Friday, 23 April 2010

Greenhouse? What Greenhouse? by Philip Foster

Greenhouse? What Greenhouse?

When I was learning physics I was taught the usual theory about how a greenhouse warmed. As a physics teacher in the 1970s, I also taught my students the same theory. But despite it being in all the text books the theory is wrong and has been known to be so for a hundred years!

Note on the Theory of the Greenhouse

by Professor R. W. Wood, 1909.

THERE appears to be a widespread belief that the comparatively high temperature produced within a closed space covered with glass, and exposed to solar radiation, results from a transformation of wave-length, that is, that the heat waves from the sun, which are able to penetrate the glass, fall upon the walls of the enclosure and raise its temperature: the heat energy is re-emitted by the walls in the form of much longer waves, which are unable to penetrate the glass, the greenhouse acting as a radiation trap.

I have always felt some doubt as to whether this action played any very large part in the elevation of temperature. It appeared much more probable that the part played by the glass was the prevention of the escape of the warm air heated by the ground within the enclosure. If we open the doors of a greenhouse on a cold and windy day, the trapping of

radiation appears to lose much of its efficacy. As a matter of fact I am of the opinion that a greenhouse made of a glass transparent to waves of every possible length would show a temperature nearly, if not quite, as high as that observed in a glass house. The transparent screen allows the solar radiation to warm the ground, and the ground in turn warms the air, but only the limited amount within the enclosure. In the “open,” the ground is continually brought into contact with cold air by convection currents.

To test the matter I constructed two enclosures of dead black cardboard, one covered with a glass plate, the other with a plate of rocksalt of equal thickness. The bulb of a thermometer was inserted in each enclosure and the whole packed in cotton, with the exception of the transparent plates which were exposed. When exposed to sunlight the

temperature rose gradually to 65°C, the enclosure covered with the salt-plate keeping a little ahead of the other, owing to the fact that it transmitted the longer waves from the sun, which were stopped by the glass. In order to eliminate this action the sunlight was first passed through a glass plate.

There was now scarcely a difference of one degree between thetemperatures of the two enclosures. The maximum temperature reached was about 55°C. From what we know about the distribution of energy in the spectrum of the radiation emitted by a body at 55°C, it is clear that the rock-salt plate is capable of transmitting practically all of it, while the

glass plate stops it entirely. This shows us that the loss of temperature of the ground by radiation is very small in comparison to the loss by convection, in other words that we gain very little from the circumstance that the radiation is trapped.

Is it therefore necessary to pay attention to trapped radiation ind educing the temperature of a planet as affected by its atmosphere? The solar rays penetrate the atmosphere, warm the ground which in turn warms the atmosphere by contact and by convection currents. The heat received is thus stored up in the atmosphere, remaining there on account

of the very low radiating power of a gas. It seems to me very doubtful if the atmosphere is warmed to any great extent by absorbing the radiation from the ground, even under the most favourable conditions.

I do not pretend to have gone very deeply into the matter, and publish this note merely to draw attention to the fact that trapped radiation appears to play but a very small part in the actual cases with which we are familiar.

Following are diagrams showing, in a very simplistic way, why CO2 and H2O (along with O3, N2O and CH4 - not included in the diagrams) in the atmosphere cannot cause warming. If they did we would have access to unlimited energy for no cost! The very small amount of radiated infrared from H2O and CO2 reaching the ground cannot warm the ground as the

temperature of these gases is lower than the temperature of the ground - just as hot coffee in a Thermos does not start boiling! By suggesting that it can is to break one of the laws of thermodynamics.The only role they can play is like that of a glass plate as opposed to a rock-salt plate as described by Prof. Wood above: namely to slightly inhibit the warming of

the ground. But as they cannot trap the convecting air (unlike solid glass in a greenhouse) all comparisons with a ‘greenhouse effect’ are invalid.

As Kevin Trenberth (head of CAS at NCAR) has done:

This is part of the work of Alan Siddons, a radiochemist, and Hans Schreuder, an analytical chemist and a member of Mensa. Philip Foster MA (Nat. Sci. & Theol.) (an initiator of theCopenhagen Climate Challenge, in Dec 2009)

International Journal of Modern Physics Vol. 23 No. 3 (2009) 275-364 FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE EFFECTS WITHIN THE FRAME OF PHYSICS by GERHARD GERLICH (Prof.) Institut fur Mathematische Physik, Technische Universitat Carolo-Wilhelmina zu Braunschweig, Mendelssohnstrasse 3, D-38106 Braunschweig, Federal Republic of Germany & RALF D. TSCHEUSCHNER Dr. Ralf D. Tscheuschner, Dipl.-Phys. Postfach 602762, D-22377 Hamburg, Federal Republic of Germany The abstract can be downloaded from: but the full article is available only by subscription.


Jim Baxter said...

Kirchhoff's law makes clear that the detailed balance of absorptivity and emmisivity conforms to a Markov transition matrix and shows ‘Karelian Independence’ of extended non-negative real numbers whether these be associated to metric space or vector space.

In practice, this means that the you may as well do as you please and put what you like in your bins (compare Zermelo’s, 1904, exposition of the Axiom of Choice), as the science is entirely up in the air.

subrosa said...

Jim, you took the very words out of my mouth. :)

Dark Lochnagar said...

WTF that all about?

subrosa said...

Jim's comment DL? Erm ...

But he's right about the science being up in the air.

Jim Baxter said...


It's simple. See here:

Zermello's argument is that you can put what you like for collection in an infinite number of bins so the whole recycling thing is a waste of time at best, and a total con at worst.

That help at all?

subrosa said...

It certains helps me Jim. Thanks.

forfar-loon said...

Hmmm, looks to me like a cack-handed attempt at sophistry there...

One important piece of information is missing: most of the energy output of the Sun, i.e. the incoming solar radiation, is in the visible part of the electro-magnetic spectrum (i.e. inbetween IR and UV frequencies). In contrast the vast bulk of radiation that the Earth emits is in the IR part of the spectrum.

So the diagrams really show the vast bulk of incoming radiation making it past the CO2 and H2O without being absorbed, then hitting the Earth and being absorbed, then being re-emitted as IR radiation, at which point lots of the IR radiation is absorbed by the CO2 and H2O and doesn't make it into space, thereby heating the atmosphere. A hotter atmosphere is a more energetic atmosphere, i.e. stormier.

subrosa said...

So, are you saying humans add a far greater percent to climate change then forfar-loon? My understanding is that it's only around 1-2%.

Jim Baxter said...

It's cack all right. I'll grant you that.

forfar-loon said...

Nope, I was very careful not to mention humans subrosa. That's an entirely different debate :o)

But since you ask, it seems pretty obvious to me that if we pump lots of stuff into the atmosphere then we might just change the properties of the atmosphere somewhat. How much or how little, and in what ways, nobody knows for sure (and don't believe anyone who tells you "the answer"!). It's a complicated beast. But given that humans have evolved to thrive in the atmosphere that we have, it seems a little risky to be screwing round with it too much. We've only got the one atmosphere after all. Just look what a little Icelandic burp can do.

If we can change our ways to be more efficient with the finite resources that the planet offers us, then why not do it? That doesn't mean progress has to stop, just that we don't fritter away the few goodies that we have. Seems a sensible principle regardless of our impact on climate change.

Jim Baxter said...

'If we can change our ways to be more efficient with the finite resources that the planet offers us, then why not do it?'

See, that's fair enough. To be burning such a rich resource as natural gas to make electricity when there are other ways to make it is nothing short of criminal.

(Oh, FL, regarding the foregoing of mine, MTS, I merely believe in throwing their own rubbish back at them. It's a kind of recycling).

subrosa said...

I'm all for pollution control forfar loon, because that makes sense to me and yes that is man made.

What I do object to is turning my kitchen or another room in my home into a mini recycling centre or else the climate change bogeyman will get me. How the elderly manage in flats beats me and I know many do take it all seriously.

There's common sense and there's hysteria. Finding the balance is difficult.

subrosa said...

I agree wholeheartedly there with you Jim.

Dark Lochnagar said...

James, could you not have said that the first time!

subrosa said...

Auch DL, Jim likes to confuse at times. Well certainly confuse me - although I was halfway there.

Jim Baxter said...

The thing is, we've become manured to such tripe, I mean innured. People tend to assume it's just more of the same. The troubling thing for me is how little of it I have to alter to make it fit (for) my reactionary purpose. I know, I shouldn't bother.

It's time now to learn lessons and move on so that we can focus on doing what's right for Britain.

Remember how keen Nixon always was to 'move on' from Watergate and concentrate on the real problems that the country faced?

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