The conversation on the Venus thread has gone way past my tolerance for stupid.
Venus is not a closed system. It is located near this object – which provides a steady stream of shortwave radiation to the top of the Venusian atmosphere.
The ideal gas law is PV=nRT . R is a constant. P(ressure) and n(umber of molecules) are essentially constants, because the n(umber) of molecules in the atmosphere and Venusian gravity doesn’t change much over short time periods. The atmospheric P(ressure) is fixed by the weight of the atmosphere, which doesn’t change.
The only things that can change in the Venusian system are V and T. V(olume) is determined by the height of the atmosphere, which remains fixed due to the steady stream of solar radiation that keeps the molecules in the atmosphere vibrating. So T(emperature) at the surface remains constant. During the long Venusian night (thousands of hours) the temperature doesn’t drop. It behaves nothing like a greenhouse.
If the Sun turned off, the height of the atmosphere would shrink, as would the temperature. Eventually the atmosphere would freeze, so there would be no gas volume and the temperature would approach absolute zero.
It is similar on Earth. Our average surface temperature remains relatively constant because we receive a steady stream of solar radiation and the number of molecules in the atmosphere doesn’t change much over short time periods. What makes Earth different is that we have much less cloud cover, and we have oceans with a large heat capacity. Unlike Venus, the albedo of Earth can change due to variations in snow/ice and cloudiness. Ocean circulation also has an effect on temperature, so Earth’s average surface temperature can vary +/- 10C.
Comment from Omnologos :
What would be the temperature at the bottom of the Mediterranean if the sea evaporated again, as it has done in the past?
As every student of planetary atmospheres know, the existence of a lapse rate is a property of every troposphere – it even applies deep down in the Jupiter’s hydrogen ‘ocean’. This has nothing to do with the presence of greenhouse gases.
Therefore once the Cytherean tropopause is determined, together with the average lapse rate, the temperature at the surface can be computed, with or without CO2.
If the GHGs have any effect, it has to be seen in the height of the tropopause.
In fact one could think heat as exchanged via conduction (in the planet), convection (in the troposphere) and radiation (above the troposphere). Even pierrehumbert’s planetary atmospherics book says that radiation is in first approximation irrelevant when studying the troposphere.
Ask your commenters to answer a thought experiment.
What would be the temperature at the bottom of the Mediterranean if the sea evaporated again, as it has done in the past?
As every student of planetary atmospheres know, the existence of a lapse rate is a property of every troposphere – it even applies deep down in the Jupiter’s hydrogen ‘ocean’. This has nothing to do with the presence of greenhouse gases.
Therefore once the Cytherean tropopause is determined, together with the average lapse rate, the temperature at the surface can be computed, with or without CO2.
If the GHGs have any effect, it has to be seen in the height of the tropopause.
In fact one could think heat as exchanged via conduction (in the planet), convection (in the troposphere) and radiation (above the troposphere). Even pierrehumbert’s planetary atmospherics book says that radiation is in first approximation irrelevant when studying the troposphere.
Lemme see if I can still do this from memory: given P = (rho)RT, dQ = CpdT – (1/rho)dP.
Let dQ = 0, no change in internal heat, and rho = P/RT,
CpdT = (RT)dP/P, dT/T = (R/Cp)dP/P, integrate: Ln(T1/To) = kLn(P1/Po), where k = R/Cp.
And T1 = To(P1/Po)^k, Poisson’s Equation, adiabatic process, QED.
Yep, can still do that, next given dx/dt = V, and dV/dT = a, derive x = (1/2) at^2 + Vot, then
using the chain rule, derive V1^2 – Vo^2 = 2ax.
-Jerry
PS Venus is a perfect example of a run away greenhouse effect. The difference is that we have a large amount of liquid H2O. The H2O never reached saturation on Venus and boiled away into space leaving behind mostly CO2 from outgassing. If the oceans had not rained out, the earth would have suffered a similar fate. We should thank out lucky stars for the oceans.
So I guess Mars has a runaway green house effect too since 95% of it’s atmosphere is CO2, just like Venus. OH, but it’s atmospheric pressure is much much less. It’s so cold on mars that the ice caps are made of its atmosphere that condenses out. Must have something to do with atmospheric pressure not atmospheric composition, hey?
Scott, are you aware that the planets are all different distances from the sun?
Yes. I forgot, you must correct for the distance from the sun. That is a very well known variable.
Sorry, thought I was responding to something else. So you agree with me that the composition of the atmosphere is not the critical variable. You say it is the distance from the sun? Venus is closer to the sun so it is hotter than earth. Mars is further from the sun so it is colder than earth. That is part of the answer, you are right.
Distance from the Sun has little to do with the temperature on Venus. Venus’ atmosphere has a thick layer of clouds which reflects most of the sunlight back into space. The surface of Venus receives much less solar radiation than Earth’s surface.
Saturn has a much thicker layer of clouds and is colder than a Sports Illustrated swimsuit shoot in Antarctica:
http://www.google.com/search?q=sports+illustrated+antarctica+shoot&client=safari&rls=en&tbm=isch&tbo=u&source=univ&sa=X&ei=9cEZU7DIOYrkyAHI4YHoAg&ved=0CCYQsAQ&biw=1280&bih=608
Talking of gas giants, another silly meme debunked by Venus is the idiotic idea that stronger weather is associated to the presence of more energy in the form of temperature.
Venus is warmed than an oven and the breeze is gentle. The very cold clouds of Neptune sport winds in excess of 1,300mph.
The idea is that the atmosphere of Venus contained more water vapor than Earth initially, possibly hundreds of bars. The primordial atmosphere was blown away when the Sun went through its T-Tauri phase. Subsequent outgassing from volcanoes produced an atmosphere of H2O, N2, and CO2. But the atmosphere on Venus never reached saturation vapor pressure. All of that water vapor in the atmosphere created a strong greenhouse effect. Eventually all of the water vapor boiled off into space. On Mars, water rained out to form lakes and rivers but the atmosphere was too thin and gravity too weak to hold it. Again, most of the water was lost to space. There is most likely a significant amount of water ice locked just beneath the surface of Mars, especially near the poles. This water could be harnessed if and when a base is established there. It’s like Goldilocks and the three bears. Venus was too hot, Mars was too cold, Earth was just right.
The primordial atmosphere was blown away when the Sun went through its T-Tauri phase.
Not an expert, but isn’t the T-Tauri phase right at the start of a star’s existence? That is, before fusion has even begun? At that point, I don’t believe that there would have been any planets at all.
Venus’ surface receives very little sunlight. Obviously it is not behaving anything like a greenhouse.
Actually Steve, in a sense it is.
A real greenhouse works by suppressing convection : the air is trapped inside and unable to cool itself through exchange with the air circulating in the free atmosphere.
The way I see it, the enormous weight of the overlying atmosphere on Venus has the same overall effect (although the processes are different) as the walls and roof of a greenhouse. On the surface of Venus, it would need an enormous amount of energy to generate the convective overturning which would enable the surface to cool and, as you rightly point out, it never receives it.
That is what the “greenhouse effect” truly is, as opposed to the arm-waving “greenhouse gas” nonsense, espoused by climate alarmists.
Venus is a very windy place – nothing like a greenhouse:
http://starryskies.com/solar_system/venus/winds_of_venus.htm
@ Anto.
The upper and middle atmosphere? Sure.
The surface, not so much. Read your own link again!
@AIP – it’s not a greenhouse – that’s the point! The pressure at surface of Venus is 93 bar. Once you get to 1 atmosphere pressure (about 50km up), the temerature is around a balmy 40C.
“Once you get to 1 atmosphere pressure (about 50km up), the temerature is around a balmy 40C.”
Where does the energy come from to make it a balmy 40C 50km up.Directly from the Sun or indirectly from the surface or …?
If Earth had 100% cloud cover wouldn’t day temperatures and night temperatures by the same ? Wouldn’t that eliminate a great part of the Convection factor on the surface.
What’s heating the atmosphere at 50km over Venus? The sun is. Remember the temperature is a direct and simple function of the distance from the tropopause and the temperature at the tropopause. It matters not how deep the atmosphere below is.
At the surface there’s very little direct radiation from the Sun either.
The atmosphere of Venus is mostly CO2, but CO2 is colourless and transparent to visible light, while the atmosphere of Venus is not transparent to visible light. Thus, we can conclude that with respect to radiation, trying to pretend CO2 is the driving factor would be ignoring the obvious.
It obviously can’t come up from the surface unless it came down through the atmosphere to begin with. However, given that radiation cannot penetrate that atmosphere, we have to presume that the surface merely holds heat with minimal through-flux either in or out. That’s very different to Earth where we have large day/night temperature swings, and large summer/winter temperature swings.
“PS Venus is a perfect example of a run away greenhouse effect.”
There is simply NO greenhouse effect on Venus.
Thus, there can be NO run away greenhouse effect.
Gravitational compression gives the lower atmosphere its basic starting temperature. This comes from warmer, thinner air rising and then cooler air sinking and getting heated on the way down. Solar energy heating the surface then adds some heat and it starts over again.
BTW, it is the presence of an atmosphere that makes our surface much cooler than otherwise, as an atmosphere offers conductive and convective energy transfer and no atmosphere only allows radiative energy emission. Only the sunlit side is considered here as the global climate models model a flat Earth with sunlight 24/7. Our surface is much cooler on a sunny day than the sunlit side of the moon.
Hi Higley7. My derivation was only to show that I can do that without notes and Poisson’s equation applies only to adiabatic (reversible) processes. As touching my claim that Venus is a perfect example of a runaway greenhouse, you must consider the ancient past when Venus contained ~100 bars of water in vapor form. Water vapor is a much stronger GHG than CO2 and the theory is that the atmosphere of Venus never reached saturation vapor pressure (never rained out) and what’s left is 95% CO2 from outgassing after the surface temperature soared. In conclusion, the evidence suggests that there was a runaway greenhouse effect on Venus but that is not the case now because, the H2O boiled off into space a long time ago, some 4.5 billion years ago. And I am well aware of the power of the Sun over Venus. The equatorial winds blow around an upwelling column that rises over local noon. The effect is seen as a y-shaped pattern in the cloud structure in an atmosphere that circles the entire planet in four Earth days.
Also, I wanted to comment on the T-Tauri theory. You can Google the recent research. The embryos of the terrestrial planets were in place during the onset of T-Tauri and “if the planets were formed before the end of the Sun’s T-Tauri phase, their atmospheres would have been substantially lost due to the extreme T-Tauri winds at that time. The resulting atmospheres seen today would therefore consist predominantly of outgassed volatiles from the mantle subsequent to the end of the T-Tauri phase.” [1] Sheesh, tough audience.
-Jerry
1. http://funkyscience.net/wp-content/uploads/2014/02/6023_Baines_reprint.pdf
When studying Geology at university in the mid 80s the following rational for the depth of the Venusian atmosphere was given, in comparison to Earths.
Sometime after the formation of the earth (and Venus) convective overturn occurred. This is where the melting point of iron is reached in the body of the undifferentiated planet. This iron sinks and forms the core producing a differentiated body. Heavy core surrounded by mantle and light crust.
The impact of “Thela” with the earth was at a low angle, sometime after differentiation, and preferentially removed lighter crustal material which went on to form the moon. The effect of this was twofold;
1) reducing the effective thickness on the earth’s crust
2) the creation of the moon and its associated tidal forces.
The thinner crust and tidal forces allowed the development of plate tectonics on earth, water is also thought to be very important in action of plate tectonics however was it volcanic/tectonic, or Cometry, or both in origin.
Venus on the other hand suffered no such collision. Studies of meteorite impact frequency and size on Venus’ surface appeared to show most impacts being very (geologically) recent, it was theorised that the Vensuian surface was therefore young, circa 200 million years old.
The theory went on to suggest that the lack of tidal forces caused by a moon (at one time a lot closer to the earth) coupled with the (much) thicker crust of Venus led to periodic massive resurfacing of Venus as the planet attempted to release the heat generated by formation, gravity and radioactivity. This massive volcanic resurfacing would create a very thick and noxious atmosphere that simply did not have the time or the conditions to dissipate/moderate.
And as for the temperature of the surface?
Well I am all for proximity to the sun and pressure myself!
Unless it’s those Henry Kuttners’ Venusian Sea Monsters driving SUVs!
Regards
Ian
New paper provides an interesting perspective.
http://faculty.washington.edu/dcatling/Robinson2014_0.1bar_Tropopause.pdf
http://www.washington.edu/news/2013/12/09/astronomers-solve-temperature-mystery-of-planetary-atmospheres/
Nice paper, and it sounds remarkably like what the sceptical blogs have been saying for some years. In the troposphere convection dominates — PV=nRT means that any localized temperature increases are going to see a lowering density and thus a rapid rise of warm air that moves the heat toward the tropopause. At the tropopause and higher, the air is thin enough that an average IR photon path makes it out to space before being reabsorbed by another molecule — radiation dominates! Additionally, absorption of UV makes the stratosphere warmer, which is why the Earth undergoes a slow warming when solar UV peaks (as it has the last few decades) and then cools (as it is doing now) when the UV decreases.
How clever of the astronomers to figure this out. I wonder if they have been reading sceptical blogs?
That’s great news, I have been arguing the point about the troposphere for several years, it’s basic/obvious physics indeed.
Convection does NOT dominate in the global troposphere, the constant vertical temperature lapse rate (temperature gradient) does; that is the stage upon which weather (and climate) plays its part. Convection just drives the weather (primarily horizontally), it does not create or maintain the vertical lapse rate–the hydrostatic condition does that (and Jerry Gorline needs to understand that his derivation above is even more easily, and effectively, done as: mcΔT= -mgΔx, as provided by the hydrostatic condition). The stable lapse rate means heat rises naturally “down” the temperature gradient–convection would only destabilize such a precise structure, and so cannot dominate, rather that structure dominates, on the global scale (too many–incompetent “experts” and lay citizens alike–in the global warming debate continue to be confused by local and transient effects that have no global effect).
The critical piece of evidence remains (I brought it out in November 2010) that the Venus/Earth tropospheric temperatures comparison shows that essentially the only difference in temperatures in the two atmospheres, at points of equal pressure over the range of Earth tropospheric pressures, is due to the difference in distance from the Sun–and that is a PRECISE quantitative fact above and below the Venus cloud layer (so clouds don’t affect the global lapse rate structure either, nor does planetary albedo, at least for Venus and Earth, because that great difference between them also has no effect–obviously, unless you want to try to explain how these various effects DO matter, but add up to PRECISELY zero in the comparison of Venus and Earth). The only explanation for this is that both atmospheres are warmed by direct absorption of incident heat (infrared) energy from the Sun (so, for example, it doesn’t matter that they have quite different reflections of VISIBLE light–albedos–or that little light reaches the Venus surface to heat it–atmospheric warming, to the ruling temperature lapse rate structure, has already occurred. So I concur with Jason Calley, that the astronomers are not experts–or really, all that competent–in their attempts to understand, and in their claims to fine new discoveries. (Nor do I claim to have all the answers myself. Nor am I as interested in the climate field as are most of those engaging in the unending “debate”, which consists of vainly lobbing theoretical points past each others’ unheeding heads, in an insane controlling political environment to boot.)
@ harryduffman “it does not create or maintain the vertical lapse rate”
Hey harry, thanks for your input. I think you are correct, convection does not maintain the lapse rate. The lapse rate is a consequence of the interaction between PV=nRT and the gravitational field. If you could somehow construct a planetary atmosphere without convection (quite a trick!) you would still have the same lapse rate (or at least the same dry lapse rate). So, if convection is not the reason for the lapse rate, why bother with convection? The atmosphere is never in equilibrium; it is constantly being stirred by alternating day and night and changing seasons. That non-equilibrium is what drives the convection, with the result being that incoming energy is spread around the Earth much more quickly and evenly than either radiation or conduction could otherwise do. What convection does is to move energy around in such a way that the transfer of heat from localized warm spots (for example a warm air bubble over a newly plowed dark field) to the upper troposphere happens much more quickly than if only conduction or radiation were involved. Toss in some phase changes taking place with various states of water, and the lower atmosphere becomes a very effective heat engine, one that moves gigantic quantities of heat from near surface up toward the tropopause. So, yes, we agree that convection does not cause the lapse rate, but I maintain that convection enormously increases the lower atmosphere’s ability to move heat to the tropopause and then have that energy radiate out to space. Think of the lapse rate as a description of what the atmosphere approaches as it tries to reach equilibrium. Think of convection as a mechanism that helps that equilibrium be approached more quickly.
If there were no gravitationally induced lapse rate, and if there were no convection, and if there were no water vapor, and if the CO2 IR band was not effectively saturated, and if IR excited CO2 molecules passed all or most of their extra energy off to other molecules, and if heat transfer were dominated by only conduction and radiation, then the so-called “climate scientists” would have a much better chance of demonstrating a potential danger in extra CO2.
That, at least, is my current understanding of it — but I am open to any reasoned dissent!
Bill Illis,
Thanks for citing such an excellent paper that I would otherwise have missed. Given the complexity it will take a while to absorb it. Two years ago I used the “One Bar” approach to evaluate N&K’s “Unified Theory of Climate”:
http://diggingintheclay.wordpress.com/2012/03/13/unified-theory-of-climate/
It is interesting to note that Robinson gives the temperature of Titan at one Bar pressure as 94 Kelvin while N&K’s equation said 93 Kelvin. The HASI experiment observed 86 Kelvin. I guess HASI picked a cold day to visit Titan!
“In thermodynamics, a closed system can exchange energy (as heat or work) but not matter, with its surroundings.” Definition of closed system from Wiki.
Steve says: “Venus is not a closed system. It is located near this object – which provides a steady stream of shortwave radiation to the top of the Venusian atmosphere.”
Steve, I think by definition Venus is a closed system as it and the sun do not exchange matter.
Solar wind is matter.
Venus is not just a hellish place. Venus is also an Earth twin with no magnetic field, a retrograde totally upside-down extremely slow spin, no satellites, completely resurfaced 500 million years ago. Any theory should explain the lot.
Morgan what is the matter that Venus sends to the sun? Please note the word exchange in the definition.
I happen to agree with Steve on why Venus is hot, but I think it is a closed system by definition.
E=mc^2
Matter and energy are the same thing.
In strict thermodynamic terminology, Venus (with its atmosphere) is not an “isolated” system, because it exchanges energy with its surroundings, but it is essentially a “closed” system, because it does not exchange any (significant) matter with its surroundings.
Steve was obviously trying to emphasize the fact that Venus is not an isolated thermodynamic system.
PV=nRT Ideal gas, and n is generally moles (number of avagadro’s number of molecules, usually of a certain species)
What does science have to do with anything relating to the CAGW argument in today’s bizzaro world? NOAA, NASA (and consequently NSIDC) and the rest of the ‘Team’ abandoned science long ago in favor of an emotional religious cult.
This fits and it is too good not to pass on:
No, no, no. The White House Web Site has that honor wrapped up in perpetuity.
Shouldn’t it be The Black House?
Mulatto House i believe 50/50
After a moments reflection I quite agree.
How this blatant racism has lasted so long is a deep stain on the country.
Venus’s tropopause starts at about 52 to 54 km. Surface tempertures are about 740 deg K.
http://en.wikipedia.org/wiki/Atmosphere_of_Venus
Venus has a Black body temperature of about 184 deg K (even with an albedo of 0.9)
http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
The lapse rate is about 10.4 deg C/km
http://pds-atmospheres.nmsu.edu/education_and_outreach/encyclopedia/adiabatic_lapse_rate.htm
54*10.4 + 184 = 745.6 vs 740 measured. The calculation is close.
Also, see this Wiki page for calculating heat from pressure.
http://en.wikipedia.org/wiki/Adiabatic_process
It should also be noted, that just above height in the Venusian atmosphere where the pressure is one bar (about 50 km), the temperature is about earths temps.
Another thing to note, is that at the Venusian surface, the CO2 becomes supercritical at the CO2 concentration and pressure. Heat is transported almost instantly. Hence, no convection, and no night time low temperatures.
There may be a misnomered greenhouse effect from the CO2, but the vast majority of the temperatures seen are from increased solar strength, and adiabatic lapse rate.
Most of the gang has shown up. Omnologos, Harry Dale Huffman, Gail Combs.
In their different ways they assert that it is the total mass of the atmosphere (the n in PIVNURT) that has the greatest influence of the Greenhouse Effect. While I am not ready to buy Nikolov & Zeller’s theory it is much closer to explaining reality than Hansen’s version of the GRE.
http://diggingintheclay.wordpress.com/2012/03/13/unified-theory-of-climate/
Do not forget the top of the atmosphere moves in response to the sun.
Venus’s tropopause starts at about 52 to 54 km. Surface tempertures are about 740 deg K.
Venus has a Black body temperature of about 184 deg K (even with an albedo of 0.9)
http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
The lapse rate is about 10.4 deg C/km
54*10.4 + 184 = 745.6 vs 740 measured. The calculation is close.
It should also be noted, that just above height in the Venusian atmosphere where the pressure is one bar (about 50 km), the temperature is about earths temps.
Another thing to note, is that at the Venusian surface, the CO2 becomes supercritical at the CO2 concentration and pressure. Heat is transported almost instantly. Hence, no convection, and no night time low temperatures.
There may be a misnomered greenhouse effect from the CO2, but the vast majority of the temperatures seen are from increased solar strength, and adiabatic lapse rate.
Should be:
There may be a misnomered greenhouse effect from the CO2, but the vast majority of the temperatures seen are from increased solar strength, and adiabatic lapse rate.
Earths blackbody temperature is about 70 deg K higher than Venus. The increased solar radiation at Venus’s orbit is more than offset by the albedo.
Strikeout didn’t work.
There may be a misnomered greenhouse effect from the CO2, but the vast majority of the temperatures seen are from the adiabatic lapse rate.
Earths blackbody temperature is about 70 deg K higher than Venus. The increased solar radiation at Venus’s orbit is more than offset by the albedo.
Carl Sagan did this calculation in 1967, predicting a surface temperature of 865 Kelvin on the assumption that the cloud tops were 65 km above the surface. Later he realized that Cp is a function of pressure so he used 7.9 Kelvin/km for the adiabatic lapse rate in the lower Venusian atmosphere.
He published a correction to his earlier papers which you can find at the link shown below if you click on the “Send PDF” button:
http://adsabs.harvard.edu/doi/10.1086/149625
Note that Sagan’s revised prediction was 721 Kelvin, a remarkable achievement given what was known about Venus back in 1968.
Wave–particle duality
An even better example that adiabatic compression of gases is the real cause of the greenhouse effect is Uranus, The base of the troposphere on Uranus is 320K [32K hotter than Earth’s] at 100 bars pressure, despite the planet only receiving 3.71 W/m2 energy from the Sun. By the Stefan-Boltzmann Law, a 320K blackbody radiates 584.6 W/m2. How do greenhouse gases amplify solar radiation 157.5 times to create an additional 581 W/m2? It’s absurd, but that’s what @TheresPhysics keeps insisting in our twitter debate.
Nobody knows for sure what heats Uranus and Neptune…unless that is, it’s the lapse rate…
ps another Venus mystery that no CO2 can explain: some winds in the upper atmosphere circle the planet in a few Earth days, 60 times faster than the planet’s own rotation.
The top of Jupiter’s atmosphere is around -174C, increasing to 21C at around ten atmospheres pressure. Then to around 24,000C at the core. Saturn -175C at top to 12,000C core. Neptune -218C to 7,000C. Uranus -224C to 4,700C. Sounds pretty adiabatic to me.
[omnologos – BTW, why do you think Uranus doesn’t radiate excess heat?]
Anto – I was being sarcastic
omnologos – yes, I know. I was agreeing with you.
My question re: Uranus was geniune – I don’t know.
“How do greenhouse gases amplify solar radiation 157.5 times to create an additional 581 W/m2?”
I’ll take oscillation for one thousand dollars…
A radio receiver incorporates a tuned circuit, also known as a tank circuit, a combination of inductor (magnetic field) and capacitor (electric field) in parallel. It takes only a tiny bit of energy to start this thing swishing back and forth and depending on the “Q” of the circuit, the circulating current will be hundreds of times stronger than the weak signal that “excites” it. Of course, you cannot bleed more energy out of it than you are putting in, so this huge circulating current isn’t all that useful outside of the tank.
In other words, the high temperature at the surface produces the requisite amount of radiation but photons cannot go very far and a high density atmosphere further confines it.
http://en.wikipedia.org/wiki/Uranus#mediaviewer/File:Tropospheric_profile_Uranus_new.svg
Very high pressure combined with obvious greenhouse gases methane and water keep the energy bouncing back and forth near the surface with very little escaping into space.
Alarmists say its all about Mars, rather than Venus.
Obviously Hansen’s PhD thesis is not something they want anyone to remember.
http://m.smh.com.au/federal-politics/political-news/ross-garnaut-slams-abbott-governments-direct-action-policy-as-like-a-martian-beauty-contest-20140307-34atj.html
The Accelerating Winds of Venus
http://youtu.be/4Taz18Ss1vU
It 2:32 minutes there is a slide that says:
“…the planet’s thick atmosphere that keeps Venus scaldingly hot via a runaway greenhouse effect.”
This demonstrates that the narrator has swallowed Hansen’s loony theory “hook, line and sinker”.
There is no “Runaway Greenhouse Effect”. The surface temperature of Venus and all other planets with a significant atmosphere can be explained using thermodynamics.
Here is something that should stop the stupid. No observable temperature effect based on the gaseous composition of the atmosphere.
http://globalwarmingsolved.com/2013/11/summary-the-physics-of-the-earths-atmosphere-papers-1-3/
Real observations, falsifiable hypothesis, you know real science.
All planets in the solar system with significant atmosheres have a region where the temperature gradient approximates to -g/Cp. In the case of Jupiter the agreement is particularly close. To make it a clean sweep (seven bodies out of seven) let’s look at Titan. Here are some measurements from the European Space Agency’s HASI probe:
Altitude (m) Pressure (Pa) Temperature (K)
7,512 100,053 85.8
0 146,645 93.5
Note that the temperature gradient is 7.7 K for a 7.5 km change in altitude which equates to a lapse rate of -1.03 K/km.
The surface gravity of Titan is 1.352 m/s^2 and the Cp of Nitrogen is 1.039 kJ/kg-K so the theoretical DALR (Dry Adiabatic Lapse Rate) for Titan is 1.30 K/km. Titan’s lower atmosphere contains about 1.6% of methane vapor which lowers the adiabatic lapse rate just as water vapor does on Earth.
That table did not come out as intended so here it is again:
Altitude (m) Pressure (Pa) Temperature (K)
7,512——— 100,053 ————85.8
—0———– 146,645 ———— 93.5
If anyone revisits or is interested. I have a conspiracy theory. Maybe, Ste would you like to post a suitably overlay image?
The money shot views of pressure/temperature of the planets have this single interesting issue. One can never find an image with Venus & Mars together. One or the other only. … Why??
http://astrobites.org/wp-content/uploads/2013/12/Robinson_Catling_2013_f1.png
Below we have Mars but no Venus. Mars is hopelessly wrong. Needs fixing to 210K
http://lasp.colorado.edu/~bagenal/3720/CLASS14/AllPlanetsT.jpg
To me this is a killer to the theory of AGW. Has anyone printed a full image?