A short primer: The Greenhouse Effect Explained

I am sorry if this has already been posted. http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v3.pdf

“Falsification of the Atmospheric CO2 Effect Within the Frame of Physics”
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v3.pdf
Short Hand Supposition and Conjecture is rudimentary theorizing … which can lead to something but in itself is not science.

AlexB,
If you are suggesting that convection increases as a result of GHG warming, is that not a feedback?

Jerry Lee Davis,
The burning of fossil fuels does provide direct greenhouse warmth. In buildings and in in people’s homes!

Finally a discussion on the physics of the Greenhouse Effect. I have a few observations and questions.
1) Steve, statements like: “These are undisputed facts” and “There is no dispute about this in the scientific community” does nothing to help me understand the physics of first order, non feedback Greenhouse effect. When a Physicist explains Relativity, they never leave it at “Scientific consensus”, they explain experiments that prove predictions of Relativity such as the optical displacement of Mercury when viewed next to the Sun. Where are the experiments that demonstrate the greenhouse effect?
2) Phil’s Makes a very powerful point that an excited CO2 molecule will almost certainly transfer its ‘excess’ energy to surrounding O2 and N2 molecules. This is *very* important because O2 and N2 don’t principally radiate at a frequency that is absorbed by traditional Greenhouse gases. Correct me if I am wrong but it is O2 microwave radiation that satellites observe to infer the temperature of the Earth’s atmosphere (i.e. RSS and UAH). Although Phil also suggests that O2 and N2 don’t radiate? I thought all mater above absolute zero temperature radiates?
3) If my interpretation of Phil’s comments are correct then radiative energy transfer in the lower atmosphere should be negligible next to convective energy transfer. So the Greenhouse effect should be working at an altitude where radiative transfer becomes substantial. What is the predicted altitude?
4) Heat flow from surface of the earth to space occurs by, radiation, conduction, convection and phase change of H20. Since we are unable to know perfectly the breakdown of heat transfer in the atmosphere by these 4 mechanisms, lets just consider heat flow in the aggregate. I remain unconvinced that an increase from 250ppm of CO2 to 500ppm could possibly lead to a measurable increase in temperature. If so why isn’t CO2 the greatest insulator know to man? why do they fill insulated windows with expensive Argon and not cheap CO2?
5) I remain unconvinced that the radiative absorption/emission properties of a gas are correlated with gas’s thermal insulative properties. At minimum the greenhouse effect, as popularly described, requires that spectral properties of a gas be considered in isolation and seperate from other properties that may be pertinent to energy flows through the gas such as molecular weight, specific heat capacity, thermal conductivity and others.
chico sajovic

I thank Simon Evans (16:02:27) for responding to my post (14:56:21). I would like to respond to Simon’s remarks.
Simon wrote:
“Since you ask questions I will respond to your post, despite
your consistent use of the pejorative label ‘alarmist’ (I do not
understand why this term is considered acceptable here. I do
not label you or others whose views I do not share with
perjorative terms).”
In his response to my post it’s true Simon personally didn’t use any pejorative terms, and I thank him for that–no sarcasm intended–I mean what I say. However, in my opinion the term “alarmist” is a mild description of someone who says:
“The climate is nearing tipping points. Changes are beginning to
appear and there is a potential for explosive changes, effects that
would be irreversible, if we do not rapidly slow fossil-fuel
emissions over the next few decades. ”
“As species are exterminated by shifting climate zones,
ecosystems can collapse, destroying more species.”
“The amount of carbon dioxide in the air has already risen to
a dangerous level. ”
“Arctic sea ice will melt away in the summer season within the
next few decades. Mountain glaciers, providing fresh water for
rivers that supply hundreds of millions of people, will disappear –
practically all of the glaciers could be gone within 50 years – if
carbon dioxide continues to increase at current rates.”
“The greatest danger hanging over our children and grandchildren
is initiation of changes that will be irreversible on any time scale
hat humans can imagine.”
All of the above are quotes from one person, Dr. James Hansen, in a single article he wrote–see URL
http://www.guardian.co.uk/commentisfree/2009/feb/15/james-hansen-power-plants-coal
I’d call some if not all of those statements “alarmist”. If they aren’t “alarmist”–that is, if there’s no alarm–what’s the rush to limit fossil fuel use?
Finally, as far as pejorative terms go, I’ll trade “alarmist” for “holocaust denier”, “flat earther”, “tobacco-lawyer”, “in the pocket of big oil”, “immoral”, and “criminal”, which are used by AGW supporters (but admittedly not Simon) to characterize AGW nonsupporters. The term “immoral” was used by Dr. Gro Harlem Brundtland when she told reporters “This discussion is behind us. It’s over. The diagnosis is clear, the science is unequivocal — it’s completely immoral, even to question now, on the basis of what we know, the reports that are out, to question the issue and to question whether we need to move forward at a much stronger pace as humankind to addres the issues. James Hansen labelled at least some AGW nonsupporters as “criminal” when he said:: “When you are in that kind of position, as the CEO of one the primary players who have been putting out misinformation even via organisations that affect what gets into school textbooks, then I think that’s a crime.”
Simon then criticized my knowledge of history. He wrote:
“You don’t know your history. Milankovitch theory was well-
supported by the 1970s ( the Vema 28-238 core and others
having provided good verification), and the search then was
for an explanation of how small solar variations could explain
the extent of the glacial cycles. Scientists were considering
positive feedbacks as an explanation in advance of
discovering the relationship between temperature and CO2.
When the Vostok cores were pulled up, by 1985, the correlation
was evident, but it was always seen in terms of feedback. Your
suggestion of an ‘adjustment’ in the argument is simply an
invention.
Simon is right, I don’t know the history of AGW theory very well; and undoubtedly, Simon’s description of some scientists was right on. But if Simon is trying to convince me that when Al Gore first presented his slide show, Al (and others like him) knew that the initial temperature rises were not CO2 induced and carefully mentioned as much every time he gave his presentation, I can’t, or more correctly, won’t believe it.
In response to my question: “So the AGW alarmists have increasing CO2 levels acting as both an originating and a feedback phenomenon. I’d like to know which if either is correct.” Sinom answered: “Both”. When I asked: “if both, then what stopped runaway global warming in the past?” Simon answered: “The temperature feedback is less than the input.”
That answer is confusing to me because I thought the AGW supporters agree that the temperature changes from a doubling of CO2 by itself is at most 1.2 degrees, but the “feedbacks” will amplify this change by at least three degrees and somewhere I’ve read by as much as seven degrees.” And since the temperature effect as a function of CO2 level is logarithmic, more of the temperature change will occur early in the doubling process rather than later. As such I don’t understand how Simon can answer: “The temperature feedback is less than the input.” If Simon wants to talk about absolute temperatures, not temperature change, then he has a point. But I thought AGW theory was best described in terms of changes to a nominal level. This is in part why I want to see a clear diagram of the system inputs, outputs, feed forward, and feedback mechanisms.
And for what it is worth, the stability of a linear, time-invariant system with feedbacks is defined by the location of the system’s “poles” not by the system’s input. [For discrete-time systems, any pole on or outside the unit circle means the system is unstable. For a continuous-time system, poles on the vertical axis or in the “right half-plane” make the system unstable.] In turn, the location of a system’s poles are a function of its feedback loops, not the system’s input. Even for a large input, the system output may initially be small compared to the input but over time the system output will grow without bound.
Then I asked “If the larger temperature deltas at the system output are “fed back” into the system input, why won’t they cause even larger temperature deltas at the system output.” Simon answered”
“They are not – at least, not fully. I don’t like the use of the
term ‘feedbacks’ in climate science since it gives rise to this
confusion, but I guess we’re stuck with it. Yes, CO2 induced
warming may give rise to further increase in CO2 concentration,
but is not likely to equal the ‘input’ (although some do consider
the danger of methane release from the permafrost/sea bed,
which I expect is what Hansen has in mind when he considers
the possibility of a runaway effect if we were to burn all fossil
fuels).
I agree with you that the use of the term “feedback” is confusing; but as far as I am aware (and I have already admitted that my history of AGW theory is weak) it was the AGW supporters that coined the term “feedback” for the phenomena that resulted in larger temperature increases that could be supported by the initial forcing. In my opinion, and I’m NOT an expert on AGW climatological models, the phenomena AGW supporters argue will lead to catastrophic global warming are more respresentative of “feed forward” effects than feedback effects. But even with that caveat, Simon’s answer confuses me. First he says “They are not – at least, not fully”–meaning the larger delta temperature changes at the system output are “not fully” fed back to the system input. By “not fully” does he mean the output temperatures are not fed back to the system input but to an intermediate point in the system; or does he mean only a portion of the output temperatures are fed back to the system input; or both? The lack of precision of his answer is one of the reasons I want to see of “circuit diagram” for climate model used by AGW supporters.
Then after answering “not fully”, Simon then mentions methane gas and opines that Dr. Hansen just might have had a “full feedback” in mind for methane gas. If someone can clarify what’s going on, I’d appreciated it.
Finally, when I mentioned that I’d like to see a circuit diagram of the AGW theory, Simon responded: “I’d recommend Chapter 8 of the AR4. It may not be quite in the form you want, but you can figure out answers to your questions” Simon was kind enough to give the URL
http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter8.pdf
for that document.
When I did a quick look (and I mean quick), although I saw a lot of “discussion”, I didn’t see anything that even remotely resembled a circuit diagram. I’ll take a closer look when I get the chance; but if someone could refer me to a page number or figure number where such a diagram can be found, I’d appreciate that, too.

^Chico: I believe O2 and N2 radiate at UV wavelengths, not IR, i.e., they are called IR-inactive.
Mark

Btw, Reed, there is at least one legitimate feedback that I can reasonably identify, though the tortured language used to define it, as well as the properties it is assigned, are a bit hard to swallow for anyone that has ever stepped foot in a system or control theory class.
Namely, raising the temperature of the oceans causes them to release more CO2 (or it decreases the net flux), which in turn adds to the greenhouse effect which raises the temperature of the oceans, etc. It seems somewhat like a single pole system with some delay (I don’t know what it is). By “partial feedback,” I would surmise that perhaps they assume some decay in the effect, which would imply a less than unity feedback path (after all the conversions), and hence a stable, lowpass system (there’s no apparent sign inversion, either, so the feedback term is positive). Since most of potential input frequencies likely have much greater periods than the delay element (just a guess), there’s some net gain associated with the process.
Some of the descriptions of how this behaves (the feedback “takes over” after some point, for example) have me about as confused as you seem to be.
Mark

In newspeak I write far from airstrip one on the outer borders of Oceania. With a bellyfeel for the blackwhite I must use crimestop and agree with BB that Co2 is an important GHG. There is no use in crimethink against a doublespeak concensus of science. We must be goodthinkers use duckspeek and appear fullwise and unbad to please the inner party.
Oceania ‘Tis for Thee.

After reading comments to the effect that “hot air can’t heat cold water”, garbled definitions of “relative humidity”, etc. I’m of the opinion that Al Gore’s Nobel Prize has festered some otherwise perfectly good brains.