The Hidden Flaw in Greenhouse Theory

American Thinker ^ | February 25, 2010 | Alan Siddons

[neverdem]

Insulated by an outer crust, the surface of the earth acquires nearly all of its heat from the sun. The only exit for this heat to take is through a door marked "Radiation." And therein lies a tale...

Recently, I chanced upon an Atmospheric Science Educator Guide [PDF] published by NASA. Aimed at students in grades 5 through 8, it helps teachers explain how so-called "greenhouse gases" warm our planet Earth.

These guides are interesting on a number of levels, so I recommend you look them over. But what caught my eye was this:

• Question: Do all of the gases in our atmosphere absorb heat?
• Answer: (Allow students to discuss their ideas. Don't provide the answer at this time.)

Indeed, that's a good one to think over, yourself. Almost all of what we're breathing is nitrogen and oxygen -- do these gases absorb heat? Lakes and rocks absorb heat, after all, and thereby reach a higher temperature. So can nitrogen and oxygen molecules do the same?

Well, I won't keep you hanging. After allowing students to discuss it, the instructor is instructed to give them the final verdict.

• Answer: No. Only some gases have the unique property of being able to absorb heat.

These are the infrared-absorbing "greenhouse gases," of course, substances like carbon dioxide and water vapor, not nitrogen and oxygen.

Now, is something wrong here? Most definitely, for NASA has a finger on the scale. Let's review a few basics that NASA should have outlined.

Heat consists of vibrating and colliding molecules. The motion of these molecules jostles their electrons around, and this emits light. Heat and light are thus strongly related, but aren't the same. For instance, heat can't actually be radiated, only the light that heat brings about. By the same token, light itself has no temperature because temperature is an index of molecular motion, and a beam of light isn't composed of molecules. In short, "heat" can be regarded as molecular excitement and light as electromagnetic excitement.

Observe how NASA describes this relationship, however.

• Question: What is the relationship between light and heat?
• Answer: Things that are hot sometimes give off light. Things under a light source sometimes heat up.

Utterly false. Heated masses always emit light (infrared). Always. That's a direct consequence of molecules in motion. And while it's true that some substances may be transparent to infrared light, it doesn't follow that they can't be heated or, if heated, might not emit infrared. Yet NASA's misleading formulation implies precisely that.

There are three ways for heat (better to say thermal energy) to move from one zone to another: by conduction, convection, and radiation. Conductive heat transfer involves direct contact, wherein vibrations spread from molecule to molecule. Convective transfer involves a mass in motion: expanded by heat, a fluid is pushed up and away by the denser fluid that surrounds it. Radiative transfer arises when molecules intercept the light that warmer molecules are emitting, which brings about a resonant molecular vibration, i.e., heating.

Heat is transferred and absorbed in several ways, then, and no substance is immune from being heated, which means that all gases absorb heat -- contrary to what NASA tells children.

So how does NASA go wrong? By consistently confusing light and heat, as you see in the illustration below, where infrared light is depicted as heat. Elsewhere, NASA expresses heat transfer in terms that pertain to radiant transfer alone:

The Earth first absorbs the visible radiation from the Sun, which is then converted to heat, and this heat radiates out to the atmosphere, where the greenhouse gases then absorb some of the heat.

Nowhere in its teacher's guide are conductive and convective heat transfer even mentioned. By selective context and vagueness, then, NASA paints an impression that only light-absorbing substances can be heated. Thus, since nitrogen and oxygen don't respond to infrared, NASA feels justified to say that "only some gases have the unique property of being able to absorb heat."

Astonishing.

But a mix-up like this raises a deeper question: why does NASA go wrong? Because it has a flimsy yet lucrative theory to foist on the tax-paying public, that's why. As the space agency explains in the Main Lesson Concept, the core idea of greenhouse theory is that downward radiation from greenhouse gases raises the earth's surface temperature higher than solar heating can accomplish.

To make this idea seem plausible, therefore, it's crucial to fix people's attention on the 1% of the atmosphere that can be heated by radiant transfer instead of the 99% and more that is heated by direct contact with the earth's surface and then by convection. NASA is stacking the cards, you see. If they made it clear that every species of atmospheric gas gets heated mainly by conductive transfer, and that all heated bodies radiate light, then even a child could connect the dots: "Oh. So the whole atmosphere radiates heat to the earth and makes it warmer. All of the atmosphere is a greenhouse gas."

Crash, boom, there goes the theory. And there goes the abundant funding that this fear-promoting "science" attracts so well. For what CO2 and water vapor emit is miniscule compared to the buzzing multitude of heated nitrogen, oxygen, and even argon, all of it radiating infrared too. Keep in mind that thermal radiation from this forgotten 99% has never been proposed or imagined to increase the earth's temperature, although by the theory's very tenets it should. You simply take the NASA formulation:

Greenhouse gases absorb heat that radiates from Earth's surface and release some of it back towards the Earth, increasing the surface temperature

And make allowance for conductive transfer too...

All gases in the atmosphere absorb heat from the Earth's surface and radiate infrared back towards the Earth, increasing the surface temperature.

Consider too that since most air molecules are infrared-transparent, they can't be heated by the infrared that CO2 and water vapor emit. This means that downward radiation from "greenhouse gases" can only explain how the earth's surface might get warmer, not the rest of the atmosphere. Which underscores, of course, how much the surface is heating this 99% by conduction and convection alone, since radiative transfer can't do the job.

To repeat: Irrespective of the manner of transfer, all gases absorb heat and all heated gases radiate heat (infrared light) in close proportion to their temperature. Major gases like nitrogen and oxygen, then, do not just radiate heat to the earth below, but the  total of this radiation vastly exceeds what minor players like carbon dioxide and water vapor contribute. Ironically, another NASA publication [PDF] reinforces this point.

In solids, the molecules and atoms are vibrating continuously. In a gas, the molecules are really zooming around, continuously bumping into each other. Whatever the amount of molecular motion occurring in matter, the speed is related to the temperature. The hotter the material, the faster its molecules are vibrating or moving.

Electromagnetic radiation is produced whenever electric charges accelerate - that is, when they change either the speed or direction of their movement. In a hot object, the molecules are continuously vibrating (if a solid) or bumping into each other (if a liquid or gas), sending each other off in different directions and at different speeds. Each of these collisions produces electromagnetic radiation at frequencies all across the electromagnetic spectrum.

... Any matter that is heated above absolute zero generates electromagnetic energy. The intensity of the emission and the distribution of frequencies on the electromagnetic spectrum depend upon the temperature of the emitting matter.

Accordingly, any heated gas emits infrared. There's nothing unique about CO2. Otherwise, substances like nitrogen and oxygen would truly be miracles of physics: heat ‘em as much as you wish, they'd never radiate in response. 

Yet this amounts to a double whammy. For meteorologists acknowledge that our atmosphere is principally heated by surface contact and convective circulation. Surrounded by the vacuum of space, moreover, the earth can only dissipate this energy by radiation. On one hand, then, if surface-heated nitrogen and oxygen do not radiate the thermal energy they acquire, they rob the earth of a means of cooling off -- which makes them "greenhouse gases" by definition. On the other hand, though, if surface-heated nitrogen and oxygen do radiate infrared, then they are also "greenhouse gases," which defeats the premise that only radiation from the infrared-absorbers raises the earth's temperature. Either way, therefore, the convoluted theory we've been going by is wrong.

An idea has been drummed into our heads for decades, that roughly 1% of the atmosphere's content is responsible for shifting the earth's surface temperature from inimical to benign. This conjecture has mistakenly focused on specifically light-absorbing gases, however, ignoring heat-absorbing gases altogether. Any heated atmospheric gas radiates infrared energy back toward the earth, meaning that the dreadful power we've attributed to light-absorbing molecules up to now has been wildly exaggerated and must be radically adjusted, indeed, pared down perhaps a hundred times. Because all gases radiate the heat they acquire, trace-gas heating theory is an untenable concept, a long-held illusion we'd be wise to abandon.

[Right Wing Assault]

The whole greenhouse analogy is flawed. Greenhouses get hot because light heats the solid matter inside the greenhouse. Air inside gets warmer by contacting (conduction) the solids. The warm air rises but meets a physical barrier only a few feet away. So, a major element of the earth’s atmosphere, large scale convection, is prevented in greenhouses. How do you cool a greenhouse? Open vents in the top and allow convection to take place. The earth does not have anything approaching a glass ceiling.

[Publius6961]

Sometimes we all forget to check the links we post.

Specially at 1:26 AM...

: )

[Right Wing Assault]

Thank you!

[wastoute]

I am not a physicist, but I did have to take a couple semesters thirty years ago. It seems to me that I read the ORIGINAL guy that did the greenhouse effect work discovered that it was the GLASS not the gas that caused the IR trapping. That would make sense to me. This may be simplistic, but I see the earth’s atmosphere as symmetrical in the sense that it would absorb as much IR in one direction as the other. If someone could explain to me how this isn’t so we can stop right there. If it is so then there is no such thing as “greenhouse gas”.

[Rapscallion]

All green plants we use for food require CO2 to live. They starve without carbon dioxide. If we need to reduce greenhouse gasses, lets plant more trees and shrubs and crops (and use Al Gore as a scare-crow (get it?))

[justa-hairyape]

It seems to me that I read the ORIGINAL guy that did the greenhouse effect work discovered that it was the GLASS not the gas that caused the IR trapping.

Glass absorbs infrared light. That is why the glass bulb of a radiative light source is hot. Please just take our word for it, unless of course you like the sound of sizzling flesh. So the glass panels of greenhouses will heat up from solar infrared and conduct energy in both directions. Since the outside world typically has cooler wind, most of that energy will be transferred to the outside wind. Some will conduct inwards. So the heated glass represents water vapor et. al.. The conduction of that heat to the inner and outer atmosphere represents the general atmospheric gases. The total of the atmospheric gases also determines the important Total Heat metric. All atmospheric gases trap heat and can be considered greenhouse gases, if that term was even accurate. Might be better to call them green planet gases. Perhaps the airheads will be happy with that phrase. Atmospheric gas sounds so boring and clinical. Additionally, the heat capacity of the atmosphere increases with higher density and it will ultimately determine the temperature of the atmosphere at given heat fluxes.

[Gorzaloon]

This may be simplistic, but I see the earth’s atmosphere as symmetrical in the sense that it would absorb as much IR in one direction as the other. If someone could explain to me how this isn’t so we can stop right there. If it is so then there is no such thing as “greenhouse gas”.

Light of all wavelengths can be absorbed and converted to heat. Red light absorbed by the chloropyll in the plants, most wavelengths absorbed by dark soil,black plastic, etc.. These warm the air, but also radiate in the infrared at wavelengths characteristic of temperature and in proportion to the emissivity of the material. These longer wavlengths often are not well transmitted by the glasses, so their heat energy is trapped in the greenhouse. Transmission of IR wavelengths of 10µ or so require exotic materials like zinc sulfide, salt, etc.

[JustDoItAlways]

This is very close to what the theory is based on.

Now what could possibly be wrong with that theoritical framework?

Only about 20 key aspects of it, that is.

The worst part of it is when they say the IR photons are “trapped” - like they never make it out of the atmosphere ever. A CO2 molecule only holds onto that IR photon for a few picoseconds to less than a millisecond. If anything the “trapped” IR photons still escape from the atmosphere (perhaps in other wavelengths though) a few seconds or a minute or two later than they would have escaped at 280 ppm.

[NicknamedBob]

"So why is the sky blue?"

Because that's the prettiest color. (If you want to be technical about it.)

[wastoute]

But consider a “thought experiment” if you will. Suppose I am a moeclue of H20 vapor in the atmosphere. I am “seeing” IR coming primarily from one source, the sun but I radiate what I have received in all directions. I warm up some and through convection I warm the gasses around me. There is my “cousin” who is at a lower altitude than I and he sees somewhat less IR than I because of what I have absorbed before it got to him but what he does receive he raditates and also through convection warms symmetrically in all directions. All these molecules also recieve reflected IR from the surface and all of that is proportionately reduced on the way up as it was on the way down. This process is repeated infinitely (almost) and so as these molecules all radiate and convey heat symmetrically, how is it they “trap” anything? There is a gradient of IR aborption on the way down from the sun and a smaller one in the opposite direction on the way up but just where is the “trapping”?

[Free Vulcan]

save for later

[Gorzaloon]

But consider a “thought experiment” if you will. Suppose I am a moeclue of H20 vapor in the atmosphere. I am “seeing” IR coming primarily from one source, the sun but I radiate what I have received in all directions. I warm up some and through convection I warm the gasses around me.

You warm the gases around you with collision. The wavelength emitted is longer and of lower energy than the wavelength you absorbed to warm up, and the wavelength you radiated is no longer the peak absorbtion wavelengths. The strong absorbtions are at 2500, 1950 and 1450 nM.

[TigersEye]

Yes, we do, and it was 2:26 AM here. Thank you for picking up the slack for me.

[Right Wing Assault]

I just went back to the original link and clicked it and got the ‘doesn’t exist’ message and ‘Okay.’ My usual response is, no, not OK! I hit the back arrow. I just found now that if I had hit the Okay, it would have taken me to the correct link.

Learn something everyday. Great link, BTW.

[Right Wing Assault]

Oops. No it didn’t. It took my back to this thread. Oh, well.

[TigersEye]

So the glass panels of greenhouses will heat up from solar infrared and conduct energy in both directions.

That is true of the properties of glass but the main source of heating within a greenhouse comes from infrared light that passes through the glass and hits the solid objects below like floor, walls and the plants themselves. Those solid objects then release that energy through conduction to the gases within the greenhouse passing in direct contact over them.

[TigersEye]

That's strange. I hit it but didn't go past the "doesn't exist" message. I'm still on my first cup of coffee today so I am nearly as goofy as I was early this morning when I cut & pasted the link so I didn't look into my mistake.

OK, I just tried what you did and I got this thread not the one I intended to link. I see that I cobbled together two FR URLs (don't axe me how)(and don't axe me how they still manage to do anything either).

[justa-hairyape]

The infrared does not significantly penetrate the glass. The glass on a green house has to be of a significant thickness to withstand wind, hail, etc.. In fact, infrared only penetrates a few inches into water. Gets primarily absorbed. The solar energy that heats the interior of the green house is visible light. An experiment was done that painted an inside of a clear glass green house white. Did not significantly heat. Basically, visible light gets absorbed by colored surfaces inside the greenhouse, the surfaces warm and conduct heat to the interior atmospheric (green planet) gases which are trapped by the glass.

[DrDavid]

Did not significantly heat. Basically, visible light gets absorbed by colored surfaces inside the greenhouse, the surfaces warm and conduct heat to the interior atmospheric (green planet) gases which are trapped by the glass.

Everybody realizes that CO₂ forms an barrier just like glass on a greenhouse ceiling right?</sarcasm>

Surrounded by the vacuum of space, moreover, the earth can only dissipate this energy by radiation.

Hot or energetic molecules can leave the atmosphere into the vacuum of space, dissipating heat without radiation.

[Alamo-Girl]

Thanks for the ping!