying to say, “imagine you could instantly remove the lowest 17 km of atmosphere and let gravity distribute the remaining atmosphere–what would the surface temperature be?”

    Well, I’m the wrong guy to precisely calculate that, though I can see in a general way how it might be done, but here’s my imaginary qualitative description FWIW: given that the first thing that happens is that 4 x 10e18 kg of air falls 17 km, things get very, very hot. Potential energy converted to kinetic. . .

    Radiation into space increases markedly in accordance with Stefan-Boltzmann, and temperature accordingly declines, rapidly at first, then more and more gradually. One might think that we’d now lost nearly all our water vapor, but your conditions didn’t involve removing the oceans, so during the thermal spike atmospheric water vapor would have been replenished to the levels possible. It’s an interesting question what happens to water vapor, actually; glancing at the phase diagram of water, the existence of liquid water on the surface could actually be at risk, I think, as temperatures drop. Of course, as long as there’s lots of water vapor to act as a GHG, that helps keep the temperature from dropping too fast. Again, quantitative treatment is needed–and the evolution of the atmosphere would have to be considered very carefully, I think.

    But given that the atmosphere we magically eliminated accounts for about 80% of the original mass, my guess is that due to the weakened greenhouse effect, we’d end up with an equilibrium temperature a good deal lower than presently exists–as well, of course, as a planet scoured of most Terrestrial life.

    Why, Dave–what do you think would happen?

    • Oops, it’s *1* x 10e18 kg of air. The other number should be roughly what we magically “disappeared” by sheer thought power.

      Also, I should have written “. . . as temperatures and pressures drop. . .”

  135. A Response to bwdave’s first comment of 2010 Sept 13

    Note: I have divided my responses into sections before but to make them easier to read this time around I will be titling those sections.

    Potential Energy Again

    bwdave wrote:

    … somehow prompted by my earlier observation: “Timothy Chase, your argument that gravity is nearly constant from surface to top of troposphere ignores that there is a difference in potential energy between objects (including molecules) at different altitudes.”, but totally missing the subject, which was potential energy.

    Why exactly do you think potential energy is “the subject”? It isn’t “the subject” when it comes to surface pressure — which is determined by the weight of the atmosphere and surface area of the Earth — which was the context for our consideration of the gravitational field.

    *

    A Hypothetical Situation

    bwdave wrote:

    Please consider this hypothetical situation: Imagine an Earth clone, exactly like Earth, with the same mass distribution, motions, positions, etc. around the same sun, except totally without atmosphere but with a total albedo the same as Earth with the portion of the albedo that stems from Earth’s atmosphere suspended 25 km above the clone’s surface. Now imagine you have a giant balloon containing dry air, of the same composition and total mass as the dry portion of Earth’s atmosphere. Further imagine the pressure in the balloon is 90 mb, and the temperature is -18°C. The balloon is perfectly insulated with respect to heat and gravity, perfectly elastic, and has an exit nozzle that allows the air inside the balloon to be instantly discharged without any change in temperature or pressure, 17 km above the surface over the entire clone, allowing gravity to distribute the air. What will the air temperature be at the surface?

    Speaking as the philosophy major that I am rather than as the physicist that I am not…

    First off your question is incoherent. Water vapor constitutes on average about 2-3% of the atmosphere. Consequently, when you say “same composition and thotal mass as the dry portion of Earth’s atmosphere” this will determine an air pressure that will not be equal to 90 mb but somewhat higher, then when it settles towards the earth’s surface we are more likely looking at 97-98% current air pressure — or roughly 980 mb — since a standard atmosphere is actually slightly higher than 1,000 mb.

    Second, I presume you are talking about the absence of moist air convection that takes much of the heat above a fair amount of the atmosphere and thus above much of greenhouse gases. This implies that rather than being emitted above much of the greenhouse gases the energy from that heat would have to be radiated and absorbed from one layer to the next starting at the earth’s surface with half of it being radiated upwards and half being radiated downwards at each step. So at that point we are talking about warmer days that would have to be averaged with cool nights.

    Third, water vapor is also a greenhouse gas — one with an absorption spectra that overlaps with other greenhouse gases including carbon dioxide. By itself, water vapor at current concentrations in the earth’s atmosphere water vapor would be responsible for 66% of the longwave absorption. However, if you were to remove the water vapor much of the absorption which is currently performed by water vapor at the lower levels would be taken up by other greenhouse gases, most notably carbon dioxide. So at that point we are looking at 64% of the longwave radiation being absorbed — and that is with current moist air convection.

    Fourth, while moist air convection is responsible for maintaining cooler days — which is the main reason why deserts are cooler than regions with higher soil moisture — moist air also means a stronger greenhouse effect — which is what is responsible for maintaining warmer nights in most areas. As such deserts cool off rapidly at night by means of thermal radiation. So you are talking about warmer days and colder nights — and then an averaging of the extremes — and this wouldn’t apply just to the deserts we currently have but to the whole surface of the Earth. But then most of the Earth has a lower albedo due to vegatation — meaning that such areas absorb more sunlight than what is absorbed in the deserts — so conditions would actually be warmer than with the desert.

    Fifth, evaporation is also responsible for driving much of the atmospheric and oceanic circulation that redistributes the heat — and with the heat being redistributed you are talking a reduction in the variation in temperature from that which we would get simply with solar insolation. So in the absence of water of such evaporation and atmospheric circulation — keeping everything else the same — there would be greater variation — and with that we would have to keep in mind how warm bodies emit thermal radiation roughly proportional to the fourth power of their absolute temperature — but with variation due to spectral emissivity not being a constant with respect to wavelength.

    There is certainly more that we could take into account — but I believe this is a good start.

    What should be clear by now is that in order to answer your question — besides clarification that would make the question more well-defined — we would need either a General Circulation Model or Earth Systems Model. However, lets say that one starts with a dry atmosphere and a surface temperature due to insolation alone at -18°C we would have forcing due to carbon dioxide and presumably other greenhouse gases. Now lets assume one holds the albedo of the earth constant — including the vegetation. This is admittedly unrealistic, but vegetation is treated as a slow feedback and therefore not included in the calculation of Charney Climate Sensitivity and as such not normally included by General Circulation Models. So with a constant albedo we are already speaking of a General Circulation Model. But now lets assume an ocean with the potential for evaporation and where water vapor is both capable of moist air convection and the absorption of longwave radiation. By the time the system achieves equilibrium we are probably looking at roughly what we have now.

    *

    CO2 Uniformity

    bwdave wrote:

    The CO2 non uniformity comment was in response to the satellite image that Timothy Chase linked. It does not appear uniform, and there is no reference to where on Earth the image was taken.

    My question is still this: “Look at satellite images that show the radiating temperature distribution of Earth. Where is the correlation to CO2?”.

    I already mostly written a response to your earlier comment — that of 2010 Sept 11 — where this issue is covered and I will be posting it shortly.

  136. BW Dave: “Look at satellite images that show the radiating temperature distribution of Earth. Where is the correlation to CO2?”

    I’m not sure what you are asking. There are quite deep absorption lines in Earth’s radiated spectrum corresponding to CO2 and indicating that the radiation is occurring at colder temperatures and so at high altitude. Moreover, those features have exhibited change over time consistent with greenhouse warming. Again, I’m not sure what you are asking–perhaps because the influence of CO2 is obvious.

  137. A Response to BigWaveDave’s Comment of 2010 Sept 11

    Note: I have divided my responses into sections before but to make them easier to read this time around I will be titling those sections.

    Responding to Goddard’s Argument

    BigWaveDave wrote:

    The variation in gravitational force due to position isn’t the point.

    No, the absence of any significant variation in gravitational force due to altitude is the point when it comes to showing that surface pressure isn’t affected by much of anything other than the mass of the atmosphere and the gravitational force at the surface of the Earth — which is one thread in an arguement showing that Goddard’s arguement that roughly speaking “given the perfect gas law the high surface pressure (rather than the greenhouse effect) is what explains the high surface temperature” is invalid.

    But as far as I can tell you aren’t interested in arguing Goddard’s thesis so lets move on.
    *
    Millibars and Standard Atmospheres

    BigWaveDave wrote:

    20 mb of atmospheric pressure is roughly 1/50 of the air pressure at sea level), not 1/1000.

    Yes, I had written:

    Furthermore, we know that above 20 mb of atmospheric pressure (roughly 1/1000 of the air pressure at sea level) these molecules will be undergoing roughly a million collisions over the half-life of a state of excitation.

    … when what I meant to say was “… (where 1 mb is roughly 1/1000 of the air pressure at sea level)… “. Thank you for catching that.
    *
    Energy Flow in the Climate System

    BigWaveDave wrote:

    Most heat that leaves the Earth doesn’t follow a straight line from the surface on its way to space. (e.g. twice as much heat leaves the polar areas as they recieved.),…

    Quite true. I believe that is largely the result of atmospheric and oceanic convection from the warmer latitudes. If you think about it for a moment, higher temperatures imply more water vapor, water vapor being a greenhouse gas implies a reduction in the rate at which thermal radiation is able to escape the atmosphere at the lower latitudes, but this also implies moist air convection and thus atmospheric circulation which will tend to result in poleward atmospheric circulation.

    However, there is less moist air convection at the poles because the rate of evaporation/sublimation increases roughly as an exponential function of temperature at approximately 8% per 1°C or a factor of 2 for every 10°C. As such an enhanced greenhouse effect due to carbon dioxide becomes relatively more important there and this is one reason why we expect polar amplification.

    Anyway, since you are interested in the flow of energy as broken out by moist air convection vs. thermal radiation and whatnot, you might like the following diagram:

    Global Energy Flows
    http://www.aps.org/units/fps/newsletters/200904/images/trenberth-fig1.gif
    http://www.aps.org/units/fps/newsletters/200904/trenberth.cfm
    *
    The Rosetta Image

    BigWaveDave wrote:

    The satellite image just shows that CO2 isn’t uniformly distributed in whatever section of atmosphere from whatever direction the image represents.

    I assume you mean this satellite image:

    This infrared image of the Earth was taken on 5 March 2005 after Rosetta’s closest approach to Earth by VIRTIS from a distance of 250 000 kilometres and with a resolution of 62 kilometres per pixel.
    The image shows the distribution of CO2 bands in the Earth’s atmosphere. In the green areas the CO2 concentration is enhanced.

    CO2 bands in Earth’s atmosphere
    http://www.webcitation.org/5rgo0J0X0
    http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=37190

    It shows that carbon dioxide is reducing the rate at which radiation is escaping in the band that the satellite is measuring — as this is the way in which they measure the levels of carbon dioxide.

    Earlier I gave the link to a graph showing the incoming shortwave and outgoing longwave radiation spectra and the absorption spectra for the different greenhouse gases:

    http://www.globalwarmingart.com/wiki/File:Atmospheric_Transmission_png

    This shows you how absorption by greenhouse gases leave their imprint upon outgoing radiation as the bands in which they absorb radiation correspond to bands in the outgoing longwave radiation where the intensity of radiation has been reduced. So when in the above image shows you higher concentrations in carbon dioxide it is able to do so only because higher concentrations reduce the rate at which thermal radiation escapes the atmosphere in the wavelengths being imaged by the Rosetta satellite. Keep the rate at which thermal energy enters the system constant but reduce the rate at which thermal energy leaves the system and thermal energy — heat — will build up raising the temperature — as a consequence of the conservation of energy.
    *
    Total Upwelling Radiation

    BigWaveDave wrote:

    Look at satellite images that show the radiating temperature distribution of Earth.

    Is it possible you are thinking of the watts per square meter outgoing radiation?

    The Earth Radiation Budget Experiment (ERBE)
    http://asd-www.larc.nasa.gov/erbe/erbe.gif
    http://asd-www.larc.nasa.gov/erbe/ASDerbe.html
    *
    A Question of Correlation

    BigWaveDave wrote:

    Where is the correlation to CO2?

    Are you thinking of comparing the ERBE image to an image of CO2 concentration — and trying to see whether there is some sort of correlation in their patterns? I can’t find the same years, but I presume the idea is something along the lines of comparing the ERBE image from 1985:
    http://asd-www.larc.nasa.gov/erbe/erbe.gif
    http://asd-www.larc.nasa.gov/erbe/ASDerbe.html

    … to the NASA AIRS image of CO2 concentration from 2003:
    http://photojournal.jpl.nasa.gov/jpegMod/PIA09269_modest.jpg
    http://photojournal.jpl.nasa.gov/catalog/PIA09269

    The poleward edges of the warm areas from the ERBE image come to an end just about where the concentration of CO2 increases. It might look good, but actually it is quite irrelevant.

    The spike in CO2 at those levels is presumably due to mid-latitude jet streams carrying the CO2 aloft. As such it is a matter of how the atmosphere circulates. Likewise moist air convection is carrying aloft warm moist air in the tropics as part of the atmospheric circulation pattern known as the Hadley Cells — and having lost heat the air descends again at the mid-latitude boundary of the Hadley Cell. So in both cases you are simply seeing the result of an underlying pattern of atmospheric circulation. And there are bigger problems.
    *
    A Matter of Scale

    However there is a bigger problem in trying to draw any conclusions regarding the effects of CO2 on outgoing radiation by comparing the two images. Check out the legend for the NASA AIRS image. But for the bit around Antarctica the CO2 concentrations differ by little more than 10 ppm, perhaps from 372 to 382 ppm. Given the near logarithmic dependence of radiative forcing on CO2 concentration that won’t amount to very much.

    Although the equation isn’t normally used this way, we can use the formula for radiative forcing to compare different concentrations in the NASA AIRS image to see what the difference in total watts per square meter is.

    The equation is:

    \Delta F = 5.35 \times \ln {C \over C_0}~\mathrm{W}~\mathrm{m}^{-2}

    … and using 372 ppm as our baseline we find that 382 ppm reduces the outgoing radiation by approximately 0.142 watts per square meter. However, the ERBE image showed a drop of about 50 watts per square meter as we moved from the Hadley Cell to where CO2 concentrations are higher. So at any given moment the differences in outgoing radiation shown by the ERBE image swamp the difference due to CO2 concentration. Roughly by a factore of 360 to 1.

    As Ray Ladbury has pointed out, the concentration of carbon dioxide in the atmosphere is actually rather uniform — ranging from 372 to 382 ppm in my example using the NASA AIRS image, and as such shouldn’t stand out in the ERBE image of total outgoing longwave radiation. However, this wasn’t the point that I was making by showing the Rosetta image of CO2 concentration and reduction of outgoing radiation at a given moment in time. All I intended to show was that a higher concentration of CO2 reduces the rate at which outgoing radiation escapes the atmosphere — which is something that we can see within a given band of the spectrum at a given moment in time.

    However, it is also something that we are able to see over time. Please see for example:

    Aqua/AIRS Carbon Dioxide with Mauna Loa Carbon Dioxide Overlaid (Sept 2002 – July 2008)
    http://www.youtube.com/watch?v=6-bhzGvB8Lo
    http://svs.gsfc.nasa.gov/vis/a000000/a003600/a003685/index.html

    We are able to measure the changes over the years in outgoing radiation that have resulted from changes in greenhouse gas concentrations at different parts of the spectrum for different greenhouse gases, both for upwelling thermal radiation and downwelling backradiation.

    For more please see:

    How do we know more CO2 is causing warming?
    http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect.htm

    While it is written so that the layman can follow it includes references to the actual studies themselves.
    *
    Arguing from Heat Capacity?

    BigWaveDave wrote:

    The effect of 105 ppm (vol.) CO2, representing an increase from 280 ppm to 385 ppm, reduces air’s heat capacity about 0.0016% , so to transport the same amount of heat, including the 3X contribution of latent heats in the 1% fraction of water vapor to ice, the air would have to cool from ~288.001°C verses from 288°C,. to 273°C.

    Scientists do not argue that the greenhouse effect of either water vapor or carbon dioxide is due to their heat capacity: they argue that it is due to their capacity to absorb infrared radiation. Once this radiation has been absorbed the energy is largely lost through collisions with other molecules through a process known as “quenching.”

    Energy being lost through collisions with other atmospheric molecules results in its being shared with the rest of the atmosphere. This is what maintains a local thermodynamic equilibrium in which locally all the gases are at the same temperature.

    And collisionally greenhouse gas molecules enter states of excitation. A certain percentage will be in a given state of excitation at any given time. A certain percentage undergoing spontaneous radiative decay over any given period of time.

    This is what results in thermal radiation by greenhouse gases. Non-greenhouse gases do not emit thermal radiation but simply permit it to pass through — whether it has been emitted by land, water or greenhouse gases.

    But given quenching the good majority of kinetic energy in any given volume of the atmosphere doesn’t belong to greenhouse gases but to nitrogen and oxygen. To get a very rough idea, in the desert 78% by volume of the atmosphere will be nitrogen, 21% will be oxygen and the remaining 1% will be trace gases — including water vapor.

    In the humid tropics perhaps as much as 4% of the atmosphere will be water vapor — with nitrogen, oxygen and the other trace gases proportionally reduced. But even then the great majority of kinetic energy lies with nitrogen and oxygen, not the greenhouse gases.

    Greenhouse gas molecules are essentially gatekeepers, letting energy into the atmosphere and letting energy out. “They are guarding all the doors, they are holding all the keys…” The other gases simply constitute the floors of the building in which energy resides while it is in the atmosphere.

  138. Kevin,

    The mass of magic atmosphere I was trying to describe would be about 99% of the Earth’s atmosphere, assuming our atmosphere has a moisture content of about 1%.

    I left water out, because of the complications created by not knowing what states the water would be in. The Earth, with water only, and no atmosphere, but retaining the ~70% albedo, should be near the equilibrium temperature of -18°C before the magic atmosphere is added, which is the temperature I picked for the magic atmosphere before it is released, at an elevation that is in the vicinity of where that temperature is seen in our atmosphere.

    Your answer, “:given that the first thing that happens is that 4 x 10e18 kg of air falls 17 km, things get very, very hot. Potential energy converted to kinetic. . .”, even with only 80% of the mass, is also pretty much what I would expect to happen, and is what I have been trying to say about the potential energy difference with altitude.

    Thanks,

    Dave

    • Dave–

      OK, that clarifies things some. What I still don’t understand is what is the significance you attach to the issue of potential energy in the actual situation that exists? In the catastrophic collapse scenario that I described, that potential energy became kinetic energy as a result of falling 17 km. In the Goddard thesis that Timothy refers to, that potential energy somehow affects temperature (while still remaining potential, which rather highlights how the “Goddard effect” is actually a perpetual-motion scheme.) But as Timothy also notes, you don’t really seem to be arguing Goddard’s point. Yet I remain unclear just what point you are trying to make WRT potential energy.

      Timothy Chase, thanks for your penetrating consideration on these questions–several of your comments generated light for me–no pun intended.

  139. Dave quotes Kevin:

    Your answer, “:given that the first thing that happens is that 4 x 10e18 kg of air falls 17 km, things get very, very hot. Potential energy converted to kinetic. . .”, even with only 80% of the mass, is also pretty much what I would expect to happen, and is what I have been trying to say about the potential energy difference with altitude.

    Dave, immediately after the part you quote from Kevin, he states:

    Radiation into space increases markedly in accordance with Stefan-Boltzmann, and temperature accordingly declines, rapidly at first, then more and more gradually.

    Potential energy converts into kinetic temporarily but the gas will not stay hot. Compression will not keep things hot. Hot things radiate more thermal radiation — and that is why they cool down. That is, unless there is something to reduce the rate at which thermal radiation escapes to space.

    Potential energy has nothing to do with the final temperature — just as pressure has nothing to do with the final temperature. Radiation balance theory — which follows from the principle of conservation of energy — requires the rate at which energy leaves the system to be balance the rate at which energy enters the system for the system to be in equilibrium. If surface is hotter than the temperature at which this happens then excess radiation will be emitted and the surface will cool down. If it is cooler than this less radiation will be emitted and the surface will warm up.

    But greenhouse gases reduce the rate at which thermal radiation escapes to space — which means that the surface will get hotter — and it will continue to get hotter until the rate at which energy leaves the system balances the rate at which energy enters the system. Now do you understand that this is what people have been trying to say to you pretty much since you arrived here?

  140. Again, Dave, you aren’t stating your thesis plainly. What is it?

  141. I have twice started to write a comment asked BWD what his point is; what he is trying to argue, and why.

    Those times, I gave up due to lack of caring…. but this third time, the constant back-and-forth has annoyed me sufficiently to hit “Post”.

    BWD: where are you going with this? None of your comments to date have had sufficient context or advanced the discussion. Possibly this is aided by TC’s debate style, which answers everything you might have possibly meant, without ever narrowing the discussion or worrying about the direction of debate.

    BWD, I get the impression of someone out of their depth, arguing irrelevant hypotheticals rather than wondering what relevance any of this has for the real world. Please correct this impression.

    PS: When Kevin talks about your “thesis”, he means “a position or proposition that a person advances and offers to maintain by argument”. We don’t expect (or want) a huge essay, just clarity. At many universities these days, students are penalised for going over the word limit…. :-D

    • Didactylos wrote:

      At many universities these days, students are penalised for going over the word limit…. :-D

      True — but you are supposed to be at school to learn — not to get good grades!

      • I’m not criticising the length of your comments…. I’m just saying brevity is a skill, too.

        I have always been succinct to the point of terseness, so my difficulty has always been ensuring that I have made all the points I wanted to make, with sufficient clarity.

        And now I’m noticing how many synonyms I know for “laconic”. I would list them, but that would hardly be concise.

      • No worries… Actually I was trying to be funny. Imagined the words in the voice of Brother Theo from Babylon 5. Although there was a serious point or two. I wasn’t viewing myself as debating Dave as making use of the opportunity to learn and explain. I will sometimes actually view my participation in a discussion — thinking about the thoughts that others have expressed — as a form of meditation. Additionally, in my view the first obligation of any human being is to understand. Still that doesn’t mean that one has to run off at the mouth — or the keyboard. And I suppose I was doing a bit of that.

    • Thanks, Didactylos–never occurred to me that that use of “thesis” might not be self-evident. You are, of course, correct about how I intended it.

  142. Kevin McKinney,

    “OK, that clarifies things some. What I still don’t understand is what is the significance you attach to the issue of potential energy in the actual situation that exists? In the catastrophic collapse scenario that I described, that potential energy became kinetic energy as a result of falling 17 km. ”

    Only part of the air will of the air will fall the entire 17 km. Some will remain at 17 km, and some will rise. The temperature increase will be greatest at the lowest elevation.

    “In the Goddard thesis that Timothy refers to, that potential energy somehow affects temperature (while still remaining potential, which rather highlights how the “Goddard effect” is actually a perpetual-motion scheme.)”

    Potential energy is a function elevation and gravity.

    But as Timothy also notes, you don’t really seem to be arguing Goddard’s point. Yet I remain unclear just what point you are trying to make WRT potential energy.

    Potential energy is a key to understanding the lapse rate.

    BWD

  143. Comment from the hoi polloi:

    Let’s take the same hypothetical planet….say Earth, but this time it has zero GHGs. Let’s say the atmosphere is 100% nitrogen with the same surface pressure as currently exists, no water exists in any phase on this planet). My hoi polloi sense tells me that lapse rates would still exist but they would be nothing like the “dry” adiabatic lapse rates we have now (which actually compensates only for H2O phase changes, but not the H2O GH effect.

    I don’t see follow how the potential energy is the key to lapse rate.

  144. “Only part of the air will of the air will fall the entire 17 km. Some will remain at 17 km, and some will rise.”

    Does this have anything to do with the “insulated WRT gravity” concept?

    “Potential energy is a function elevation and gravity.”

    Underwhelming insight–I think we can safely categorize this as “old news.”

    “Potential energy is a key to understanding the lapse rate.”

    Sorry, I don’t think so.

  145. Timothy Chase.
    “bwdave, What happens to a balloon — and the surrounding air — as you raise the balloon from gradually to a higher altitude?”

    It depends. What are the initial air conditions? How elastic is the balloon wall, how much tension is needed to stretch it, and does it conduct heat?

    arch stanton,
    “Let’s take the same hypothetical planet….say Earth, but this time it has zero GHGs. Let’s say the atmosphere is 100% nitrogen with the same surface pressure as currently exists, no water exists in any phase on this planet).”

    The lapse rate would be g/Cp, or about 9.5°K/km.

    BWD

  146. Kevin McKinney,
    “Does this have anything to do with the “insulated WRT gravity” concept?”

    Insulated WRT gravity was the condition before the air was released.

    BWD

  147. I wrote:

    bwdave, What happens to a balloon — and the surrounding air — as you raise the balloon gradually to a higher altitude?

    bwdave responded:

    It depends. What are the initial air conditions? How elastic is the balloon wall, how much tension is needed to stretch it, and does it conduct heat?

    Ooo…, tricky!

    I’m not looking for a precise numerical answer. Just a qualitative description. But if it helps, the balloon is at the surface on a day with average temperature (say 15°C), that the balloon is somewhat elastic although it needn’t be perfectly elastic unless you really want it it to be.

    As for the thermal conductivity of the balloon wall, if this absolutely stumps you perhaps you could just set the entire problem aside and try to answer the following riddle… “Why does a polar bear have hollow hair?”

    But if you are looking for more of a challenge, you might try describing what difference the thermal conductivity will make if the balloon rises somewhat quickly, one kilometer without bursting. Or you could just assume that it is your standard latex rubber, helium-filled balloon.

    You have let go of balloons before, haven’t you? A child’s helium-filled balloon? This really isn’t some sort of trick question, but I would like to avoid a dance of the seven veils if at all possible. Particularly if you look anything like that picture I’ve seen.

  148. Thank you for your help BWD. I think I see the problem.

    By definition the adiabatic lapse rate does not allow for transfer of energy. This is no doubt a very useful criterion for calculation purposes when the rate of change is rapid. But is not realistic over the long term or when the rate of change is very gradual and we are talking about finite masses over geologic time, is it?

    Energy transfer happens.

    arch

  149. arch stanton

    “By definition the adiabatic lapse rate does not allow for transfer of energy. This is no doubt a very useful criterion for calculation purposes when the rate of change is rapid. But is not realistic over the long term or when the rate of change is very gradual and we are talking about finite masses over geologic time, is it?

    Energy transfer happens.”

    Due to the density difference and corresponding altitude difference that gravity creates in a sufficiently dense gaseous atmosphere, the energy of molecules at different elevations canl be equal equal, only when their temperatures differ.

    BWD

  150. I accidentally clicked Post Comment before editing to read:

    Due to the density difference and corresponding altitude difference that gravity creates in a sufficiently dense gaseous atmosphere, the energy of molecules at different elevations can be equal, only when their temperatures differ.

    BWD

  151. A Critique of Dave’s Derivation of Lapse Rate from Gravitational Potential Energy

    Density Difference?

    bwdave wrote:

    Due to the density difference and corresponding altitude difference that gravity creates in a sufficiently dense gaseous atmosphere, the energy of molecules at different elevations canl be equal, only when their temperatures differ.

    “Due to the density difference and corresponding altitude difference that gravity creates in a sufficiently dense gaseous atmosphere…”

    The expression “density difference” is problematic. If you had said “Due to the difference in densities” this would have a more relaxed meaning in the sense that you would be refering to the densities simply being different. But “density difference” is far more specific, referring to one density minus the other. But given the ideal gas law (or something more precise since the ideal gas law is simply an approximation) it is not the difference in densities that is important, but the ratio of densities.

    Likewise, if you are speaking of density as a function of altitude, density drops roughly as an simply exponential function of the altitude. And this means that if density is halved going from ground to half a kilometer altitude, then density will be roughly halved again going from half a kilometer altitude to a kilometer altitude. So once again it is the ratio of the densities that is important — not the arithematic difference.
    *
    Molecules, Energy and Temperature

    “… the energy of molecules at different elevations can be equal, only when their temperatures differ.”

    This is problematic on a couple of different levels. First, a molecule cannot have a temperature. Gases can have temperature but not the individual molecules that compose them. Temperature is a of the gas, not the individual molecules that compose it. Second, the temperature at two different altitudes could easily be the same and the molecules have the same sum of(gravitational) potential and kinetic energy if the molecule at the lower altitude has less than the mean kinetic energy of molecules in that region, or if the molecule at the higher altitude more than the mean of molecules at its altitude.
    *
    Altitude, Energy and Temperature

    But there is something else I find problematic: why you do expect the energy of molecules to be equal at different altitudes?

    I believe this goes back to your view that the lapse rate is somehow explained by the transformation of potential energy into kinetic. We know that if you drop a rock total energy is conserved since the sum of the potential energy and the kinetic remains constant. And this would seem to be essentially what you were thinking with your hypothetical experiment in which we “drop” the atmosphere on to the planet, except that rather than thinking of a single rock you are thinking of the individual molecules of that atmosphere.

    Earlier you stated regarding Kevin’s response to your thought experiment:

    Your answer, “:given that the first thing that happens is that 4 x 10e18 kg of air falls 17 km, things get very, very hot. Potential energy converted to kinetic. . .”, even with only 80% of the mass, is also pretty much what I would expect to happen, and is what I have been trying to say about the potential energy difference with altitude.

    … and here we have it again, that somehow the lapse rate is explained in terms of gravitational potential energy.

    But there is a fairly significant problem — even in the case of a single central mass. The velocity that an object will pick up falling from one altitude to another is independent of its mass. This means that if two objects fall from one altitude to another starting from a state of rest they will have the same velocity at the latter altitude. So for example, if two objects fall from infinity to a given altitude their velocity upon reaching that altitude will be the same, name the escape velocity:

    v_e=\sqrt{\frac{2GM}{r}}

    However, kinetic energy is half the mass times the square of the speed.

    So for a given gas temperature is proportional to the mean kinetic energy of the molecules of a given gas:

    \langle \frac{1}{2}mv^2 \rangle = \frac{3}{2}kT

    Furthermore, where the local mix of gases are all the same temperature the mean kinetic energy the molecules of different gases will all be the same. The mean kinetic energy will be the same even though the masses of the molecules of different gases are different.

    So if the mean kinetic energy of each species of molecule is the same at a given altitude where each species has a different molecular mass, then for a fall from one specific altitude to another at most only one species of molecule will have a mean kinetic energy equal to the potential energy lost by members of that species in going from one altitude to the other. Thus the difference in temperature between two altitudes cannot be explained in terms of the difference in molecular potential energy between one altitude and the other.

    \langle \frac{1}{2}mv^2 \rangle = \frac{3}{2}kT
    *
    Adiabatic Exchange of Energy

    Incidentally there was another mistake made — one by arch stanton — which however you did not correct when you quoted the mistaken passage.

    arch stanton wrote:

    By definition the adiabatic lapse rate does not allow for transfer of energy.

    An adiabtic process is one that does not involve the exchange of heat. However, an adiabatic process may involve the exchange of energy. For example, if a piston compresses a gas no heat is transferred, but energy is transferred causing the gas to warm.

    Then if the gas expands, pushing the piston outwards, this does not involve the transfer of heat, but it does involve the use of energy to do work. And the same would apply in the case of a rising balloon where the internal pressure of the balloon stretches the rubber, doing work as the balloon rises. This is analogous to the stretching or compression of a spring.

    Alternatively one might consider a balloon that is infinitely elastic. The parcel of air within it is unconstrained by the balloon itself — but only by the surrounding air to the extent that it is constrained. Even then as the parcel of air rises and expands it is doing work — namely by pushing against the air just outside of the parcel.

    As it expands force (where the force per unit area is atmospheric at the given altitude) is applied over the distance of expansion meaning that work is being done. And as work is done the thermal energy of the parcel drops — which implies that the temperature drops. During an adiabatic process of expansion thermal energy is being used to do work, cooling the parcel of air — just as the parcel of air that pushes back on the piston does work. Anyway, for those who are interested, the dry adiabatic lapse rate is derived here.

    • Timothy, you are a patient man.

      I’m not, so much–or at least not in this regard, today.

      So, how about an actual experiment for our friend Dave (or anyone interested) to try?

      Requirements:

      –A rock;
      –A car;
      –The most sensitive and accurate thermometer you care to use;
      –A cooler;
      –A large hill.

      Put the rock and the thermometer in the cooler, with the top open. The thermometer should be in good thermal contact with the rock. Drive to the base of the hill, park with the engine and the air conditioning running until the thermometer reading remains stable for a specified interval. Record the temperature of the rock/thermometer system.

      Now, close the top of the cooler and drive to the top of the hill. Open the cooler and read the temperature. Did it change?

      If not, why not? After all, you increased the rock’s potential energy by lifting it to the top of the hill, didn’t you?

      But we all know that rocks don’t warm just because you lift them. (Though the waste heat generated by your muscles may warm you.) Potential energy has no, nada, zip, zilch effect on temperature–unless and until the appropriate interaction transforms that potential energy into kinetic energy. For example, suppose there is a nice cliff at the top of that hill–drop the rock off it, and if it survives the fall intact, you (or better, an assistant) may be able to measure an increase in temperature, if you’re quick, clever and skilled enough.

  152. Thank you for your clear explanation and patience Timothy Chase. I realize I also made other erroneous assumptions in my original post. I discovered these myself when I checked BWD’s formula for adiabatic lapse rate.

    arch

  153. CORRECTION

    In the first sentence of the last paragraph of my comment datetime stamped September 17, 2010 at 8:31 am I should have written:

    As it expands force (where the force per unit area is atmospheric pressure at the given altitude) is applied over the distance of expansion meaning that work is being done.

    Sorry. It was getting late (Seattle time), I was tired — and there was some discussion regarding who would feed the cats and then make sure the tom didn’t grab all the food– which was distracting. (The tom is affectionate but at times a glutton.)

  154. Timothy Chase,

    I appreciate your critique of my writing. “Density difference” was too specific, and is different than “difference in densities”, which is what I intended to mean. I will try to be more careful. Thank you.

    “An adiab[a]tic process is one that does not involve the exchange of heat”,
    and an adiabatic process that also involves no work, while imaginary in practice, will result in conditions having equal total energy. This is where I thought arch was coming from.

    Earth’s atmospheric density declines with altitude, within the troposphere.

    “Likewise, if you are speaking of density as a function of altitude, density drops roughly as an simply exponential function of the altitude”

    This is incorrect. The density to altitude relationship of Earth’s troposphere is very close to linear (gravity does vary a little, with altitude).

    … the energy of molecules at different elevations can be equal, only when their temperatures differ.

    “This is problematic on a couple of different levels. First, a molecule cannot have a temperature.”

    While I thought my initial condition of a “sufficiently dense atmosphere” should have covered this, I believe I also backed this up by saying molecules. The difference between this and molecule is that I have added an s to the end, representing plural, as in more than one molecule; without which, the temperature analogous to the frequency of collisions between molecules or boundaries would not be evident..

    “Second, the temperature at two different altitudes could easily be the same and the molecules have the same sum of(gravitational) potential and kinetic energy if the molecule at the lower altitude has less than the mean kinetic energy of molecules in that region, or if the molecule at the higher altitude more than the mean of molecules at its altitude”

    Yes, perhaps instantaneously, maybe during a rain shower; but will they be there in a state of equilibrium?

    “… and here we have it again, that somehow the lapse rate is explained in terms of gravitational potential energy.
    But there is a fairly significant problem — even in the case of a single central mass. The velocity that an object will pick up falling from one altitude to another is independent of its mass. This means that if two objects fall from one altitude to another starting from a state of rest they will have the same velocity at the latter altitude. So for example, if two objects fall from infinity to a given altitude their velocity upon reaching that altitude will be the same, name the escape velocity:

    v_e=\sqrt{\frac{2GM}{r}}

    However, kinetic energy is half the mass times the square of the speed.

    So for a given gas temperature is proportional to the mean kinetic energy of the molecules of a given gas:

    \langle \frac{1}{2}mv^2 \rangle = \frac{3}{2}kT”

    This is not quite correct. At a given pressure, temperature will be proportional to the mean kinetic energy of the molecules of a given gas, or in a given volume, pressure will be proportional to temperature.

    “Furthermore, where the local mix of gases are all the same temperature the mean kinetic energy the molecules of different gases will all be the same. The mean kinetic energy will be the same even though the masses of the molecules of different gases are different.”

    Doesn’t the term “mean” imply that there may have been different individual values ?

    Sorry, I can’t figure out what you are trying to say here.:
    “So if the mean kinetic energy of each species of molecule is the same at a given altitude where each species has a different molecular mass, then for a fall from one specific altitude to another at most only one species of molecule will have a mean kinetic energy equal to the potential energy lost by members of that species in going from one altitude to the other. Thus the difference in temperature between two altitudes cannot be explained in terms of the difference in molecular potential energy between one altitude and the other.”

    Let’s look for a moment at total energy of a unit mass (not individual molecules). Total energy is equal to the sum of internal energy( U,) plus kinetic energy (v^2/2 or KE) and potential energy (gz or PE). Total energy equals U + v^2/2 + gz, or U + KE + PE.

    Let’s imagine a unit mass that is a contiguous parcel of air, with each molecule within that parcel located within a micrometer of the same height above the surface, and for simplicity assume that the parcel is dry, and the gravitational field is uniform with respect to surface location (latitude or longitude) above and beneath the parcel. If the parcel if it is raised or lowered without work being done or heat exchanged, what happens to its total energy?

    BWD

  155. Okay, I think I understand the meaning and derivation of the dry and moist adiabatic lapse rates. Thank you, Wikipedia and Timothy Chase.

    The balloon thought experiment is very apropos, since it relates exactly to the assumptions used in the concept of an adiabatic lapse rate. But BWD’s comments are just really, really confusing.

    You know, I think the “key” to understanding the dry adiabatic lapse rate and BWD’s theories may actually be hydrostatic equilibrium. And by “understand”, I mean “spot the holes”.

    This thread is way too long.

  156. On an earlier subject, I’m trying to find a definition for “well mixed gas”. It’s not really nailed down anywhere.

    Clearly, “well mixed gas” does not imply exactly homogeneous concentrations in a dynamic atmosphere. Taking CO2, there are massive carbon sources and sinks constantly altering surface concentration, which is then diffused gradually and transported by air movements.

    Also fairly clear – the definition cannot apply above the turbopause. No mixing makes “well mixed” meaningless.

    So that leaves us with a constant vertical (relative) concentration, assuming that the gases have mixed fully.

    Is this explained somewhere?

  157. Game Over

    “Density Difference”

    bwdave wrote:

    I appreciate your critique of my writing. “Density difference” was too specific, and is different than “difference in densities”, which is what I intended to mean. I will try to be more careful. Thank you.

    It is a very good indication that even after trying to debate people for two weeks who clearly know more than you do you haven’t a clue what you are talking about. But there have been a fair number red flags of this nature pretty much since the beginning.

    Density an Exponential Function of Altitude

    I had stated:

    Likewise, if you are speaking of density as a function of altitude, density drops roughly as a simple exponential function of the altitude

    bwdave responds:

    This is incorrect. The density to altitude relationship of Earth’s troposphere is very close to linear (gravity does vary a little, with altitude).

    For the sake of accuracy, scientists and engineers will refer to geopotential altitude — which differs slightly from the actual altitude (less than 1% at an altitude of 40 km) in that it takes into account how gravitational force is proportional to the inverse square of the distance. But as an approximation and for the sake of simplicity, given the fact that gravitational force is roughly constant within the atmosphere one may use altitude instead of geopotential altitude as I have acknowledged and done previously.

    But now I will turn to the equations that make use of geopotential altitude, and I would recommend the following reference:

    The Hydrostatic Equations
    Ralph L. Carmichael
    January 23, 2003
    http://www.pdas.com/hydro.pdf

    The author gives the equation of state for a perfect gas as…

    \rho=\frac{MP}{RT}

    … where \rho, \ M, \ P, \ R \ and \ T are the air density, mean molecular weight of air, the air pressure and the universal gas constant, respectively. Likewise, assuming a constant lapse rate, he gives the temperature as a function of geopotential height as…

    T = T_b + L(H-H_b)

    … where T, \ T_b, \ L,\ H \ and \ H_b are the temperature, base temperature, temperature gradient, geopotential height and base geopotential height, respectively.

    Under the unrealistic assumption that temperature is constant (that is, an isothermal-barotropic atmosphere) he arrives at an equation (14) which when rearranged to solve for air pressure is:

    P=P_be^{\left(-\frac{GM(H-H_b)}{RT_b}\right)}

    … where G is the gravitational constant and M is that mass of the earth. This is an equation of the same form as the one I had given previously for air pressure in an isothermal-barotropic atmosphere:

    P_h = P_0e^{-h/H}

    Substituting his equation for air pressure in an isothermal-barotropic atmosphere into the equation of state gives us the equation for air density :

    \rho=\left(\frac{MP_b}{RT_b}\right)e^{\left(-\frac{GM(H-H_b)}{RT_b}\right)}

    … which is an equation of the same form as I had given for air density in an isothermal-barotropic atmosphere:

    \rho_h =\rho_0e^{-h/H}

    He also does the same set of calculations where the temperature gradient is not assumed to be equal to zero but merely constant. Rearranging his equation (15) for air pressure and substituting the equation for temperature with constant gradient gives us:

    P=P_b \left( \frac{T_b+L(H-H_b)}{T_b}\right) ^{-\frac{g_0M}{RL}}

    … and then substituting this and the equation for temperature with constant temperature gradient into the equation of state gives us:

    \rho=\left(\frac{MP_b}{R(T_b + L(H-H_b))}\right) \left( \frac{T_b+L(H-H_b)}{T_b}\right) ^{-\frac{g_0M}{RL}}

    Now I have a few observations to make. Earlier you wouldn’t accept the isothermal-barotropic atmosphere as a reasonable approximation and model for the actual atmosphere. You argued that it might be a good model for a liquid, but not a gaseous atmosphere. (!?) Apparently the author of the paper I have cited disagrees — as does every other author that studies the isothermal-barotropic atmosphere.

    However, given simply the equation of state, equation for temperature with constant gradient and fundamental hydrostatic equation it is possible to derive the equations for air pressure and air density for a model that is no longer isothermal. Both equations are exponential in nature — although no longer the simple exponential functions one arrives at under the assumption of constant temperature.

    Now you had stated, “The density to altitude relationship of Earth’s troposphere is very close to linear (gravity does vary a little, with altitude).” However, given both sets of equations, one where temperature is held constant and the other where temperature gradient is held constant we can see that air pressure and air density are not linear functions of altitude but that the functions are in fact exponential in nature.

    The US Standard Atmosphere

    However, rather than simply rely upon the equations from the above paper I thought that I would consult the US Standard Atmosphere of 1976:

    The Engineering ToolBox: US Standard Atmosphere
    http://www.engineeringtoolbox.com/standard-atmosphere-d_604.html

    I will be using the metric figures. Using geopotential altitudes for 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 15000, 20000, 25000, 30000 and 40000 meters and the corresponding air pressures and air densities I decided to run some comparisons for trendlines. For something to compare the results against I chose to calculate trendlines for air pressure, then I tested linear and exponential trendlines for closeness of fit using R^2 (R-squared).

    For air pressure a linear trendline has a coefficient of determination R-squared of 0.729, however the exponential trendline has R-squared = 0.9992. So clearly the exponential trendline is a better fit. The results barely differ when we turn to air density. For the linear trendline we have R-squared at 0.7912 and for the exponential trendline it is 0.9955. The exponential trendline is clearly a much better fit for both air pressure and air density.

    The Temperature of Molecules

    bwdave had written:

    … the energy of molecules at different elevations can be equal, only when their temperatures differ.

    I had responded:

    This is problematic on a couple of different levels. First, a molecule cannot have a temperature. Gases can have temperature but not the individual molecules that compose them.

    bwdave now complains:

    While I thought my initial condition of a “sufficiently dense atmosphere” should have covered this, I believe I also backed this up by saying molecules. The difference between this and molecule is that I have added an s to the end, representing plural, as in more than one molecule; without which, the temperature analogous to the frequency of collisions between molecules or boundaries would not be evident.

    “Molecules at different elevations” may easily mean just two molecules, one at one elevation, the other at a different elevation. And someone familiar with physics would not speak of the molecules of a gas having a temperature or of the molecules of the atmosphere as having a temperature. They would speak of the gas as having a temperature or an atmosphere as having a temperature — because to do otherwise would be a sure sign that one doesn’t know what one is talking about.

    Temperature and Mean Molecular Kinetic Energy

    I wrote:

    \langle \frac{1}{2}mv^2 \rangle = \frac{3}{2}kT

    bwdave responded:

    This is not quite correct. At a given pressure, temperature will be proportional to the mean kinetic energy of the molecules of a given gas, or in a given volume, pressure will be proportional to temperature.

    See the third equation here:

    KE_{avg}=\bar{\left[\frac{1}{2}mv^2\right]}=\frac{3}{2}kT

    Kinetic Temperature
    http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kintem.html

    It is the same equation I gave above but using a slightly different notation — bar (which should be over everything in the square brackets) and angle brackets both imply that you should take the mean. And the equation is derived from the ideal gas law. As such the qualification “At a given temperature” is entirely superfluous. You want to insist on including it? Take it up with the physics departments. Of every university and college that has one.

    What “Mean” Means

    I wrote:

    Furthermore, where the local mix of gases are all the same temperature the mean kinetic energy the molecules of different gases will all be the same. The mean kinetic energy will be the same even though the masses of the molecules of different gases are different.

    bwdave responded:

    Doesn’t the term “mean” imply that there may have been different individual values ?

    You win a prize! The mean is the arithematic average. My equation indicates that you should calculate the mean by means of the angle brackets. The equation at hyperphysics? They use the bar-notation. But it means the same thing.

    Rise in Temperature Due to Drop in Potential Energy?

    I had written:

    So if the mean kinetic energy of each species of molecule is the same at a given altitude where each species has a different molecular mass, then for a fall from one specific altitude to another at most only one species of molecule will have a mean kinetic energy equal to the potential energy lost by members of that species in going from one altitude to the other. Thus the difference in temperature between two altitudes cannot be explained in terms of the difference in molecular potential energy between one altitude and the other.

    bwdave responds:

    Sorry, I can’t figure out what you are trying to say here.

    It means that the temperature corresponding to the mean kinetic energy of molecules will not be the same for molecules falling from the same height if the molecules have different molecular masses. For example, water molecules, carbon dioxide molecules and nitrogen molecules are different species of molecule and all have different masses. Because they have different masses at the same height they will have different potential energies. If they drop the same distance their kinetic energies will not be the same. However, given your theory that attempts to explain lapse rate as a simple function of altitude they would have to be. Therefore you should probably not seek a position in a physics department.

    Afterward

    bwdave writes:

    Let’s look for a moment at total energy of a unit mass (not individual molecules)…

    Give it up, Dave. I am not a physics professor or even a physics student. I am a philosophy major with a master’s degree in the liberal arts. But you and I aren’t even in the same league.

    And you want to criticize the experts? You want to argue that drop in temperature with altitude is due the increasing gravitational potential rather than the adiabatic exchange of energy? To tell them that their satellites can’t measure the opacity of the atmosphere? That when carbon dioxide absorbs infrared radiation its not going to heat up? Please! Big Wave Dave — you are in way over your head. Time for you to get to shore — and maybe take a class or several.

  158. Timothy Chase,

    Density verses Altitude

    Look at the graph here.
    http://www.engineeringtoolbox.com/air-altitude-density-volume-d_195.html

    Nothing in the paper you cited (http://www.pdas.com/hydro.pdf) disagrees with anything I have tried to say, there is no mention of the atmosphere being isothermal, and the paper does define lapse rate lapse rate as a simple function of altitude.

    Sometimes what you say that I want to argue suggests that you may be reading things in that aren’t there.

    My credentials read BS JD PE, I have worked primarily in the fields of thermodynamics, heat transfer and fluid mechanics for close to forty years. I have worked side by side with colleagues who have science masters doctorate degrees . I have authored four patents, created complex computer models of energy systems including large scale solar thermal electric generating, and have developed new innovative devices. I agree, you and I are not in the same league, but I fear your concerns may be misplaced.

    BWD

    Are you really sure whose

  159. Rattus Norvegicus

    Dave, here is the key paragraph from the Wikipedia article on the lapse rate:

    Under these conditions when the air rises (for instance, by convection) it expands, because the pressure is lower at higher altitudes. As the air parcel expands, it pushes on the air around it, doing work. Since the parcel does work but gains no heat, it loses internal energy so that its temperature decreases. The rate of temperature decrease is 9.8 °C per 1,000 m. (The reverse occurs for a sinking parcel of air.)[7]

    You, as Timothy pointed out, are way out of your league here, unless you have a theory which overturns the ideal gas law…

  160. CORRECTION

    In the comment “Game Over” section “Temperature and Mean Molecular Kinetic Energy” I had written:

    See the third equation here:

    … followed by:

    KE_{avg}=\bar{\left[\frac{1}{2}mv^2\right]}=\frac{3}{2}kT

    Kinetic Temperature
    http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kintem.html

    … then stated:

    It is the same equation I gave above but using a slightly different notation — bar (which should be over everything in the square brackets) and angle brackets both imply that you should take the mean. And the equation is derived from the ideal gas law. As such the qualification “At a given temperature” is entirely superfluous. You want to insist on including it? Take it up with the physics departments. Of every university and college that has one.

    As should be obvious given the context, the bolded word temperature should have been pressure.

  161. Rattus Norvegicus,

    I’m unclear about what you feel I may have misrepresented related to the ideal gas law, or how the wikipedia passage addresses conditions needed for each of two equal mass parcels of dry located at different elevations within the troposphere to have equal total energies. Which, I thought, was the subject being disxussed.

    BWD

  162. Timothy Chase,

    Kinetic energy is only part of total energy, there is also internal energy and potential energy. Total energy is the sum of the three.

    BWD

  163. CORRECTION
    In my posted reply to Rattus Norvegicus , I left out the word “air” between “dry” and “located”, and I mistyped “discussed”.

    It should have read:

    Rattus Norvegicus,

    I’m unclear about what you feel I may have misrepresented related to the ideal gas law, or how the wikipedia passage addresses conditions needed for each of two equal mass parcels of dry air located at different elevations within the troposphere to have equal total energies. Which, I thought, was the subject being discussed.

    BWD

  164. If you include potential energy the gas is not ideal. The three conditions for a gas to behave ideally are

    1. The size of the molecules/atoms is vanishingly small
    2. There are no forces which act on the molecules except during collisions with the wall of the container that they are in
    3. The motion of the molecules is random

    You can relax 1 and 2 to allow perfectly elastic collisions with each other.

    In practice what this means is that you use the hydrodynamic equation to get the pressure profile.

  165. Timothy Chase,

    If you carefully read The Hydrostatic Equations by Ralph L. Carmichael, you will see that M is defined as “the mean molecular weight of air”, not the mass of the earth.

    In the parts starting with “The Perfect Gas Law” you will see that Mr. Carmichael states that rho =MP/RT and uses the perfect gas law to derive equation 8, dP = – (MP/RT)GdH and goes on to say that “Within an atmospheric layer, the temperature T is a linear function of geopotential altitude H”

    He then introduces the case where L = zero, but offers no explanation why, or where L might be zero. (it is nearly zero in bodies of water)

    In his closing statement he summarizes the benefit of using “geopotential altitude” and a gravitational constant verses using actual altitude and the corresponding gravity, as a means to simplify calculations; which seems to be the primary point of this paper.

    BWD

  166. Okay, please will someone tell me if I have this straight:

    The adiabatic lapse rate is based on an ideal parcel of air moving (upward). When the parcel is at a low altitude, it has less potential energy then when it is at a higher altitude. This difference in potential energy is equal to the work done in raising the parcel of air.

    Lapse rate does not consider potential energy because it doesn’t involve a change in heat, so the force involved in raising the parcel of air isn’t relevant. Therefore, the total internal energy of the parcel is different at each elevation – which is fine, since this isn’t a closed system.

    And let’s be clear: we are discussing gravitational potential energy here, not any other kind of potential energy.

    As a result, the statement “Potential energy is a key to understanding the lapse rate” is missing a negation.

    Am I right?

  167. It seems I missed where BigWaveDave wrote on September 3, 2010

    :It seems there are a lot of people who don’t understand the dry adiabatic lapse rate and its relation to the ideal gas law. Perhaps changing the form of PV=nRT to P=”rho”RT might help clear up some of the confusion.

    He has been playing village idiot all this time.

  168. It has been dance of the seven veils — except with someone who is merely playing stupid — and who hinted that he actually understood the reason for the dry air lapse rate early on.

    Dave, I don’t think that anyone here has disputed the existence of a linear lapse rate in the troposphere. Not something that we normally put a great deal of time into as we are more concerned with radiation balance at the top of the atmosphere.

    But if you are bright enough to understand the role of the perfect gas equation in determining the lapse rate within the troposphere then you are also bright enough to understand that physicists don’t believe that the greenhouse effect has much of anything to do with the heat capacity of carbon dioxide or how it changes the heat capacity of the atmosphere.

    Despite trying to argue against such a strawman:

    The effect of 105 ppm (vol.) CO2, representing an increase from 280 ppm to 385 ppm, reduces air’s heat capacity about 0.0016% , so to transport the same amount of heat, including the 3X contribution of latent heats in the 1% fraction of water vapor to ice, the air would have to cool from ~288.001°C verses from 288°C,. to 273°C.

    You are also bright enough to understand that increasing the concentration of carbon dioxide will increase the height from which thermal radiation finally escapes. That radiation will get emitted from higher up in the atmosphere where it is colder. That this effective radiating layer has to warm up to emit upwelling infrared sufficient for energy leaving the system to balance the rate at which energy enters the system. And given the increased distance from the effective radiating layer to the surface and a constant lapse rate this will imply a warmer surface.

    In any case, I don’t mind being made a fool and I most certainly don’t mind learning something. As I wrote earlier:

    … in my view the first obligation of any human being is to understand.

  169. Chris Colose kicked off a bit of a stink by posting about Goddard’s latest folly on the “Jerk” thread, but for the sake of thread consistency and non-hijacking I’m posting here.

    Not that it’s actually anything earth-shattering, but I simply couldn’t resist preserving for posterity this little gem from Stevengoddard Lookatmedes.

    Phil. says:
    April 15, 2011 at 6:11 pm

    Yes, they are the same, but the gas laws don’t determine the temperature of the planets.

    stevengoddard says:
    April 15, 2011 at 6:25 pm

    Yes they do. Tell me P V and n and I will tell you T

    Just… wow!

    So it doesn’t matter at all if the atmosphere is 100% nitrogen, or 100% xenon, or 100% carbon dioxide?

    Personally, I’d want to know the atmosphere’s chemical composition and mass, the planet’s orbital radius, and the sun’s EM output amongst other things, but that’s just me.

    The guy’s surely an unrecognised genius if he had predict the temperature of a planet’s atmophere with no more than P, V, and n.

    Or not.

  170. Wherein Goddard pwns (…or not) Chris Colose, so much so that Lookatmedes starts a thread to crow about it:

    chriscolose says:
    April 16, 2011 at 1:12 am

    suyts,

    Atmospheric scientists don’t typically deal with the form of equation of state being discussed here, because we can’t go out and measure the ‘volume’ of an air parcel or an air mass. Rather, p=ρR’T is a typical equation used in our field (note the R’ has a different meaning than the R in pV=nRT, since you need to account for the mean molecular weight of the atmosphere; in either case we can think of it as a constant so it doesn’t matter here)

    Concerning the argument about the thickness of a warm vs. cold body of air, it is easily demonstrated that if you fix two pressure surfaces (say, between 1000 and 500 mb), the thickness between those two layers (Δz) is increased for warmer air. I leave it as an exercise to show that Δz = z2-z1~ (R’ T/g)*ln(p1/p2), where T is the average column temperature between the two pressure surfaces p1 and p2 (hint: use the hydrostatic equation and the ideal gas law I presented here)….the important point that a higher T corresponds to a higher Δz.

    stevengoddard says:
    April 16, 2011 at 1:14 am

    http://stevengoddard.wordpress.com/2011/04/16/ivy-league-alarmist-proves-my-point/

    • Goddard is actually correct about some things. The ideal gas law doesn’t apply everywhere (certainly not as you get close to absolute zero!) but it’s not a bad approximation for most behavior in Earth’s atmosphere – as Chris’s statement indicates also. The thing is – to determine T he needs two numbers, p and V. Where do those numbers come from? That’s what you should be asking…

      That is, a given atmosphere’s density and pressure (and temperature) profiles are not pre-determined by some fundamental law of physics inherent in that atmosphere. What are our starting criteria? We might specify, say, the total mass (and composition) of the atmosphere. We would likely have the planetary radius, and so know the relevant surface area. Clearly the planet’s gravitational constant factors in, drawing the atmosphere closer in as gravity increases.

      So, to Steven Goddard or anybody else who thinks along those lines – show how you would derive surface temperature given those physically relevant starting criteria, rather than pressure and density.

      Thinking you can use pressure to determine temperature is circular reasoning – if one is causative of the other, the same holds in reverse – temperature can be thought of as the cause of pressure in a given region (and as Chris mentioned, density also varies slightly). If temperature is free to vary, then pressure (with some admixture of density) is equally free to vary. If pressure (and density) is fixed, temperature is already fixed and we’re not discussing anything interesting. The interesting question is how pressure got to be that way. What’s your argument for that?

      • Arthur, that’s essentially to where I was hoping to goad Goddard.

        I don’t think that anyone disputes that the ideal gas law describes gaseous conditions well: the thing that seems to be slipping past Goddard’s notice is the matter of cause versus effect.

        If he’s not too proud he might actually read this, and many other threads, and begin to understand that he has his cart before his horse.

  171. I blame the American education system. Some teacher somewhere utterly failed to impress upon Stevie-boy the very important piece of information that he is an idiot.

  172. A non-responsive “answer.”

    What a shock.

    • Stevie can’t even pass a Turing test.

      • Goddard is back at it again,
        https://stevengoddard.wordpress.com/2011/04/17/what-would-the-temperature-be-in-death-valley-if/

        I left one comment, but I don’t know how much longer I can deal with this…

      • Rattus Norvegicus

        Gawd. The stupid is strong with that crowd…

      • There are certainly some great Dunning-Kruger exponents there. Can anything be done? I doubt that such unshakeable belief, utter lack of scepticism, and unwillingness to learn can be countered with any brief attempts at education. Those minds are probably fixed in that state until they die.

      • Hmm, correct me if I’m wrong, but if you were to scale up Death Valley such that it was a 5km deep valley that could be heated by the sun at the same way that it is at present, it is indeed true that it would be warmer than it is now.

        But this doesn’t relate to the temperature of Venus in the slightest. I will admit that despite having a degree in meteorology I find the whole Venus argument confusing (despite reading many explanations) but it seems to be Goddard has highlighted a red herring in that link, because

        i) if you sliced 5km off the surface of the Earth everywhere it would still have the same temperature, and

        ii) if instead the atmosphere* was such that the surface pressure everywhere is what it would be at the bottom of a 5km deep trench, the surface temperature would remain unchanged because the surface pressure and total volume are both higher.

        *this assumes that the greenhouse effect is unchanged in this new atmosphere, I think this necessitates the concentrations of GHGs decreasing.

  173. TrueSceptic,
    Actually these guys make Dunning and Kruger look naive–after all, remember that they ultimately concluded that education could not only increase competence, but also lead to more realistic assessment of competence. These guys…well, the learning curve doesn’t have a positive slope.

  174. Stu,

    where are you confused with Venus? There’s at least three things being talked about in this Goddard back-and-forth. The first one is the runaway greenhouse process itself, which *is not* because of a very high CO2 atmosphere (in fact a runaway occurs largely independently of the CO2 concentration, and for many situations would probably happen in a low-CO2 environment because weathering could be very efficient). The second is why Venus is so hot today, which is largely because of CO2, but there’s some trace amounts of SO2 and H2O that matter too. The third is Goddard’s “pressure” argument, which presumably exists completely separate from the reality of energy balance.

    The problem with Goddard is that you cannot arbitrarily select your profiles of temperature, pressure, density, and composition independently. Sure, if you select some reference temperature (T0) and pressure (p0) at sea level, then descending to a higher pressure would cause T to increase, but what factors determine (T0,p0)? The dry adiabat gives a relation between temperature and pressure, if you know the reference values. It is,

    T=T0*(p/p0)^(R/cp)

    What Steve Goddard wants to do is specify a pressure at some point on Venus, say that it is high, and with no other information, determine that T must be high. This just doesn’t work

    • Thanks Chris, the trouble I have is conceptually tying together all the processes in Venus’ atmosphere that lead to its very high surface temperature. I guess I’m just used to what happens here on Earth! That’s not to say that I can’t plainly see that Goddard’s arguments about why Venus is hot are wrong; I’d just have a hard time articulating exactly why.

  175. Against my better judgment, I commented at SG’s blog:

    OK–how can one reconcile the assertion that the energy heating Earth and Venus comes from isolation (made elesewhere by SG) with the assertion that pressure completely determines temperature? (That is what is being asserted by this (mis)-use of the ideal gas law.)

    Do tell.

    That seems to me to go to the incoherent heart of his argument.

  176. In response, Goddard accused me of raising a strawman, to which I replied:

    I did read it.

    Your use of the ideal gas law implies that atmospheric temperature are determined by pressure. You reinforce this viewpoint explicitly in several comments–for example, 4/18 at 5:13 PM, below:

    “. . . it is the pressure of non-GHG gasses which keep Earth’s temperature up.”

    This leaves no room for insolation to affect temperature, which is counterintuitive, to say the least. I didn’t raise any new issues here; I simply asked you to reconcile this idea about pressure with statements you have made elsewhere–for example, 4/18 at 4:13 PM, above:

    “The Sun heats the system, obviously.”

    Frankly, I don’t see how these statements can be reconciled, and therefore I don’t see you presenting a coherent picture of how atmospheres react to solar heating.

    Bernard and Chris Colose have engaged him at length; particularly telling, I thought, was the latter’s invocation of the case of Mercury, which of course has a very high temperature with a very thin atmosphere indeed.

    But watching the equivocations, evasions, and sophistry SG employs reminded me forcefully of my uncle, who, when I was a kid, used to argue with me that the world was really flat. My uncle, I think, was trying to provide a little harmless mental exercise.

    By contrast I now believe Goddard to be a pure troll–albeit one with the initiative to build his own bridge under which to lurk. (Yes, I know that’s dubious etymology for an internet “troll.” But the metaphor strikes me as a good one.) After this interaction, I think he’s both less stupid and less sincere than proposed by some here. FWIW.

    • arch stanton

      “…I think he’s both less stupid and less sincere than proposed by some here. FWIW.”

      I agree, and would say this comment also applies to SG’s previous “host”.

      Hanlon’s razor is quoted too often. IMO.

  177. Hmm. Troll? Idiot? How about lying sack of rat feces?

    • Yebbut but you would simply be accused of ad hom (it’s OK for them to do it all the time but not for anyone who tries to correct them).

  178. To be fair to Goddard he does admit that the energy originally comes from the sun.

    My first gripe is that he, all too often, frames the argument so that non-knowledgable people of a denialist bent take his comments as meaning that the source of the heat that warms a thick atmosphere is its pressure. Whether this happens through ignorance or malice I cannot say.

    My second issue with Goddard is that he skirts around discussing the additional impact on atmospheric warming that greenhouse gases have. He mostly waves his hands and says that that line of questioning is a strawman or some-such, and again leaves his followers with the impression that the effect is insignificant or, in the minds of the more recalcitrant denialists, that is is non-existent.

    Leading on from this second point, I suppose it should be said that the abiotic and biotic effects of even slight changes in temperature regimes can be profound, so the whole exercise in rabbitting on about the effect of pressure is itself a strawman. What matters to us, here on earth, is what a doubling, or more, of CO2 in the atmosphere will do for conditions that are currently conducive to life and society on the planet.

    Again, whether Goddard is distracting from this fundamental point through ignorance or through malice, I cannot say.

    • Goddard’s problem is that he doesn’t do the math before drawing conclusions. He draws conclusions and then tries to do math that appears to support them. That’s what makes mim a special brand of idiot.

  179. Hello,
    PArdon my ignorance, but I was wondering if someone could help my intuition as to where Goddard is going wrong. I can fully accept that he is, but it’s hard for me to follow precisely why. I have read through the comments here and would like to pose some follow up questions to the points covered:

    1) Some have talked about the difference between equilibrium conditions and the process of “compression” while it is occurring. pV=nRT however does not have derivative terms, and applies in equilibrium. So, if one were to suddenly increase p (say by injecting 90 bars of N2 into the air) and let the system equilibriate, the only way I see for T not to rise is for V to decrease; but does the volume of the atmosphere really change that much? If I am applying this completely wrong please let me know.

    2) Is Goddard correct concerning his hypothetical situations in which you dig a hole 5 km deep? That is, would the temperature that deep really be (10 K/km)*(5 km)=50 K warmer than the surface. I guess I’m confused as to why these boundaries (such as the bottom of the hole, the surface, etc) are significant in any way.

    3) Could someone elaborate on Chris vs. Goddard concerning the influence of the GHG’s on the lapse rate. Chris claims Goddard’s derivation was incorrect, but Goddard maintains independence of the adaibatic lapse rate and GHG’s.

    • AC, well, for one, how do you define the “volume” of the atmosphere? There is no outer boundary. The density decreases exponentially with height. The gas molecules are in a gravitational potential and on and on. It’s an absolutely absurd idea to apply the ideal gas law in that form to the atmosphere. Goddard is trying to apply high school physics. It doesn’t work.

    • AC,
      Regarding question 1.
      As others have remarked, Goddard is thinking about this barse ackward, and your question kind of does the same – you don’t really add pressure to the system, rather you change some other quantity and a change in pressure results. Your example works in reverse – decreasing volume will result in an increase in pressure (in practice, temperature will also rise before returning to equilibrium). Equally, heating the gas will increase the pressure if other variables are held constant.

      But here’s the thing – you don’t add “90 bars of N2″. You add enough molecules of N2 to cause the pressure to rise by 90 bars. You aren’t directly changing p, but n; n rises, so to balance the equation, either p or V or both must also rise (T may or may not). Certainly, increasing the pressure will not cause the volume to decrease, though the reverse will.

      • Oops!
        Hit post while still editing.
        The last sentence should read: “Certainly, increasing the pressure will not cause the volume to decrease, though the reverse will apply, obviously – decreasing the volume will increase the pressure.”

  180. AC, I can really only address your point 1.

    In the thought experiment you devise, the atmosphere would certainly expand a great deal; Venus’s 92-bar atmosphere is much deeper than Earth’s. (Compare the Wikipedia articles on Earth’s and Venus’s atmosphere for more detail on that.) But assume that the ‘sudden injection’ of all that N2 did cause temperature to rise. Would it stay high indefinitely? Of course not; the heat would radiate away over time.

    But Goddard fails to allow for such a process, or for insolation added heat to the system for that matter. And that is a big problem. You see, Goddard’s source (link below) says this about the dry adiabatic lapse rate, which is the lapse rate pertaining to the equations that he presents:

    The dry adiabatic lapse rate (DALR) is the rate of temperature decrease with height for a parcel of dry or unsaturated air rising under adiabatic conditions. . . The term adiabatic means that no heat transfer occurs into or out of the parcel.

    Of course, the atmosphere does have heat transfers in and out, and isn’t even at equilibrium presently. I think that leads to the essential point that chriscolose was making: the forms of the lapse rate equations chosen by SG cut out energy transfers, but that’s essentially an assumption–and the assumption can’t prove itself correct!

    SG’s using the concept of the (d)alr inappropriately, so it’s not surprising that the result is multiplied confusion. That’s why I kept pushing on the question of how solar radiation was affected by pressure, since he claims that, on the one hand, pressure determines temperature, and on the other that the energy comes from the solar radiation.

    But as you saw, no answer to that question was forthcoming. I imagine that’s because there is no such answer, in Mr. Goddard’s head or anywhere else.

    Hope this doesn’t add to the confusion. . .

  181. Ian Forrester

    AC asks:

    Is Goddard correct concerning his hypothetical situations in which you dig a hole 5 km deep? That is, would the temperature that deep really be (10 K/km)*(5 km)=50 K warmer than the surface

    The answer is no, in fact the temperature would be approximately 125 to 150 K warmer due to the geothermal gradient which averages 25 to 30 K per Km in areas with no tectonic activity.

  182. AC, for similar elevation drops on Earth, we usually get about a 30 degree difference, not 50 degrees. Not sure how he calculates it, but it doesn’t ring accurate to me, just on that basis. Now, he may argue that the greater pressure would add another 20 degrees — but if that’s so, there should be a significant effect between Death Valley and Jericho and the Dead Sea, which are even farther below sea level than Death Valley. Are those differences there, in line with his predictions?

    I’m no climate scientist, and to be frank, I’m so far out of science right now much of this discussion is beyond my grasp. But just looking at history, and looking at conditions present on the Earth now, I think his conclusions are extraordinary, and not in line with actual observations.

    If you go down into a mine 5 km deep, you’ll find it much warmer than the surface. But that difference is caused by heat from the Earth. I’m not convinced Goddard is paying any attention to proximate causes for anything.

  183. Chris Colose

    Maybe it’s worth putting up a SkepticalScience piece about this. I’ll work one out…

    • chris–or other interested parties–one question that was raised by SG does interest me. That’s the issue of Venusian insolation. The Wikipedia article on the atmosphere of Venus says:

      Venusian clouds are thick and are composed of sulfur dioxide and droplets of sulfuric acid.[28] These clouds reflect about 75%[29] of the sunlight that falls on them, which is what obscures the surface of Venus from regular imaging.[1] The reflectivity of the clouds causes the amount of light reflected upward to be nearly the same as that coming in from above, and a probe exploring the cloud tops could harness solar energy almost as well from below as above, enabling solar cells to be fitted just about anywhere.[30]

      The cloud cover is such that very little sunlight can penetrate down to the surface, and the light level is only around 5,000–10,000 lux with a visibility of three kilometres. At this level little to no solar energy could conceivably be collected by a probe. Humidity at this level is less than 0.1%.[31] In fact, due to the thick, highly reflective cloud cover the total solar energy received by the planet is less than that of the Earth.

      As with Earth, though, the surface layer is the hottest. I’m presuming that that is because that’s where the insolation is actually absorbed; the famously reflective clouds, one presumes, would be good at reflecting and/or scattering visible wavelengths, but not actually absorbing the energy. So what does make it down to the ground is what’s absorbed, then re-emitted as IR.

      From there, the differences between Terrestrial and Venusian greenhouse effects would be quantitative, more than qualitative in that the fact that energy can only escape the system via the top of the atmosphere compels temperature gradients (or lapse rates, if you prefer) in both cases.

      Rightish, or am I off-track?

      • Chris Colose

        Kevin,

        You’re right that the temperature gradient is what sustains the greenhouse effect. That’s always the other side of the puzzle aside, aside from just the IR opacity, that determines the efficiency of greenhouse effect. Note that Venus also has a non-negligible IR scattering greenhouse effect too, quite unlike Earth, and you can inhibit cooling that way (and this is not so dependent on the lapse rate).

        On Venus, it’s pretty important that you have a small amount of solar radiation that actually reaches the surface. If you absorb all the solar radiation in the upper atmosphere, the layers below this become isothermal and the greenhouse would essentially collapse. This is the essence of the “anti-greenhouse effect” that helps to offset part of the greenhouse on Titan. However, Venus is still in a regime that the solar radiation at the ground is important enough and establishes convection.

    • Thanks, chris–much appreciated. And I’m glad to be on the right track.

      There was a counterfactual that SG sort of slipped in to the original Venus post, IIRC–that the clouds eliminated so much light that the GE could be ruled out on that basis. (I’m paraphrasing from a not very clear recollection.) But when I thought about it and checked the light level, it became clearer what the real situation is.

      I understand the relation of the temperature gradient and the greenhouse effect less well than you seem to be assuming, but I’m going to go away and think about it a bit before asking any more impertinent questions.

      Well, I guess the last question actually pertinent; maybe the next one will be, too.

      • Chris Colose

        Kevin

        This is best visualized looking down at the planet, at a spectrum such as this
        http://chriscolose.files.wordpress.com/2010/03/upwelling_toa1.png

        Or equivalently viewed in terms of “brightness temperature” (Essentially the inverted Planck function, assuming an emissivity of one)
        http://chriscolose.files.wordpress.com/2010/03/upwelling_brightness1.jpg

        Ray Pierrehumbert’s 2011 paper on Infrared Radiation and Planetary Temperature (Figure 3) shows similar graphics for Venus and Mars as well.

        The reason the greenhouse effect depends on the temperature gradient is straightforward from these plots. If you’re an IR sensor looking down at the planet, you see emission by the surface at the transparent wavelengths (for example the 8 to 12 microns except for the ozone band). As you become more optically thick by adding greenhouse gases, you see emission closer to the sensor. If you’re looking up from the surface, that means your emission is coming from the very low atmosphere, since that is where IR is being absorbed strongly. If you are looking down, the low transparency (highly opaque) wavelength regions show emission coming from the very high atmosphere, where it is very cold. Thus, on the brightness temperature plot, you see a ~220 Kelvin surface at 15 microns (667 cm^-1) but a 285 K surface around 11 microns or so. This is because Earth radiation is absorbed much more strongly at 15 microns than at 11 microns.

        You can also think of this as looking through a tube placed between you and wall. If you look through the tube, you see the wall, and in terms of radiation you see whatever energy the wall is emitting (given by the Planck function). But if you start to add some opaque substance inside the tube, the wall you are seeing is gradually faded, and any radiation the wall emits disappears from your line of sight and instead you see radiation coming from inside the tube right in front of your eyes. This is, by the way, how satellites gather information.

        It’s the temperature gradient that allows you to see 220 K radiation at opaque wavelengths, and 285 K at transparent wavelengths. If the atmosphere were completely isothermal, then you’d still see 285 K radiation in the very strongly absorbing wavelengths.

        When you think about this in terms of energy balance, the total emission by the planet is obviously the emission integrated over all wavelengths. So if you start decreasing the flux at certain wavelengths where greenhouse gases absorb, the total flux by the planet has gone down. In the CO2 band around 15 microns for example, a measure of its impact is the area taken out under the curve at the surrounding wavelengths. If the temperature aloft is the same as the surface, there is no “bite” taken out of the spectrum and an observer looking down would not be able to tell the difference between a surface at the ground and a “radiating surface” 5 km high.

        Once we accept that the total area under the curve, and thus the energy output of Earth is reduced, we can now imagine that there is no longer radiative equilibrium since the planet takes in more sunlight than it is radiating. This means the temperature of the planet has to rise, until eventually the whole area under the Planck curve is equivalent to the absorbed solar radiation (and it will, because the emission depends on temperature). This establishes a brand new radiative equilibrium, but in such a way to keep the surface temperature hotter than before.

      • A generous response, Chris. Thanks once again. Still thinking, and with even more to think about. It makes sense, how all these pieces fit together. What’s harder for me is thinking about causality–seems that GE should sustain the lapse rate and not vice versa–or so my mind wants to make it.

      • Chris Colose

        I think you are right. If the atmospheric energy flows cease, the atmosphere should relax into an isothermal state at the effective radiating temperature where the tropopause moves to the surface.

      • Gavin's Pussycat

        Kevin — another good model for understanding this is the Sun. Also there, the energy source is at the bottom of the atmosphere. The reason we see dark spectral lines in the Solar spectrum is that there is a negative temperature gradient within the Solar atmosphere going up. When looking in the centre of a spectral line — with the aid of a filter — you see a higher-up, and cooler, and thus darker, layer of the atmosphere, compared to looking in the continuum.

        (During a total Solar eclipse you can see this high gas layer, called the chromosphere, creating bright emission lines, while the lower, warmer layers are blocked out by the dark Moon. It is really very hot, only “cool” relatively by solar standards.)

        This relates BTW directly to limb darkening: near the Solar limb, because your line of sight is oblique, you are also looking at a higher layer of the atmosphere, which is cooler and thus darker, than in the middle of the Solar disk.

        Actually it was a somewhat related phenomenon that Arrhenius used — with Langley’s Lunar infrared measurements — to get a handle on the greenhouse effect: the longer path lengths when the Moon is low in the sky emulate increased greenhouse gas concentrations, as there are more molecules along your line of sight.

      • Rattus Norvegicus

        Chris, you might be interested in this faux pas which he just posted today.

  184. AC:

    On 1: if you inject a lot of nitrogen into the atmosphere, you’re increasing the ‘n’ term as well (number of moles of gas). V and T don’t have to change at all while p increases. Or p and T can be constant while V increases. Or some combination of change of all 3. The ideal gas law is only one constraint on 3 independent variables (p, V, T) so it can only constrain the changes of 1 of them (or some single fixed combination them) in response to other system changes. The question is what are the other constraints on the system. Goddard seems not to want to get into that issue at all, but it’s the central one for the greenhouse effect (the gas law constraint is pretty much trivial, “given” from the start – it’s not like anybody ever ignores it).

    2 – It helps to understand what Goddard’s hypothetical requires. First, we do have holes close to 5 km into the Earth now – at least, the TauTona mine reaches a depth of 3.9 km. By Goddard’s calculation the temperature at the bottom should be about 40 degrees C warmer than the surface and it isn’t far from that, about 55 C relative to an average South African surface temperature of about 18 C. But that temperature is not determined by the same processes that determine Earth surface temperatures; it is almost entirely a consequence of the temperature of the rock at that depth. Below ground rock temperatures increase by up to 30 C per km, much faster than Goddard’s number.

    However, if you drill several km into an icesheet (as has been done) the air temperature is almost the same as at the surface, because the core of the icesheet is at about the same temperature as the surface. If you make a “hole” in the ocean – for example an airline hose for diving – the temperature of the air at the bottom of the hose is pretty much the same as at the top, or perhaps colder, because the water gets colder as you go down in most regions.

    That is, Goddard’s rule only works when the bottom of the hole is already considerably hotter than the surface – it *requires a temperature gradient* to start with! If their is no initial temperature gradient then the adiabatic lapse rate doesn’t come into play at all. The real question is – what is causing the bottom of the hole, or Earth’s surface in the greenhouse case, to be hot in the first place? That is the causative factor. The lapse rate just provides a constraint on the temperature profile, it doesn’t tell you how it got to be that hot. If the bottom of the gravity well is not hot, the temperature gradient can be zero or negative, as it is in the stratosphere, or in the ice core and ocean air line examples.

    So if Goddard’s 5 km hole for some reason has a bottom surface that would be hotter than the 50 C from the lapse rate, then 50 C would be the air temperature to expect from the lapse rate effect (i.e. even with a super-hot bottom, you wouldn’t expect more than 50 C air temperature difference due to the convective instability associated with the adiabatic lapse rate). If the bottom-top temperature difference was less than 50 C though, the air temperature difference would also be that much less.

    3. I don’t believe Chris ever claimed the adiabatic lapse rate was dependent on GHG’s. The lapse rate is a stability constraint determined by the properties of the major components of the atmosphere. In a sense it depends on greenhouse gases because the value strongly depends on the water vapor content, and water vapor is an important greenhouse gas. But that dependency has nothing to do with the greenhouse (infrared absorption) properties of water vapor; rather it’s due to the latent heat released when water vapor condenses to liquid water at lower temperature and pressure. But other than that, they are two independent things. Greenhouse effect, and lapse rate. The “lapse rate feedback” (associated with increasing water vapor in the atmosphere) is an important negative feedback on greenhouse warming investigated in climate models.

  185. Ian, I think we can ignore geothermal heat (even if it would be hotter down such a deep hole), as I did when considering this question above.

    I think Ed is closer, as the temperature would be higher according to the environmental lapse rate rather than the DALR, but they’d be pretty close in a desert environment, by day at least.

    Ed, the Dead Sea is ~300m below sea level compared to Death Valley’s ~50m. I presume the Dead Sea is the cooler of the two locations simply due to the weather differences between the two locations. Certainly, nominal pressure (i.e. not corrected to sea level) is higher at the Dead Sea by about 25 hPa on average.

  186. Ian Forrester

    Goddard is now saying that 60% CO2 will result in a “snowball earth”:

    http://stevengoddard.wordpress.com/2011/04/22/95-co2-would-be-snowball-earth/

    http://stevengoddard.wordpress.com/2011/04/22/snowball-earth-part-ii/

    Anyone care to have a go at refuting this?

  187. Goddard calls his blog Real Science.

    Whoever said that “irony is dead” had no idea what was to come. Is Goddard trying to outdo Denial Depot?

  188. Ian,

    I’m not familiar with the model he decided to run (maybe I’ll look at it this weekend) but there are couple points to make upon casual inspection

    1) I fully agree that without water vapor, Earth would be very cold. You would certainly freeze the oceans over. We all obviously know about the water vapor feedback too. And by the way, water vapor, as little as it is on Venus, is actually still pretty important for the radiation budget there.

    2) Looking at the tropical change in downward LW radiation is a rather poor measure of how the greenhouse effect changes. The tropical boundary layer is very moist, so if you take away all that moisture it will show up significantly. A corollary is to change the CO2 when the lower atmosphere is so moist that it already radiates like a blackbody at a given temperature, in which case holding the temperature fixed while raising CO2 will not increase the downward IR flux. But it can still have a warming effect by altering the TOA energy balance, through the mechanism I just described to Kevin. This applies to Venus too, where the lower atmosphere is saturated, but you can still warm Venus by increasing the emission height in the atmosphere. In this case, any increase in the downward longwave radiation will be dominated by the increase in the atmospheric temperature, not the emissivity change from direct CO2 change.

    3) When you enter the high CO2 partial pressure limit, you start to open up a number of odd absorption features unimportant on modern Earth, and also can make CO2 a more effective greenhouse gas through pressure broadening. You get out of the logarithmic dependence on forcing rather quick in this regime. The continuum absorption is extremely important on Venus, and radiation transfer models that are Earth-centric are still not up to the task of dealing with these kind of paleo-Earth/Mars high CO2 atmospheres very well (e.g., Halevy et al., 2009). Venus is so far out into a different regime than Earth or Mars to make the comparison pointless.

    4) Goddard has also talked about the high % of CO2 on Mars. Mars actually does have about 1-2 orders of magnitude more CO2 over a square meter on its surface than Earth, but its atmosphere is so thin and pressure broadening so weak, that the “ditch” taken out of the Planck spectrum is less than on Earth. The relevant quantity here is the Equivalent Width. In that sense, pressure does matter a lot, but not for the ideal gas reasons Steven thinks.

    5) As I’ve told Steve several times, the “runaway greenhouse” is not an argument about CO2, and in the case of Venus is actually one about water. Why he continues to throw up this strawman is beyond me.

  189. Question: Why spend so much time and effort on an idiot? It would be one thing if correcting his mistakes were in some way edifying. However, he is so stupid that his mistakes are largely transparent. Steve Goddard could not find his ass with both hands, a flashlight, a GPS and the longitude and latitude of his co-located head.

    • Well, I did learn something via this last foray–more thanks to Chris than to anyone else. Not that I’m going to repeat the exercise very often.

      • Yes, but you learned as a result of your interaction with Chris–Goddard was still pioneeringly stupid.

  190. Horatio Algeranon

    Goddard is the black hole of denial,”broadcasting” his influence to remote corners of the denyosphere like gravitational waves and capturing every partisanicle in his immediate neighborhood.

    Once one reaches the Goddard Horizon, there is no escaping.

    Even Einsteinium feels its pull. Just look at all the in-depth analysis by very smart people here and elsewhere devoted to debunking Goddard’s endless goofy claims (sucking up how many hundreds [thousands?] of hours?)

    • As in, “no information can escape the event horizon?”

      Evidently I was hanging out in the accretion disk.

      • Horatio Algeranon

        Kevin,

        You and others here who debunk Goddard are galaxies away.

        The attraction is exceedingly weak and the reaction mostly one of astonishment — that a part of nature could behave in such a bizarre way.

        However, there are some who have tempted the beast by getting too close and have fallen into his clutches, never to escape.

  191. Steve Sykes

    What I love about this “compare atmospheres according to pressures” approach is that there are oodles of commenters jumping on the bandwagon, after years of stating that “the greenhouse effect violates the laws of thermodynamics.”

    After years of stating that it’s impossible to add a greenhouse gas to the atmosphere and thereby insulate the surface from heat loss, they will gladly claim that adding ANY mass of gas to the atmosphere (even exchanging greenhouse gases for an increased mass of pure N2) will increase the temperature at the surface! No insulative property is needed, just mass.

    So a cooler atmosphere can’t possibly keep a warmer surface from cooling to the the vacuum of space (thermodynamics!), but a more massive atmosphere can (thermodynawhat?).