Model CO2 as Greenhouse Gas: Tips & Results

[sylas]

Sorry, I thought this forum was about experimental tests of CO2's effect on temperature when exposed to IR.

Bye.

Well... that clarifies what is going on, and answers my confusion.

You've been given several examples of precisely that here in the thread; and they are linked in the post to which you reply. I do assume good faith as long as possible, and will continue to assume that for other readers. But not beyond reason, and not for you. You've established that you are not even trying to be sensible, and are just refusing to even read what is right in front of your nose.

Bye. Sylas

 

[cleanwater]

Repeating what I've been saying "The greenhouse gas effect" is a fairy -tale There is no scientific proof that it exists.
The experiment that claims to prove the ghg Effect is junk. below are a list of thing that are questionable or wrong with the experiment and the results.
1. Are the two containers the same size, shape and type of glass? Different types of glass
absorb different wave lengths of IR and heat up differently.
2. Where are the thermometers located relative to the light? Are they in the light path
were they would absorb some of the IR thus skewing the data.
3. If the greenhouse gas effect exists there should be a different temperature of the black
cardboard in the CO2 container. The temperature was not measured therefore this
experiment only illustrates that the CO2 heats up. Does it heat from absorption or from
conduction of different heating of the container?
4. Was the experiment done with other “greenhouse gases?” as CH4 butane, natural
cooking gas, Nitrogen trifluoride ?
5. Did the experimenters reverse the gases to the other container to evaluate differences
in the set-up.?
6. Was more than one set of test done? Is there more data to evaluate?
7. Did you monitor the temperature of the water in the trays? If the trays are in contact
with the gases there is conduction of heat from the bottom of the glass trays to the gases.
8. I can not be sure from the photos but it appears that the top of C1 container is closed ,if
this is true then you have created a confined space heating container (greenhouse effect).
It has been proved by R.W. Wood and others that the heating in a greenhouse is caused
by the restriction of heat convection and not back radiation of IR. The top of C2 appears
open thus keeping the temperature lower by convection. Good job of cheating..
9. What you have shown is what has been known from IR spectroscopes that different
gases absorb different wave lengths of IR but in accordance to Niels Bohr that absorption of IR does not cause the gas to heat up
10. I have done a similar experiment except I used clear Mylar balloons (very little or no
absorption of IR as opposed to glass) Based on IR thermometer reading and available
data on IR absorption by glass much of the heating in the experiment was from the glass.
This was not measured in the experiment. By using Mylar balloons in bright sunlight
there was no heating of the gases inside 4 balloons above ambient temperature (measured
with an IR thermometer reading to O.1 degrees F. The contents were 100% CO2, 100%
butane, natural gas (CH4 and CO2) and air. The black cardboard I used did not show any
differential heating between areas in the “shadow” of the balloons compared to “unshadowed”
areas –no back radiation from the “greenhouse gas effect” The black
cardboard did increase in temperature from ambient of 95 degree F to 175 degree F.
uniformly across the surface.
11. If the greenhouse gas effect exist why hasn’t it been applied to something useful like
thermopane window filled with a “greenhouse gas” that would back radiate IR into the
house and create insulated windows with R=30 values.
You ask the question “Why can it be warmer at night than during the day? Any
elementary school students that can read a weather report know that daily temperature are
effected by hot or cold air masses moving across the area. It is also obvious that
on a clear night the temperature will cool down much faster that on a cloudy night. Water
is not a greenhouse gas in spite of what many people say- it has known properties that
explain temperature differences 24/7/365. There is no back radiation –there is reflection
of light or blockage of light(clouds) energy release as lightning and other thermo effects
that are within the Laws of physics and thermodynamic.
When you find reliable experimental data that proves that the “greenhouse gas effect
exists please share it with the world.
In the mean time read “Falsification of the Atmospheric CO2 greenhouse effects within
the frame of Physics” by Gerhard Gerlich and Ralf D. Tscheuschner and when you
understand it in five or ten years( a PhD level –way above your level of intelligence) and
the global temperature has dropped by the 0.6 degrees that it has gone up over the passed
120year you will realize that man-made global warming is a hoax.
Posted by: cleanwater | May 14, 2009 3:09 PM
Below are the intro and abstract to very relevant technical papers.

Greenhouse Gas Hypothesis Violates Fundamentals of Physics*
by Dipl.-Ing. Heinz Thieme*
*
Deutsche Version siehe:*http://freenet-homepage.de/klima/index.htm
*
The relationship between so-called greenhouse gases and atmospheric temperature is not yet well understood.* So far, climatologists have hardly participated in serious scientific discussion of the basic energetic mechanisms of the atmosphere.* Some of them, however, appear to be starting to realize that their greenhouse paradigm is fundamentally flawed, and already preparing to withdraw their theories about the climatic effects of CO2 and other trace gases.
At present, the climatological profession is chiefly engaged in promoting the restriction of CO2 emissions as a means of limiting atmospheric warming.* But at the same time, they admit that the greenhouse effect - i.e. the influence of so-called greenhouse gases on near-surface temperature - is not yet absolutely proven (Grassl et al., see: http--www.dmg-ev.de-gesellschaft-aktivitaeten-pdf-treibhauseffekt.pdf ).* In other words, there is as yet no incontrovertible proof either of the greenhouse effect, or its connection with alleged global warming.
This is no surprise, because in fact there is no such thing as the greenhouse effect: it is an impossibility.* The statement that so-called greenhouse gases, especially CO2, contribute to near-surface atmospheric warming is in glaring contradiction to well-known physical laws relating to gas and vapour, as well as to general caloric theory.
The full paper is available on line.

Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics
Version 1.0 (July 7, 2007)
Gerhard Gerlich &
Ralf D. Tscheuschner
Abstract
The atmospheric greenhouse effect, an idea that authors trace back to the traditional
works of Fourier 1824, Tyndall 1861 and Arrhenius 1896 and is still supported in global
climatology essentially describes a fictitious mechanism in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics such a planetary machine can never exist. Nevertheless, in almost
all texts of global climatology and in a widespread secondary literature it is taken for
granted that such mechanism is real and stands on a firm scientific foundation. In
this paper the popular conjecture is analyzed and the underlying physical principles are
clarified. By showing that (a) there are no common physical laws between the warming
phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33 _C is a meaningless number calculated wrongly,(d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiatively balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.
The full paper is available on line.
Going back to 1909 -R.W.Wood proved the gh effect as discribed is confined space heating and the ghg effect does not exist.

 

[BrianG]

It's a real shame our educational system has sunk so low, this is the state of our popular science:

 

[sylas]

Repeating what I've been saying "The greenhouse gas effect" is a fairy -tale There is no scientific proof that it exists.
The experiment that claims to prove the ghg Effect is junk. below are a list of thing that are questionable or wrong with the experiment and the results.

No, they aren't questionable issues. You are making up spurious objections asking if the experiments used elementary common sense.

The simple fact that carbon dioxide absorbs thermal radiation much better than ordinary air (mainly Nitrogen and Oxygen) has been known for well over 150 years, and the physics of is now well understood.

11. If the greenhouse gas effect exist why hasn’t it been applied to something useful like
thermopane window filled with a “greenhouse gas” that would back radiate IR into the
house and create insulated windows with R=30 values.

R values are a measure of insulation; which is not the relevant quantity. The relevant quantity here would be the thermal emissivity, with the added requirement that it be transparent to visible light.

Glass is already somewhat opaque to infrared, and treated glass can enhance this effect; which does have some benefits. But it is not the same as insulation quantified with an R-value.

You could get a similar effect with a very strong greenhouse gas like some of the fluorocarbons, but it is more efficient to use treated glass. A window is a bit thinner than the atmosphere. It is idiotic to compare an atmosphere with a thin layer of gas that could be reasonably placed inside a window cavity.

You ask the question “Why can it be warmer at night than during the day? Any
elementary school students that can read a weather report know that daily temperature are
effected by hot or cold air masses moving across the area. It is also obvious that
on a clear night the temperature will cool down much faster that on a cloudy night. Water
is not a greenhouse gas in spite of what many people say- it has known properties that
explain temperature differences 24/7/365. There is no back radiation –there is reflection
of light or blockage of light(clouds) energy release as lightning and other thermo effects
that are within the Laws of physics and thermodynamic.

My actual remarks are in the thread; and I did not say it is warmer at night than in the day. (Good grief!)

Water most certainly is a strong greenhouse gas, and that is a major reason why clear nights are colder.

Atmospheric backradiation is directly measured, and has been for over 50 years. It is very elementary thermodynamics that a warm gas which is opaque to thermal radiation -- like the atmosphere -- will also radiate thermal radiation. An early direct measurement of this is described in Stern, S.C., and F. Schwartzmann, 1954: An Infrared Detector For Measurement Of The Back Radiation From The Sky. J. Atmos. Sci., 11, 121–129. (http://ams.allenpress.com/perlserv/...&issn=1520-0469&volume=011&issue=02&page=0121)

The measurements are made in the night, and in the day. There is a large flux of radiation coming to the surface of the Earth from the atmosphere day and night, though of course the flux is larger in the daytime. It's measured. It's real. And basic thermodynamics means that the atmosphere is emitting radiation; which by Kirchoff's laws means that it also absorbs those same wavelengths.

When you find reliable experimental data that proves that the “greenhouse gas effect
exists please share it with the world.

Done already in the thread. You merely invented a bunch of wholly unfounded objections, which is why people like you are "deniers" rather than "skeptics".

In the mean time read “Falsification of the Atmospheric CO2 greenhouse effects within
the frame of Physics” by Gerhard Gerlich and Ralf D. Tscheuschner and when you
understand it in five or ten years( a PhD level –way above your level of intelligence) and
the global temperature has dropped by the 0.6 degrees that it has gone up over the passed
120year you will realize that man-made global warming is a hoax.

Actually, I have a PhD already, thanks. The main benefit of that is that you appreciate just how facile it is to argue by credentials. An argument stands or falls on its intrinsic merits. The paper by Gerlich and Tscheuschner is one of the worst failures of peer review I have ever seen in a physics journal. It is gross pseudoscience.

In fact, the paper was published without the normal peer review processes normally used in the journal. I sent a message to the journal advising them of its errors after it came out, on my own behalf. It was suggested I reply formally to the journal. I have since done so, as a co-author of a reply that has been submitted to the same journal pointing out some of the many errors; but in my view this should not have been necessary. There's no need to refute the paper for people who know basic atmospheric thermodynamics; the main problem is the failure of the journal editors to pick up such arrant nonsense before publication.

Going back to 1909 -R.W.Wood proved the gh effect as discribed is confined space heating and the ghg effect does not exist.

Wood explained the mechanisms of a glasshouse. He shows, correctly, that it works mainly by limiting convection; not by trapping infrared radiation. That is, he showed that a glasshouse does not work in the same way as an atmosphere opaque to infrared radiation.

This is basic stuff from the first lecture in an introductory course on atmospheric physics. To treat Wood's work as a refutation of the atmospheric greenhouse in the atmosphere is bizarre.

Sylas

 

[negitron]

Water most certainly is a strong greenhouse gas, and that is a major reason why clear nights are colder.

Eh, I have to disagree with the underlined portion (and only with that; I agree with the thesis statement). Cloud cover is an excellent reflector of IR; this works in both directions, obviously. At night, with little incoming energy, the ground and everything on it radiates its usual blackbody spectrum, peaking in the IR. On clear nights, this IR just mostly passes through the atmosphere, with a small portion being absorbed and re-radiated by various atmospheric gases--nothing special here. However, on cloudy nights, the ground-radiated IR is largely reflected from the cloud bottoms back down to the ground where a percentage of it is subsequently re-absorbed; the warmer ground heats the air above it and, voila, you've got a warmer-than-expected night. No greenhouse property of water vapor (which I agree is a real effect, don't get me wrong) is required.

 

[sylas]

Eh, I have to disagree with the underlined portion (and only with that; I agree with the thesis statement). Cloud cover is an excellent reflector of IR; this works in both directions, obviously. At night, with little incoming energy, the ground and everything on it radiates its usual blackbody spectrum, peaking in the IR. On clear nights, this IR just mostly passes through the atmosphere, with a small portion being absorbed and re-radiated by various atmospheric gases--nothing special here. However, on cloudy nights, the ground-radiated IR is largely reflected from the cloud bottoms back down to the ground where a percentage of it is subsequently re-absorbed; the warmer ground heats the air above it and, voila, you've got a warmer-than-expected night. No greenhouse property of water vapor (which I agree is a real effect, don't get me wrong) is required.

My understanding is that the effect you are describing is not "reflection", but absorption and re-emission of radiation... and that is a greenhouse effect. Clouds are good at this because they are made of water.

But I'll check a bit further.

Thanks -- sylas

 

[Skyhunter]

Cleanwater,

Reposting the same cut and paste over and over again is spamming.

https://www.physicsforums.com/showpost.php?p=2285824&postcount=17"

 

[negitron]

My understanding is that the effect you are describing is not "reflection", but absorption and re-emission of radiation...

That's what reflection is thought to be, at a fundamental level. However, clouds are not water vapor, but liquid water droplets. These are MUCH better at reflecting light, including IR, than water vapor (or any transparent gas, for that matter).

 

[chriscolose]

Actually reflection is a much different process, and sylas is right that it is not an important term for Earth's clouds (in the IR, obviously this not apply in the visible). In a lot of planetary applications though (like early Mars, Venus) scattering of IR light is very important. And water vapor or clouds are both very important considerations, whether it be day or night.

 

[negitron]

Actually reflection is a much different process, and sylas is right that it is not an important term for Earth's clouds (in the IR, obviously this not apply in the visible)

I don't believe this is correct. See the following chart:

 

[sylas]

I don't believe this is correct. See the following chart: (chart removed... see above... sylas)

That's not thermal infrared. Look at the wavelengths. The wavelength for thermal infrared radiation is more like 10 microns, way off to the right of the diagram where reflectance drops off sharply. The AVHRR channel 1 band in your chart is pretty much centered on visible light, I think.

I may not get back to this for a bit; but a quick look at my references confirms my opinion that the warmth of a cloudy night is a very strong greenhouse effect from cloud; meaning it is due to thermal emissions, not reflection. A detailed cloud model does consider infrared reflectance; but it is not a major factor, and not the main factor for why cloudy nights are warmer.

I'm not totally confident on this; but for the time being I still think my original statement is correct as given.

Cheers -- sylas

 

[Andre]

I may not get back to this for a bit; but a quick look at my references confirms my opinion that the warmth of a cloudy night is a very strong greenhouse effect from cloud; meaning it is due to thermal emissions, not reflection.

But who is paying the energy bill? If clouds emit IR sponaneously, then they would cool rather strongly, which would facilitate the condensation process, hence generating more clouds.

However most clouds tend to dissipate in the night.

 

[sylas]

But who is paying the energy bill? If clouds emit IR sponaneously, then they would cool rather strongly, which would facilitate the condensation process, hence generating more clouds.

EVERYTHING radiates infrared spontaneously. It's a basic property of matter. What I am describing is not any different to what you are used to; I'm describing the thermodynamics of the world you and I experience right now. This includes cooling at night, and condensation on the washing I forget to bring in this afternoon.

The Sun pays all the energy bills that matter.

It may help to bear in mind that the backradiation from the sky is real. It's measured. It's significant; night time included. Hence as you try to work on the physics of what happens to clouds and temperatures, you know for a fact you are going wrong somewhere if you think the atmosphere doesn't provide radiation to the surface at night, all night. That follows anyway from the physics; but it's still a handy sanity check to keep us on track.

With that in mind as an empirical fact about the world, let's see how the physics works.

The atmosphere does cool down at night; but the heat capacity of air is sufficiently high (about 1 kJ/kg/K) that it easily remains warm all night. There is about 10⁴ kg of air per m², so the heat capacity of the atmosphere is roughly 10⁷ Joules/m²/K.

This radiates to space about 240 W/m²; which is offset by a net energy flow up from the surface. Don't be confused by physically naive descriptions which suggest that greenhouse warming means that there's a net flow of energy from atmosphere to the surface. Its the other way around. The atmosphere is heated from the surface, at night as well as in the day. The effect is analogous to a blanket, which keeps you warmer even though it is colder than you are, and the net flow of energy is still from you into the blanket. The atmosphere is warmed by the surface, or a blanket is warmed by a body; and that means you are warmer than if you were radiating direct to space without impediment.

I don't know the rate at which heat energy is lost from the atmosphere at night, but will be less than 240 W/m². Over 11 hours we have about 40000 seconds; so the energy lost at night should be, ball park, 10⁷ J/m², or less; which is enough of itself to lower temperatures about a degree.

This is not an attempt to actually calculate the temperature change; just give a bit of basic thermodynamics to show that there's plenty of heat in the atmosphere to keep things mild over the span of a night. In more detail, we would find that night time usually brings an "inversion" in the lower part of the atmosphere close to the surface, so much of the temperature drop occurs low in the atmosphere, which makes good sense thermodynamically. And this means, by the way, that the clouds don't actually drop in temperature as much; most of the changes to cloud will probably be related to the inversion and currents.

And given that the cooling is pretty limited, effects on cloud are going to depend on a lot more than the simple measured facts of backradiation and associated cooling. The physics of cloud is actually pretty complex.

Cheers -- sylas

 

[chriscolose]

Guys, much of this is basic physics or atmospheric stuff, and shouldn't really feature much disagreement. Reflection is not the same thing as absoprtion and re-radiation. The physics is different. Clouds tend to have a cooling effect in daytime (depends on the cloud type, altitude, etc) and warm during the night time. Clouds especially have a warming effect in the polar night. Clouds or greenhouse gases also do not reflect IR light to any significant degree at Earth-like conditions. When an absorbing surface is present, the average emission temperature is less than the surface value, and the loss of energy to space is much less efficient than the infrared emission from the surface. Thus you can define the greenhouse effect as \sigma T^{4}_{s} - \sigma T^{4}_{eff} \approx 150 W m^{-2}

One significant difference between an absorbing greenhouse effect and a scattering greenhouse effect (the latter requires considerations in many alien planets) is that one's magnitude is essentially dependent on the temperature profile vertically, wheras in a scattering case you have near independence of the cloud altitude.

 

[Andre]

.

With that in mind as an empirical fact about the world, let's see how the physics works.

It appears that the problem is more terminology and definitions. So we agree that the noctural cooling of the atmosphere due to radiation amounts to an order of magnitude of one degree. However there is a distinct difference between Earth surface cooling with or without cloud cover, at least an order of magnitude higher in no wind conditions. Why?

Before it was called greenhouse effect, it was explained that the clouds reflected the surface heat radiation, and the clear dark night did not. Hence, what's in a name?

.more detail, we would find that night time usually brings an "inversion" in the lower part of the atmosphere close to the surface, so much of the temperature drop occurs low in the atmosphere, which makes good sense thermodynamically.

We won't find so much of an inversion under a cloud cover, it's more a clear air property like shown http://www.myoops.org/twocw/usu/Forest__Range__and_Wildlife_Sciences/Wildland_Fire_Management_and_Planning/Unit_7__Atmospheric_Stability_and_Instability_2.html :

http://www.myoops.org/twocw/usu/Forest__Range__and_Wildlife_Sciences/Wildland_Fire_Management_and_Planning/inversion2.jpg

See also this post:

But the first thing in greenhouse effect is understanding how it works.

The global warming hypothesis assumes that the difference between basic Earth black body temperature and actual atmospheric temperature is caused by radiative properties of the greenhouse gases, of which water vapor is the most important, basically nullifying all other mechanisms. In reality it is convection and latent heat transport, which heats the atmosphere from the surface at daylight, while there is no comparable mechanism at night to cool it again. So this mechanism is one way only. This can be demonstrated when comparing day and night lapse rates in the atmosphere, where the difference between day and night is greatest at the Earth surface

http://mtp.jpl.nasa.gov/missions/texaqs/austin_poster/Image11.gif

http://mtp.jpl.nasa.gov/missions/texaqs/austin_poster/MTP_Austin_Paper.htm

Hence the upper levels hardly cool at night as the only cooling mechanism is ... greenhouse effect, radiation out. And at those levels, with strongly reduced water vapor, radiation escapes to outer space much easier. This effect appears to be neglected in the IPCC endorsed literature and if you don't account for it in the models, you're basically stuck to the GIGO principle.

It is all in this thread, discussing the Chilingar et al 2008 study.

https://www.physicsforums.com/showthread.php?t=252066

In this mechanism the concentration of greenhouse gasses for temperature is strongly reduced. More greenhouse warming simply increases the convection rate, removing the excess heat again from the surface.

 

[sylas]

It appears that the problem is more terminology and definitions. So we agree that the noctural cooling of the atmosphere due to radiation amounts to an order of magnitude of one degree. However there is a distinct difference between Earth surface cooling with or without cloud cover, at least an order of magnitude higher in no wind conditions. Why?

Before it was called greenhouse effect, it was explained that the clouds reflected the surface heat radiation, and the clear dark night did not. Hence, what's in a name?

The answer to "Why?" has been given. It's an atmospheric greenhouse effect; arising from the capacity of cloud to absorb and emit thermal radiation.

Cloud is much more complex than a gas like carbon dioxide, because it also reflects, absorbs and scatters shortwave radiation. Hence the net effect of cloud in the atmosphere is very complex; and still far from well understood. But at night, the effect is much simplified; since there's really only the longwave to worry about.

This is not just terminology. This was a real physical error in the description by someone. If a technically incorrect term is used in a physics forum, it is picked up. When negitron proposed reflection was more important, he was making a genuine substantive physical comment, which I appreciate. As it turns out, he was incorrect, but it was still a useful substantive contribution. Next time it might be me who gets the details wrong. I was not completely sure, and so I went back to check on the physics of it. I am sure now, having checked, that the effect of cloud is due to thermal emission; not infrared reflection. Had it been the other way around, I'd have acknowledged and fixed it. That's how we all make substantive progress in real physical understanding.

I do not think this process was ever called "reflection", except (even now) in descriptions that are physically inaccurate. It's one of my pet peeves with simplistic accounts of the atmospheric greenhouse effect that speak of infrared being reflected. The real cause -- thermal absorption and emission -- has been known for about 150 years. It turns out that the impact of cloud on longwave radiation is also by absorption and emission, rather than by scattering and reflection as applies to shortwave.

Indulge me... I loved the description of what we now call the atmospheric greenhouse effect given by Victorian scientist John Tyndall in a public lecture in 1863, after his discovery of the strong thermal emission and absorption of "greenhouse gases". I mentioned it also back in msg #10. A DjVu reader will be required, and with this you can read Contributions to Molecular Physics in the Domain of Radiant Heat (Tyndall, 1872) [17 Mbyte djvu file, 446 pages]. The public lecture is recorded on pages 421-424. It focuses on water vapour, which is the strongest contributor to Earth's atmospheric greenhouse. Cloud is not mentioned, but it works in the same way. Here's an extract:

Looking at the single atoms, for every 200 of oxygen and nitrogen there is about 1 molecule of aqueous vapour. This 1, then, is 80 times more powerful than the 200; and hence, comparing a single atom of oxygen or nitrogen with a single molecule of aqueous vapour, we may infer that the action of the latter is 16,000 times that of the former. This is a very astonishing result, and it naturally excited opposition, based on the philosophic reluctance to accent a fact of such import before testing it to the uttermost. From such opposition a discovery, if it be worth the name, emerges with its fibre strengthened; as the human character gathers force from the healthy antagonisms of daily life. It was urged that the result was on the face of it improbable [...]

(snip here about a page describing experimental tests for other possible causes)​

No doubt, therefore, can exist of the extraordinary opacity of this substance to the rays of obscure heat; and particularly such rays as are emitted by the Earth after it has been warmed by the sun. It is perfectly certain that more than 10 per cent. of the terrestrial radiation from the soil of England is stopped within 10 feet of the soil. This one fact is sufficient to show the immense influence which this newly-discovered property of aqueous vapour must exert on the phenomena of meteorology.

This aqueous vapour is a blanket more necessary to the vegetable life of England than clothing is to man. Remove for a single summer-night the aqueous vapour from the air which overspreads this country, and you would assuredly destroy every plant capable of being destroyed by the freezing temperature. The warmth of our fields and gardens would pour itself unrequited into space, and the sun would rise upon an island held fast in the iron grip of frost. The aqueous vapour constitutes a local dam, by which the temperature at the Earth's surface is deepened; the dam, however, finally overflows, and we give to space all that we receive from the sun.​

The analogy of the dam is apt. The Earth still radiates the energy to space which it receives. It just needs to be warmer than it would be without this barrier to thermal radiation. This lecture remains an accurate intuitive account of the relevant physics. Elsewhere in this lecture he also notes the equality of emissivity and absortivity.

We won't find so much of an inversion under a cloud cover, it's more a clear air property like shown

I think you've missed the point here. I gave inversion only as an easy example of how the atmosphere does not simply drop uniformly in temperature. I calculated a uniform temperature difference just to address your claim that cooling is "strong". In fact, the total cooling at night over the atmosphere is small, because of the substantial heat capacity.

The inversion is only a simple example to show that the temperature change is not uniform. Whether there is an inversion or not, it remains the case that the fall in temperature at night is mostly at low altitudes.

Be that as it may, inversions tend to be quite common at night, and they quickly break up in the morning. What your photograph shows is a case where the nighttime inversion persists into the day. You are quite right that inversions are stronger when the there is no cloud, of course; this is because of the increased low level cooling when there is not so much of the atmospheric greenhouse effect at work.

A friendly caution: beware of relying on Chilingar. He's not an atmospheric physicist at all, and it shows. He's a petroleum geologist (a good one, by all accounts) who for some reason has taken up denial of conventional climatology, with some dreadful error ridden papers that show his lack of familiarity with the field and which conflict with pretty basic physics. The papers have had no impact on real climate science and have been something of an embarrassment to other critics of conventional climatology; though of course they are uncritically lapped up in low quality blogs and the like with no background to tell sense from nonsense in atmospheric physics.

Perhaps it might be best for me to add a more specific reply to that thread you have quoted. It's about a year old, but I think it may be useful anyway, if it is going to be cited now in other discussions.

Cheers -- sylas

 

[BrianG]

Mainly, we all agree CO2's greenhouse effect is too weak to measure experimentally. Bummer, pseudo science strikes again.

 

[chriscolose]

Mainly, we all agree CO2's greenhouse effect is too weak to measure experimentally. Bummer, pseudo science strikes again.

Perhaps if you actually bother to listen to anything sylas writes or read a standard textbook on the subject you would not make such outrageous statements. There is a long history of experiments and developments on the subject of the greenhouse effect, with the 33 K greenhouse influence being a very well-defined number and not disputed in science, and yet you're so confident you know the answer.

 

[BrianG]

Perhaps you could post a SINGLE experiment showing a temperature increase with two samples, one at 200ppm CO2, or more and the other at 500ppm CO2 or less, something in the range our contemporary atmosphere. Even a field experiment would be satisfactory; we’ve done controlled releases of manmade aerosols and verified their cooling effect. I'm not questioning the spectral qualities of CO2, any more than I question the sky is blue, but I've never seen an experiment where a few hundred, or even thousand parts per million of CO2 causes any kind of temperature change in a sample exposed to light.

You go on ad infinitium about spectra, but you have no evidence of temperature change from human emission of CO2.

 

[sylas]

Perhaps you could post a SINGLE experiment showing a temperature increase with two samples, one at 200ppm CO2, or more and the other at 500ppm CO2 or less, something in the range our contemporary atmosphere.

As I explained to you previously, this won't work. The atmosphere is ten kilometers and more thick. What you are doing is proposing to test whether a wool blanket can warm you more than cotton by experiments on two threads.

You can do that, if you study the properties of the material in the thread... just as you can study directly the interactions of radiation and different gases. But you don't drape a thread over a thermometer, or put jars with 200ppm and 500ppm of CO2 over a thermometer, and expect to learn anything useful.

Even a field experiment would be satisfactory; we’ve done controlled releases of manmade aerosols and verified their cooling effect. I'm not questioning the spectral qualities of CO2, any more than I question the sky is blue, but I've never seen an experiment where a few hundred, or even thousand parts per million of CO2 causes any kind of temperature change in a sample exposed to light.

As I explained previously, it is the total amount that is more relevant for how much radiation is absorbed and emitted in total, and hence for the temperature impact, not the density.

The energy consequences for an atmosphere follow by elementary thermodynamics from the known spectral properties; and temperature effects are indeed measured in a lab, with quantities of CO2 comparable to the quantities in an atmosphere.

Field experiments do measure directly the thermal radiation from the sky, at day, and in the night, and look at the spectrum and the energy, and get results which are... of course... consistent with the fact that carbon dioxide and water mainly lead to one heck of a lot of energy coming down to the surface from out of the sky... energy that is the driver of a surface greenhouse effect.

You go on ad infinitium about spectra, but you have no evidence of temperature change from human emission of CO2.

CO2 is the same no matter how it is emitted. And I HAVE given a number of experiments which show temperature change from the interactions of radiation with carbon dioxide.

You appear to want to focus on the proportion of carbon dioxide, as if so many ppm tells you the temperature, no matter how much of it you are using... even if in a small lab based experiment. What you SHOULD be looking at is the temperature effect of roughly 60 kilograms of CO2 per square meter... which is a column of about 3 meters or so of pure carbon dioxide.

Nor will that give you the same temperature effects, as these things don't scale so simply. But using the right total amounts would certainly be closer than trying to compare 200ppm and 500ppm in a flask by measuring temperatures. We have indeed given the experiments here which give strong temperature effects from this quantity of carbon dioxide; if you read the link to John Tyndall's book from the nineteenth century, you get a wealth of detail of about the early experiments in which they worked to rule out every other possible cause of their observations, and ended up with this new and surprising discovery (as it was then) that carbon dioxide, and water, are both hundreds of thousands of times more effective than the other major constituents of the atmosphere for its capacity to trap heat at the surface and maintain a livable climate.

------

I can't tell you any different from what I have told you already. You can't do a lab experiment on an entire atmosphere. You CAN do lab experiments with comparable quantities of carbon dixoxide or water vapour and obtain clear and strong temperature changes. These experiments are not longer particularly significant for real science, though they can be useful for teaching in schools. The idea that a small flask with 200ppm or 500ppm is going to give any great effect is simply an error of understanding of basic thermodynamics.

The experiments you want have been described already. The experiments you are proposing are invalid, because they use far too little gas for useful temperature results... though you can study the basic thermodynamics properties with small quantities.

Finally, let me assure you that I don't have any real animosity over this. I'm not much of a social campaigner: I just like to help with science education in general, in this and in other topics.

Cheers -- sylas

 

[chriscolose]

By the way, the whole atmospheric greenhouse effect requires a declining vertical temperature profile (i.e., the lapse rate). So even testing the infrared abilities of CO2 in a confined setting, you're not going to get a good picture of how the actual atmosphere works.

 

[sylas]

By the way, the whole atmospheric greenhouse effect requires a declining vertical temperature profile (i.e., the lapse rate). So even testing the infrared abilities of CO2 in a confined setting, you're not going to get a good picture of how the actual atmosphere works.

Precisely.

 

[BrianG]

What your saying is pure speculation and theory, that changing a small amount of CO2 will have an effect on temperature.

It takes a container 40 meters in diameter to detect neutrinos, are you telling me neutrino/matter interactions are stronger than the greenhouse warming effect? What about increasing the pressure in both containers, if the containers are ten meters high and the atmosphere is held at 1,000 bar, that can represent a significant amount of gas. As long as the gasses are swapped from container to container, you can eliminate extraneous variables.

I'm not worried about spectral properties; I don't lose sleep over blue sky. Its climate change mitigation that's got me going and you cited no experimental proof at all.

 

[cleanwater]

Brian G: The greenhouse gas effect does not exist no mater what BS Sylas says- he has acknowledged that he does not have any education in physics- and it is obvious to anyone that has taken at least college physics that Sylas makes up his answers as he goes along. If you want to get correct information go to one of the following web-sites or read the paper "Greenhouse Gas hypothesis Violates Fundamentals of Physics" by Heinz Thieme
the web-site to see is www.strata-sphere.com
As I have said repeatedly water and its many forms are responsible for all of the warming above Black body theoretical temperature. Water has none of the properties of a supposed ghg. CO2 or Methane cannot and will not cause an increase in global temperature.
Your proposed test will show nothing because the ghg effect is a fairy-tale.
Skyhunter complains that I repeat the same info -well the truth is worth repeating when people show that they don't want to understand.

 

[sylas]

What your saying is pure speculation and theory, that changing a small amount of CO2 will have an effect on temperature.

On the contrary. I have described experiments several times, which you either ignore, or don't understand. This is very much experimental science, and has been for over a century. Just as in any other area of the science, what you learn from experiment can be applied to the real world; but it is flatly false to say my remarks are pure speculation and theory. What I am explaining here is really very elementary thermodynamics, discovered by good old experimental physics.

You should be aware that that skepticism about global warming is not at all the same thing as denial of a greenhouse effect altogether. Skepticism comes in many forms, from legitimate caution about open research questions, to a naïve failure to follow high school physics.

I'm not meaning this as an insult; because we all start out this way... but your objections are the latter. The good news is that it is comparatively easy to fix, and if you are able to learn then it opens the way for you to either understand climate science a lot better, or -- if you remain a skeptic -- to let your skepticism become at least consistent with thermodynamics.

I've described the experiments several times, and most relevant to direct measurement of temperature are the experiments of John Tyndall in the 1860s, which directly measured substantial temperature changes with small amounts of carbon dioxide in a lab. Similar experiments can be and are performed now at high school level.

What is a "small amount"?

It is quite true, of course, that a jar with 200ppm and another with 500ppm CO2 is a tiny amount of carbon dioxide, and this has a negligible effect on temperature.

Do you agree that this amount is many orders of magnitude less that the amount of carbon dioxide found in a column of atmosphere the same width as a jar?

For example. How much CO2 is involved in the greenhouse effect on Earth? Well, the density of air at sea level is about 1.25 kg/m³. There's about 10 tons of air per square meter in the atmosphere (air pressure is just the weight of this air) and if it was all at sea level conditions, you'd have about 8000 cubic meters of air, or a column 8 kilometers high.

Now 1ppm is one part per million by volume. So 385ppm is the same amount of carbon dioxide as in a blanket of pure carbon dioxide about 3 meters thick. That is the amount of CO2 involved in the greenhouse effect.

The experiments I have described for you measure significant temperature impact with substantially less CO2 than this.

It takes a container 40 meters in diameter to detect neutrinos, are you telling me neutrino/matter interactions are stronger than the greenhouse warming effect? What about increasing the pressure in both containers, if the containers are ten meters high and the atmosphere is held at 1,000 bar, that can represent a significant amount of gas. As long as the gasses are swapped from container to container, you can eliminate extraneous variables.

Ten meters high is a fraction of a percent of the atmosphere. There's just no comparison. What you need to do is increase the density of the carbon dioxide in your container, or else you cannot possibly get anywhere near the amounts involved in the greenhouse effect.
----

By the way; I don't ask you to take anything from me on faith. You should check further for yourself, and learn more about the relevant physics without just relying on one person.

However, for the record, cleanwater's remarks about me personally are false. I DO have university level education in physics. What I actually said is that I did not pursue that as a career -- I am not a physicist; though I have of course studied physics at Uni. When I went into postgraduate studies, I went the direction of maths and computer science. But my first degree was a BSc, and physics was one of my areas of study.

You are best to check the claims of anyone, no matter how qualified, by further study on your own behalf. That's what I have done for myself also. It's also a good idea to step back from hot topics and brush up on underlying basics.

Cheers -- sylas

 

[sylas]

"Greenhouse Gas hypothesis Violates Fundamentals of Physics" by Heinz Thieme the web-site to see is ...

This is not an acceptable reference for this forum. Check the rules.

Furthermore Thieme is a nut, and couldn't do basic thermodynamics to save his life. Seriously. He's way WAY off in the extreme of the lunatic fringe when it comes to climate. One of his favourite arguments, in the private website you have listed, is that atmospheric backradiation is impossible.

Atmospheric backradiation is directly measured, and has been for over 50 years. An early direct measurement of this is described in Stern, S.C., and F. Schwartzmann, 1954: An Infrared Detector For Measurement Of The Back Radiation From The Sky. J. Atmos. Sci., 11, 121–129. (online) Thieme's "refutations" are pseudoscience at the same level as young Earth creationism. In a field full of confusion and poor argument, Thieme stands out as a far extreme of willful ignorance of physics.

 

[cleanwater]

Sylas -The minute you tell me that you put the CO2 in a jar tells me that you do not understand that you have a faulty experiment. CO 2 or dry air do not heat up when they absorb IR radiation. ( Check the work of Niels Bohr) The glass jar can and does absorb IR and does heat up. This heating of the glass is what heats the gas inside the jar- this is one of the things that is wrong with the University of Bremen experiment. If you want proof of this I can supply you with the paper that was peer reviewed that shows just how much heating is caused by IR radiation absorbsion by glass.
AS I have described earlier and you have not understood is that I have done the experimental work that shows that the ghg effect is a Fairly -tale that Thieme and Gerlich &Tscheuschner know a hell of a lot more than you. The fact that you try to put them down is because you do not understand what they have proven.

 

[chriscolose]

Actually he does understand what they're doing. In fact, sylas, myself, and several others have a paper in the works detailing their errors, as does Smith (2008). You continue to repeat "check Niels Bohr" when gases heating up isn't even what the greenhouse effect is about. Just like G&T, you've only introduced a lot of strawmans, just like G&T made a whole essay about how the greenhouse effect is unlike real greenhouses, and how pots of boiling water falsify a greenhouse effect because the pot is cooler with water in it.

There is a 33 K gap (and a 150 W/m^2 gap) between the surface temperature (emission) and the effective temperature (emission). This is the greenhouse effect and it's been understood for well over a century. It also serves to have remarkable predictive and explanatory power over a broad range of planetary applications (faint young sun, early Mars, Venus, etc). Repeating the same stuff won't change that.

 

[Andre]

There is a 33 K gap (and a 150 W/m^2 gap) between the surface temperature (emission) and the effective temperature (emission). This is the greenhouse effect and it's been understood for well over a century.

Really? Isn't just an explanation, disregarding/downplaying the effect of other heating processes like latent heat, convection and advection as discussed in the other thread? Yes I know, the radiation numbers seem far more bigger, but the other effects are one way only while radiation is two ways, in and out, and tending to balance and cancel out.

If the atmosphere was unable to radiate, it would still be heated by those three until a certain equilibrium, which definitely bigger than zero; especially since there is no way that the atmosphere could loose the heat without radiation, since it can't convect or advect downwards. So not all, if any of those 33 degrees can be greenhouse effect.

It also serves to have remarkable predictive and explanatory power over a broad range of planetary applications (faint young sun, early Mars, Venus, etc). Repeating the same stuff won't change that.

Could you please indicate in the Fourth assessment report of wg1of the IPCC where it substantiates a remarkable predictive and explanatory power over a broad range of planetary applications?

 

[sylas]

Sylas -The minute you tell me that you put the CO2 in a jar tells me that you do not understand that you have a faulty experiment. CO 2 or dry air do not heat up when they absorb IR radiation. ( Check the work of Niels Bohr)

You've mentioned Bohr several times now.

What Bohr actually did was pioneer physics of how electrons interact with light by changing energy levels in an atom. This does not heat up materials much; since temperature depends on the motions or kinetic energy of atoms; not the potential energy of electrons in different orbitals.

However, Bohr never suggested anything so silly as to think this disproved the measured fact that that gas does heat up when it absorbs IR radiation. The excitation of electrons to different energy levels is not the only way light and matter interacts!

The main process by which IR radiation is absorbed in a gas is interaction with vibration modes of the whole molecule. These involve lower energy levels than excitation of electrons, and so interact well with low energy IR radiation. Molecules like O2 or N2, which are the major components of air, do not have suitable vibration modes. But CO2 and H2O (the major contributors to the greenhouse effect) are dipolar, and have a shape that admits a range of vibration modes and give them the capacity to absorb IR radiation.

Vibration energy of a molecule is a form of kinetic energy, unlike the energy of an electron raised to a higher orbital, which is a form of potential energy. Hence the IR absorption does indeed correspond to higher temperatures, whereas absorption by raised electron levels... not so much.

There are some diagrams of the relevant vibrational modes here: http://chemistry.boisestate.edu/people/richardbanks/inorganic/electromagnetic%20spectrum/vibrational_modes.htm . (Supplied as part of online chemistry tutorials by Prof. Richard Banks, Boise State University.)

Slightly more technical, including spectra and energy levels here: Water Absorption Spectrum. (Supplied by Prof. Martin Chaplin, London South Bank University).

From Professor Banks' http://chemistry.boisestate.edu/people/richardbanks/inorganic/electromagnetic%20spectrum/spectrum.htm :

Infrared Radiation

Infrared radiation has an intermediate energy and extends from about 1 millimeter in wavelength to the visible region. Infrared radiation has the same energy as molecular vibrations. Chemical bonds are analogous to springs and can either be bent or stretched. The stretching and bending vibrations of bonds between different atoms all have different energies. When infrared radiation matches the specific stretching or bending energy of a particular bond, it will be absorbed if there is a dipole associated with the bond.

When a molecule absorbs infrared radiation, the amplitude of vibration is increased and the molecule heats up. This heat can be lost in either of two ways. The molecule can come into direct contact with another body and directly transfer the heat or the molecule can re-emit infrared radiation.​

Τhe is really basic stuff. The heating of certain gases by absorption of infrared radiation is a simple and straightforward measurement.

I suspect you are getting distorted information from unreliable sources. For example, there is absolutely nothing by Bohr to deny that you can heat a gas by absorption of IR radiation. Bohr studied a different process, involving higher energies and electron levels, which was foundational to understanding the quantum nature of the atom. I would love to know who started the idea that this could be interpreted as a disproof of all other lower energy IR interactions! It is either completely clueless, or worse, deliberately dishonest. It is definitely not from Bohr himself.

Cheers -- sylas