Guest post by Reed Coray
The following example illustrates the issues I have with reasoning often used to argue that increasing the amount of CO2 in the Earth’s atmosphere will increase both the Earth’s surface temperature and the Earth’s atmosphere temperature. Immediately following is a direct quote from URL
http://www.school-for-champions.com/science/heat_transfer_earth.htm
“The present situation is that there has been an increase in infrared-absorbing gases in the atmosphere, such as carbon dioxide (CO2) and methane (CH4). Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere and spreading through convection currents. The average temperature of the atmosphere has increased 0.25 °C since 1980, mainly attributed to an increase in infrared-absorbing gases in the atmosphere.”
Although the above statement makes no direct reference to Earth surface temperature, I believe it carries the implication that greenhouse gases in the Earth’s atmosphere increase the Earth’s surface temperature.
I make two comments: the first is relevant only if the above implication is valid, the second is relevant independent of the validity of the implication. First, placing matter adjacent to a warm surface such that the matter is capable of absorbing/blocking radiation to space from the warm surface can lead to a decrease in the warm surface’s temperature. Second, increasing the amount of the absorbing/blocking matter can lower the temperature of the absorbing/blocking material.
Take for example an internal combustion engine whose metal surface is exposed to a vacuum. In addition to doing useful work, the engine produces thermal energy (heat). That thermal energy will produce a rise in the temperature of the engine’s surface such that in energy-rate equilibrium the rate energy is radiated to space from the engine’s surface is equal to the rate thermal energy is generated within the engine. By attaching radiating plates to the engine’s surface, some of the energy radiated to space from the engine’s original surface will be absorbed/blocked by the plates; but because thermal energy can be transferred from the engine to the plates via both radiation and conduction, the temperature of the engine’s original surface will be lowered. This is the principle of an air-cooled engine[1]: provide a means other than radiation of transferring heat from an engine to a large surface area from which heat can be removed via a combination of conduction, convection and radiation, and the engine’s surface temperature will be lowered.
If plates at a temperature lower than the original engine surface temperature are attached to the engine, it’s true that the temperature of the plates will increase to establish energy-rate equilibrium. Once energy-rate equilibrium is established, however, increasing the plate radiating area (adding additional matter that blocks more of the energy radiated from the original engine surface) will likely lower the plate temperature.
Thus, blocking the amount of surface radiation escaping to space does not necessarily increase the surface temperature; and increasing the amount of radiation blocking material does not necessarily increase the temperature of that material. In both cases (the Earth/Earth-atmosphere and the internal combustion engine in a vacuum), the heat eventually escapes to space–otherwise the temperature of the Earth’s surface and the engine would continue to rise indefinitely. The difference isn’t that the energy doesn’t eventually escape to space (it does in both cases), the difference is in the path the energy takes to reach space. The amount of generated thermal energy in conjunction with the path the thermal energy takes to get to space determines temperatures along the path; and adding more material may increase or decrease those temperatures. To say that “Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere…” by itself is unwarranted; because an equivalent statement for the case of adding extra plate material to the engine would be “Energy that would normally escape to space from an engine with small attached plates is absorbed by additional plate material, thus heating the plates…” For air-cooled engines, this statement is not true—otherwise the plate surface area of air-cooled engines would be as small as possible.
It’s fairly easy to visualize why (a) adding thermally radiating plates to an air-cooled engine might decrease the engine’s surface temperature, and (b) increasing the area of the radiating plates might decrease the plate temperature. It’s not so easy to visualize, and may not be true, why (a) adding greenhouse gases to the Earth’s atmosphere decreases the Earth’s surface temperature; and (b) increasing the amount of atmospheric greenhouse gases lowers the temperature of the Earth’s atmosphere. I now present one possible argument. I do not claim that the argument is valid for greenhouse gases in the Earth’s atmosphere, but I do claim that the argument might be valid, and can only be refuted by an analysis more detailed than simply claiming “Energy that would normally escape into space is absorbed by these molecules, thus heating the atmosphere.”
If we assume that (a) matter cannot leave the Earth/Earth-atmosphere system, and (b) non-greenhouse gases radiate negligible energy to space, then for a non-greenhouse gas atmosphere the only way thermal energy can leave the Earth/Earth-atmosphere system to space is via radiation from the surface of the Earth. The rate radiation leaves the surface is in part a function of both the area and temperature of the surface. For a greenhouse gas atmosphere, energy can leave the Earth/Earth-atmosphere system to space both via radiation from the Earth’s surface and radiation from greenhouse gases in the atmosphere. Suppose it is true that the density of greenhouse gases near the Earth’s surface is such that radiation emitted from low-altitude greenhouse gases does not directly escape to space, but is in part directed towards the Earth’s surface and in part absorbed by other atmospheric greenhouse gases. As the atmospheric greenhouse gas density decreases with increasing altitude, radiation emitted from high-altitude greenhouse gases can directly escape to space.
Now it’s not impossible that since (a) in addition to radiation, heat is transferred from the Earth’s surface to greenhouse gases via conduction, and (b) convection currents (i) circulate the heated greenhouse gases to higher altitudes where energy transfer to space can take place and (ii) return cooler greenhouse gases to the Earth’s surface, that the process of heat transfer away from the Earth’s surface via greenhouse gases is more efficient than simple radiation from the Earth’s surface. Many engines are cooled using this concept. Specifically, a coolant is brought into contact with a heated surface which raises the coolant’s temperature via conduction and radiation, and the coolant is moved to a location where thermal energy transfer away from the coolant to a heat sink is more efficient than direct thermal energy transfer from the heated surface to the heat sink.
One way to realize increased thermal transfer efficiency would be to use a coolant, such as greenhouse gases, that efficiently radiates energy in the IR band (i.e., radiates energy at temperatures around 500 K). Another way would be to spread the heated coolant over a large surface area. Since surface area increases with increasing altitude, thereby providing expanded “area” (in the case of a gas, expanded volume) from which radiation to space can occur, it’s not clear to me (one way or the other) that greenhouse gases won’t act as a “coolant” reducing both the temperatures of the Earth’s atmosphere and the Earth surface.
[1] It’s true that for most air-cooled engines the main transfer of heat from the engine plates is via a combination of (a) conduction of heat to the air near the plates, and (b) convection that replaces the warm air near the plates with cooler air. To aid this process, a fan is often employed, or the engine is located on a moving vehicle and the vehicle’s motion through an atmosphere provides the flow of air across the plates. Although conduction/convection may be the primary means of heat dissipation from the plates, radiative cooling also dissipates heat.
TA: “And 1 will end up radiating 4000 watts. Another geometrical progression, but now as 1 + 2 + 4 + 8 +.. (2^n) where 1 is the outer plane and, let’s say 8, is “the ground”.”
Sorta. Consider a radiating plate, as you had it, and two receiving plates with no distance between them. Assume some fraction of the radiation passes the prior plate but is absorbed by the second plate. What radiation is re-emitted from the latter plate in the sandwich is largely meaningless. When a photon is dumped it will either travel generally toward or away from the prior plate in the sandwich. And if it is toward the prior plate, reaches the prior plate, and is absorbed by the prior plate, then the process repeats. Just as you have it generally.
But place a gap, in a vacuum for convenience, between the plates of the sandwich. Such that a photon generally exiting one bulk and headed toward the other bulk cannot be absorbed by anything. Then the only thing that can or does change is the lateral displacement of a photon leaving one bulk to the other. The entire system is unchanged otherwise. However it’s meaningless so long as we’re positing infinite plates. Lateral displacement is of no interest as there is no worth worrying about where it gets off to as the plates are infinite, parallel, and uniformly irradiated.
Now make it concentric spheres radiated from a external point source. Now, given the geometry, the the lateral displacement matters greatly. For if the enclosing sphere dump a photon across the gap to the enclosed sphere then it is going to get itself off to a point on the enclosed sphere that receives less radiation; by a maniacal average. Nothing fancy about it at all.
Now add a third sphere, between the previous two, and with a gap on either side of it. Any back-radiation from the uppermost sphere will laterally transfer to a point on the sphere underneath it. And should any back-radiation be emitted from that, it will laterally transfer again. Again nothing fancy. But given the geometry, gaps, width and material of the plates, and a given temperature profile for each of then across their surface and depth: Then what are the odds that a given statistical photon, of a chosen wavelength, will exit the system the t time?
It’s really two questions: What are the odds that a given statistical photon will exit its bulk towards an enclosed sphere in t time? And what are the odds that it will exist its bulk towards an enclosing sphere and/or the universe in t time?
This all matters only for reducing your ‘2 in the limit’ value. Which is interesting and perhaps important to model. But it is a purely academic exercise, a ‘toy model’, in that there are numerous heterogenous layers, that are each hetergenous but considered to be homgenously mixed. They are gaseous, have convective currents, and their are no vacuum gaps. All except the lower most sphere, or course. The absorpta spectra are not continuous and is a non-linear relationship with temperature when measured as such. And the whole thing rotates with respect to the point source.
And clouds, of course.
You’re on the right track. But even to get the toy-model off the ground we have to acknowledge that while black-bodies are useful, we do not have one. That geometry matters a great deal. And that energy exchange models via statistical photons are not synonymous with ‘temperature’ as we measure it on airport tarmacs.
joeldshore: “What I was saying was that the statements by the APS and the textbooks represent …”
Apologies. So would your authority agree with the conditional: If the Rapture is tomorrow, then it would be dangerous not to be baptized today?
Reed Coray,
Thanks for a very interesting article!
Robert Austin says regarding CO2:
“…that control knob is logarithmic and there is little temperature to be gained in cranking it up…. This is why I can give some credence of up to about 1C warming for a doubling of CO2 but consider the concept of amplification by water vapour or other positive feedbacks to be bogus.”
Exactly. The planet is just not acting as if CO2 is controlling anything. It may cause a small amount of [entirely beneficial] warming. But with every passing day it becomes more obvious that the CO2=CAGW conjecture is nonsense. Scientific skeptics understand this, but the alarmist contingent is still stuck on stupid; CO2 is not a problem, it is a benefit. More is better.
I am surprised at the number of those posting comments that don’t seem to understand some of the basic physics behind the greenhouse effect. There is little argument among skeptics and alarmists who do understand the physics, concerning whether the greenhouse effect is real or not. The only big arguments I see are over the effect of doubling CO2 and how much of the recent CO2 increase is anthropogenic.
I think it would be of benefit to everyone if someone good at explaining physics to students were to submit an explanation, that Anthony can use as “The Greenhouse Effect” reference page here on “Watts Up With That”. This could be a starting point, that could be commented on and continually improved by the feedback provided by everyone else. The combined expertise of the physicists that post here, together with the questions and comments from those having trouble understanding the greenhouse effect, form a team that could do wonders toward developing a better text on the subject.
The whole idea of GHG “absorbing heat” is erroneous. CO2 absorbs a photon, goes into the “bending” mode of molecular vibration and almost immediately radiates the photon which it absorbed. It cannot give up any fraction of this energy; there is no state between this 667 wavenumber excited state and its vibrational ground state. It cannot “warm the air” The effect of this re-radiation of 15 micron IR is to take upward directed radiation from the surface of the earth and aim one half of it back to the earth;s surface. Same for any GHG. The downward re-radiated IR then becomes part of the surface radiation budget. At the “top” of the atmosphere, all of this must equal the solar radiation absorbed by the surface (average=~238W/sq. meter). Night sky radiance shows about 20% of IR that would otherwise go directly into space is backscattered back to the surface. Let f be the fraction of surface IR absorbed by the atmosphere (~65%) and bs = the fraction backscatterd. Then radiative eq. implies
238=I(earth)*f/2+(1-bs)(1-f)*I(earth) => I(earth)=393w/sq.meter~ 15.5C
I(earth)*f.2=>temp. ay tropopause=128W/sq. meter=>-55.3C
(1962 Standard Atmosphere values for surface and tropopause are obtained by f=.645 and bs=.195)
This gives correct values! Only derivation that does that I have seen. (Yes , it is mine)
Considering the proper physical mechanism gives right answer
(Tropopause height, wet and dry adiabatic lapse rate can be similarly calculated using conservation of energy)
@ur momisugly Richard111 says:
July 21, 2012 at 9:33 am
I have a copy on file. Send an email to supportATjoannenovaDOTcomDOTau and ask them to forward it on to me. I’ll send you the pdf
Alan D McIntire says: July 21, 2012 at 10:37 am
Alan wrote (bold text below):
“First, placing matter adjacent to a warm surface such that the matter is capable of absorbing/blocking radiation to space from the warm surface can lead to a decrease in the warm surface’s temperature.” It will always lead to an INCREASE in the surface’s temperatue..
(Emphasis mine)
It will? Take a sphere of radius 1 meter, place the sphere in cold space, put a constant thermal energy source symmetrically just below the sphere’s surface, wait for thermal energy rate equilibrium, and measure the surface temperature. Now surround the sphere with material identical to the material of the sphere. Wait for energy-rate equilibrium, and measure (a) the surface temperature of the expanded sphere and (b) the temperature of the sphere at its original radius. The surface temperature of the expanded sphere will be lower than the surface temperature of the original sphere because the area of radiation has been increased. With the same rate of input thermal energy, the increased area implies a reduced surface temperature at energy rate equilibrium. Now, if the material making up the original sphere (and the added material) is highly thermally conducting, the temperature at the radius of the original sphere will be governed primarily by the thermal conduction properties of the materal and can be made to be approximately the same as the temperature of the expanded sphere’s surface. Thus, it seems to me we can placing matter capable of absorbing/blocking radiation to space adjacent to a warm surface and the temperature of the “surface” at the original radius will be lowered relative to its original temperature in isolation.
And to the objection that with the expanded material the original surface doesn’t exist, I respond by saying don’t cover the entire surface of the original sphere. Leave a small area uncovered for a small height–i.e., leave a small cavity in the added material. Put a gas in the cavity. Now (a) we have a portion of the original surface, and (b) because the gas is material that is placed next to the original surface, I believe your claim implies that the area of the original surface exposed to the gas will be warmer than the original surface in isolation. I don’t believe it. Because the sphere is highly thermally conducting, I believe the exposed surface area will be much closer to the temperature of the sphere at nearby points, which can easily be made to be lower than the original sphere’s temperature in isolation.
Can GHGs in the atmosphere receive conducted energy from non GHGs, (I think this is how they form a LTE,local thermal equilibrium) and then radiate that energy away?
It the answer to this question is yes, then are not those CO2 molecules (the ones which receive conducted energy from non GHGs) accelerating the loss of energy to space, which, in the absence of GHGs, would not be able to leave the atmosphere?
John West says:
July 21, 2012 at 7:26 am
Fact: CO2 is a GHG.
Conjecture: Adding CO2 to the atmosphere will increase the temperature.
It seems pretty obvious, but is it true? Is it always true?
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John, it is much worse than that.
That “fact” is not a fact, it is a conjecture. And they change their narratives if necessary to obfuscate that. All what they have in the hand is the Tindall’s experiment, the rest is conjectures. They do not have any (not fake) experiment proving CO2 ability to warm the surface.
Pochas asks Eli
My house is insulated with an R value of 10. But I am a rugged individualist so I have no connection to electricity or source of fuel. I don’t even occupy the house. I Iive in a tent in the back yard. But I measure and record the temperature inside the housd every hour. At the end of the year I average all the readings. But an environmentalist has convinced me that if I remove all of the insulation the average temperature inside will go down, so I do. What do you think will happen to the average temperature?
Eli responds: since this is a normal house, sunlight will enter through the windows. The insulation will slow the flow of the energy deposited by the sunlight out of the house, thus the interior will heat, as in a car. If the insulation is removed (or the house is leaky), the temperature on the inside will be lower without insulation, but still higher than the outside average. Both convection and radiation work on temperature difference.
Dave (and others) talk about re-radiation by green house gases.
Eli responds: Thee is a relatively rapid transfer of vibrational to kinetic energy in ghg molecules that absorb photons so essentially all greenhouse gas molecules that absorb photons do not re-radiate the energy (the radiation rate is five to six orders of magnitude slower, so only one in a million will reradiate promptly. OTOH there will be some ghg molecules that are excited by other collisions, the proportion being controlled by the local temperature. Some more details
Reed writes
“First, any “slow down” in the rate the Earth emits energy to space must be transient–i.e., it can’t last forever.”
Damn right, and the way the Earth re-establishes equilibrium is by heating up, so that the emission from the top of the atmosphere matches the incoming.
cba accuses Eli of being a character in a childrens novel and throws much detail against the wall which really does not shift the argument much. cb, if you want detail go read the science of doom articles on the greenhouse effect that KR provided. The mechanism remains what the Bunny pointed to.
http://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/
joeldshore says: (July 21, 2012 at 2:56 pm)
Reed Coray says:
There is something important that you are missing here: The simple arguments that are presented to the public may be vast simplifications but they have underlying them much more complicated and detailed calculations that back up the basic conclusions. Your arguments on the other hand have nothing to back them up.
You seem to somehow be trying to say that because the scientists don’t present the public with thousands of lines of radiation code to explain the greenhouse effect but instead simple explanations, the simple explanations that you come up with that lead to very different conclusions are just as valid scientifically. I hope you can see the obvious flaw of such a notion.
No, I’m not saying and didn’t say any such thing. Nor did I “seem to somehow be trying to say…”. I mentioned at least twice that greenhouse gases might warm the Earth’s atmosphere. I just don’t know. I never said that the argument that greenhouse gases cool the atmosphere was scientifically valid. What I said was, the arguments presented in the referenced article (and many other places–see Eli Rabett’s comments on this post) imply conclusions for which counter examples can be constructed. Such arguments are at best incomplete; and if used in an attempt to convince the general public that societal changes having major impacts to mankind must be immediately implemented, then I say shame on the people making those arguments.
Here is a fairly accurate simulator you can run yourself the shows that if anything, without GHG the atmosphere would be warmer at altitude than at the surface.
ferdberple says:
July 22, 2012 at 12:28 am
New jar with updated source. Still seeing negative gradient. Which is interesting. One possible explantin is that GHG actually cools the atmosphere, not warms it. Which explains the hot thermosphere where GHG is rare.
Added time correction at boundaries and increased molecules to 2000. Made the speed and gravity controls exponential to increase their range. Decreased the low range and increased the high. Changed the grid which appears to smooth the motion.
http://www.filedropper.com/gas20120721
Also fixed a few bugs. On occasion the code was throwing NAN’s where there were lots of collisions
rgbatduke says:
July 21, 2012 at 8:08 am
I personally do think that it is quite reasonable to take moderate public measures to minimize the production of CO_2. … we need to try to establish a civilization that will last not just the next century but the next 10,000, or 100,000 years. …If we could only turn the public debate away from alarmism and panic (and the associated political grabs for money and power) to something like a…
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“We need to try to establish a civilization that will last not just the next century” ??? (shock) This is the most extreme example of alarmism I have ever seen.
And then later in the same comment you said “if we could only turn the public debate away from alarmism and panic“… Your “end of civilization” IS alarmism and panic.
TA. says (July 21, 2012 at 2:37 pm): [snip]
TA, your setup resembles Willis Eschenbach’s “Steel Greenhouse”, still one of my favorite articles on WUWT. If you haven’t already, check it out and see if it answers your questions:
http://wattsupwiththat.com/2009/11/17/the-steel-greenhouse/
I want to thank Anthony for allowing publication of this article. Until now, I assumed that all but a very small minority of WUWT visitors accepted the physics of the basic “greenhouse effect”. The comment thread suggests the number of “doubters” is higher than I thought. 🙁
Robert Austin says:
So the bulk non GHG’s which do not radiate appreciably at normal temperatures are the medium of storage and transport of the heat energy apprehended by the GHG’s,
About six percent of all CO2 at STP is vibrationally excited by the local thermodynamic equilibrium (2 fold degenerate, ~700 cm-1 vibrational energy, and 300K is ~200 cm-1), so essentially 6% is always ready to radiate, of course which molecules are excited is a constantly changing dance, but the amount of emission measured at various altitudes is in accord with this BOE,
I’m not sure you’re right about this.
A larger sphere has more surface area than a smaller sphere.
An earth without any GHGs represents a warm sphere the size of the earth which is radiating IR into space.
Adding GHG’s to the earth creates a larger warm sphere (the earth plus its atmosphere) radiating IR into space. Hence, “the surface area available to radiate the heat away” is increased.
The Sun is radiating a form of energy that has the ability to penetrate the earth’s atmosphere. Upon hitting the top of the surface this energy interacts with the surface atom clusters or molecules. The electrons in the said atoms increase their speed resulting in increased molecular friction. A product of friction is always what we call “Heat”.
Therefore heat is a product of energy-use, it can no more be emitted as radiation than speed can.
Remember radiation cannot be seen by the human eye. Nor can it be “seen” by any modern derivative of the “Thermopile”. All that can be “seen” is the source of radiation. The heat-source can be seen as light. Radiation, at certain wave-lengths, from the Sun only turns into “Light” upon interaction with the atmosphere. – Once again read Tyndall and Fourier.
By the way, sarcasm becomes no-one.
Perhaps not, but Adam Sandler fans will recognize the following:
Mr. Madison, what you’ve just said … is one of the most insanely idiotic things I have ever heard. At no point in your rambling, incoherent response were you even close to anything that could be considered a rational thought. Everyone in this room is now dumber for having listened to it. I award you no points, and may God have mercy on your soul.
Radiation cannot be seen by the human eye? Sheesh. Radiation from the sun only turns into light in the atmosphere? For the love of God, man, go steal a physics book and read it — or visit the ones I’ve put on the web for free — before ever opening your mouth in a public forum discussing it again.
rgb
davidmhoffer says on July 21, 2012 at 3:33 pm:
“I used to wonder how people could wind up believing in witchcraft, blood letting, ghosts, goblins, and other manner of superstitious nonsense that could be so easily debunked by the slightest investigation of the facts combined with a bit of logic. Reading this thread I realise people still cling to superstitious nonsense in the face of facts and logic, all that has changed is the nature of the superstitions.”
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Dear davidmhoffer.
Please tell me why does CO2 absorb LWIR radiation from the ground but not from other GHGs? – You see if your nice and neat theory is correct there can be no end to warming by GHGs never mind how few they are.
I know it is fashionable to adjust the GHG theory as you go along, i.e. it’s not a greenhouse – it’s a blanket. – GHGs don’t heat the surface it just retains the heat that was here yesterday. – Or, the best and most convincing one of them all: I’m, or we are, not doubting that CO2 has a positive radiative heating effect in our atmosphere, due to LWIR re-radiation, that is well established by science.”
Well established by science? – Who’s science? – a science that turns a blind eye to “conduction” rejects convection and still clings to the theory that beauty is a thing that can be radiated across the room”
Keep your witchcraft, blood letting, ghosts and goblins in your own poxy cupboard oh righteous one.
davidmhoffer says:
July 21, 2012 at 9:47 am
The notion that GHG’s serve to cool the earth is absurd. The earth is far warmer than the moon, which gets the exact same amount of insolation, but has no atmosphere.
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Unfortunately you have committed a logical fallacy. Even if you had made a correct comparison “with atmosphere – without atmosphere” (the other conditions being equal), you could have only conclude something on atmosphere, no more than that. You comparison however does not prove anything about any specific part of the atmosphere.
rgbatduke says on July 21, 2012 at 4:55 pm:
“Perhaps not, but Adam Sandler fans will recognize the following:
Mr. Madison, what you’ve just said … is one of the most insanely idiotic things I have ever heard. “
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So, you call on Adam Sandler fans to recognize something somebody else said.
When are you warmists and Co2 fans going to say things like: “I know, because I have done the necessary experiments?” – And when are you going to stop hiding behind the “somebody else said” quotations?
You AGW lot have got no personal experience of science, no personal opinions and no personalities. STOP QUOTING OTHER PEOPLE, LET US HEAR WHAT YOU HAVE GOT TO CONTRIBUTE!
I may admit I may not always be right but sure as hell you lot do not even know the people you are quoting.
rgbatduke says:
July 21, 2012 at 11:31 am
GHGs do not warm anything. They slow the cooling of something being actively warmed elsewhere, by other means, and just like the insulation in your walls makes you house warmer given a furnace inside than it otherwise would be, the Earth end up being warmer with them than it would be without them.
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I am very surprised, I thought the “insulation” argument was dead, but no…
Apparently your GHGs do not work like a house nor like a greenhouse. Even Wikipedia has abandoned this narrative recently.
An enclosed space stays warmer only when being heated and second because the warmer air can not escape and be replaced by colder air from the outside. If you mean it is because of “back radiation”, then you need to prove it, and you know very well that neither you nor other warmists have ever presented a real experimental proof. All what we have seen are either fakes or unrelated stuff or “thought experiments”.
You might get a better example than your engine block for heat transfer problems from this document. It’s a very interesting read.
http://www.projectrho.com/public_html/rocket/supplement/Presby_Engineer_Degree_Thesis.pdf
“We need to try to establish a civilization that will last not just the next century” ??? (shock) This is the most extreme example of alarmism I have ever seen.
And then later in the same comment you said “if we could only turn the public debate away from alarmism and panic“… Your “end of civilization” IS alarmism and panic.
Piffle. Civilization requires energy. Lots of it. In fact, a direct measure of the growth of civilization — perhaps the direct measure of the growth of civilization — is the per-capita availability of energy, its cost per capita. If energy is abundant enough, we can desalinate the oceans and make the deserts bloom. If energy is abundant enough, the standard of living of every person in the world can be increased to that of today’s wealthiest individuals and beyond, just as today’s lower-middle-class first world citizens are wealthier in all the ways that matter than the kings of the world a mere century or two ago. Energy poverty is the worst poverty of all, a kind of poverty from which there is no escape.
I’m not talking about things in my own lifetime — I’ll be dead long before any of these things matter to me or to my own children or possibly even my grandchildren (who are just now starting to be born). But fossil fuels were and are never going to be more than a stopgap, a stepping stone, a boosting point that we can use to uplift human civilization to a state where energy scarcity isn’t the fundamental scarcity, the one that dominates and limits all other scarcities. You can mine coal and oil and natural gas all you want and — assuming that you are correct and CO_2 truly isn’t any sort of risk whatsoever — you will still run into issues of scarcity and political and economic control that make them undesirable fuels to use in the very long run.
We once heated our homes with wood. Wood seemed inexhaustible — until we cut down all the trees from from measurable fractions of the surface area of the world to burn for fuel and were still hungry for more. Coal then seemed inexhaustible — and to some extent still does — if one neglects the risk and hidden costs of mining it. Oil was plentiful, but oil fields proved finite and ever more expensive to find and exploit, and our thirst for it is inexhaustible because everybody wants to drive cars — not just in the US, everybody in the world, all 7 billion of them (including the children too young to drive). Everybody wants their own car, and fuel for their car so cheap that they can go anywhere they like. There are no limits on our desire for cheap energy and our ability to put that energy to work to make our lives better.
I (as a physicist) can see precisely two energy resources capable of sustaining the human race ‘indefinitely’ — long enough that we will have recognizably evolved long before we run out. One is solar energy. The other is thermonuclear fusion. So both are thermonuclear fusion. Geothermal and hydroelectric are distant runners up — inexhaustible in reasonable time frames, but also scarce and far from ubiquitous. Indeed, solar isn’t truly ubiquitous, although we may be able to solve transport problems — to give us total control, we have to master fusion.
I’m not saying these things to institute a panic. How could they? I’m talking about things that will be necessary over centuries, that I think we should very deliberately start working on now. I might say “I think we should work on colonizing the planets” and it is hard to see how that would be causing a panic either. Or that I think it would be truly nifty if we work on computers that interface directly with the human brain and can understand speech and thought. Does that cause you to panic and run screaming that yes we should, or no we shouldn’t? No, it opens up a dialogue where people can contribute and agree or disagree.
So let me state again, in terms that are clear enough not to be misunderstood. I think — that is to say in my opinion — a worthy goal for the human race in the 21st century, that is to say, now, is to pursue two goals before all others. One is freedom from religion. The other is complete energy independence, the establishment of a steady state civilization that does not rely on a fundamentally scarce resource that more or less guarantees a kind of creeping erosion of wealth as it is slowly exhausted. I’ll go one step further and note that the only possible reasonable basis for currency that is somehow more than empty promises and an act of faith is to have a currency that is backed by energy, as the fundamental scarcity. Only such a currency is proof against inflation.
We can debate the need to be free from religion and all of its mythologies and absurdities another time, but I think that it is difficult to argue that your life doesn’t beat time to the tune of energy prices in countless ways, and price is always at some point an expression of scarcity and demand.
rgb