Guest Post by Ira Glickstein
The Unified Theory of Climate post is exciting and could shake the world of Climate Science to its roots. I would love it if the conventional understanding of the Atmospheric “Greenhouse” Effect (GHE) presented by the Official Climate Team could be overturned, and that would be the case if the theory of Ned Nikolov and Karl Zeller, both PhDs, turns out to be scientifically correct.
Sadly, it seems to me they have made some basic mistakes that, among other faults, confuse cause and effect. I appreciate that WUWT is open to new ideas, and I support the decision to publish this theory, along with both positive and negative comments by readers.
Correlation does not prove causation. For example, the more policemen directing traffic, the worse the jam is. Yes, when the police and tow trucks first respond to an accident they may slow the traffic down a bit until the disabled automobiles are removed. However, there is no doubt the original cause of the jam was the accident, and the reason police presence is generally proportional to the severity of the jam level is that more or fewer are ordered to respond. Thus, Accident >>CAUSES>> Traffic Jam >>CAUSES>> Police is the correct interpretation.
Al Gore made a similar error when, in his infamous movie An Inconvenient Truth, he made a big deal about the undoubted corrrelation in the Ice Core record between CO2 levels and Temperature without mentioning the equally apparent fact that Temperatures increase and decrease hundreds of years before CO2 levels follow suit.
While it is true that rising CO2 levels do have a positive feedback that contributes to slightly increased Temperatures, the primary direction of causation is Temperature >>CAUSES>> CO2. The proof is in the fact that, in each Glacial cycle, Temperatures begin their rapid decline precisely when CO2 levels are at their highest, and rapid Temperature increase is initiated exactly when CO2 levels are their lowest. Thus, Something Else >>CAUSES>> Temperature>>CAUSES>> CO2. Further proof may be had by placing an open can of carbonated beverage in the refigerator and another on the table, and noting that the “fizz” (CO2) outgasses more rapidly from the can at room temperature.
Moving on to Nikolov, the claim appears to be that the pressure of the Atmosphere is the main cause of temperature changes on Earth. The basic claim is PRESSURE >>CAUSES>>TEMPERATURE.
PV = nRT
Given a gas in a container, the above formula allows us to calculate the effect of changes to the following variables: Pressure (P), Volume (V), Temperature (T, in Kelvins), and Number of molecules (n). (R is a constant.)
The figure shows two cases involving a sealed, non-insulated container, with a Volume, V, of air:
(A) Store that container of air in the ambient cool Temperature Tr of a refrigerator. Then, increase the Number n of molecules in the container by pumping in more air. the Pressure (P) within the container will increase. Due to the work done to compress the air in the fixed volume container, the Temperature within the container will also increase from (Tr) to some higher value. But, please note, when we stop increasing n, both P and T in the container will stabilize. Then, as the container, warmed by the work we did compressing the air, radiates, conducts, and convects that heat to the cool interior of the refrigerator, the Temperature slowly decreases back to the original Tr.
(B) We take a similar container from the cool refrigerator at Temperature Tr and place it on a kitchen chair, where the ambient Temperature Tk is higher. The container is warmed by radiation, conduction and convection and the Temperature rises asymptotically towards Tk. The Pressure P rises slowly and stabilizes at some higher level. Please note the pressure remains high forever so long as the temperature remains elevated.
In case (A) Pressure >>CAUSES A TEMPORARY>> increase in Temperature.
In case (B) Temperature >>CAUSES A PERMANENT>> increase in Pressure.
I do not believe any reader will disagree with this highly simplified thought experiment. Of course, the Nikolov theory is far more complex, but, I believe it amounts to confusing the cause, namely radiation from the Sun and Downwelling Long-Wave Infrared (LW DWIR) from the so-called “Greenhouse” gases (GHG) in the Atmosphere with the effect, Atmospheric pressure.
Some Red Flags in the Unified Theory
1) According to Nikolov, our Atmosphere
“… boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K!”
If, as Nikolov claims, the Atmosphere boosts the surface temperature by 133K, then, absent the Atmosphere the Earth would be 288K – 133K = 155K. This is contradicted by the fact that the Moon, which has no Atmosphere and is at the same distance from the Sun as our Earth, has an average temperature of about 250K. Yes, the albedo of the Moon is 0.12 and that of the Earth is 0.3, but that difference would make the Moon only about 8K cooler than an Atmosphere-free Earth, not 95K cooler! Impossible!
2) In the following quote from Nikolov, NTE is “Atmospheric Near-Surface Thermal Enhancement” and SPGB is a “Standard Planetary Gray Body”
NTE should not be confused with an actual energy, however, since it only defines the relative (fractional) increase of a planet’s surface temperature above that of a SPGB. Pressure by itself is not a source of energy! Instead, it enhances (amplifies) the energy supplied by an external source such as the Sun through density-dependent rates of molecular collision. This relative enhancement only manifests as an actual energy in the presence of external heating. [Emphasis added]
This, it seems to me, is an admission that the source of energy for their “Atmospheric Near-Surface Thermal Enhancement” process comes from the Sun, and, therefore, their “Enhancement” is as they admit, not “actual energy”. I would add the energy that would otherwise be lost to space (DW LWIR) to the energy from the Sun, eliminating any need for the “Thermal Enhancement” provided by Atmospheric pressure.
3) As we know when investigating financial misconduct, follow the money. Well, in Climate Science we follow the Energy. We know from actual measurements (see my Visualizing the “Greenhouse” Effect – Emission-Spectra) the radiative energy and spectra of Upwelling Long-Wave Infrared (UW LWIR), from the Surface to the so-called “greenhouse” gases (GHG) in the Atmosphere, and the Downwelling (DW LWIR) from those gases back to the Surface.
The only heed Nikolov seems to give to GHG and those measured radiative energies is that they are insufficient to raise the temperature of the Surface by 133K.
… our atmosphere boosts Earth’s surface temperature not by 18K—33K as currently assumed, but by 133K! This raises the question: Can a handful of trace gases which amount to less than 0.5% of atmospheric mass trap enough radiant heat to cause such a huge thermal enhancement at the surface? Thermodynamics tells us that this not possible.
Of course not! Which is why the conventional explanation of the GHE is that the GHE raises the temperature by only about 33K (or perhaps a bit less -or more- but only a bit and definitely not 100K!).
4) Nikolov notes that, based on “interplanetary data in Table 1” (Mercury, Venus, Earth, Moon, Mars, Europe, Titan, Triton):
… we discovered that NTE was strongly related to total surface pressure through a nearly perfect regression fit…
Of course, one would expect planets and moons in our Solar system to have some similarities.
“… the atmosphere does not act as a ‘blanket’ reducing the surface infrared cooling to space as maintained by the current GH theory, but is in and of itself a source of extra energy through pressure. This makes the GH effect a thermodynamic phenomenon, not a radiative one as presently assumed!
I just cannot square this assertion with the clear measurements of UW and DW LWIR, and the fact that the wavelengths involved are exactly those of water vapor, carbon dioxide, and other GHGs.
Equation (7) allows us to derive a simple yet robust formula for predicting a planet’s mean surface temperature as a function of only two variables – TOA solar irradiance and mean atmospheric surface pressure,…”
Yes, TOA solar irradiance would be expected to be important in predicting mean surface temperature, but mean atmospheric surface pressure, it seems to me, would more likely be a result than a cause of temperature. But, I could be wrong.
Conclusion
I, as much as anyone else here at WUWT, would love to see the Official Climate Team put in its proper place. I think climate (CO2) sensitivity is less than the IPCC 2ºC to 4.5ºC, and most likely below 1ºC. The Nikolov Unified Climate Theory goes in the direction of reducing climate sensitivity, apparently even making it negative, but, much as I would like to accept it, I remain unconvinced. Nevertheless, I congratulate Nikolov and Zeller for having the courage and tenacity to put this theory forward. Perhaps it will trigger some other alternative theory that will be more successful.
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UPDATE: This thread is closed – see the newest one “A matter of some Gravity” where the discussion continues.
Bart @ur momisugly January 8, 6:17 pm
Bart, I value your contributions here, please don’t go. Strange how Joel has complained how he gets frustrated with people who have a different view than his. Please hang-in there.
Stephen,
I saw your comment here http://tallbloke.wordpress.com/2012/01/08/joel-shore-the-art-of-scientific-discourse/ . In response, I would say the following:
(1) If you made a direct admission that the gravitational redshift is not relevant, then I missed it. Could you point me to where it was?
(2) You are now saying that my suggestion that you relied on the redshift is dishonest. It is not dishonest at all; It is generous. Basically, your words about how the gravitational field somehow extracts energy from photons and so on and so forth is garbled and incomprehensible. However, in such cases, rather than assuming the worst, I try desperately to come up with some intelligent point that the person might try to be making. The only known physical phenomenon that I could extract from what you were saying was that the gravitational redshift was causing the discrepancy. And, this was at least an explanation that was based on real physical principles so I went with it. (And it was at least something you were enamored with for a while http://wattsupwiththat.com/2011/12/29/unified-climate-theory-may-confuse-cause-and-effect/#comment-853220 , and to my knowledge never renounced.) Now that you have said that this isn’t what you were talking about (or at least not what you are talking about anymore), we are left with just incomprehensible statements again.
Joel Shore said:
“However, it ignores the physical reality which is that convection can only drive the lapse rate down to the adiabatic lapse rate because lapse rates lower than that are stable and convection is suppressed.”
Precisely.
And the adiabatic lapse rate is therefore the inviolable minimum set by atmospheric pressure.
That is the second time you have conceded the point without realising it.
If GHGs try to influence the lapse rate beyond that set by pressure then convection will increase to drive it down to or towards the adiabatic lapse rate.
There is however a climate effect in terms of the temperature at the surface, height of the tropopause and the positions of the permanent climate zones but too small to measure in the face of natural variability driven by sun and oceans.
Virtually no change in total system energy content though because of the scale of the oceans as an energy reservoir.
How do you concede the existence of an adiabatic (pressure driven) lapse rate whilst simultaneously announcing that a gravity based GHE is like having fairies at the bottom of one’s garden ?
Joel Shore @ur momisugly January 8, 6:23 pm
Joel, you claim to be a physicist, although somehow I seem to have confused you on some really elementary physics. OK, let’s take this one step at a time:
1) Do you agree that an N2 atmosphere will exhibit energy transfers other than radiative, = conductive, convective and advective? If so, could you please explain where this energy comes from?
Answer this without obfuscation, and we can move on to step 2), next time.
“If you made a direct admission that the gravitational redshift is not relevant, then I missed it. Could you point me to where it was?”
Someone pointed out that the redshift was a phenomenon at least partly related to the perspective of the observer relative to the movement of the photon and I accepted that by not pursuing the issue further. It was the other person who mentioned the redshift in the first place.
I have expressed my thoughts in many other posts without reference to the redshift so you could not have honestly linked my basic premise to the brief exchange about the redshift.
shawnhet @ur momisugly January 8, 7:09 pm
As to your first point again:
Yep, I agree entirely. As to the rest of your waffle, I don’t think it merits comment, other than to say why not try to understand what I’ve attempted to convey, even if it is outside of your dogma?
As to your second point again:
I don’t have a strong view against your opinion, other than to comment that I’ve not asserted anything in the way you suggest. (I’ve suggested a possible mechanism that no one has yet dismantled)
Bob F-J asks:
“1) Do you agree that an N2 atmosphere will exhibit energy transfers other than radiative, = conductive, convective and advective? If so, could you please explain where this energy comes from?”
I agree that a purely N2 atmosphere can transfer energy 1) back and forth between the atmosphere and the ground and 2) from one part of the atmosphere to another part of the atmosphere. These can happen through microscopic motions (collisions of individual molecules aka conduction) and through macroscopic motions (large scale movements of molecules, aka winds or convection).
Furthermore, there would indeed be no significant radiative transfers, either within the atmosphere or between atmosphere and ground
The only source/sink of this energy in a transparent atmosphere would be conduction with the surface. (Looking ahead a step, the ground would also have radiation as a source/sink of energy along with some small geothermal energy which we are all ignoring for this discussion).
I suspect Joel would agree too. It will be interesting to see where you are going with this.
@Bart (and a few others):
I admire your tenacity, but apart from what you’re learning yourself and from the offerings from others, you’re wasting your time with these guys. They can’t quit, because they have too much invested in the meme, including jobs and reputations.
In the face of GHG levels steadily “spiralling out of control”™, they’re just hanging in there, hoping like hell that the temperature and sea levels will start going back up, and that someone will find Trenberth’s missing energy or the missing tropospheric hot-spot.
It wouldn’t have mattered what Nikolov and Zeller might have presented. If it doesn’t conform to the dogma, they will just try to shout it down.
/dr.bill
“The mean surface temperature of Mercury is 442.5 K,but it ranges from 100 K to 700 K due to the absence of an atmosphere and a steep temperature gradient between the equator and the poles. The subsolar point reaches about 700 K during perihelion then drops to 550 K at aphelion.On the dark side of the planet, temperatures average 110 K.The intensity of sunlight on Mercury’s surface ranges between 4.59 and 10.61 times the solar constant (1,370 W·m−2).”
http://en.wikipedia.org/wiki/Mercury_%28planet%29#Surface_conditions_and_.22atmosphere.22_.28exosphere.29
Is there anyway one could have an atmosphere on Mercury?
Have dome. Use reflectors. Easy.
What about something global, an atmosphere rather than a building?
Requirements: Large areas with air pressure that gives enough pressure
in breathe, this minimum is 2 1/2 psi. Air doesn’t need to be breathable, but
can’t be poisonous. And maximum I suppose is say 10 atm.
A requirement does need to have atmosphere a long time in terms of geological
long- in term costs it probably have lifetime of say a century or more.
So how about water?
Since said 10 atm- the max would on earth be 100 meters. Mercury has a bit more
than 1/3 of earth’s gravity. So less than 300 meter depth.
Mercury has very long day: more than 56 days: 1407.5 hours.
Not as long as our arctic winter nites, but would get ocean sea ice or is this sort of
wishful thinking:)
Well, let’s start with 10 meter depth and see what happens.
Lets start with tropical water like temperature- 80 to 90 F
90 F is 32 C and 306 K.
Since we have pressure from water [+4 psi] don’t need any gas atmosphere. And
this will give us a water vapor atmosphere.
When first dumping water, it will make steam, but since there is atmosphere the steam
will be cold- water with no air pressure boils near it’s freezing point.
To cool the hot half of surface of planet shouldn’t require much water.
Something like one meter of the 10 meters. Why?
Because Mercury gets as cold as the Moon’s nite- 100 K. So roughly at meter
depth on nite side it similar to lunar regolith at nite, which is well below freezing.
And means the warming will due to this one long day of very hot sunlight.
So as wild guess say top 1/2 meter is average of 700 K to 300 K or 500 K
and needs to cooled to 300 K.
The density is about 2. And specific heat of rock is: Basalt rock 0.84 kJ/kg K
So 1/2 meter of rock is one tonne per square meter. And 1 degree is
1000 times kJ. Want 200 K lower, so 200 times 1000 times is KJ:
200,000.
Water requires 2,270 kJ/kg to vaporize so per sq meter need 100 kg- or 1/10th
of cubic meter. So 1 meter is 10 times more than needed. So you dump enough
water so gives 10 meter depth. It will create cold steam equal to 1/10 of meter.
And this steam travel around planet and freeze on nite side, and dump a lot of
heat. So dump warm water and the result should be cooler water. But wanted
to start with warmer water and on that blazing hot planet, all it means is dumping
water not in one instant. So as said, start point will global water at 32 C and some
water as atmosphere.
So 32 C or 306 K radiates 497 watts per square meter. And mercury distance is
“4.59 and 10.61 times the solar constant (1,370 W·m−2)”
So furthest from sun it’s 4.59 times 1,370 or 6288 watts per sq meter. That’s a decent
amount solar power- solar panels would actually make economic sense.
With low atmospheric pressure water going boil, it’s going build up an atmospheric pressure,
and going race across planet and rain on the nite side. It seems without sunlight, at 32 C
the water will evaporate, and with sunlight, evaporate and boil. So until there enough atmosphere all solar energy will go into boil and evaporating the water.
So you have 6.288 kW and takes 2,270 kW to vapor kg of water 2.27 kW boil a gram, and so
2.77 grams per second per square meter. And in 24 hours 239 kg of water, more than 2/10th of meter.
So we aren’t going to get sea ice on nite side. And in first couple days, it’s going build an atmosphere of water vapor. And the pressure will reduce boiling and have more affect on warming the water.
So let’s assume that max water temperature desirable would be 48 C or 321 K
And 321 K radiates 602 Watts per square meter.
And 1/4 of 6288 is 1572 watts per square meter.
So that is an obvious problem. Try adding more water. But what is temperature
gradient is ocean?
No answers.
It seems to me that with rapid warming, and if there isn’t
a lot wind the top meter of water could much warmer. And limit of 48 C would apply
to “sea floor” level. So what if 20 C warmer at surface? 341 K
766.6 watts per square meter. hmm. Ok, needs to over 400 C- over boiling at 1 atm,
so that won’t work.
So can’t think of natural way to cool Mercury and have resort to devices. With devices you can always cool a planet. Instead of what I am going to describe- you can simply block sunlight in the space environment- at say L-1 or orbit. You could simply block or for reasons economic you use the solar power to generate power and if also blocking sunlight from reaching the planet.
So, what is needed is higher temperatures in certain locations- locations that are receiving the most amount of sunlight. The most amount of energy received on sphere is the area where the sun is directly over head- noon at the equator. If you don’t have an atmosphere and you can face the sun [with reflector] is factor is negated.
In other words in vacuum and if sun is in the sky you point a meter square solar panel and get the same amount of energy. And one get more energy at the poles, if elevated- you could get continuous get sunlight. Meaning twice the solar energy over an entire day [day and nite cycle]. And near the poles you also get more hours of sunlight.
But for purposes cooling planet you want near equator- every square meter of surface receives
the most sunlight.
So we know that natural terrain on Mercury can get 700 K when sun is directly overhead [subsolar point], but that could when mercury is nearest Sun. And at moment doing where Mercury is furthest.
700 cubed times .0000000567 is 13,000 watts per square meter. And need temperature at 6288 watts. Which is more the 575 K.
You could have pillars which are higher than the water which are in the equatorial region- and have area of 1 square meter [or 100 square meters]. There surface heat up to 575 K and they could made from stone or other poor conducting material and so instead radiate at water temperature below 100 C you are radiating at over 300 C.
These pillar would need to cover a fair amount of area- 10% maybe 25% – so huge area.
But if follow the sun [by floating instead being pillars] this total amount area can reduced by
about 1/4.
Anyways, I am done for moment. Maybe I finish later.
Bob Fernley-Jones says:
January 8, 2012 at 8:43 pm
“Yep, I agree entirely. As to the rest of your waffle, I don’t think it merits comment, other than to say why not try to understand what I’ve attempted to convey, even if it is outside of your dogma?”
Of course, the flaw must all be in me and not in how you are communicating your ideas. Why not try to not make broad assumptions about what my “dogma” is and try to communicate your ideas better? (For the record, I can pretty much guarantee that my opinions are substantially different than you think they are). From my POV, if you agree with the above then you agree that convection/advection *cannot* be a meaningful part of the GHE (ie the 33K or more difference between what the average temperature of the Earth should be under a purely solar regime and what the average temperature is). If you believe that both of these things can be true at the same time, you will have to demonstrate it (ideally with links to research and hopefully some math). You may understand what you are talking about but you are not doing a very good job of articulating it IMVHO.
“I don’t have a strong view against your opinion, other than to comment that I’ve not asserted anything in the way you suggest. (I’ve suggested a possible mechanism that no one has yet dismantled)”
Well, I thought you were arguing that there was something that acted similarily to the GHE but was not the GHE as currently understood. If this is not correct, then, at a minimum, you should be able to give a description of how your mechanism actually works and *demonstrate* how your theory does not violate conservation of energy. You seem to think that it is other people’s responsibility to do this for you. You don’t seem to understand that it is pretty hard to discern if you can dismantle something if you don’t know how it is put together.
Bob Fernley-Jones says:
Yes…It will and that energy ultimately comes from the sun. However, there are a couple of important points to realize:
(1) Energy can be transferred both in and out of these modes. In particular, if you were to propose that advection and convection supply the additional energy (390 W/m^2 vs 240 W/m^2) then the conclusion would be that the wind speeds on the Earth would have to be rapidly decreasing. In reality, I don’t think there is any big change going on in the wind speeds on the earth.
(2) It is also worth knowing the relative scales of these energies. It turns out that the kinetic energy of bulk motions in the atmosphere is pretty small in comparison to, say, thermal energies. This can be seen by noting that the rms speed of a nitrogen molecule at room temperature is about 500 m/s, which is about 1100 mph. This is, of course, a much larger speed than typical bulk motions…and kinetic energy is proportional to the square of the speed.
Stephen Wilde says:
Well, to the extent that you make points that are actually correct, I do not disagree with them. Since the argument for the greenhouse effect is not based on the GHGs changing the lapse rate, you are creating a strawman argument. (In the near or complete absence of GHGs, the lapse rate may no longer be pegged to the adiabatic lapse rate but rather be lower; however, even if the case, it isn’t really relevant to the current discussion.)
First of all, I am going to stick to the height of the effective radiating layer (which is probably at least positively correlated to the height of the tropopause, but is the more relevant quantity).
Second of all, you don’t know how small or large it is without actually doing calculations. And, in fact, the current Earth provides a data point: The addition of greenhouse elements (gases + the greenhouse effect of clouds) raises the effective radiating layer from 0 in their absence to ~5 km at their current concentration, and because of the lapse rate of ~6.5 K per km, this raises the surface temperature by about 33 K.
The fact that the oceans are a large energy reservoir does not determine the magnitude of the effect. It just determines the time scale over which a change in forcing causes a change in surface temperature. I.e., a planet without large thermal inertia responds to the changes more rapidly while one like Earth with large thermal inertia responds more slowly.
I am not saying that gravity plays no role at all in the discussion of the greenhouse effect. Gravity plays a role by determining the adiabatic lapse rate, which in turn determines how much of the radiative greenhouse effect can get cancelled out by convection. However, gravity is not a net source of energy for the earth-atmosphere system because we are not undergoing gravitational collapse.
By the way, in discussing the fit that constitutes Eq. (7) and Figure 5 of N&Z’s paper, I noted that the way in which they chose to define T_gb (the planetary temperature in the limit that pressure goes to zero), while not supplying a formal fitting parameter, did constitute another thing that they could play around with.
I have done a quick investigation of that this morning and the results are rather interesting: One thing that they did which I found a bit strange is to define T_sb assuming that all the planets have an albedo of 0.12 and an emissivity of 0.95 in the infrared in the limit that pressure goes to zero. They would presumably justify this as being realistic because in that limit the clouds should all go away. However, one could equally well make arguments that you should do the computation under the assumption that the albedo of the planet is one of the things that one assumes stays the same as its currently-observed value. It turns out that making this assumption makes their data much less monotonic and smooth…and so, as a result, the best fit one can get with the four-parameter form of Equation (7) is considerably worse than before.
I suppose that N&Z would argue that this demonstrates that their way of computing T_sb has the correct physics in it…although I would be curious to understand how they would ever explain this mechanistically! But, what it does show, at any rate, is that there was this additional element of tuning of the empirical fit that they did to the data…I.e., it seems likely to me that, unless they were extremely lucky, they likely did shop around for a way of expressing T_sb that led to the data having a nice behavior for N_TE vs surface pressure before they even attempted to determine the form for N_TE that then provided a good fit.
gbaikie,
Before you go into too much depth on determining the sort of atmosphere Mercury might have, you might check this link — especially the first figure http://abyss.uoregon.edu/~js/ast121/lectures/lec14.html
Basically, the high temperature and low gravity will allow almost any gas to escape from Mercury, so the rest of your work needs to consider escape velocity.
“Before you go into too much depth on determining the sort of atmosphere Mercury might have, you might check this link — especially the first figure http://abyss.uoregon.edu/~js/ast121/lectures/lec14.html
Basically, the high temperature and low gravity will allow almost any gas to escape from Mercury, so the rest of your work needs to consider escape velocity.”
There are problems. One problem I had not address would be sun’s ionizing affect on H2O.
Another minor problem is the hotter surface [e.g. pillars] would increase H2O molecules velocity.
The escape velocity of Mercury is 4.3 km/sec. Air velocity on earth is .5 Km/sec- but obviously it’s hotter on Mercury.
There is calculator for molecular gas here:
http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/kintem.html
I forget all variables I need to input [at moment] but I think the difference of say 300 K to
say 700 K is not huge. different gases can have more differences than just temperature differences. So as wild guess, I would say H2O molecules are going less than 1 km/sec.
But would have look more into this.
Of course one way to cool such a hot planet as Mercury might be to have gases leave the planet- use gases that would would get to escape velocities- helium or argon would example of fast moving molecules.
I mistype in first post. I mean to say, it would not have to be designed to keep an atmosphere for millions of years- but rather centuries or say 1000 years would be fine.
Joel Shore: “I am not saying that gravity plays no role at all in the discussion of the greenhouse effect. Gravity plays a role by determining the adiabatic lapse rate, which in turn determines how much of the radiative greenhouse effect can get cancelled out by convection. However, gravity is not a net source of energy for the earth-atmosphere system because we are not undergoing gravitational collapse.”
I agree with you but I think you also need to look at how gravity affects the distribution of CO2 in the atmosphere. When you double the quantity of CO2 you also double the weight. The energy in the atmosphere is what keeps the gases from falling to the ground. When you add the CO2 you don’t add anything to the energy in the system. That means the same amount of energy has to lift double the weight of CO2.
Just like my rocket ship analogy this has a limiting effect on how much higher the gases can rise. And, if they can’t rise to any degree they can’t raise the effective radiation altitude.
“However, gravity is not a net source of energy for the earth-atmosphere system because we are not undergoing gravitational collapse.”
It doesn’t need to be a net source of energy in itself.
It just slows down the flow of solar energy through the system by increasing density at the surface to produce more opportunities for molecular collisions before the energy is released back to space.
The result is an accumulation of solar energy within the system at the surface so that a higher surface temperature can be achieved.
Stephen Wilde says:
More nonsense. We know what temperature the surface of the Earth is at and therefore how much it radiates. How exactly does such an atmosphere “slow down the flow” of energy when it can’t even interact with this radiation?
Richard M: What keeps gases mixed in the atmosphere is entropy, not energy. There is no experimental support for your claim that CO2 is not well-mixed (except near sources and sinks at ground-level). And, there is no physical reason to believe that it shouldn’t be well-mixed. Hence, your notion fails on both experimental and theoretical grounds.
Joel Shore says:
January 9, 2012 at 10:43 am
“gravity is not a net source of energy for the earth-atmosphere system because we are not undergoing gravitational collapse”
That’s something I’ve been thinking about. My neighbor across the street, apparently to make me look even more pathetic, put up quite a Christmas display. Among the assorted decorations were several inflatable figures (snowmen, Santa, and the like). On a couple of evenings I stood on my front porch to admire/resent his ambition and could hear the sound of an air compressor. The inflatable characters are apparently designed to deflate without a constant input of air, pretty handy in our wind-prone area.
The idea here is that after total inflation, which I’m comparing to gravitational collapse, an equilibrium is reached where the incoming air is balanced by air going out the escape valves. The constraint is Santa’s volume, so the IGL apparently requires pressure and temperature to go up until some upper limit is reached, then they stay stable. I didn’t go over and take Santa’s temperature (probably get arrested), but I’m guessing it was higher than ambient due to the constant work being done by the compressor. My (limited) understanding of what N&Z are saying is something similar, i.e. the constant heat input is manifested as a maintenance of both temperature and volume of the atmosphere, since pressure is fixed. If there is indeed a one to one correspondence between temperature and volume (don’t know), then it stands to reason that increasing the pressure (more molecules of air) would have to result in a corresponding rise in both temperature and volume according to the IGL. Or would the volume not rise? Can it rise and the temperature not?
That’s what I think they are saying, anyway. Me, I don’t know, but I don’t think it’s fair to say they are trying to get around the laws of thermodynamics. I think everybody understands the argument about blackbody emissions and there’s no reason to keep endlessly repeating it, as Willis did in his post today, although the title took me back to my teenage couldn’t-get-enough-of-Heinlein years. N&Z acknowledge that this is the conventional wisdom and say it is wrong. Repeating it doesn’t make it more right. Now the burden is on them to make their case and they may very well fail. Or not.
Joel Shore;
More nonsense. We know what temperature the surface of the Earth is at and therefore how much it radiates. >>>
We do?
I showed pretty conclusively that we do not. I showed conclusively that the values of 255K (effective black body) and 288K (“average” surface temperature) were not just inaccurate, they are wildly inaccurate.
Yet here you are, once again quoting what we “know” and relying on those numbers despite the fact that we know them to be wrong, not just a little wrong, a LOT wrong. 255K is the MAXIMUM average temp the earth could possibly be at based on 240 w/m2, and as you AGREED to in my explanation up thread, given the variance in temperatures across the globe and in over the course of a year, 255K is likely more than 100 degrees too high. You not only agreed to this, you demanded to know why it was that I was wasting your time explaining something to you that you already knew.
So now here we are, a number of comments later, and you are basing your arguments on the values of 255K and 288K!
Did you forget what you knew?
“How exactly does such an atmosphere “slow down the flow” of energy when it can’t even interact with this radiation?”
The incoming solar energy gets converted to kinetic energy before leaving as longwave.
The length of time it stays as kinetic energy depends on the density of the atmosphere.The longer it stays in kinetic form the more energy accumulates and the higher the temperature can get.
Whilst in kinetic form it is transferred between molecules by convection and conduction involving molecular collisions.
Joel Shore says:
January 9, 2012 at 4:22 pm
Richard M: What keeps gases mixed in the atmosphere is entropy, not energy. There is no experimental support for your claim that CO2 is not well-mixed (except near sources and sinks at ground-level). And, there is no physical reason to believe that it shouldn’t be well-mixed. Hence, your notion fails on both experimental and theoretical grounds.
So, even with no energy supplied to the atmosphere you’re saying the atmosphere would continue exist in its present condition? Yeah, right? I suppose if I dropped 1000 baseballs from an airplane they’d be mixed into the atmosphere by entropy? Really, Joel?
Also keep in mind, it is mixed in a gravitational field vs. mixed without gravity. Do you understand the difference? Over time the heavier substances tend to “fall” to lower heights. If you put more heavier stuff into the mix it will tend to force the lighter stuff up. That’s why balloons filled with helium or hot air will float. Of course, I realize you know all this, so why the obfuscations?
Yes, winds and convection do make a difference. Without them all the gases would eventually stratify based on weight. However, it does not eliminate the continual pull of gravity. And, more importantly, gravity gets it’s way more and more as the density decreases. Fewer kinetic collisions to keep the heavier gases mixed. I suspect this is part of the reason that the mass of the atmosphere is one of the factors in the UTC.
Once the air pressure gets low enough the heavier CO2 cannot be kept aloft, hence adding more CO2 will not significantly increase the average height of gas.
Joel Shore says: “What keeps gases mixed in the atmosphere is entropy, not energy.”
Richard says: “Over time the heavier substances tend to “fall” to lower heights. ”
And of course, the truth lies somewhere in between. Gases do tend to mix in order to maximize entropy. Denser things do tend to move closer to the ground. The exact contribution of each factor will depend on the relative masses of the molecules.
I agree there would be SOME stratification due due to mass, but it would not be anything like “oil and water”. Even after 1000 years in a sealed room, you would not find all the helium at the ceiling and all the CO2 at the bottom. Even with some sort of sealed column 10,000 m tall, I suspect there would only be slight enhancements of the heavier molecules at the bottom and lighter molecules at the top.
(Of course, a baseball would be a completely different story, since it has a mass on the order of 10^24 times as much as a gas molecule, which WOULD cause it to settle to the bottom.)
One practical application of this is the “gas centrifuge”. By artificially “enhancing gravity” by a factor of several thousand, the isotopes of Uranium can be separated (at least slightly). By repeating this process many times, you can finally arrive at enriched uranium.
The fact that such effort must be made to separate the isotopes suggests to me that separation of gas molecules in the atmosphere would be relatively small. While the relative difference in mass is much greater in the atmosphere, the gravitation acceleration is much, much less than the centripetal acceleration.
Here’s a paper to illustrate my point:
http://juwel.fz-juelich.de:8080/dspace/bitstream/2128/4339/1/J%C3%BCl_1836_Ehhalt.pdf
Look at figure 1. Notice how the mixing at lower altitudes is quickly lost at higher altitudes especially for heavier gases. This is my point. Adding more CO2 will have a smaller and smaller impact due to the force of gravity. Essentially, this is like another log scale in addition to the saturation effect. Instead of the assumed 1.2C increase per doubling of CO2, it’s probably more like .12C.
I think the fact of gases being well mixed at lower altitudes actually leads to a quicker increase to the GHE at low concentrations. However, it also means once a certain effect is reached it takes significant increases to garner additional warming. This is shown very well in figure 1 of the reference. Adding more CO2 at the present time will change that vertical profile very little which means no significant increase in the average emitting altitude .