<p>In the paper &quot;<a href="http://hharde.de/index_htm_files/Harde-Schnell-GHE-m.pdf" rel="nofollow noreferrer">Experimental Verification of the Greenhouse Effect</a>&quot; (full version: &quot;<a href="https://scienceofclimatechange.org/wp-content/uploads/Harde-Schnell-2022-Verification-GHE-Experiment.pdf" rel="nofollow noreferrer">Verification of the Greenhouse Effect in the Laboratory</a>&quot;, Hermann Harde, Michael Schnell 2022), the authors describe an experimental setup that demonstrates the atmospheric greenhouse effect.</p>
<p>The experimental setup is as follows (from the paper):</p>
<p><a href="https://i.sstatic.net/aHKxO.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aHKxO.png" alt="enter image description here" /></a></p>
<blockquote>
<p>For our studies we use an experimental set-up, which consists of two plates in a closed housing, one plate heated to 30°C, the other cooled to -11.4°C (Fig. 1). The plates have a distance of 1.11m to each other, and the tank can be filled with different gases to study the radiation transfer between the plates in the presence of the GH-gases.</p>
</blockquote>
<p>They found that when keeping the energy input to the Earth plate constant, and adding IR-active gases such as CO<span class="math-container">$_2$</span>, the temperature of the Earth plate increases due to the back-radiation effect:</p>
<p><a href="https://i.sstatic.net/YVzWi.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/YVzWi.png" alt="enter image description here" /></a></p>
<p>(Note: the &quot;Reduced Heating&quot; section at the end is when they decrease the energy input to the Earth-plate until it gets back to 30°C; the difference in energy input is used to calculate the magnitude of the back-radiation effect.)</p>
<p>My question is: why did the addition of the IR-interacting gas not result in any increase in air temperature (denoted by T1, T2, T3, and T4)?</p>
<hr />
<p>My understanding is that the IR-active gas (say, CO<span class="math-container">$_2$</span>) interacts with the infrared light emitted by the Earth plate, by absorbing it, which causes the CO<span class="math-container">$_2$</span> molecules to vibrate. This is described as it heating up, for example (emphasis in the original):</p>
<blockquote>
<p>When photons bump into other atoms, some of their energy can get the electrons in those atoms <em><strong>resonating</strong></em> or moving faster than they were before - that’s what we call <em><strong>heat</strong></em>. The properties of these molecules and their bonds determine if a gas in the atmosphere will absorb infrared radiation or not. [<a href="https://gml.noaa.gov/education/info_activities/pdfs/LA_whats_so_special_about_co2.pdf" rel="nofollow noreferrer">source</a>]</p>
</blockquote>
<p>Then the CO<span class="math-container">$_2$</span> spontaneously re-emits infrared light of the same wavelength, but this time in a random spherical direction. Some of it is emitted back to the Earth plate which is what results in its higher temperature.</p>
<p>However, between the period of absorption and emission, the CO<span class="math-container">$_2$</span> is vibrating more -- shouldn't this mean it has more kinetic energy? And as 10% of the air (in this trial) now has more kinetic energy for a constant amount of the time -- shouldn't that directly translate in a higher air temperature?</p>
<hr />
<p>For another example with a different explanation (emphasis in the original):</p>
<blockquote>
<p>Once the atmosphere is absorbing radiation something has to happen. [...] energy absorbed has to go somewhere and and in this case the energy goes into increased heat of that section of the atmosphere, as we saw in Part Two of this series.</p>
<p>In general, and especially true in the troposphere (the lower part of the atmosphere up to around 10km), the increased energy of a molecule of CO2 (or water vapor, CH4, etc) heats up the molecules around it – <strong>and that section of the atmosphere then radiates out energy</strong>, both up and down. [<a href="https://scienceofdoom.com/2010/01/31/co2-an-insignificant-trace-gas-part-three/" rel="nofollow noreferrer">source</a>]</p>
</blockquote>
<p>In this case it's described as heating the air directly, which air then radiates energy out. But we observe no higher heating in the experiment.</p>
<hr />
<p>What's the explanation for the air not getting hotter?</p>

CC BY-SA 4.0
2023-04-14T22:26:33.443Z
Have you read the paper? Specifically section 4.5?
AtmosphericPrisonEscape
CC BY-SA 4.0
2023-04-15T16:44:06.707Z
@AtmosphericPrisonEscape: Thanks for the note, I re-read it but still doesn't make sense. 4.1 *"The absorbed radiation by the gas is in a first step converted into local heating [...]"* Also from the full version of paper (link at top), 3.2.1 _"the lifetime of ro-vibronic states with transitions in the IR or far-IR range easily attains milliseconds to seconds"_ . I understand that in 4.5 _"the total balance of absorption and emission of the gas is zero"_ , but there is non-zero time of gas excited where otherwise it wouldn't be, how can this not translate into a higher temperature?
Dale Cloudman
CC BY-SA 4.0
2023-04-15T21:17:08.387Z
Note: this doesn't appear to be a significantly peer reviewed paper.  If you read http://hharde.de/climate.htm, the author's website, it appears to be someone more aggressively interested in debunking climate change, making sweeping conclusions rather than involved in open scientific discourse?  Doesn't directly mean anything to the question if their results are valid... but still may open a little skepticism on the reproducibility/legitimacy of their experiment?  Just worth keeping that in mind?
JeopardyTempest
CC BY-SA 4.0
2023-04-15T21:30:29.160Z
Without having read the paper much, it does seem odd that 1 meter of gas would lead to like a 1°C change in the TPE.  And indeed, if the temperature of one of the outer borders increases, and the other remains about the same, the suggestion would be that T of the gas between them would increase some (just as the low level atmosphere in the end gets most of its heating from conduction from the surface of the Earth?)  I'm a person who celebrates skepticism always, not one who tends to make confident conclusions quickly, but I'd be likewise a bit skeptical of much of this on a quick quick look?
JeopardyTempest
CC BY-SA 4.0
2023-04-16T03:31:24.923Z
I see nothing to prevent the gases circulating within the container. In a space that small convection will carry heat from one end to the other very quickly.
Ken Fabian
CC BY-SA 4.0
2023-04-17T04:08:47.860Z
a thermometer might not be the best instrument for measuring light(long wawe infrared radiation).using an imaging infrared camera is probably a better way to measure radiation in co2 and other gasses.
trond hansen
CC BY-SA 4.0
2023-04-17T08:13:32.443Z
@trondhansen my understanding is the infrared excites the co2 molecules ie increases kinetic energy, and temperature is average kinetic energy, so given we add 10% of gas to the chamber that now has higher kinetic energy how can it be that the temperature of the air doesn’t increase? Basically am not asking why it didn’t measure the infrared but why it didn’t heat up which according to the theory and explanation of the author it should ..
Dale Cloudman
CC BY-SA 4.0
2023-04-17T08:14:32.337Z
@KenFabian that’s true but shouldn’t the steady-state temperature of the gas increase similarly to how the steady-state of the earth plate increases?
Dale Cloudman
CC BY-SA 4.0
2023-04-18T00:33:26.763Z
@DaleCloudyman only if thy screwed up there set up. That is if the cold plate can;t remove the heat being generated, which would invalidate the setup because it would show warming regardless of adding co2.
John
CC BY-SA 4.0
2023-04-18T00:43:17.180Z
Why should you expect infrared heat transfer to the other end of the tank to increase when you add an infrared absorbing gas? the only place you should see heating is near the IR source, which is what we see.
John
CC BY-SA 4.0
2023-04-18T01:26:07.947Z
There is nothing to indicate any problems with the various methods used to measure the radiative properties of gases including CO2. John Tyndall's 19th Century laboratory setup did it well enough, with the sample gas in a horizontal tube, ie not affected by internal convection - https://commons.wikimedia.org/wiki/File:Tyndalls_setup_for_measuring_radiant_heat_absorption_by_gases_annotated.svg
Ken Fabian
CC BY-SA 4.0
2023-04-18T08:01:00.963Z
@John: doesn’t the CO2 absorb infrared light, thus heating up before releasing it? So as there is non zero time of being heated shouldn’t it’s temperature increase?
Dale Cloudman
CC BY-SA 4.0
2023-04-18T21:15:01.030Z
@DaleCloudyman which it did. near the IR source. Maybe if the heat source was at the bottom you might see it spread quickly but not with this setup.
John
CC BY-SA 4.0
2023-04-18T21:15:55.903Z
@KenFabian that is a horizontal tube, this is a vertical one,  that alone will make it very poor at spreading the heat.
John
CC BY-SA 4.0
2023-04-18T22:01:15.067Z
@John: hmm so T1 T2 T3 and T4 are measuring the air temperatures in the apparatus and none of them increased at all , not even T1 which was nearest the IR source
Dale Cloudman
CC BY-SA 4.0
2023-04-18T23:51:10.900Z
look at Tdome the one actually close to the heat source, and the "back radiation" also now that you made me actually sit down a read the study it is absolute crap, the device construction and soap boxing at the end of the conclusion make it clear this was not a scientific study but an ad hoc apparatus.
John
CC BY-SA 4.0
2023-04-19T07:38:29.957Z
@John TDom stays at 30C though it doesn’t increase. TPE (ie earth plate temperature) is only one that increases!
Dale Cloudman
<atmosphere><co2><greenhouse-gases><atmospheric-radiation><radiative-transfer>
Why did the air not heat up in this experiment demonstrating the atmospheric greenhouse effect?
Dale Cloudman
# Why did the air not heat up in this experiment demonstrating the atmospheric greenhouse effect?

(Asked by: username_0 on 2023-04-14)

In the paper "[Experimental Verification of the Greenhouse Effect](http://hharde.de/index_htm_files/Harde-Schnell-GHE-m.pdf)" (full version: "[Verification of the Greenhouse Effect in the Laboratory](https://scienceofclimatechange.org/wp-content/uploads/Harde-Schnell-2022-Verification-GHE-Experiment.pdf)", Hermann Harde, Michael Schnell 2022), the authors describe an experimental setup that demonstrates the atmospheric greenhouse effect.

The experimental setup is as follows (from the paper):

[![enter image description here](https://i.sstatic.net/aHKxO.png)](https://i.sstatic.net/aHKxO.png)

> For our studies we use an experimental set-up, which consists of two plates in a closed housing, one plate heated to 30°C, the other cooled to -11.4°C (Fig. 1). The plates have a distance of 1.11m to each other, and the tank can be filled with different gases to study the radiation transfer between the plates in the presence of the GH-gases.

They found that when keeping the energy input to the Earth plate constant, and adding IR-active gases such as CO$\_2$, the temperature of the Earth plate increases due to the back-radiation effect:

[![enter image description here](https://i.sstatic.net/YVzWi.png)](https://i.sstatic.net/YVzWi.png)

(Note: the "Reduced Heating" section at the end is when they decrease the energy input to the Earth-plate until it gets back to 30°C; the difference in energy input is used to calculate the magnitude of the back-radiation effect.)

My question is: why did the addition of the IR-interacting gas not result in any increase in air temperature (denoted by T1, T2, T3, and T4)?

---

My understanding is that the IR-active gas (say, CO$\_2$) interacts with the infrared light emitted by the Earth plate, by absorbing it, which causes the CO$\_2$ molecules to vibrate. This is described as it heating up, for example (emphasis in the original):

> When photons bump into other atoms, some of their energy can get the electrons in those atoms ***resonating*** or moving faster than they were before - that’s what we call ***heat***. The properties of these molecules and their bonds determine if a gas in the atmosphere will absorb infrared radiation or not. [[source](https://gml.noaa.gov/education/info_activities/pdfs/LA_whats_so_special_about_co2.pdf)]

Then the CO$\_2$ spontaneously re-emits infrared light of the same wavelength, but this time in a random spherical direction. Some of it is emitted back to the Earth plate which is what results in its higher temperature.

However, between the period of absorption and emission, the CO$\_2$ is vibrating more -- shouldn't this mean it has more kinetic energy? And as 10% of the air (in this trial) now has more kinetic energy for a constant amount of the time -- shouldn't that directly translate in a higher air temperature?

---

For another example with a different explanation (emphasis in the original):

> Once the atmosphere is absorbing radiation something has to happen. [...] energy absorbed has to go somewhere and and in this case the energy goes into increased heat of that section of the atmosphere, as we saw in Part Two of this series.
>
> In general, and especially true in the troposphere (the lower part of the atmosphere up to around 10km), the increased energy of a molecule of CO2 (or water vapor, CH4, etc) heats up the molecules around it – **and that section of the atmosphere then radiates out energy**, both up and down. [[source](https://scienceofdoom.com/2010/01/31/co2-an-insignificant-trace-gas-part-three/)]

In this case it's described as heating the air directly, which air then radiates energy out. But we observe no higher heating in the experiment.

---

What's the explanation for the air not getting hotter?

**Tags:** atmosphere, co2, greenhouse-gases, atmospheric-radiation, radiative-transfer

> **Comments:**
> **username_1**: Have you read the paper? Specifically section 4.5?  
> **username_0**: @username_1: Thanks for the note, I re-read it but still doesn't make sense. 4.1 *"The absorbed radiation by the gas is in a first step converted into local heating [...]"* Also from the full version of paper (link at top), 3.2.1 _"the lifetime of ro-vibronic states with transitions in the IR or far-IR range easily attains milliseconds to seconds"_ . I understand that in 4.5 _"the total balance of absorption and emission of the gas is zero"_ , but there is non-zero time of gas excited where otherwise it wouldn't be, how can this not translate into a higher temperature?  
> **username_2**: Note: this doesn't appear to be a significantly peer reviewed paper.  If you read http://hharde.de/climate.htm, the author's website, it appears to be someone more aggressively interested in debunking climate change, making sweeping conclusions rather than involved in open scientific discourse?  Doesn't directly mean anything to the question if their results are valid... but still may open a little skepticism on the reproducibility/legitimacy of their experiment?  Just worth keeping that in mind?  
> **username_2**: Without having read the paper much, it does seem odd that 1 meter of gas would lead to like a 1°C change in the TPE.  And indeed, if the temperature of one of the outer borders increases, and the other remains about the same, the suggestion would be that T of the gas between them would increase some (just as the low level atmosphere in the end gets most of its heating from conduction from the surface of the Earth?)  I'm a person who celebrates skepticism always, not one who tends to make confident conclusions quickly, but I'd be likewise a bit skeptical of much of this on a quick quick look?  
> **username_3**: I see nothing to prevent the gases circulating within the container. In a space that small convection will carry heat from one end to the other very quickly.  
> **username_4**: a thermometer might not be the best instrument for measuring light(long wawe infrared radiation).using an imaging infrared camera is probably a better way to measure radiation in co2 and other gasses.  
> **username_0**: @username_4 my understanding is the infrared excites the co2 molecules ie increases kinetic energy, and temperature is average kinetic energy, so given we add 10% of gas to the chamber that now has higher kinetic energy how can it be that the temperature of the air doesn’t increase? Basically am not asking why it didn’t measure the infrared but why it didn’t heat up which according to the theory and explanation of the author it should ..  
> **username_0**: @username_3 that’s true but shouldn’t the steady-state temperature of the gas increase similarly to how the steady-state of the earth plate increases?  
> **username_5**: @DaleCloudyman only if thy screwed up there set up. That is if the cold plate can;t remove the heat being generated, which would invalidate the setup because it would show warming regardless of adding co2.  
> **username_5**: Why should you expect infrared heat transfer to the other end of the tank to increase when you add an infrared absorbing gas? the only place you should see heating is near the IR source, which is what we see.  
> **username_3**: There is nothing to indicate any problems with the various methods used to measure the radiative properties of gases including CO2. username_5 Tyndall's 19th Century laboratory setup did it well enough, with the sample gas in a horizontal tube, ie not affected by internal convection - https://commons.wikimedia.org/wiki/File:Tyndalls_setup_for_measuring_radiant_heat_absorption_by_gases_annotated.svg  
> **username_0**: @username_5: doesn’t the CO2 absorb infrared light, thus heating up before releasing it? So as there is non zero time of being heated shouldn’t it’s temperature increase?  
> **username_5**: @DaleCloudyman which it did. near the IR source. Maybe if the heat source was at the bottom you might see it spread quickly but not with this setup.  
> **username_5**: @username_3 that is a horizontal tube, this is a vertical one,  that alone will make it very poor at spreading the heat.  
> **username_0**: @username_5: hmm so T1 T2 T3 and T4 are measuring the air temperatures in the apparatus and none of them increased at all , not even T1 which was nearest the IR source  
> **username_5**: look at Tdome the one actually close to the heat source, and the "back radiation" also now that you made me actually sit down a read the study it is absolute crap, the device construction and soap boxing at the end of the conclusion make it clear this was not a scientific study but an ad hoc apparatus.  
> **username_0**: @username_5 TDom stays at 30C though it doesn’t increase. TPE (ie earth plate temperature) is only one that increases!  

---

## 0 answers

