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I appreciate your being patient with me.

The molecules transfer the radiant energy to some combination of kinetic energy. You were right. I was wrong.

The effect must be small otherwise there would have been a temperature difference between the two boxes. Looking at why increased IR radiation would have a small effect, I see a few reasons.

1. The rock salt encasement reflected some higher energy photons offsetting the temperature change due to the increased amount of IR.

2. The heat transfer coefficient for the molecules that absorb IR radiation is small enough that the IR radiation is re-emitted quickly.

3. The rock salt allowed more IR to escape since there was likely more outgoing than incoming.

Then again, it is visible light that increases the amount of heat while the IR band is already low on the energy totem pole. IR is the result not the cause. In other words, IR radiation cannot cause more heat wherease visible light can.

Now that I have figured out that I was wrong about the absorption of a photon not changing to dynamic kinetic energy, I will finally go back to your #26261 post above.

Originally Posted By: samwik
Just to be clear, when you say "leaves little radiation," it's important to realize that there is lots of heat at 4-5 microns, as well as more at the shorter wavelengths. There's no danger of "running out of 4-5 micron radiation" for CO2 to absorb or "reflect."


Most of the IR at the 4-5 microns is already being absorbed by the much more plentiful (78% vs 0.0387%) Nitrogen while the 2-3 micron range is absorbed by the much more plentiful water vapour.

http://www.coe.ou.edu/sserg/web/Results/Spectrum/n2.pdf

You can check other molecules at this link:
http://www.coe.ou.edu/sserg/web/Results/results.htm

Of course, that N2 spectrum does not help my Woods link argument, but it does bring us back to the actual topic of human influence on climate -- finally.

.
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Originally Posted By: John M Reynolds
Most of the IR at the 4-5 microns is already being absorbed by the much more plentiful (78% vs 0.0387%) Nitrogen while the 2-3 micron range is absorbed by the much more plentiful water vapour.

Be back later, but....

This is new information for me here, and that coe link.

Those are Fourier transformed spectra. I don't know what to make of them, but will get back to you about that. ...and the rest.

Thanks,
~SA
smile

p.s. heat is considered to be about 4-100 microns, so the 2-3 micron point is.... ...but water absorbs above 5-6 also, so it is a strong absorber of heat also.


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"Atmospheric nitrogen is an inert, colorless, odorless gas, and has no known influence on the greenhouse effect."
This is from a GW denier site, renewamerica; that then goes on to say:
Quote:
Although neither nitrogen or oxygen has an influence on the greenhouse effect, for some reason CO2 is assumed by environmentalists to influence the greenhouse effect so as to cause global warming. We are all waiting for an explanation of how CO2 differs from nitrogen and oxygen in its influence on the greenhouse effect. Until such explanation is forthcoming, it seems reasonable to suspect that the theorists are failing to differentiate between wholesome CO2 and poisonous CO1 (carbon monoxide) and other toxic gases that accompany CO2 in industrial pollution. Why are the global warming theorists singling out a wholesome gas that is necessary for life on earth as the culprit of the impending disasters they are predicting?
Conclusion:
The burden of proof lies with those who claim that CO2 gas has a greenhouse effect, because they have presented no understandable mechanism or process that explains how CO2 gas in the atmosphere increases heat on earth.


Hmmmm. Other than this "Nitrogen masking-effect" *^* which you've hypothesized, haven't we already (post#26288, above) visualized the mechanism by which absorbed IR "increases heat on earth?"

"Why are the global warming theorists singling out a wholesome gas that is necessary for life on earth as the culprit of the impending disasters they are predicting?"
Why? Because CO2's having the largest effect and it is the easiest to change?

Well, enough of that stuff.
===

...also indicating that Nitrogen has no significant IR absorbance:
http://www.globalwarmingart.com/wiki/Image:Nitrogen_Molecule_VdW_png
The strong bond makes it chemically stable and non-reactive in most circumstances. Nitrogen's simple structure is unable to absorb either visible or infrared light. As a result, nitrogen is not a greenhouse gas.

Yes it is from wikipedia frown

Every technical thing I found was dealing with molecular nitrogen in high temperature or high pressure, bound states, dealing with materials science. See my "surfings" at:
http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=26306#Post26306

Anyway, the coe site you linked to is a semiconductor type, material science site.
http://www.coe.ou.edu/sserg/
Solid State Devices
Welcome to the Solid State Devices research group at the University of Oklahoma. We perform research in a number of areas related to development of mid-infrared optoelectronic devices as well as development of applications for these devices. Specific research areas include semiconductor materials growth and characterization, laser fabrication, and tunable laser spectroscopy.
Here's a list of their publications, indicating what type of materials they work with.
http://www.coe.ou.edu/sserg/web/Publication/paper%20title.htm

I noticed that their HITRAN-96 spectrum of CO2 bears no resemblance to the standard IR spectra of atmospheric gasses that we normally see (update: I see more commonalities now... -see below).

*^*Despite the fact that you have that beautiful, rich spectrum of N2 at the very specific wavelength that we're talking about here, I don't think it applies as proof about your Nitrogen masking hypothesis; but if you can find any more information about the pressure, temperature or state of that N2 (or a comparison of it's absorbance at 4.5 microns with CO2's, in terms of relative strength), I'd be happy to acknowledge that. From my reading around about those Fourier Transform spectra, I think those are used for high precision observations of electron shell changes during bonding processes, or some processes which are not related to gasses at atmospheric conditions.
...hmmmm, maybe not: see update below.

Update:
Oh, I see from their 6 pages of CO2 spectra, that their studying different isotopes of CO2.
Oh, ...and I think I see a comparison:
Their 2nd page of CO2 (first image) shows the 4.5 (~2300+ wavenumber) peak with a line strength of 1e-18;
The Nitrogen peak has a line strength (whatever that is) of 1e-28.

As negative exponents, I take it to mean the Nitrogen's absorbance is much smaller than is the CO2.

I'd also note that the dark (solid) central peak in the N2 spectrum is very narrow, whereas the CO2 solid area is much broader.
I don't even know if that dark, solid area is significant in these Fourier Transforms, but it was a noticeable difference.

Well, again, this is way too much talking. I guess I'll leave it over to you. What do you think about all this Nitrogen stuff.
How come nobody's ever mentioned N2 before if it's at all involved in heat absorbance effects.
It couldn't be much if, without water vapor, the air temp would fall by 70-100 degrees (post#26261).

...not quite as fun as I'd hoped, but still worthwhile....
smile


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My apologies for being away for a bit. I don't have enough time to read through all the recent postings, so I'll just respond to your response to my post.


Originally Posted By: samewise

H2O is stronger (there's more of it and it absorbs over a wider range of wavelengths), but it does not absorb where CO2 absorbs (between 4-5 microns); hence the "strength" of the two is unrelated in terms of IR absorbance (apples and oranges logic).

I fully understand the different absorption bands that H20 and C02 have. CO2's absorption bands are in the 2, 3, 5, and 13-17 micron ranges. I never said H2O absorbed IR within these ranges, just that is it responsible for, by far, the majority of IR absorption.

Originally Posted By: samewise

But what the heck is your second paragraph talking about?
Extinction? At atmospheric pressure ranges? Where did you get this from?
The blackbody radiation from Earth (at 4-5 microns) far outstrips the capacity for CO2 to absorb it all (until our atmosphere gets up to >85% CO2). smile


You're saying there's enough IR radiation in the 4-5 range, that it would take a atmosphere made up of 85% CO2 before the IR was absorbed to extinction??? Reference please. I'd love to know where you got this from.
This is completely at odds with everything that I've read. Here's a link to a wikipedia page with showing the atmospheric transmission of IR.
http://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.png
You'll notice that in all of the CO2 absorption bands (2, 3, 5, and 13-17), the amount of IR leaving the earth is 0. The IR that is leaving the globe is within a fairly narrow band of ~8-13 microns. There's next to no IR leaving the earth's atmosphere other than within that range. Which, I'll remind you, is outside the absorption range of CO2.
That same page has the absorption that is responsible from each major GHG, and you can easily see 100% absorption already occurring in the each of the absorption bands for CO2.

The theory of AGW is that as the atmosphere becomes more "optically thick" with CO2, there is more CO2 available to reabsorb emitted IR from the CO2 molecules which originally absorbed the initial IR emitted from earth. This, in theory, warms the earth, as energy is held within the atmosphere longer before being lost to space.

The other thing (which I did have wrong), is the pressure broadening of the CO2 absorption bands due to increases in partial pressure (brought along by the increased concentration), not lowering pressures as I stated. My apologies.....this idea that absorption characteristics can change depending on the concentration of molecules seem a little odd to me. I need to do some more reading on this.

Originally Posted By: samewise

Maybe we're talking about different layers of the atmosphere here, but the "physics" that I know predicts higher concentrations of CO2 will increase cooling in the upper levels (lower pressure levels) of the atmosphere.


I believe we are talking about different portions of the atmosphere. As you mention, the stratosphere is supposed to cool, this is because as the atmosphere becomes "optically thicker", heat takes longer to reach the atmosphere. This reduces the heat flow to the stratosphere (until the atmosphere reaches steady state), and because the stratosphere continues to radiate heat to space at the same rate as before, it cools down.
The upper troposphere (which is much lower than the stratosphere), is supposed to warm. And at a greater rate than the near surface.

This page has good info on the cooling/warming characteristics of the various portions of the atmosphere.
http://www.remss.com/msu/msu_browse.html

This seems (to me) to be a good page on describing the IR adsorption physics behind AGW - and a quote for you samewise
Quote:

It is generally accepted that the concentration of carbon dioxide in the atmosphere is already high enough to absorb almost all the infrared radiation in the main carbon dioxide absorption bands over a distance of only a few km

http://brneurosci.org/co2.html

Last edited by Canuck; 05/30/08 04:23 AM.
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Originally Posted By: Canuck
Originally Posted By: samewise
But....
The blackbody radiation from Earth (at 4-5 microns) far outstrips the capacity for CO2 to absorb it all (until our atmosphere gets up to >85% CO2). smile


You're saying there's enough IR radiation in the 4-5 range, that it would take a atmosphere made up of 85% CO2 before the IR was absorbed to extinction??? Reference please. I'd love to know where you got this from.
This is completely at odds with everything that I've read. Here's a link to a wikipedia page with showing the atmospheric transmission of IR.
http://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.png
===
This seems (to me) to be a good page on describing the IR adsorption physics behind AGW - and a quote for you samewise
Quote:
It is generally accepted that the concentration of carbon dioxide in the atmosphere is already high enough to absorb almost all the infrared radiation in the main carbon dioxide absorption bands over a distance of only a few km

http://brneurosci.org/co2.html
You caught me!
I knew when I wrote that, about the 85%, I'd get in trouble. Hopefully the smiley face indicated something to be looked at more closely. Thanks for finding that reference for me (I figured if it was wrong, then someone would let me know).

And Thanks for the other reference too, I have some more studying to do!

One point I think I can ask about:
Originally Posted By: Canuk
The theory of AGW is that as the atmosphere becomes more "optically thick" with CO2, there is more CO2 available to reabsorb emitted IR from the CO2 molecules which originally absorbed the initial IR emitted from earth. This, in theory, warms the earth, as energy is held within the atmosphere longer before being lost to space.
Good description, but....
There's no reason that the warmer CO2 can't also warm up the surrounding oxygen and nitrogen molecules (through contact... -loss of vibrational energy), is there?

...off to study now; thanks again!
~samwise
smile


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Alright Samwick. Here we go again.

First, I will concede that N2 does not seem to be a greenhouse gas. I too was surprised by that graph, but the e-28 makes sense. Good catch Samwik!

You are incorrect when you say that, "CO2's having the largest effect." CO2 does not have the largest effect. Water vapour has that honour by a long shot. This is mostly due to water vapour's vastly larger concentration.

As well, we did not visualize "the mechanism by which absorbed IR 'increases heat on earth?'" (Why did you put 'increases heat on earth' in quotes?) Molecules that absorb UV and visible light (and shorter wavelengths) are what can increase the heat of the earth. Looking at Canuck's link, the O2/O3 molecules will absorb UV rays allowing that energy to be converted to infrared heat through collisions with cooler molecules.

The absorption of IR radiation does not increase the heat on earth. It slightly slows rate at which the IR heat can escape. That increases the chances of it being reduced to a longer and less energetic wavelength, but it does not cause more heat. This has to happen for the energy to leave the earth since Canuck's link shows all energy from 0.2 to 70 microns, except in the ~8-13 micron band, being kept here.

Even so, increasing CO2 by 0.0002% from 0.0385% to 0.0387% will not have a large change in the amount that IR is slowed in its escaping our globe. Over 100 years, a change of 0.02% will have little effect since water will still have a many times higher concentration. You wrote that "heat is considered to be about 4-100 microns." Assuming that is correct, and looking at your earth observatory gif, water absorbs quite a bit between 1 and 3.5 microns. The only way for CO2 to increase heat on earth is through its ability to absorb energy at the 2-3 micron band. That is the only real chance for CO2 to warm the planet. Then again, it could also COOL the planet by converting the energy from the 2-3 micron range to the 8-14 micron range that can escape through collisions with other molecules. Unfortunately, water also absorbs in that 2-3 band, so CO2's effect will still be negligible.

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Real quickly,
You point out,
Originally Posted By: JMR
You are incorrect when you say that, "CO2's having the largest effect." CO2 does not have the largest effect. Water vapour has that honour....

However, with the rest of the sentence, "and it is the easiest to change," then water vapor drops out of the running for GHG's to be "singled out."
But yes, good catch; it is a poorly written sentence. The answer to 'why we should single CO2 out' should have been, '....of the GHG's that are easy to change, CO2 is having the largest effect'

Next you asked about,
Originally Posted By: JMR
(Why did you put 'increases heat on earth' in quotes?)
I was just reusing the phrasing of that website that I had quoted (from directly above) talking about nitrogen, oxygen, and CO2. It wasn't meant as sarcasm, or anything sinister. smile
===
That is a neat link Canuk provided. It's all a documented opinion piece, but it's gotta be over 90% "spot on," and much more detailed with depth, than most sites have when talking about "the greenhouse effect." It's the best I've seen, except maybe for these science fora.

Originally Posted By: JMR
Molecules that absorb UV and visible light (and shorter wavelengths) are what can increase the heat of the earth. Looking at Canuck's link, the O2/O3 molecules will absorb UV rays allowing that energy to be converted to infrared heat through collisions with cooler molecules.

The absorption of IR radiation does not increase the heat on earth. It slightly slows rate at which the IR heat can escape.


I agree, what we're talking about is the heat radiated away from the earth (whatever the higher energy, shorter wavelength source originally was).
...and it seems the correct wavelength should be about 3; and not 4-5, like I've been saying (based on reading a low-res. graph), though that's something that needs checking because the "4-100 micron" figure for "heat" is from the same graph.
...another good catch... more later.

But I have to ask about how, slowing the "rate at which the IR heat can escape" "does not increase the heat on earth," unless you're using different definitions for "heat."

I suppose the answer is, "That increases the chances of it being reduced to a longer and less energetic wavelength, but it does not cause more heat;" but I think there is room for more understanding here.

... and also for the rest, about concentrations and wavelengths; I need to look long, and think about this before a better reply.

~be back later
smile


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When you ask about the slowing of the rate, you are talking about time frame for the CO2 molecules to release the energy. The heat transfer coefficient will determine CO2's propensity to retain the energy for longer periods. I googled 'heat transfer coefficient' (without the quotes) and found the http://biocab.org/Heat_Storage.html site. I read that last year while people at Climate Audit were still making suggestions. Perhaps now is a good time to re-read it. I will take the time this weekend to read through it again.

Just a thought I had though is that air is a good insulator. This also corroborates Canuck's graphic. We use clothes that have air pockets to keep warm. We use fiberglass insulation that traps air while preventing conduction and convection. We and our houses end up cooling by radiating heat. As Canuck's graphic shows, most of the IR radiation is trapped.

How long does it take for the tables, floor, pots, and ground of a greenhouse to cool when the clouds block the sun depends on the materials of which each component is made. Metal pots will cool quickly to room temperature. Concrete walkways will take longer to cool. In light of air being a good insulator, how long will it take to cool? I am hoping that the link will analyse which components of air affect its ability to be a good insulator. Most importantly to our discussion is the degree to which each molecule contributes to the insulation effect.

Then again, this is all about trapped air. The atmosphere is much more complex, but this may be a good starting point.

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Well, I'm still looking and thinking....
See some surfings at:
http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=26349#Post26349

...there's lots of stuff about 4.5 microns (so maybe I wasn't wrong after all?)

Meanwhile....
...as you say, a greenhouse is trapped air (it also involves glass for it's effect, unlike our atmosphere). I don't think we can answer these CO2 questions "starting at" a real greenhouse; we need to look at studies of real gasses.

That "biocab" page on CO2 Heat_Storage looks like an introductory course in physical chemistry, so it should provide some insights; and the rest of the site is quite a trip too.

I'm hoping you'll be interested in a site I found, and let me know what you think. I'm just starting to explore it "now."
http://www.docstoc.com/docs/529696/Physical-basis-of-the--Greenhouse-Effect--The-%E2%80%9Cwavelength-shift%E2%80%9D-
Physical basis of the Greenhouse Effect -The “wavelength shift”-
-& scroll down for many other papers linked to this topic--
===

btw... feel free to "fisk" this, from post #26318 above:
"There's no reason that the warmer CO2 can't also warm up the surrounding oxygen and nitrogen molecules (through contact... -loss of vibrational energy), is there?"

smile


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Hmmmm, well after exploring, I'm very disappointed. That docstoc site is a jumble of tertiary sources and opinion (wrong & right); and that biocab site is just too unique to be the final word.

I may be able to trace some of the Docstoc sources back; and biocab cites Stephen Schwartz's paper (that we've cited a few months ago, along with Levitus), so that's cool... good potential leads.

I'll see what I can find at the library about heat.
It may be a few days....

~Later
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"Heat always moves from places of higher density of heat to places of lower density of heat, thus states the Second Law of Thermodynamics (Van Ness. 1969. Page 54). In daylight, air is always colder than soil; consequently, heat is transferred from the soil to the air, not vice versa."

The heat from a CO2 molecule to another molecule within the air will not increase the heat of the air. As we seem to have established here, the CO2 will cause the heat transfer to slow down, but by how much? The Biocab link includes this:

"Does this mean that air temperature would increase by 0.02 °C per second until it reached scorching temperatures? No, it does not, as almost all of the absorbed heat is emitted in the very next second. Thus the temperature anomaly caused by CO2 cannot go up if the heat source does not increase the amount of energy transferred to CO2."

That must be why the air cools quickly when the sun goes behind a cloud. It is the sun that heats up the globe and not CO2. With respect to the forcing of CO2, that site says, "[c]onsidering that the difference between the temperature of the soil and the temperature of the air was 11.5 °C, the amount of 0.15 °C is negligible (just 1.3% of the total)." And for water vapour, "[i]t is evident that water vapor is a much better absorber-emitter of heat than carbon dioxide. Under the same conditions, water vapor transfers 160 times more heat than carbon dioxide.

The above quotes are from this reference:

Nahle, Nasif. Heat Stored by Greenhouse Gases. Biology Cabinet. 27 April 2007. Obtained on 2008/06/03; from http://biocab.org/Heat_Stored.html

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Yes, that biocab site is very entertaining... did you see Nasif's comment here on SAGG?
===


In googling around to find the correct wavelengths for CO2 absorption, I ran across several GW denialist sites.
Curiously, they all seem to have top quality numbers and explanations of the physical mechanisms involved; but then they go on to describe some final mechanism, or process, which makes the "greenhouse heating" conclusions invalid. These "final mechanisms" seem to be completely speculative; as they never cite any sources for this part of their exposition (though the more preliminary parts are well documented).

I've seen some of these "final mechanisms" promulgated earlier in this thread even; and referred to them as a kind of "new physics." My favorite, from a wacky website, was "There's no significant difference ... for global warming, because convectional currents mix the air in such short distances."
...Maybe I just missed class that day... (along with the rest of the alarmist scientists).

Okay, enough ranting.
===

John,
I think I see the point about total absorption (at 4.3 microns) already; therefore any increase in CO2 will not change the emission spectrum of heat escaping Earth.
I'm not sure if that really is true, or if there is some other mechanism (reabsorption and translational heating?) involved that I'm not thinking about; but....

Even if it is true, there are some other details that are being overlooked, which may explain our two differing views on CO2's capabilities.

Looking at Canuk's wiki link:
http://en.wikipedia.org/wiki/Image:Atmospheric_Transmission.png

...of the relevant spectra, lined up so nicely. Please note their logarithmic scale in microns (two thru nine microns, in the middle; & 20 - 60 microns, on the right-hand side) is the same for all of these spectrographs. ~[between 1, 10 & 70 microns, right?]

The heat we're talking about, the "upgoing thermal radiation," is pictured in blue, around ~10 microns (and 'black' for each side 'bump,' at ~4 & at ~15 microns). This is heat escaping into space.

Its mirror images (roughly), the "white areas" in the next lower graph, are the gaps in atmospheric absorption, through which heat escapes into space. It is the sides of these "white windows," those shoulders of the atmosphere's absorption range (in grey), on which we need to focus.

This "Total Absorption..." Graph is a Summation of those following graphs, from the various atmospheric gases, CO2, methane, nitrous oxide, etc. Its bump and peaks are created by the addition of all the bumps and peaks from the lower spectrographs.

If you'll notice the sides of those windows, these windows are made a bit smaller by the various absorption bands (wider, taller grey areas) of CO2 (from 4 - 20), as well as the N2O absorption peaks. Just follow the various gas peaks straight up to the "Total..." graph to see their contribution. In fact, you can even see the two diminutive peaks of CO2 (just to the right of the tall 4.3 peak) expressed in the Total Absorption Graph as two little notches added onto the left-hand shoulder of the water absorption area beginning at (to the right of) ~4 microns. The largest contribution seems to be from the ~15 micron band, but even the minor CO2 absorption bands at ~9 and ~10 microns show up above, in the Total Absorption Graph.

All of these noted absorption bands for CO2 fall within the open, "white windows" that let heat out to space.
While they are not close to absorbing all of the IR that currently escapes into space, they are making the atmosphere more opaque to escaping heat, retaining heat in the atmosphere, as the concentration of these gases increases.

It's a miniscule effect, only changing the temperature by a small percentage of the temperature change caused by water vapor.
I wouldn't dream of trying to quantify the amount of temperature change. I'll leave that up to the professionals; but I think these points above qualitatively explain the mechanism of CO2's "greenhouse effect," absorbing IR in the ranges where heat normally escapes to space.

Namasté
~ smile


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Originally Posted By: samwik
While they are not close to absorbing all of the IR that currently escapes into space, they are making the atmosphere more opaque to escaping heat, retaining heat in the atmosphere, as the concentration of these gases increases.

It's a miniscule effect, only changing the temperature by a small percentage of the temperature change caused by water vapor.


So, it is a miniscule effect of CO2 whose concentration is changing only minimally... Are you suggesting that if the level of CO2 doubles, then this miniscule effect will/could double?

The graph itself explains the greenhouse effect of CO2. The absorption effect of CO2 is logarithmic itself. The first 20 ppm absorb most. Increasing the concentration to 40ppm has a much lower effect on the temperature.


http://www.mikechurch.com/joomla/daily-features/global-cooling-for-dummies-pt.-iii.html

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p.s. ...should I post this without checking the facts first; without looking at the link to that logarithmic graph?
Should I rant about how anyone can take a real graph of something and then just re-label it to suit thier own opinion (or add their own trend lines, or conflate data from two different graphs, etc., etc.)?

Let's go look. Up to now i've only been looking on my Kindle -and can't follow links.

Hey! There's no citation at all. Is this just some made up graph? I went through that whole unpublished "scientifically denialist" technical paper,
http://www.mikechurch.com/joomla/images/stories/global_NOT_warming/Falsification_of_CO2.pdf
thinking it must come from there; but no... not there. FromWhere?

Thanks for the link to another of those wacky sites, much like the Creationist/ID'er sites, that dazzle folks with scientific information (much of it valid) and then draw completely unwarranted conclusions to so obviously suite their own agenda.
--> end p.s.
& here's a link to some relevant surfings:
http://www.scienceagogo.com/forum/ubbthreads.php?ubb=showflat&Number=26454#Post26454
===
p.p.s. I see my memory of the graph was wrong, but I'm confident that my points below are still valid....

I haven't looked yet, but I'm betting someone has taken a graph showing the extinction of IR in an absorbing medium (and then relabeled it as the heating potential of IR -or was it CO2).

I'll have to look at the graph again (and the source!).

ummm....
Several times along this thread, I thought it was important to try and describe how energy flows in the atmosphere. It's quite a story; an action tale, set in a landscape bordering on the quantum and macroscopic worlds.

[put in explanation here, or the rc link]
...yea, ...since your source is MikeChurch, I'm just gonna include this neat clip from a realclimate blog.
http://www.realclimate.org/index.php/archives/2008/04/back-to-the-future/feed/
Originally Posted By: by Rod B.

For all practical purposes the energy from a photon at 15 microns is absorbed in a CO2 molecule’s vibration. This energy is more than twice the kinetic energy of a molecule’s translation at a nominal 300K, and does not affect the temperature, other than from the likely trivial momentum transfer just mentioned. By equipartition quantum probabilities it will strongly want to relax This relaxation is predominately transferring energy to another atmospheric molecule’s translation via collision, at other than very low pressure (density). This does raise the atmosphere’s temperature. It can, though unlikely, transfer to its own translation; however this becomes trivial since the molecule will still quickly relax its new found translation energy again via collision. It can also re-emit a photon instead, the probability of which increases as pressure decreases (among other factors). Conversely, a CO2 can sometimes collide with another molecule, pick up some kinetic energy and immediately relaxing via photon emission, transiting through vibration, and provide a net cooling of the atmosphere

Some of my calculations as a reference (and a check if anyone is so inclined):
The energy of a 15micron photon is 1.325×10^-20 joules; its momentum is 4.4×10^-29 [you’d think by now physicists would have come up with momentum units; I suggest OOMPHS!]
The kinetic energy of a CO2 molecule at 300K is 6.214×10^-21joules (3742 joules for a mol); its momentum is 3.0×10^-23; its velocity (or the average velocity for a mol) is 412.5 m/sec.
One photon’s energy going into one molecule’s translation will raise its temperature from 300K to 630K; the mol’s avg. temp would increase to 300.038K.

The standard relaxation process has a complex formula of probabilities. Of interest is the vibration to translation transfers usually require a large number of collisions before occurring. 10,000 to 100,000 is often quoted, but that is usually at high temperatures (500-1000K) where the molecule is more “comfortable” with its vibration. At atmospheric 200-300K (and normal pressure) it is less : 100-10,000 I would guess (haven’t done the cumbersome math), and more likely to make the transfer. The lower rotation energy takes 5-100 collisions to make a translation transfer and is highly likely — H2O to N2 or O2, e.g. Going the other direction — translation to vibration to emission — I would think (no math again) at low temp and pressure, e.g. stratosphere, somewhere around the 10,000-100,000 collisions range is more the normal and not as likely to occur.
...

In the lower atmosphere there are a lot of CO2 molecules being blasted with thermal radiation from the surface of the earth. They will lose their absorbed vibrational energy to the translational energy of the air molecules through collisions which preserve momentum but transfer energy.

In other words, the surface air will be radiatively heated, just as food is heated in a microwave oven.

Cheers, Alastair.
...

http://www.realclimate.org/index.php/archives/2008/04/back-to-the-future/#comment-85606

p.s. ...that's also a very neat site; thanks for pointing me at that also. Much to explore....
=

So, the important point to realize that while this graph is true, the origin of that IR can be anywhere in the atmosphere; its origin is not relegated to the earth's surface.

I think this is an accurate characterization of the weird quantum side of the story.
Any molecule of CO2 can spontaneously emit IR (say ~14.7 microns) simply by colliding with a higher temperature molecule of N2 or O2. It doesn't even need to be a collision of a specific energy, as long as it's over a certain lower limit; with the bulk of the energy being converted into the IR emission and the remainder adding on to the momentum and vibration of the CO2 molecule.

...and of course, the reverse can also happen... after absorbing some IR. It's not as if there is a particular quantum of 14.7 IR that leaves earth and you can track it's journey. Well, you can; but you have to follow all its many transitions, from potential energy to kinetic energy, and back again while being added into the sea of energy that is out there and then split off again at some other level (part of some higher energy quantum -or as some, or several, lower energy quanta).

More simplistically, you could envision a particular quantum of 14.7 IR being absorbed a foot above the surface
...and then being emitted, to then be absorbed another foot away, higher above the ground. Now it's two feet above the ground as it gets emitted again, only to be absorbed a foot away (at 3 feet above the ground)... etc., etc....

CO2 could be seen as a series of relay stations, ferrying a quantum of IR up to the higher reaches of the atmosphere where it can finally radiate away (without hitting something and raising its temperature... as it may do all the way up through those thicker layers of the atmosphere).

That extinction graph is a snapshot of what one quantum does, on average, in an absorbing medium (each medium having its own extinction coefficient). It's not a measure of how a quantum will heat the air, but of how easily a quantum gets absorbed.

After it gets absorbed is the story of how energy is stored and transmitted and heat flows.
smile


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John

Quote:
In daylight, air is always colder than soil; consequently, heat is transferred from the soil to the air, not vice versa."


if I go outside and stick a thermometer in my yard it will read 65 F even if the "air" temperature is 95 F
even if the "air" is 45 F the ground is 65 F

so the air is always colder must be incorrect.

stable ground temperatures is how geothermal cooling and heating works.

the thermal mass earth is greater than that of air because its density is greater than that of air.

heat moves into the earth from the air , it is the shear mass of the earth that allows this heat transfer to occur.

if you feel your desk with your hand it feels colder than the air
in the room , this is because the heat from your hand is moving / transfering into the desk because it has a higher thermal mass than your hand , just like the ground has a higher thermal mass than the air.

have you ever wondered why water pipes are underground?

it is because the ground stays warmer than the air in winter.

In simple terms, the second law is an expression of the fact that over time, ignoring the effects of self-gravity, differences in temperature, pressure, and density tend to even out in a physical system that is isolated from the outside world.

your hand is an observance of the second law , as you place your hand on your desk your hand feels the coldness of the desk , then your hand begins to warm as the heat from your hand transfers into the desk.

your hands temperature is equalizing with your desk temperature , the heat is flowing from hot to cold not vice versa.


Last edited by paul; 06/09/08 04:57 AM.

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Paul, don't blame John for that one....
Originally Posted By: JMR
The above quotes are from this reference:
Nahle, Nasif. Heat Stored by Greenhouse Gases. Biology Cabinet....


This explains the disjointed nature of the citations, observations, and conclusions. Did you see my "review" of that site?

Any comments, suggestions, or reviews of the CO2 debate would be welcome (hint, hint, ...anyone); is it all "greek to me," or does it evoke a unified picture?

~ smile


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Originally Posted By: samwik
So, the important point to realize that while this graph is true, the origin of that IR can be anywhere in the atmosphere; its origin is not relegated to the earth's surface.


The source of the IR is irrelevant. The graph shows how much CO2 affects atmospheric temperature based on concentration. The point is that if CO2 is only at 20ppm, there is about 1.5 C of warming. Doubling the amount of CO2 only adds about 0.3 C. Doubling from 280 will have minimal effect.

Here is another set of graphs that were in a paper I had found a while ago.


That paper also concludes that the IPCC has overestimated the effect of CO2 through anthropogenic global warming. This minimizes the human influence on climate.

That RealClimate site is terrible. They do not allow discussion. Many have documented comments that have not been allowed because they ask difficult questions. If you want a vetting of either the RealClimate site, or the biocab paper, both were done at ClimateAudit.org. The vetting of the biocab paper is mentioned in that biocab paper itself. Search the Climate Audit site for Heat_Stored to get a few links to posts where it was at least mentioned if not discussed.

You then discuss the movment of a "quantum of 14.7 IR." That does not make sense. When two molecules collide, some portion of the energy is transferred. For you to follow the quantum of 14.7 IR is to assume that the energy is re-radiated before a collision can happen. I think we are going in circles here. You mentioned, "that extinction graph is a snapshot..." Which is the extinction graph?

Originally Posted By: paul
if I go outside and stick a thermometer in my yard it will read 65 F even if the "air" temperature is 95 F even if the "air" is 45 F the ground is 65 F so the air is always colder must be incorrect.


You cannot use a thermometer. It is the surface layer that gets warm. You need to use a better instrument. You need one that can produce a picture like the second one in Anthony Watts' "I love the smell of sewage in the morning" blog post. The only possible way for the surface to be lower in temperature is if it is a cloudy day and warm air is blown in from some other locale. That air was warmed by being in contact with the ground in that locale. This is how all forced air heating systems work. Heat the air and blow it to another room. The heat does not generally move from the air to the ground on sunny days. Heat rises. The ground gets warmed by the sun. The air is warmest right next to the ground when the sun is shining on it.

About your desk example, that a surface can transfer heat more efficiently away from your hand does not mean that it is colder than the air. I put my hand onto my desk and it feels hot, but it is in the sun. Fast moving air can remove heat from our bodies than still air. The air temperature is the same, but the rate of cooling is faster. These are similar principles. The dashboard in the car is much hotter when I park in the sun than is the shaded car seat.

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Originally Posted By: John M Reynolds
The source of the IR is irrelevant.
I'd like to get back to this and the IR stuff, but first....


I suppose my last post should have been greatly revised.
I was talking as if your graph was something else, and I went on and on about heat flow, IR absorbancy and emissivity.

I'd like to get back to that, but first please let me know where that graph came from. Other than MikeChurch writing,
Quote:
David Archibald of LaVoisier breaks this down even further for us (Figure X). You see, each gas has it's own heat retention factor"
I find no citation for this graph.

Well, let's google: "David Archibald" LaVoisier
Oh, good source! [said sarcastically]
http://n3xus6.blogspot.com/2007/02/dd.html
"The worst climate science paper ever of all time anywhereFeb 1, 2007 ... a fellow by the name of David Archibald popped up, ... Now, Lavoisier is a crazed denialist group based in Australia so the fact that ..."
&
www.realclimate.org/index.php/archives/2007/10/my-model-used-for-deception/
"Lavoisier Society’s own programme says “David Archibald is a Perth-based scientist operating in the fields of cancer research, climate science and oil ..."
&
http://scitech.blogs.cnn.com/2008/04/09/americas-biggest-belchers/
"David Archibald is perhaps the most discredited voice in the world of climate science.
The Lavoisier Group, with which Archibald is closely associated, and to which he presented the paper to which Franko refers, defines the purpose of its existence in terms of its ideological opposition to the Kyoto Treaty and the Howard government’s embrace of the principles of that treaty; the group identifies no positive purpose for its own existence. Like the American Enterprise Institute, The Lavoisier Group appears to derive its funding primarily from the coal and oil industries, making its credibility dubious, at best.
Archibald’s presentation is, on its face, a tissue of statistical sophistry. He proposes no coherent explanation for the data he cherry-picks to tenuously support the conclusions from which he appears to have tried to work backwards.
[/quote]

Hey! That's just what I was saying about the graph; someone's taken a graph of the extinction coefficient in an absorbing medium and relabeled it to suite their agenda or "theory."

This all makes sense if you assume that after the IR is absorbed, it is "sequestered" and doesn't heat the atmosphere further. Based on that "theory," one could assume a graph of the extinction coefficient was proportional to the "warming effect."

Unless you can point me to some authoritative source for that graph, I have to say it's worthless.
Worse than worthless, it is leading intelligent folks to draw the conclusions that so obviously emerge from the data in that graph; but erroneous conclusions, based on a falsified document.

To repeat, someone's taken a graph of an IR extinction coefficient in an absorbing medium (CO2) and relabelled it, IMHO.
.
.
.
.
.
.
.
....Found the graph in Archibald's actual paper.
It was originally submitted at a "conference" as:
[PPT] The Past and Future of ClimateFile Format: Microsoft Powerpoint - View as HTML
David Archibald. Lavoisier Conference, Melbourne ..... By my calculations, every day’s delay in the onset of solar cycle 24 will lower the average ...
http://www.tech-know.eu/uploads/The_Past_and_Future_of_Climate_May_2007.pps

The Past and Future of Climate; [graph on p.16]; Lavoisier Conference, Melbourne
The Warming Effect of Atmospheric Carbon Dioxide

...and it seems as if he submitted it later for publication in the International Journal of Oncology. Perhaps that's still pending, but it didn't make it into the March, 2008 issue, as the link might indicate.

[PDF] Int J Oncol File Format: PDF/Adobe Acrobat - View as HTML
Solar Cycle 24: Implications for the United States. David Archibald. International Conference on Climate Change. March, 2008 ...
http://www.warwickhughes.com/agri/Solar_Arch_NY_Mar2_08.pdf

Erroneously cited as if from the:
International Journal of Oncology 1019-6439
"Solar Cycle 24: Implications for the United States"
[graph on: p.22].

But look at the science in this Archibald paper.

While the blogosphere is almost exclusively full of praise for ClimateAudit, the fact that he uses Archibald and that "bio-cab" site as sources of basic information does not lend more credibility to Steve McIntyre's blogAudit site.

It seems that ClimateAudit has helped uncover mistakes, falsifications, new ideas and hypotheses, and conspiracies. These are all great functions of the blogosphere; but his site shouldn't be taken as a final word, any more than any other site or source can ever be a final word.

While alarmist sites regale us with a lot of elitist handwaving at the discovery of any more supportive information, hopefully inching up the "certainty" factor; the denialist blogs seem to take a more plebian glee in falsifying an idea, putting the final nail in the coffin, while it's back to the drawing board, ...that is swinging in the wind, overturning the whole GW conspiracy, ...and so achieve some presumed finality.

Revision, refinement, and reviling are a part of the normal scientific process. These things are not indications of some final triumph.
===

What does Archibald report about his graph, ...and stuff in general?

"David Archibald
International Conference on Climate Change
March, 2008"
...
Do we live in a special time in which the laws of physics and nature are suspended? No,
we do not. Can we expect relationships between the Sun’s activity and climate, that we can
see in data going back several hundred years, to continue for at least another 20 years?
With absolute certainty.
In this presentation, I will demonstrate that the Sun drives climate, and use that
demonstrated relationship to predict the Earth’s climate to 2030. It is a prediction that
differs from most in the public domain. It is a prediction of imminent cooling.
...

...about that graph
Originally Posted By: David Archibald

Confirming the logarithmic effect of carbon dioxide is possible using the MODTRAN
facility hosted by the University of Chicago.
Oh, so this is just a proposition, or a hypothesis, of Archibald's....
...Not something he's tested or experimented on, or cited from somewhere else.

...his paper continues, "objectively:"

AGW Proponents are Exactly Wrong
1. The Earth is getting colder and this will accelerate.
2. Carbon dioxide has a minuscule warming effect.
3. Increased atmospheric carbon dioxide will
increase agricultural productivity.
4. The ideal atmospheric carbon dioxide level is a
minimum of 1,000 ppm

Dr Hansen’s statement that the maximum safe level of carbon dioxide in the atmosphere is
350 ppm begs the question of what the actual ideal level is. I have taken the 1,000 ppm
figure from the level that commercial greenhouse operators prefer to run their greenhouses
at. The ability to grow food is going to be the overriding concern next decade.

Stopping coal-fired power generation due to carbon dioxide emissions is exactly wrong in
science. The more carbon dioxide you put into the atmosphere, the more you are helping
all living things on the planet and of course that makes you a better person.
A further big dimension to this debate is US fuel supply security. The oil price is now well
above the level at which coal to liquid fuels plants are profitable. With a breakeven price
of US$40/bbl, they have become quite profitable.
The US has very large coal reserves and the conversion of this coal to liquid fuels could
provide the US with fuel security. If the building of conversion plants is delayed by
notions of supposedly harmful carbon dioxide emissions associated with the conversion
process, those notions are unnecessarily harmful to US national security.

This is my message.
David Archibald
david.archibald@westnet.com.au
===

...oh, I thought this was a scientific paper. Never mind.

smile

p.s. "...what the actual ideal [CO2] level is. I have taken the 1,000 ppm figure from the level that commercial greenhouse operators prefer to run their greenhouses at." ...well there's my best laugh of the day....
~


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Samwik

They are slightly mixed up here.

Quote:
In daylight, air is always colder than soil.


this is wrong , air temperature is in no way as stable as ground temperature.

if the ground is moist and warm and the humidity is low the moisture in the ground will evaporate into the air , as this happens the resulting water vapor absorbs heat from its surroundings.

this causes the remaining air to cool , as the air cools some of the heat from the ground is transfered into the air.

but you cannot say that the air is always colder than the ground.

and you are basing your findings on this error?

I havent read the whole page yet.

however if they are basing findings or theory on this as a foundation then there will most likely be many more errors.


.

Last edited by paul; 06/11/08 01:31 AM.

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Originally Posted By: Paul
but you cannot say that the air is always colder than the ground.


You missed the "In daylight" part. That is the key. Or is your problem with the 'always' being too strict?

Originally Posted By: Samwik
To repeat, someone's taken a graph of an IR extinction coefficient in an absorbing medium (CO2) and relabelled it, IMHO.


I am sorry, but I don't understand. What is an extinction coefficient? The way I see it is CO2 will absorb 100% of the IR radiation at about 15 microns. It is difficult to read from that graph, so for argument's sake, I will say that CO2 will only absorb 30% of the energy at 18 microns. As the concentration increases, more of the 18 micron energy will be absorbed, but the amount absorbed at 15 microns will not change. Is this what you mean by a graph of extinction coefficient?

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