Table of contents for Greenhouse Experiment
- Home Science Experiment Disproves Global Warming Theory
- More Data Disproving Global Warming
- Model of Global Warming
- Greenhouse Quiz
- Maxpower Datasheet Experiment 2
Here is a simple science experiment you can try at home to disprove one of the main aspects of global warming. One of the main assumptions of anthropogenic global warming (AGW) is that the temperature will continue to increase as the opacity of the atmosphere increases due to carbon dioxide gas (CO2). We can test the theory that increasing opacity increases temperature very easily.
For this experiment, you will need a combined temperature and humidity weather station with a remote temperature transmitter (like the Atech from Dick Smith, pictured, $59) and a large clear container, large enough to contain the weather station. I used an old flour container.
I sealed the receiver inside the container and put it in the sun. I then periodically recorded the humidity and temperature in the container, and the temperature outside. The results are shown at end, are plotted in the figure below.
Figure: Red - temperature inside the container, blue - temperature outside container, green - humidity. A small amount of warm water was added after time 16:45 (break in lines).
The temperature inside the container (red) increased from the ambient of 26.3C to almost 50C. Simultaneously the humidity dropped (green), but the amount of water vapor remains constant, as the container is sealed. This shows the classic greenhouse effect, whereby temperature are raised above ambient (blue).
After time 16:45, I added a small amount of warm water to the container increasing the humidity (green line). The inside temperature remained the same temperature as previously, despite an increase in the opacity of greenhouse gas in the container, from the increase in water vapor.
Conclusions
1. The increase in temperature due to the greenhouse effect has a maximum.
2. At this maximum, additional greenhouse gas absorbers do not increase the temperature, to the limits detectable in this setup (about 0.2C).
The standard theory of atmospheric global warming is based on radiative equation developed by Milne and Eddington for the atmosphere of stars. Their approximation shows temperature B increasing linearly with the opacity of the atmosphere τ.
B(τ) = (3/4π)Hτ+B
The continuing increase in atmospheric temperature with greenhouse gases is disputed by one researcher, Ferenc Miskolczi, who has developed a comprehensive theory of greenhouse effect on planets (see discussion here and introduction to the theory here). One part of the theory maintains that the atmosphere has a achieved its maximum greenhouse effect, and hence maximum temperature, according to the equation:
Su=3OLR/2
Where Su is the infrared radiation a ground level, and OLR is the radiation into space. This ratio of 3/2 in radiation gives an increase in temperature due to the greenhouse effect.
The amount of greenhouse effect expected can be calculated easily from the fourth-power relationship between radiant heat and temperature. From the fourth root of 3/2 we get 1.107, meaning a maximally developed greenhouse effect on earth would increase temperatures by 10.7%. The temperature of the experiment in degrees Kelvin was 299.3K, meaning an increase of 31.4 degrees was possible. The increase achieved was only 23.6 degrees, 75% of the maximum, but approaching that figure. The greenhouse effect on earth is said to raise the global average temperature from -18C to +14C or 32 degrees, very close to the maximum greenhouse effect predicted by Miskolczi.
Miskolczi’s theory does not claim that increasing greenhouse gases won’t increase temperatures initially. In fact, his radiative relationship of temperature to atmospheric opacity is very similar to the Eddington solution with an additional exponential term: 1+τ+e-τ. However, he claims that due to the constraint of 3/2, after an initial perturbation, temperature over the long term cannot increase any more, unless the Sun’s output increases. The simultaneous satisfaction to these two constraints, maximum greenhouse effect, and the radiative relationship, occurs at a constant opacity over the long term of τ=1.84. The actual observed global opacity is very close to this figure, at 1.87. This optimal figure is presumable maintained through changes such as cloudiness, the lapse rate, and atmospheric circulation.
Next, I will show in another simple experiment demonstrating that greenhouse effect has little to do with concentrations of greenhouse gases. I have to find a bigger container.
Results
Humidity Inside Outside Time
48 29.7 26.3 16.24
47 34.3 26.3 16.26
47 36.2 26.2 16.28
44 39.6 26.3 16.33
32 48.8 26.3 16.37
20 49.3 26.3 16.43
48 49.9 26.3 16.45
45 49.4 26.3 16.49
42 49.3 26.3 16.52
46 49.1 26.3 16.56
233 responses so far ↓
“Miskolczi’s theory does not claim that increasing greenhouse gases won’t increase temperatures initially. In fact, his radiative relationship of temperature to atmospheric opacity is very similar to the one above with an additional exponential term: 1+τ+e-τ. ”
But didn’t you just show that there was no effect from increasing greenhouse gases (i.e., the addition of water made no difference)?
Thats one area where people get tripped up. Radiative eqns suggest temperatures must increase monotonically. However, the energetic constraints at the maximum forbid it.
Finally! Thank-you. Why are there so few tests proving/disproving the theory? This was obviously easy and inexpensive.
The whole kit and kaboodle costs less than the humidity/temperature transmitter I just bought I have yet to build the data logger and the supplier of an important part for that is out of stock.
The energy consuming bits are greedy the energy from the surface used to warm the atmosphere cannot be used to raise more water from the surface. It can however be used to retain it can also be (and is) used for the Orographic Lift that causes temperatures to fall and the water to precipitated out
This exercise proves nothing. IR on this scale has a very small role in heat transport, and even that is not modified by the increased opacity of a few cm of moister air (which you have not attempted to quantify).
On a scale of metres, heat transfer is dominated by conduction and convection. These modes respond to temperature gradients, which are several degrees per metre. In the bulk atmosphere, temperature gradients are degrees per kilometre, so much less heat can be transferred by those means. IR, however, does not depend on temperature gradient, and becomes the dominant mode on large scales. For your apparatus, the temperature is determined by internal convection, and conduction through the plastic, and the neighboring stationary air boundary layers.
On the opacity side, we’ve talked of an optical depth of about 2 for the whole atmosphere. That means that on a grey-body average, IR is attenuated by a factor of about 8 over an effective distance of about 10 km. It’s logarithmic; over a meter, the attentuation is about 8^0.0001, or about 0.0002.
So the effect of IR was small anyway, and was attenuated by natural GHG by a factor of less than .0002. You might have doubled that attenuation. The temperature, determined predominantly by convection and conduction, is, as expected, unaffected.
David, I’m surprised how poorly your blog lives up to its professed faith in numeracy.
OK, before people jump on that, the attenuation factor is .9998. Afdter passing through the air, the IR is .9998 of its initial amplitude, or a reduction by a factor of .0002.
Nick:
“On a scale of metres, heat transfer is dominated by conduction and convection. These modes respond to temperature gradients, which are several degrees per metre. In the bulk atmosphere, temperature gradients are degrees per kilometre, so much less heat can be transferred by those means. IR, however, does not depend on temperature gradient, and becomes the dominant mode on large scales. ”
Well, you got the first part right, but you gotta prove the second part. Got any evidence for that IR part?
Dave I get “Easy Tiger” when I click on CoRev’s name I’m not sure that’s intended.
Nick, If you have a reference to more accurate experiments demonstrating an increase in temperature due to increased attenuation of IR in a cavity with a fully developed greenhouse effect, please let us know.
Jan, it can’t find the page. Thanks for alerting me to this.
#9 David
No, again because of scale, such experiments are unlikely. As I say, there are two issues - conduction/convection is almost certain to dominate radiation in heat transport, and trace levels of GHG will not significantly attentuate IR anyway over small distances.
Such experiments also don’t reproduce other important features of the greenhouse effect - the lapse rate in temperature, which leads to IR emission from much colder parts of the atmosphere - and also the effect of back radiation from parts of the atmosphere at different temperature.
jae #7 Not sure what you want evidence of. Stefan’s Law governs radiative transfer, and does not involve temperature gradient. As to IR being dominant - I’ll just refer to your favorite K&T cartoon, and all the experimental evidence behind it.
Nick #11
I am sure a lot of chemists will be surprised to hear that the attenuation over small distances is too small for the cuvettes that they have been using for the past 100 or more years in spectrometric analysis.
CoRev, editor
http://www.globalwarmingclearinghouse.blogspot.com/
Jan #12
Again it’s scaling. Chemists use powerful sources, much more than thermal emission levels. They would also nor
mally use higher concentrations of absorbing gases.
Nick #14
You seem to get your scales back to front quite a bit could it be because you’ve acutally never set foot in a chem lab?
Higher concentrations you say then look at the limitations near the end and see that .01 M is about the limit and CO2 is about .0165 - .017 M water at about .18 M jae might like to check the concentrations as it has been 40 years since I worked in a chem lab.
Transmittance is a ratio of incoming to outgoing power of the source is irrelevant. Sure the ratio of remission to absorbed is 1 but if you are going to invoke Kirtchoff’s law here you perhaps should think twice before criticizing FM for doing the same thing.
Nick, the title of the post is purposely provocative. I think you are cool. There are two questions however that beg for answers:
1. Is there a maximum to the greenhouse effect?
2. If so, is it affected by IR attenuation?
No-one is denying radiative equilibrium on the atmospheric scale, least of all Miskolczi. In the atmosphere, maximum greenhouse effect is achieved only at the earth surface, and the atmosphere acts as a quasi-cavity, which makes it a different set-up. This questions are about the simplified system.
Jan/David,
Looking at the posts before this one, we are working with a chemical system?
Greenhouse effect is a physical problem, according to theory.
So how can we describe the problem in terms of chemistry when the object is a gas.
Or have I missed something.
Louis #17
Not chemistry per se but infrared (and other) spectrometry are tools much used b y chemists. Determining concentrations of materials is very much the chemist’s domain.
#5 Nick Stokes
“David, I’m surprised how poorly your blog lives up to its professed faith in numeracy.”
Go beat yourself with your negatives.
Even if you are smarter and more educated,
Cannot stand the stench in the beer parlor
Stagger and Barf outside !
Your job, on your high pedestal, is to teach
Pay back the high cost of your training.
Small systems can prove the principles of larger ones
For example, Cloud Chamber
Steam in the shower, low level fog above a swamp
Turn the system upside down, to eliminate convection
I would like to see SF6 remove something
Or be removed by CO2, H2O ?
Infrared camera, looking at diffraction grated spectrum, could be a very versatile input device
Nick:
“jae #7 Not sure what you want evidence of. Stefan’s Law governs radiative transfer, and does not involve temperature gradient. As to IR being dominant - I’ll just refer to your favorite K&T cartoon, and all the experimental evidence behind it.”
Nick, I think the radiation cartoons attempt to show the radiation balance, which is a function of the temperature distribution. They say nothing about how that temperature distribution comes about. The radiation is an effect, not a cause. I think M is correct in his ideas about non-radiative inputs (K) causing the temperature distribution. To my thinking, this is where the climate scientists generally have it wrong, big time. They essentially igore convection KT gives all of 24 Watts/m-2 for convection, which they label as “thermals”. That’s nuts. The surface of the earth would be just like a closed greenhouse, were it not for convection.
Relative to a “maximum greenhouse effect,” I’m still waiting for an answer as to why temperatures in very moist areas (tropics, e.g.) never exceed about 33 C. Shouldn’t the maximum greenhouse effect exist in such humid areas? The maximum TEMPERATURE effects are found in the deserts, where there is only about 1/4 the greenhouse gases (usually somewhere around 5-8 g/m^3 absolute humidity). Maybe the maximum greenhouse effect is below 5-8 g/m^3?
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Oh for heavens sake! What makes you think there isn’t something fundamentally wrong with this experimental setup? (4)
Look at the red line (temperature inside the container) at about 16:36 - see the sudden “knee” where it stops rising and goes dead flat?
Temperature rises pretty steeply between around 16:33 and 16:36 and then goes dead flat?
C’mon what physical process does that? Unless there is some physical flaw in the experimental design. This is lent extra weight when you add the extra water at around 16:45 (the green line discontinuity).(1) (2) Despite the addition, nothing happens to any other measurement.(3)
And all this is supposed to happen over a period of what? 5-10 minutes?
What all this says to me is that the experiment is constrained somewhere so that the results are artificially held - possibly through measurement error - within bounds that don’t reflect the actual process.
Can you say “broken”?
(1) And WTF is happening when the partial pressure of h2o is falling in the face of increasing temperature between 16:30 and 16:40? Did they repeal the gas law last week or something?
(2) “A small amount of warm water was added after time 16:45″ and the temperature didn’t increase? In a “closed” experiment?
(3) You don’t provide a scale for humidity, but that looks like a helluva jump. In the face of rising temperature humidity falls and then suddenly returns to its starting value with the addition of a “small” amount of “warm” water? The word “small” communicates the idea of “an insignificant fraction of that originally present”. How much exactly?
(4) Bit of a postscript. I checked the Atech product range and http://www.atech.hk and while I couldn’t find an exact match, the picture seems to show a device in the WS-233-xxx range. This is specifed as recording “indoor temperature” between -10 and +50.
You maxed out at +50 right? Maybe your instrument just didn’t have the range you wanted.
JM: You obviously have no idea how greenhouses work. Or a notion of relative humidity. Why don’t you try to repeat the experiment?
Jae, it doesn’t matter whether I understand greenhouses or not.
The measuring instrument is a consumer device specified to operate at no more than 50 degrees and this experiment was conducted at 50 degrees or above.
The results are worthless (even given the other objections I have to the experimental design).
a.) the device is not specified to operate reliably (or at all) above 50 degrees
b.) I doubt it even measures temperatures above 50 degrees on the off chance that it might give semi-reliable estimates out of its specified range.
Thats because there are only a few measurements.
No, the relative humidity (green line) increases.
Thats what you would expect the relative humidity to do.
http://en.wikipedia.org/wiki/Relative_humidity
Enough to just cover the bottom of the container.
Good question. I will try it again today with the transmitter part. Its sitting at 57.2C now as it bakes in my mini-oven.
“Enough to just cover the bottom of the container.”
I presume you mean the original amount? Did you measure the quantity? And did you measure the quantity you added?
And also did you measure both the temperature of the original water and of the additional warm water?
“Its sitting at 57.2C now as it bakes in my mini-oven.”
It’s not specced to operate at that temperature so its readings cannot be reliable.
Good grief, GM, he isn’t doing a master’s thesis here. Suggestions, rather than rude snarks would be more appropriate. Anyway, it looks to me that the temperature hit 50 C for a very brief time, and I would imagine that the instrument doesn’t abruptly stop reading at 50 C (the accuracy probably just goes down).
It would be interesting to put SF6 in the container, since it is something like 23,000 times more powerful as a GHG as OCO.
“Thats because there are only a few measurements.”
David (it is David?), can I just ask you about this. I presumed that you were graphing a continuous series of real-time measurements so that there were vastly more than a “few”.
Can I take from your comment here that you sampled the output on a schedule and the lines in the graph represent a fit to those samples rather than a continuous read-out?
JM: Read the post again. The data are provided. BTW, the temperature never actually hit 50 C.
Brilliant !
Try a movie making type steam gnerator
(Even a small unit can cloud up the corner of a room)
Blow in steam — see if the steam removes itself
Or creates runaway, pizza oven heat, feedback effects
Will the results be IPCC dogma, runaway, rejected ?
JM, read the latest post. The specs on the transmitter go to “+60C” whatever that means. Sure I would like to do it with better gear. I am not asking you to believe it. I am asking you to try it.
Agree in general, however I would say that achieving the theoretical maximum is limited by the factors above. Do YOU dispute a theoretical maximum of 1.5 times?
David, you lost me in the second experiment. How does ambient (30C) equate to OLR?
David #33 JM said
as I did above. IR is not a significant influence on the temperature on this scale, and even if it were, a few cm of moist air will not attenuate it noticeably. The factor of 3/2 derives from IR theory, and has no relevance here.
I think the temperature measuring issue is a red herring. Your result is what is to be expected, and says nothing about AGW in the atmosphere.
Nick, you will have to do better than bald assertion. I think its exceptionally close. There is a central black body (the sensor), a convection zone as in the atmosphere (the inside of the jar), a conduction zone (the glass wall) just as in the upper atmosphere.
The purpose of a model is abstraction. Because a jar is not the atmosphere does not make it irrelevant.
David #36
Calculations were in the previous post. The absorption side is easier. With a gray-body optical depth of about 1.87, say, 10 km of atmosphere absorbs about 80% of IR. Then 1 m of air absorbs maybe 0.02%. You have much less than 1m. Adding water vapor increases this, but it is still negligible.
You can visualise this by thinking of a hazy day where hills a few km away are faint. IR absorption is on this scale. But you don’t expect such a haze to affect your ability to see your hand.
On the importance of IR, in the atmosphere, IR dominates convection, but not by that much - say 24 W/m convection vs 240 W/m2 IR. But, as I said, convection responds to temperature gradient, while IR doesn’t. And in your experiment, the temperature gradients are of the order of 1000 times greater.
These are big scale differences, and if you want to claim that your experiment does show something about AGW, I think the onus shifts to you to resolve them. Numeracy requires no less!
“On the importance of IR, in the atmosphere, IR dominates convection, but not by that much - say 24 W/m convection vs 240 W/m2 IR.”
That is one place where the current theory is so screwed up and where M is so right. It’s the other way around, as anyone who steps outside will notice. Again, if it weren’t for convection, the earth’s surface would be just like the inside of David’s jar.
What ?? — No runaway destructive feedback, imploding the container, creating a mini black hole, devouring Earth.
Shut this down David, immediately, before the God particle visits from another stringy dimension.
Protesters outside your convection oven can get very mean — pull the power plud to destruction of humanity.
Nick, We were interrupted by down time. Your issue is that the path length is too short to produce detectable attenuation of IR in this experiment right? Interestingly, addition of water does produce a change, cooling not warming, so some effect is noticeable. This is as Noor says, the net effect of more vapor is cooling through increased convection. Presumably it is heated through attenuation of IR. It a way it illustrates that its too simplistic to talk about net positive or negative feedback. Attenuation increases temperature, which increases convection which decreases temperature.
But you miss the main points I think. There is a temperature gradient across the apparatus, analogous to a lapse rate. Heat is propagated. Whether it is by convection or conduction is not so important for this purpose. There is also an IR phase, but the ratios are different in the atmosphere.
The main point, which I would be grateful if you address, is what to you think the maximum greenhouse effect should be: 1.5, 2 or something else? This is clearly falsifiable. The RealClimate toy model says 2. FM says 1.5. I strongly suspect it is 1.5, and if so the RealClimate bots are demonstrable wrong in this aspect of their understanding.
davidss last blog post..Greenhouse Heat Engine #3
Nick#37
“On the importance of IR, in the atmosphere, IR dominates convection, but not by that much - say 24 W/m convection vs 240 W/m2 IR.”
I had thought the Earth’s true convective heat flux was of the order of 80 - 100 W/m2. Is this not true?
#41 Steve
I think that figure of 80-100 includes latent heat transport. LH transport requires both evaporation and condensation (rain). It’s not clear that the condensation part of the cycle is happening here, so I quoted just the pure convective figure. But the figuring here is rough, and my argument stands if the convection is 80-100. The point is that in the whole atmosphere IR is not much more than convection, maybe a factor of up to 10, and on David’s scale, temperature gradients, which drive convection, are maybe 1000 times higher. Then you can expect convection to dominate.
jae: The ambient is the lower boundary condition.
Nick #42
Yes
aye? Is that convective transport is 10 times radiative? If so you had a different opinion earlier on.
In the container?
Then there is the interaction of the gases in the container with the container wall which conducts heat to the cooler atmosphere.
It’s not so silly.
In my distant past we had a piece of electronic equipment imported from North America that was completely sealed and had some heat being generated inside by lasers & motors and such that used to keel over in over in aussie summer heat. All we did to fix it was screw a heat exchanger on the body and that fixed it.
Now the question is only does the extra water vapour inside improve the exchange of heat inside with the wall of the container as the water vapour does in the atmosphere since it has less vapour above to absorb it’s radiation?
Huh? Not nearly as silly as a discontinuity at the earth’s surface.
It should be quite easy to fine tune this experiment to ensure that the ratio of the surface area of the water to the volume of air inside the container roughly matched that of the ocean to the troposphere (say).
The receiver may have to be suspended on a string above the water.
I also think the external temperature needs to strictly be the actual skin temperature of the container (use Bluetack or something) rather than the external air temperature as there will be convective cooling off the outside of the container. It would be wise to ensure external convective cooling was minimized by embedding container in ground up to water level.
The experiment should be run for a whole day (must get up/start at sunrise and put experiment in middle of large patio of flat field with no shade etc ;-).
IMHO results should not be considered ‘valid/steady state’ until/if/when there is some condensation visible on the inside of the container.
Steve, There was condensation on the sides, and a small amount of free water in the bottom at the end. Within the precision of this experiment, which isn’t very high, you can only try to saturate the air. I think the ambient is the right boundary condition. I think the right setup is a clear, still, sunny day so as the ambient represents as near as possible blackbody temperature.
Agree with all that. But we also have a deep pool of largely un-irradiated seawater at the bottom of our optical cavity.
As Gorshkov and Makarieva (2002) point out, the only two stable states we can be really ‘bank on’ thermodynamically are a fully frozen earth or one with a fully evaporated ocean. They note (and I agree) there is a lot of evidence of another stable state of some sort somewhere in between these two conditions. They suggest a biotic effect. Again I agree.
The existence of this mysterious stable state is the fundamental basis of M Theory although I find M’s ‘reason’ somewhat hard to swallow.
Whether that steady state actually exists (AGW orthodoxy ‘computer says no’
is the core issue.
Even if that state actually does exist, whether M has identified the correct dynamic of that state is also a moot point. This is where my own doubts creep in.
If you can get this little experiment to work OK with ordinary air and fresh tap water (which I guessed you used), then the logical next step would be to replace the water with seawater. This would impose the correct partial pressure of CO2 on the gas phase as the air cavity/surface skin of the water warmed up.
If M is right, the steady state situation (if it exists) should be pretty much the same regardless.
Next, the container could be flushed with CO2 and the experiment re-run.
If M is right, the steady state situation should still be pretty much the same regardless!
Then M either bows to thunderous applause or exits stage left.
You could also then really screw with everyone’s head big time by inserting one drop of olive oil and running the experiment again.
What fun this would all be!
David #45
Not so silly as suggesting that convection in the jar unimportant. You answered my next question: “Was there condensation on the wall?”
We know where the heat went to drop the temperature. Water condensed on the side because the walls were cool being exposed to the atmosphere. (Was there as much on the glass jar if any?). It’s the same with the atmosphere on a larger scale where we have evaporative cooling on the surface convection lifts it away (more likely cause a discontinuity than I(mu)=Io+Ii*mu ) to where it can export that heat (and entropy) to space more readily, assisted by Steve’s biotic dimethyl sulphides.
I want some idea of the temperature gradient on the walls and what if the container walls were KI?
Exactly. That would be an ideal definitive experiment. One could hope. Its amazes me it has taken so long for me to get this to the point where it can be put in a nutshell. Now I don’t know why it took me so long. Part of it is that the paper goes off on so many intricate branches, which is OK, but the discussion has been frustratingly tortuous as a result.
Gorshkov and Makarieva: look I don’t know and I haven’t had time to study another intricate paper. I don’t think snowball earth and dry oceans are consistent with the Su=3OLR/2 constraint, but unless I studied it more deeply and worked with the numbers and equations a bit more I don’t have a view. Just looking at the way variance increased when I added water at the temperature maximum, I was struck by the appearence of long term pesistent behaviour in the temperature changes. Water is strange stuff, and the capacity to phase change in the 0-100C range gives it mysterious powers. So I am skeptical of the need to invoke biotic control - just skeptical, I don’t know.
David #51
would you believe the range is -100 - 100C
Kaye & Laby
Thanks Jan.
Regarding biotic control, David, I understand your ’skepticism’.
ALL cyanobacteria need iron as an essential nutrient. One of the reasons advanced for why cyanobacteria bloom more strongly in NH oceans (actually in bimodal seasonal peaks I have found - although no-one has bothered to publish this fact) and less well in the SH oceans (actaully unimodally I have noticed) is that there is more iron in NH oceans.
Maybe yes, maybe no, but it is also known that the terminations of ice ages start in the NH due to the obliquity issue.
But now this (I’m sure you can decipher the simple Italian):
http://omniclimate.files.wordpress.com/2008/11/domec.gif
Steve David
I rather suspect that once people stop letting their emotions drive their science that we’ll find that there are several feedback paths all negative with the only “amplifier” high energy cosmic rays (it works more or less like a thermionic valve).
Positive feedback can’t happen without an internal energy source. While earth has a geothermal energy source that’s internal it’s strong enough to drive a flea off a dogs back.
I don’t see how this experiment can be meaningful. The absorption of IR by the walls of the container, and the convection of air around the walls of the container are going to be the largest influence on the temperature, even if the radiation source were held constant. In addition the radiation source, the sun, is not controlled. These factors will determine the temperature of the gas inside the container. The IR absorption of the small amount of green house gases in the container as, Nick points out will be miniscule.
There is no hope for this experiment to shed any light on the supposed saturation of the greenhouse effect. It is totally meaningless.
Eric:
I take it that your assertion is that there is no maximum temperature due to greenhouse effect. In that case your assertion is provably wrong.
David Stockwells last blog post..Model of Global Warming
Jan, When I was doing the experiment I was fascinated at how sensitive the temperature of the system was to clouds, puffs of wind, when the water was added. The 1.5 greenhouse factor is an amplification factor, but with the water the system was far more sensitive to variation than the dry container. Beats playing computer games.
David Stockwells last blog post..Model of Global Warming
David #57
Did you see as much condensation with the glass jar?
I can imagine it was fascinating to see but one supposes that with water molecules being slightly polarised when the collide with the container walls they like to stick there especially if there is a slight charge due to the breeze. If they stick there they give up all their thermal energy and condense leaving the heat to hitch a ride on the passing breeze. Any rotational or vibrational energy absorbed will go right along with it.
Back to tearing my hair out over imapd - after i take the terriers for a walk. This is no way to spend a vacation.
David #56
David, Eric isn’t asserting what you say; he’s just saying that this is a heat transfer problem mainly involving convection and effects at the plastic, including maybe some IR absorption there.
Ironically, there are AGW sceptics witht a bee in their bonnets about the greenhouse effect being misnamed - that greenhouses work just like your apparatus, by blocking convection and inserting an insulating boundary layer. They’re right that the analogy with atmospheric IR is inexact, but wrong in thinking that the inexact name invalidates anything.
Even at an IR level, your reasoning doesn’t work. FM’s theory matches Su with OLR, which is the outward radiation at TOA. Crucially, TOA is the point where no IR is coming back. This is far from being true at the exterior of your apparatus. There is the additional difficulty that FM’s theory is for planar radiation, which yours certainly isn’t.
The other aspect of your response to Eric that I didn’t understand was the reference to the existence of a maximum temperature as proving something. In this situation, there will always be a maximum, regardless of the heat transfer mechanism - otherwise you would have a wondrous furnace.
#59 Nick Stokes
“Even at an IR level, your reasoning doesn’t work. FM’s theory matches Su with OLR”
Please be precise, some might be misled, interpret “matches” with equals; see Zagoni;
(8) SU = 3 OLR / 2
One gas removes the effect of another
We have to break it down, make things simpler;
Drinking Bobbing Bird experiment
Several birds, different fluids
Buy different, easy to evaporate solvents, at your paint store
Alcohol from the drug store, even Vodka
But stay away from naptha
Use diamond drill to make a filling hole for the Bobber’s fluid.
Adding a different working fluid Bobbing Bird, to the communal drinking bowl.
One removes bobs from another ?
Runaway, self-destructive , bobbing feedbacks, resonating, butterfryng, chaotically cooking one bird after another ?
Nick,
Thanks for saving me the trouble of pointing out that David hasn’t answered my objectives.
Any scientific paper which proposes and experimental result has a section which deals with experimental error. This is supposed to prove the validity of the experiment by examining quantititively what other phenomena besides the relationship being explored by the experiment, could have contributed to the result, spoiling the experiment.
The phenomena we have listed would tend to overwhelm any radiation absorption properties of the gas inside the container that are being tested.
The burden of proof is on the experimental designer to calculate the contributions of all the other phenomena to the equilibrium temperature of the air inside the vessel, if he wants the results he is claiming to be accepted.
One cannot be allowed to claim that the experiment is scientific in any way, if this burden has not been met. In this case, it has not even been attempted.
To my mind, this is evidence that the writer is not either unaware of the requirement, or wants to pull a fast one and get away with something.
Oops I should have said objections, not objectives.
Older personal computers have 4 analog, joystick inputs.
In addition to the weather station, what extra sensors to add ?
Perhaps use a giant glass vine making bottle, well
insulated. But leaving radiation in and out the top.
Eric and Nick: I’m not smart enough to prove it, but I think the errors you are looking at are quite small, relative to the massive greenhouse effect. They are probably the reason that the actual temperature doesn’t quite get to the theoretical temperature.
Jae said,
“Eric and Nick: I’m not smart enough to prove it, but I think the errors you are looking at are quite small, relative to the massive greenhouse effect. They are probably the reason that the actual temperature doesn’t quite get to the theoretical temperature.”
No matter how smart you are, if the experiment is bogus, you can’t find a way around that fact.
Ordinary glass absorbs an re-rediates in the IR. This is one of the heat loss mechanisms that takes place as result of windows in a house, which transmit heat through them. Here is a link which explains the heat loss mechanisms associated with glass. This is common knowledge among people who deal with household energy. This is why special E glass is recommended for energy efficiency.
http://www.socalgas.com/construction/builders/Builders%20Resource%20Guide/Window%20Energy%20Concepts.htm
“Some of the long-wave energy emitted inside the room finds
its way to the window surface. This long-wave radiation is
absorbed by ordinary window glass and then re-radiated or
emitted as heat, either to the outdoors or back inside, from
the glass surfaces. Window heat loss by this means can be
reduced if the glass is treated to absorb less and emit less
long-wave radiant energy.
The ability of a surface to reflect long-wave radiation is
Measured by its emissivity. Emissivity vanes from 1 (100%
of long-wave radiation emitted) to 0 (0% emitted). For glass,
the lower the emissivity, the lower the U-factor. Clear glass
has an emissivity of about .84 while bright aluminum foil has
an emissivity of .05.”
An emissivity of 0.84 means that glass is absorbing most of the IR entering it an re-emitting it in all directions. The emissivity of the small amount of atmosphere in the jar is miniscule compared. The number of emitting and absorbing atoms is way too small. The IR will mainly bounce between the walls of the glass, where it is absorbed and remitted. The molecules of gas will get most of their energy from contact with the walls of the jar.
Eric:
“The molecules of gas will get most of their energy from contact with the walls of the jar.”
I don’t see how that’s possible, since the glass remains rather cool–at a much lower temp. than the air inside–due to losses outside. Touch the glass in your closed car from inside. Then touch the dashboard.
Since when?
jae #68
Don’t you find it amusing to find laymen teaching science to scientists such as yourself?
Any way it’s fairly obvious from the fact that the gas in the plastic jar cools over time after the introduction of warm water that the addition aids cooling. It’s also obvious from the condensation on the wall that it’s at the wall that the water is giving up it’s heat at the rate
2500 J/gm.
jae #68
” Eric:
“The molecules of gas will get most of their energy from contact with the walls of the jar.”
I don’t see how that’s possible, since the glass remains rather cool–at a much lower temp. than the air inside–due to losses outside. Touch the glass in your closed car from inside. Then touch the dashboard.”
The air inside your car is in contact with the dashboard also, which is hotter than the glass, because it absorbs practically all the solar radiation falling on it, while the glass is mainly transparent to the short wave radiation. The air in the car is heated by contact with the dashboard and convection within the car.
The experimenter has yet to provide an elementary analysis of the results of his experiment compared to the size of the effect he set out to measure.
I have yet to see an idealized version of the experiment analysed to tell what the temperature rise in an ideal bottle would be with and without the water vapor. That would be the first thing to do, to determine whether it is possible that one could learn anything from the experiment even with good equipment.
Let us try calculate the results of a simple 1 dimensional experiment, with perfectly transparent, non absorbing glass separating the earth’s atmosphere from the controlled sample of atmosphere, and look at the radiation balance alone, assuming that heat conduction and convection were not factors.
Compare the calculated temperature achieved inside the atmospheric sample, assuming it was a uniform slab, at 0%, 50% and 100% relative humidity, assuming the slab is 1 meter thick.
Use a fixed solar radiation flux and a fixed downwelling IR flux from the atmosphere, to achieve thermal equilibrium between the earth’s surface temperature and the atmosphere.
Recognize that the entire earths atmosphere will absorb a fraction, 0.6 of the IR radiation incident on it, and assume this is at 50% humidity, for illustrative purposes.
http://www.aps.org/units/fps/newsletters/200807/upload/july08.pdf
(see equation 19)
We need an estimate of how what fraction of the IR radiation passing through the air sample will be absorbed and re emitted. This will depend on the number of absorbing molecules in our sample slab.
We know the number of molecules relative to the atmosphere as a whole.
The weight of 1 square meter of the atmospheric column above us is about 7000Kg. The weight of 1 cubic meter of atmosphere is 1.225KG (at sea level)
Taking Ln(0.6)*1.225/7000 we find that about 1/10000 of the IR incident on the sample air slab will be absorbed by it if it contained the average mixture of greenhouse gases in the atmosphere 50% humidity.
If the earth’s surface underneath the slab is receiving and absorbing a solar flux of equal to S, and down-welling radiation D, with GHG’s in the sample set same as the atmospheric concentration of GHG’s, the upward radiation, assuming equilibrium U will obey the equation
U=S+D,
and the earth’s surface temperature will be give by U=s*T^4, where s is the SB constant, assuming that the surface is a perfect emitter/absorber
If we remove or add GHG’s from the sample to see what the new equilibrium temperature of the surface will be, the effective downwelling radiation has been reduced because of the absence of GHG’s in 1 Meter of atmosphere.
Let us see what happens to the surface temperature under such conditions by using equation 16 of our reference:
Ts=(n+1)^0.25 * Ta
If we add change the value of n from 0.6 to 0.6001 we can calculate the change in new value of Ts, which we call Ts’.
Ts’-Ts=Ts*((1.60001)/(1.6)-1)=0.017C.
If the temperature of the surface underneath the bottle has changed by more than this, it was due to other factors in the experiment besides the content of the air sample. The detectable limit was actually 10 times the magnitude of the temperature change the experimenter was able to measure.
eric:
“Recognize that the entire earths atmosphere will absorb a fraction, 0.6 of the IR radiation incident on it, and assume this is at 50% humidity, for illustrative purposes.”
Are you saying that the “window” radiation is then 40 percent of the total IR?
Jae 74 said
“Eric Said,
“Recognize that the entire earths atmosphere will absorb a fraction, 0.6 of the IR radiation incident on it, and assume this is at 50% humidity, for illustrative purposes.”
Are you saying that the “window” radiation is then 40 percent of the total IR?”
I don’t believe this is what is meant in the reference. The authors are dealing with the problem of absorption and re-emission during the upward and downward propagation of the IR, so the spectrum of IR that doesn’t interact with the atmosphere, which is the IR window, doesn’t come into this calculation. To me more accurate, it is the fraction of a layer of atmosphere required to absorb nearly 100% of the radiation that it can absorb.
The authors say,
“The thickness of a layer is such that almost all the incident radiation is just absorbed in that layer….”
Eric: O.K. I guess I misunderstood.
Eric #70: If you are talking about the change due to addition of water, I would say the change was detectable, downward, and the condensation on the walls of the jar indicate an evaporative cycle enhancing cooling is far greater than any warming from increased absorption.
Addition of another layer/jar is a different experiment.
David,
The experiment could be improved by starting with a mixture of air at its existing composition, plus water and do the experiment you did.
It needs an increase of CO2. How to do? Do they make those Sparklet bulbs anymore?
I have an industrial grade temperature logger with wired probe which could do the trick in terms of measuring the temperature. All one needs then is one of those old soda water pourers into which one poured some water and screwed the CO2 cartridge into its valve system to carbonate the enclosed water.
David,
looking at the graphed measurements, the internal temperature plateaued. This seems a limit of detection factor for Dick Smith marketed instruments - weather equipment is only produced to measure things within a certain measurement range, for cost factors.
The abrupt change to the slowly rising data is the clue. Data truncation is an instrumentation issue, not measurement. John Brignell should be consulted on this ASAP.
Hi Louis, I think I know how to build a more accurate experiment after this first trial. Concurrent experiments to control for environmental variation, laboratory temperature sensors, and mount the whole think on EPS foam.
davidss last blog post..Maxpower Datasheet Experiment 2
jae writes:
1. No matter how many times you say this, it still won’t be true.
2. The statement is 100% at odds with Miskolczi, who believes, along with every physicist in the world, that radiation can affect matter.
There’s this thing called “atmospheric circulation” which redistributes heat among latitudes.
Deserts are actually distinguished by lack of moisture, not high temperature. The Gobi desert, for example, can get quite cold.
admin says, of his small-scale experiment:
The attenuation coefficient of carbon dioxide in the 15 micron band averages 1.48 per reciprocal meter atmosphere (Essenhigh 2001). Let’s assume your apparatus is one meter across and that the concentration of carbon dioxide starts at 0.000387, the present concentration. The optical thickness would then be 0.000573. Double the carbon dioxide concentration and it would become 0.00115. The attenuation, by the definition of optical thickness, would change from 0.9994 to 0.9989; i.e., not enough to measure with your equipment. The experiment is meaningless. It certainly DOES matter that your apparatus is not the size of the atmosphere.
Optical thickness = k x p x L where k is absorption coefficient in reciprocal meter atmospheres, p is partial pressure in atmospheres, and L is distance in meters. You can’t get around the fact that your experiment uses a very short value for L, which makes the results nearly or completely unreadable.
Steve Short writes:
The figures from K&T97 are 24 W/m^2 for pure convection/conduction (”sensible heat”) and 78 W/m^2 for evaporation (”latent heat”), for a total of 102 W/m^2. Planetary astronomers confuse this a bit by conflating both as the “convective flux:” fc = fsens + flat.
BPL #78
I think your comprehension is a little strange I read jae’s remark a little differently “maximum temperature effects” as meaning extremes of temperature are to be found there. I believe you are telling only half the story here.
There is no upper limit to the greenhouse effect (not in practical terms, anyway; you might get an upper limit of 2000 K or so from the shift of peak wavelength due to Wien’s Law). The lower layers may become saturated, but the uppermost layer is never saturated, and each layer affects every other layer. Here’s a mathematical explanation as to how this works (just remove the hyphen):
http://www.geoci-ties.com/bpl1960/Saturation.html
BPL #82
2 things
1 your link isn’t working
2 your not making sense.
#82 Barton Paul Levenson
“There is no upper limit to the greenhouse effect … The lower layers may become saturated, but the uppermost layer is never saturated, and each layer affects every other layer. ”
Tropopaused, uppermost, water is greater than saturation, lower layers can have desert low humidity. How can we reverse the runaway accelerating cooling ? Is there a limit before Zero Kelvin ?
Jan Pompe writes:
My bad. You have to remove the hyphen and cut-and-paste it into the address window in your browser.
“You’re.” In what way am I not making sense?
BPL #85
This is a start. There is a limit to how hot the sun can make the planet. You won’t 2000k without some concentration generally if the sun is over head 75c is tops for a simple passive system. in Sydney it’s something like 60C. Of course if you can get sufficient concetration of light the theoretical limit to that is 5788. None of this is without limit.
If you think you can get it hotter in your solar furnace wit