Frequently Made Errors in Climate Science – The Greenhouse Effect
Table of Contents
1.What is meant by “The Greenhouse Effect”?
Many gases, such as H2O, CO2, CH4, are transparent to visible light but absorb and emit parts of the infrared spectrum. Most of the visible light reaching the Earth’s surface gets re-emitted, eventually, as infrared. Media that pass visible light through but block infrared can act as heat traps.
2. Real Greenhouses
X “The Greenhouse Effect does not exist; Prof R.W.Wood proved it in 1909.”
Most glass also blocks parts of the infrared band. It was widely believed that this was primarily responsible for the effectiveness of greenhouses.
Prof. Wood suspected that blocking convection was the primary mechanism, so set up a simple experiment to test this. There are a number of weaknesses in the experiment, but the essential conclusion is correct: real greenhouses work primarily by blocking convection.
✓ “Whether or not the Greenhouse Effect exists, it is not the main way real greenhouses work”
However, this just means that the term ‘greenhouse effect’ may be misleading. Wood’s result says nothing about how the atmosphere works.
3. Black Body Earth
If we treat the Earth as emitting and absorbing radiation as a “black body”, ignoring the atmosphere, and treating incoming light as spread evenly over the whole Earth’s surface all the time, we can calculate the equilibrium temperature as -18C. At that temperature, black body radiation would balance insolation.
Adding a non-greenhouse atmosphere, e.g. pure nitrogen doesn’t change this. The atmosphere would take no part in the energy balance. By conduction, it would come to match the surface temperature of the Earth, throughout its depth.
Note:
- With a non-greenhouse atmosphere but now allowing the realities of a rotating sphere, convection would boost the upper atmosphere to something approaching the temperature of the hottest spot on the surface. The surface layer of the atmosphere would be a little cooler by virtue of conduction back to the cooler surface regions.)
- The non-greenhouse atmosphere may also result in some attenuation through Rayleigh scattering. The nitrogen in Earth’s atmosphere may scatter about 4% of light power back into space, taking the temperature down by maybe 3K.
4. The Troposphere
The atmosphere has many layers, featuring quite different processes and temperature profiles.
The atmospheric convection with which we’re familiar only operates up to the tropopause, the top of the troposphere – the band where weather happens. Beyond that, temperature inversions inhibit convection.
X “The ‘greenhouse gases’ are a net coolant since convection carries the heat through the troposphere, past 80% of them. They then block reradiation back to the surface.”
It’s the 20% above the tropopause that matters. This makes the tropopause warmer and/or higher. Since convection is limited by the lapse rate, a higher or warmer tropopause leads to a correspondingly warmer surface.
The existence of this “tropospheric hotspot” is considered a fingerprint of Global Warming.
5. Temperature and Pressure
X “It’s hotter at lower altitudes because it’s at a higher pressure, and compressing a gas heats it”
Compressing a gas heats it, but won’t keep it hot. If the atmosphere were just a static layer of gases, only heated or cooled by conduction, it would all come to the same temperature.
6. The Lapse Rate
X “It’s hotter at lower altitudes because if air rises it expands and cools”
This only explains why convection cannot bring the troposphere to a uniform temperature. It does not explain why there should be a temperature difference in the first place.
Since conduction is not limited by the pressure gradient, there must be an active process producing the temperature gradient. This process is the heating of the Earth’s surface by the sun.
The full story of energy transfers is quite complex. See Trenberth and Kiehl, 1997, Fig 7. Omitting all the absorptions and reradiations:
- The Sun warms the Earth’s surface
- The heat energy is transferred back to the air in the troposphere by a mix of conduction, convection and radiation. Overall, 60% makes it up through the troposphere at least partly by convection, 40% by radiation only.
- Convection’s ability to carry up the heat is limited because of the pressure gradient: rising air expands and cools. The resulting temperature gradient is known as the Lapse Rate
- The troposphere is the layer in which convection can operate. At the top (the tropopause), the temperature gradient is insufficient.
X “We can calculate the surface temperature from the height of the tropopause, the temperature there and the lapse rate. This fixes the surface temperature.”
That has causality backward.
✓ If the mean surface temperature changes, the height of the tropopause will change.
7. Greenhouse Gases
X “There’s nothing special about CO2. All gases can absorb heat”
All gases can conduct heat, but the ability of a molecular species to absorb and emit radiation depends on the intervals in its internal energy states and the polarity of its structure.
If vibration of the atoms in a molecule does not involve a net oscillation of electric field then that vibration cannot absorb or emit electromagnetic radiation. Diatomic gases like N2 and O2 are non-polar (or”homo-polar”). A vibration in the bond between the atoms does not result in any net movement of charge. Other energy levels of those molecules do not have the right intervals to interact with light in either the visible or infrared bands, so are completely transparent to both. Only much higher energies, sufficient to ionize the gases, would be strongly absorbed.
Both water and CO2 are hetero-polar, so can act as dipoles. Some vibrations involve a negatively charged atom group moving one way while a positively charged group moves the other. This net oscillation of charge allows them to interact with radiation at certain frequencies.
X “CO2 is insignificant compared with H2O as a greenhouse gas”
H2O, CO2, CH4 and many others can absorb/emit in parts of the infrared. None of them do so in the entire infrared band. Increasing the level of relatively rare greenhouse gas has more effect than increasing the level of a more common species.
8. Forcings and feedbacks
Climate scientists distinguish factors affecting global temperature as either forcings or feedbacks.
X “Atmospheric H2O is a forcing that overwhelms CO2”
A feedback is a variable which both affects temperature and is affected by temperature. Pure feedback would be a variable entirely controlled by temperature.
These can be further divided into negative and positive feedbacks. This list is by no means exhaustive.
- A few positive feedbacks
- Atmospheric H2O: the warmer the atmosphere, the more water vapor it will hold.
- Polar albedo: as ice caps melt, less incoming light is reflected straight back through the atmosphere.
- The warming of soils and oceans can lead to the release of CO2.
- A negative feedback
- The hotter the Earth’s surface, the more infrared it emits
Note: If something is a negative feedback it acts to dampen change; it cannot make the change go in reverse. That said, delayed feedback can lead to cyclic and chaotic behaviours.
A pure forcing is a variable which affects temperature but is not affected by it. Radiative output from the Sun clearly fits that description.
More loosely, a variable tends to be called a feedback if it is primarily controlled by temperature, and forcing if primarily controlled by other factors. On that basis, anthropogenic CO2 is forcing, but H2O is a feedback.
✓ Anthropogenic CO2 is a significant force because its effect is amplified by positive feedbacks, such as water vapor.
9. The Greenhouse Effect is Logarithmic, roughly
“The light passing through a filter should fall as the negative exponential of the optical thickness, so why is the effect logarithmic?”
“Solar Spectrum”. Licensed under CC BY-SA 3.0 via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Solar_Spectrum.png#/media/File:Solar_Spectrum.png; but note the 5250C is incorrect, it is closer to 5777K.
The diagram shows the absorption bands (yellow) for incoming radiation, and the same applies to outgoing. It shows that for most of the width of an H2O or CO2 band, absorption is already substantial.
The quantum basis for specific bands suggests, at first sight, that the wavelengths should be quite precise. However, some subtler processes spread the bands. In particular, the Doppler effect means that molecules moving towards the radiation absorb at a shorter wavelength, while those moving away absorb at a longer.
The primary consequence of adding more of an already abundant gas is to increase the number of molecules at the most extreme speeds relative to the radiation. This increases absorption at the edges of the band, broadening the band slightly. It is this that grows logarithmically with the prevalence of the gas.
“How can it be logarithmic? That would mean adding the first little bit of a new gas would have an infinite effect.”
The logarithmic relationship would not apply for a rarer gas that is still well short of full absorption in the center of its bands. Likewise, it breaks down when bands broaden so much that they overlap.
Masters in Mathematics. Interests: climate change & renewable energy; travel; cycling, bushwalking; mathematical puzzles and paradoxes, Azed crosswords, bridge
[QUOTE="BillyT, post: 5328816, member: 536963"]I think that is miss leading. Even if the atmosphere were argon, the sky would still be blue.[/QUOTE]Hi BillyT:I confess that I am confused by your comment.I don't understand why you mention argon. As I understand it, there is much much less argon in Earth's atmosphere than nitrogen. Even if, as you say, an argon atmosphere would also appear blue, am I wrong that the blue sky we see are mostly the blue photons from the sun that that been scattered by nitrogen? If so, why do we see blue photons from all directions in the sky?I also do not understand your discussion of cubes. Are you saying that since 1/5 of the atmosphere is oxygen, that it also scatters blue photons, and 1/5 of the photons we see in the blue sky are scattered by oxygen rather than nitrogen?Regards,Buzz
[QUOTE="mheslep, post: 5594367, member: 70823"]Yes. At the surface, the outgoing long wave must be represent one or the other, escaping long wave or atmospheric heat gain. Conservation of energy.[/QUOTE]Thanks for the reply,Sorry, but to clarify, do you agree with the diagram in vacuo potentials shown as massive opposing fluxes, when the surface total radiative losses are much smaller?
[QUOTE="Geoffw, post: 5594103, member: 606206"]Is this thread still active?I believe the Trenberth diagram mentioned here is misleading. The massive opposing long wave fluxes are in vacuo radiative potentials and do not represent surface losses or atmospheric gains by radiation.Any comments?[/QUOTE]Yes. At the surface, the outgoing long wave must be represent one or the other, escaping long wave or atmospheric heat gain. Conservation of energy.
Is this thread still active?I believe the Trenberth diagram mentioned here is misleading. The massive opposing long wave fluxes are in vacuo radiative potentials and do not represent surface losses or atmospheric gains by radiation. Any comments?
Thread re-opened, after a massive cleanup. Let me know if it looks disjointed.
[QUOTE="haruspex, post: 5519760, member: 334404"]Because that is what determines Earth's radiative emissions and average temperature. A patch of ground at the equator at midday does not instantly heat up to the temperature required to emit 1370W/m[SUP]2[/SUP] (about 500K).[/QUOTE]No, no. What determines surface temp, and all other temps in the system, is ABSORBED intensity/m^2 and that is transformed into heat(temperature) in the radiated body and averaged as emitted intensity in double the surface area.Temperature is determined by the source of radiation, everywhere, in relation to mass and emissivity of that mass. The heated body does not have any influence over the source. It´s temperature, when source is external, is DETERMINED by absorption of the source radiative transfer, and determines only it´s emissions.
Closed pending moderation.
[QUOTE="haruspex, post: 5519760, member: 334404"]But that is irrelevant to the point being discussed at the time. You were comparing with the 1370 that arrives at the Earth's top of atmosphere from the sun. What is absorbed at ground level will obviously be less.Because that is what determines Earth's radiative emissions and average temperature. A patch of ground at the equator at midday does not instantly heat up to the temperature required to emit 1370W/m[SUP]2[/SUP] (about 500K).[/QUOTE]It´s all thermic radiation, how much that is absorbed/m^2 without gas and water interferring is not easy to know. But we know that moon is above 100C without an atmosphere, and an average including dark side that is cooling to space is not interesting for intensity reached from absorbed/m^2, it is interesting in relation to cooling by total emitted/m^2.
[QUOTE="Bandersnatch, post: 5519754, member: 399360"]Does your solar panel collect 1000W when you lay it flat on the Antarctic or during the night? The infographic shows global energy balance, not energy incident on a solar panel angled perpendicular to solar rays at noon![/QUOTE]No, it shows an energy budget, with sums of energy received in total over timer, wrongfully averaged as effect, wich is indenpendent of time as W/m^2. The panel gives about 700 to 1400 over the half sphere, When we want temperature we need effect, and effect is W/m^2 of irradiated area. Not the area that is not irradiated.
[QUOTE="haruspex, post: 5519703, member: 334404"]That is merely your opinion. It is unsupported by the facts. Do the math. A black body surface at -18C emits 343 W/m[SUP]2[/SUP], as much as the average reaching Earth's surface from the Sun. If 'empty' space were at 130K say, instead of 4K, it would add 20W/m[SUP]2[/SUP] (I think that's about right), which would be a significant addition.Of course it must be.That is merely your opinion. It is unsupported by the facts.[/QUOTE]So measurements is to be ignored because greenhouse theory says so?A measured amount of 1000W in an irradiated m^2 is not relevant for the transfer rate of heat from the sun?
[QUOTE="D H, post: 5518641, member: 42688"]That is incorrect. Without an atmosphere, the Earth's surface temperature would be below freezing. The incoming solar radiation is the solar constant, 1365.2 W/m[sup]2[/sup], divided by 4, or 341.3 W/m[sup]2[/sup]. You apparently forgot to divide by 4. The reason you need to divide by 4 is because the Earth's cross section to incoming solar radiation is that of a circle with a radius equal to that of the Earth, or [itex]pi R^2[/itex]. The Earth's surface area is that of a sphere with a radius equal to that of the Earth, or [itex]4pi R^2[/itex].[/QUOTE]But measurements show between near 700W and up to almost 1370W, from poles to sahara and similar areas, and we measure 1370W at TOA. Without an atmosphere we would have that at the surface.The whole surface area of the sphere is not irradiated, so why do you average over that?That includes "not heated" in a calculation of "heated". [QUOTE]Some of that incoming radiation will be reflected away. Assuming an albedo of 12.5% (the average albedo of land and ocean), only 298.6 W/m[sup]2[/sup] will go into heating the Earth. That yields a blackbody temperature of 269.3 kelvins. Assuming an albedo of 30% (the albedo with clouds), the blackbody temperature drops to 254.7 kelvins. The world would be an inhospitable place were it not for the greenhouse effect.[/QUOTE]So… measurements in reality is wrong when they don´t agree with your theory? It does´nt matter that we can measure the rate of heat transfer from the sun, because you calculate heat transfer with not heated surface area?Albedo can be ignored until we clear out the difference in your numbers to real time observations.[QUOTE]Instead of complaining, you should try to understand that diagram. It is fundamentally correct.[/QUOTE]A radiative balance that is very far from measured values in reality should be questioned strongly. If we have measurements we should use them and not a much lower value that is not measured anywhere.[QUOTE]We can be pretty sure it does.[/QUOTE]You are arguing that laws of nature does´nt apply here, are you aware of that?The atmosphere does not have a temperature of intensity enough to emit 333W. That nothing but a lie as we know from measurements that in reality it is at average 250K, in its warmest part![QUOTE]You have been making a number of false claims. Please read the rules that pertain to climate change.[/QUOTE]Which false claim? It is you that is saying that the atmosphere is radiating with an intensity of 276K, in only one direction at 1m^2 surface.That would take an average of 276K at least from surface to tropopause. And since we know tropopause temperature at about 220K which is 132W/m^2, we would need 310K as the hottest layer of atmosphere, as averaged over surface. Thats 22K hotter than average surface temp. For an atmosphere radiating in 1m^2, but it is radiating in 2m^2.
[QUOTE="Reality Is Fake, post: 5519749, member: 598755"]shows 161W absorbed from insolation.[/QUOTE]But that is irrelevant to the point being discussed at the time. You were comparing with the 1370 that arrives at the Earth's top of atmosphere from the sun. What is absorbed at ground level will obviously be less.[QUOTE="Reality Is Fake, post: 5519749, member: 598755"]why use 343W which would represent a long timespan average[/QUOTE]Because that is what determines Earth's radiative emissions and average temperature. A patch of ground at the equator at midday does not instantly heat up to the temperature required to emit 1370W/m[SUP]2[/SUP] (about 500K).
[QUOTE="mheslep, post: 5518501, member: 70823"]Yes CO2 molecules radiate per Stephan-Boltzman law based on their own temperature like everything else, but the scattering of IR is a different phenomenon and is independent of the temperature of the gas. Think IR "mirror", though with an arbitrary angle of reflection. Yes mirrors have their own blackbody temperature as any IR thermometer will confirm, but this has nothing to do with the ongoing reflection of light, and changing the temperature of the mirror won't change its reflective properties.http://scied.ucar.edu/carbon-dioxide-absorbs-and-re-emits-infrared-radiation[/QUOTE]And again we get problems from the use of metaphorical comparisons. Reflection is very different to absorbed energy that is re-emittid to the whole surrounding as a result of internal intensity.The co2 shows absorbing by decreasing emitted spectral intensity, that means lower temperature. It absorbs the most intense spectral fraction at a spectral intensity in emitted radiation of about 220K. It absorbs high intensity and emits it with low intensity. That means that it needs more energy to emit the same intensity as the surface emits.
[QUOTE="Reality Is Fake, post: 5519749, member: 598755"]It shows 161W absorbed from insolation. We can measure suns irradiative intensity to 1000W in large parts.[/QUOTE]Does your solar panel collect 1000W when you lay it flat on the Antarctic or during the night? The infographic shows global energy balance, not energy incident on a solar panel angled perpendicular to solar rays at noon!
[QUOTE="haruspex, post: 5518634, member: 334404"]I don't know where you got 161 from.[/QUOTE]It shows 161W absorbed from insolation. We can measure suns irradiative intensity to 1000W in large parts. I think solar cells are calibrated to around that amount. And they don`t absorb longwave radiation as a source of energy.[QUOTE]The diagram Bandersnatch posted has 343 W/m[SUP]2[/SUP].[/QUOTE]Not at the surface. And why use 343W which would represent a long timespan average when you calculate an intensity in a state. 343W is the effect calculated from a temperature and temperature is measured intensity. Effect/m^2 as a value of radiating intensity is a dimensionless expression describing energycontent in matter.It is fundamentally wrong to use an average derived from energy received over time per total area, when analyzing the earths exchange of energy with the sun when it´s heated only at half the area that it uses to transfer heat, and temperature is something that describes intensity independent of time.Temperature of earth surface is a state that is a product of the immediate relations to the surroundings, it is totally dependant on the constant feed of energy from the sun at any point in time. Temperature of the surface does never increase without suns radiation. The only thing raising temperature is insolation. Not matter.[QUOTE]The flux density from the Sun at Earth's radius is 1370. This is captured by the Earth over a radius R[SUB]E[/SUB], i.e. over a disc, so area πR[SUB]E[/SUB][SUP]2[/SUP]. If we pretend this is uniformly distributed over Earth's surface, 4πR[SUB]E[/SUB][SUP]2[/SUP], that's 343W/m[SUP]2[/SUP].Allowing for non-uniform distribution puts the average temperature down a bit.[/QUOTE]And without an atmosphere 1370W would irradiate every m^2 of irradiated surface area. Now, with an atmosphere we can measure around 1000W/m^2.When calculating absorbed intensity of radiation at the surface, the intensity that is the cause of surface temperature in a heat transfer and is directly proportional to intensity emitted, what use do we have of an average?Why would we calculate emitted intensity which is equal to surface temperature, with surface area that is not heated and only is cooling?We have measured values of absorbed intensity thats fits emitted intensity, and we have measurements showing how low intensity the atmosphere reaches. We find the balance from absorbed intensity/m^2 and that is transformed into an emitted intensity in double the surface area. The atmosphere is irradiated at same surface area that emitted from earth surface, It reaches an intensity lower than the surface as it is low in density and distributes all absorbed energy in all its volume from any surface point. Average of emitted intensity is a correct value of average cooling of 1m^2 from absorbed intensity from 2m^2.That puts the balance over heavily to cooling ability in relation to heat absorption ability.The number 343W belongs in an energybudget that describes energy use over time in the system, and should be accompanied by a unit of time, while radiative balance which is what defines temperature, uses W/m^2 or simply W for realtime state.Using 343W in radiative balance calculation or energy balance will give a flawed model for heating and cooling, implying that there is a sensitive balance easily moved. Earth is cooled at double the efficiency it is heated, as all absorbed heat of 1m^2 is emitted from 2m^2. The cooling mass of solid planet is double the heated mass of solid planet.Why use a value of not heated mass to calculate the radiative cooling resulting from heated mass?The heat transfer that we observe happens at a rate of about 1000W, not 343W, and the cooling at around 350W as a result of poor emissivity of the surface, and the atmosphere emissivity is causing more loss in intensity radiating at an intensity of about 220W in average below the tropopause. To raise surface intensity it must have higher intensity, above 350W/m^2, emitted in both directions from 2 m^2, as it emits only half of absorbed energy towards the surface.According to the colorful arrows and very unrealistic numbers displayed as "energy budget" using energy absorbed as a function of time as the value of realtime intensity in units/m^2, we can see that an absorbed amount of 343 at the TOA is transformed into total ~430W in the atmosphere that radiates a much larger part to earth than space. There is no way to increase the amount of energy in the system from 343 to 430 total just by an absorbing gasvolume between the source and the surface. The atmosphere is absorbing an amount of 430W/m^2 from 343W/m^2 and radiates 430W/2m^2=860W/m^2 since it is claimed to radiate in two directions[/QUOTE]
[QUOTE="Reality Is Fake, post: 5519676, member: 598755"]sun is the only relevant source of radiation in the area.[/QUOTE]That is merely your opinion. It is unsupported by the facts. Do the math. A black body surface at -18C emits 343 W/m[SUP]2[/SUP], as much as the average reaching Earth's surface from the Sun. If 'empty' space were at 130K say, instead of 4K, it would add 20W/m[SUP]2[/SUP] (I think that's about right), which would be a significant addition.[QUOTE="Reality Is Fake, post: 5519676, member: 598755"]maybe it is absorbed.[/QUOTE]Of course it must be.[QUOTE="Reality Is Fake, post: 5519676, member: 598755"]it is not having any measurable effect on intensity in the hot body.[/QUOTE]That is merely your opinion. It is unsupported by the facts.
[QUOTE="haruspex, post: 5518491, member: 334404"]By what magic would the Earth's surface absorb emissions from the sun but from no other emitter?[/QUOTE]By the magic that sun is the only relevant source of radiation in the area.No other radiating body in the surroundings or in contact with the planet surface has an intensity that can have an effect that raise earth´s radiating intensity.[QUOTE]Simple thought experiment: two black bodies in close proximity at different temperatures. The cooler body emits radiation as per S-B law. Some of this is in the direction of the hotter body. What, in your view, happens to that radiation?[/QUOTE]I´m not sure, and as far as I know noone is. The common description is that radiation at the scale of photons reach the hotter surface as a photon is not restricted to net flux direction, and maybe it is absorbed. What we can measure in the states of the two bodies is very clear and consistent relative development, that tells us that no matter what happens to photons emitted in direction towards the hot body from the cool body, it is not having any measurable effect on intensity in the hot body.We can confirm by observation that cold photons absorbed in a hot surface is an unmeasurable totally insignificant theoretical process, and we must not include it when we calculate heat transfer at all. We know for sure that it does not raise temperature, all observations in real processes of all kinds of heat transfer shows that cold photons has a nonexistant effect on a warm body.
[QUOTE="rbelli1, post: 5518119, member: 315621"]The ammonia is irrelevant to the fact of cooling. The system would allow cooling as a simple block of metal. The ammonia just speeds the transfer of heat.[/QUOTE]That is precisely my argument concerning the G-H hypothesis, The atmosphere speeds Heat transfer up from surface to space, by adding a radiating volume and transfer of heated mass from irradiated parts to the cooling parts, and blocks it from sun to surface. That means that it regulates the amount of irradiated energy by cutting off the most high frequent wavelenghts and absorb parts in the spectrum at several other wavelenghts. On top of that, it reflects others like white in clouds.Some good chunks in solar spectrum are heating the volume, atmosphere, and lets earth radiate at cooler temps as well as shielding it. That makes the atmosphere a limiting effect on the surface temp from insolation. A limiting effect on thermic radiation.Is it reasonable that a dampening structure in a heat exchange is increasing intensity in the heated body?Is it probable that a property of the surface of a radiating body that decrease intensity in absorbed high thermic radiation, has an opposite effect in low intensity thermic radiation?Can an ice cold gasskin that gets all it´s heat from the sun, mainly absorbed and emitted insolation from the surface, perform work on same surface by receiving energy in heat transfer and reaching a much lower intensity state. The atmosphere loses energy that is absorbed from OLR at any measured point above the surface boundary. Temperature=intensity, is massively decreasing with distance as radiation interacts with it. That is very strong dampening of radiation, and that correlates with cooling – low effiancy through lossy properties like lacking heat capacity. The atmosphere is really bad at absorbing thermic radiation in relation to the surface.When a radiating body is suspended in a vacuum of 3K without boundary preventing radiating to space, will rise in intensity when it has a surface layer of ice cold fluid lowering the radiating total intensity?The total absorbed energy is distributed in a larger mass at lower total intensity in a planet with atmosphere, than in a planet with solid surface and no fluid cool surface layer.Something that is characterized by distributing a fixed amount of energy in a bigger volume at lower concentration, both in received and radiated energy, is not a property that increase intensity. It results in lower intensity at any point measured from surface to space in emitted longwave and from space to surface in irradiated shortwave.[QUOTE]The second statement says cooling = 0 if only radiative cooling. The first says radiative cooling is possible. Please at least be consistent is your technobabble.BoB[/QUOTE]If convection is added by absorbed insolation and/or OLR and results in a bigger volume mass of lower total intensity = lower total temperature.The atmosphere absorbs a fraction of earths total emitted radiation and reaches a much lower intensity, The difference to a non existant atmosphere is more mass at lower density radiating at lower intensity.My point was that an atmosphere is only cooling if it adds mechanisms for heat transfer to space that lowers concentration of energy in the total mass. And I think that is the only effect an atmosphere can have on received energy from an external source.Actually, the only cooling possible is radiative cooling, convection and other processes is matter absorbing energy in the radiation field and gets shaped by it.
[QUOTE="D H, post: 5518646, member: 42688"]You placed the "GHG lives here" sticky at the wrong point in the picture, which might be why you are confused. The greenhouse gases "live" over on the right, and are already labeled greenhouse gases.[/QUOTE]You didn't read my postI was showing that latent heat provides a shortcut back out of the atmosphere bypassing greenhouse gasses for about 1% of total heat that made it to earth's surfacebecause from reading that report i took away that they've modelled heat fluxes as either/or not morphing over here on the right ghg should be down low where i drew it because unlike surface radiation, latent only has to traverse ~20% of the ghg which was the point of my pressure vs altitude chart
[QUOTE="jim hardy, post: 5517968, member: 327872"]
[/QUOTE]You placed the "GHG lives here" sticky at the wrong point in the picture, which might be why you are confused. The greenhouse gases "live" over on the right, and are already labeled greenhouse gases.
[QUOTE="Reality Is Fake, post: 5518046, member: 598755"]Well, since the surface temp would be heated with almost 400K without an atmosphere, it´s definately cooling incoming.[/QUOTE]That is incorrect. Without an atmosphere, the Earth's surface temperature would be below freezing. The incoming solar radiation is the solar constant, 1365.2 W/m[sup]2[/sup], divided by 4, or 341.3 W/m[sup]2[/sup]. You apparently forgot to divide by 4. The reason you need to divide by 4 is because the Earth's cross section to incoming solar radiation is that of a circle with a radius equal to that of the Earth, or [itex]pi R^2[/itex]. The Earth's surface area is that of a sphere with a radius equal to that of the Earth, or [itex]4pi R^2[/itex].Some of that incoming radiation will be reflected away. Assuming an albedo of 12.5% (the average albedo of land and ocean), only 298.6 W/m[sup]2[/sup] will go into heating the Earth. That yields a blackbody temperature of 269.3 kelvins. Assuming an albedo of 30% (the albedo with clouds), the blackbody temperature drops to 254.7 kelvins. The world would be an inhospitable place were it not for the greenhouse effect.[QUOTE]I have seen that too many times, it stings my eyes.[/QUOTE]Instead of complaining, you should try to understand that diagram. It is fundamentally correct.[QUOTE]If the atmosphere would give 333W it would have to have an average temperature of 4√(333/0.0000000567)=276KWe can be very sure that it doesn`t.[/QUOTE]We can be pretty sure it does.You have been making a number of false claims. Please read the rules that pertain to climate change.
[QUOTE="Reality Is Fake, post: 5518046, member: 598755"]The number of 161 hitting the earth is ridicolous,[/QUOTE]I don't know where you got 161 from. The diagram Bandersnatch posted has 343 W/m[SUP]2[/SUP].The flux density from the Sun at Earth's radius is 1370. This is captured by the Earth over a radius R[SUB]E[/SUB], i.e. over a disc, so area πR[SUB]E[/SUB][SUP]2[/SUP]. If we pretend this is uniformly distributed over Earth's surface, 4πR[SUB]E[/SUB][SUP]2[/SUP], that's 343W/m[SUP]2[/SUP].Allowing for non-uniform distribution puts the average temperature down a bit.
[QUOTE="Reality Is Fake, post: 5518046, member: 598755"]The number of 161 hitting the earth is ridicolous, we can measure it to 1000. Why use such a misleading number, of course you will get a conclusion that is way off.[/QUOTE]-There is a night side-Earth is not a circle but a sphere
[QUOTE="jim hardy, post: 5517968, member: 327872"]Much of that 80 watts of latent heat gets deposited above 80% of the greenhouse gas [ATTACH=full]103078[/ATTACH]where its transport mechanism changes from convection to radiation, both upward and downward of course,[ATTACH=full]103079[/ATTACH]i've not been able to figure whether they model it that wayDownward bound has to get back through the ghg layer., upward doesn'tfrom last pageold jim[/QUOTE]If I understand your reasoning, increased GHGs should just lead to a hotter tropopause. But as we know, the lapse rate represents the limit on the ability of convection to even out the temperature. So a hotter tropopause at the same altitude, or the same temperature tropopause at a greater altitude, means correspondingly hotter at ground level.The uncertainties over clouds' affect on downward radiation do not invalidate the principle of the greenhouse effect, they merely make its strength hard to assess. Until such time as clouds are better understood, we must a) look at direct measurement and b) apply risk analysis.Direct measurement from satellites shows a significant excess of incoming radiation – especially considering that for a stable temperature the net flow should be outwards.
[QUOTE="Reality Is Fake, post: 5518046, member: 598755"]I have seen that too many times, it stings my eyes. If the atmosphere would give 333W it would have to have an average temperature of 4√(333/0.0000000567)=276KWe can be very sure that it doesn`t.[/QUOTE]Yes CO2 molecules radiate per Stephan-Boltzman law based on their own temperature like everything else, but the scattering of IR is a different phenomenon and is independent of the temperature of the gas. Think IR "mirror", though with an arbitrary angle of reflection. Yes mirrors have their own blackbody temperature as any IR thermometer will confirm, but this has nothing to do with the ongoing reflection of light, and changing the temperature of the mirror won't change its reflective properties. http://scied.ucar.edu/carbon-dioxide-absorbs-and-re-emits-infrared-radiation
[QUOTE="Reality Is Fake, post: 5518010, member: 598755"]If emission is constant, nothing more is absorbed than what it gets from the sun.[/QUOTE]By what magic would the Earth's surface absorb emissions from the sun but from no other emitter?Simple thought experiment: two black bodies in close proximity at different temperatures. The cooler body emits radiation as per S-B law. Some of this is in the direction of the hotter body. What, in your view, happens to that radiation?
[QUOTE="Reality Is Fake, post: 5517989, member: 598755"]I think I saw liquid ammonia in there somewhere;)[/QUOTE]The ammonia is irrelevant to the fact of cooling. The system would allow cooling as a simple block of metal. The ammonia just speeds the transfer of heat.[QUOTE="Reality Is Fake, post: 5517989, member: 598755"]Radiative cooling is very possible,[/QUOTE][QUOTE="Reality Is Fake, post: 5516725, member: 598755"]It is only cooled when another way of transfer is added to radiation[/QUOTE]The second statement says cooling = 0 if only radiative cooling. The first says radiative cooling is possible. Please at least be consistent is your technobabble.BoB
[QUOTE="Bandersnatch, post: 5517929, member: 399360"]Sorry for the late response to my part of the conversation. I didn't want to make this a wall of quotes (and kinda hoped haruspex would take over my bit as well), but I couldn't figure out any other way to go about it. I'll try to summarise the crux of the issue as what I think it is first, and then address some of the particular misconceptions in the spoiler.[/QUOTE]No worries, I´m just very happy to discuss this with people that have a good manner and knowledge about the principles at work.[QUOTE]The last sentence here seems to be the culprit here. You're seeing the atmosphere as an additional heat sink – i.e., the idea seems to be that since for a set amount of incoming radiation Z, surface radiates X energy to space, then if we add a medium that will remove extra Y energy from the surface, and carry it away where it will then escape into space, it should mean that we've added another sink, so that the energy escaping is X+Y, meaning the radiative emissions have to go down, meaning the equilibrium temperature at the surface must become lower.[/QUOTE]Well, since the surface temp would be heated with almost 400K without an atmosphere, it´s definately cooling incoming. And it´s not as much an extra heat sink for emission, as the surface emits only according to it´s own temperature. But it it is still cooling the surface even if the surface cools anyway. The fact is that earth cools from a big volume with an atmosphere instead of a surface only. And it would be much warmer without an atmosphere. The problem is that we treat is as two bodies when the atmosphere is actually a porous low density surface that lowers the surface absorbing ability, the emissivity-epsilon.[QUOTE]The issues with this picture are:- the atmosphere is for the most part not transparent to the outgoing radiation, so it can't just escape into space – it gets absorbed and reradiated in all directions, including downwards. The actual atmospheric window for escaping radiation is just about 40 W/m^2.- the thermal heat transfer (conduction, convection, evaporation) from the surface is 1. small when compared with radiative transfer, and 2. ends up being reradiated in upper parts of the atmosphere, again including back to the surface.[/QUOTE]I have a problem with the description of bad emissive properties and high temperatures, as high temperature is an effect of good emissive properties, according to Kirchoff. "What is absorbed is emitted" he concluded, and I am not willing to abandon such a well known law unless very, very good evidence. And I think we all know that evidence of the GH-theory and co2:s heating in the atmosphere is pretty much non-existant. Even though it should be very easy to prove if a gas in an open system could do that type of work.[QUOTE]This could still be a valid objection if the energy balance at the surface was a net removal of energy, and would require quantifying – if it hasn't been done many times already. E.g. see the following paper (with its inforgraphic reproduced below):http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2634.1
All that energy that was removed from the surface and then returned in the form of back radiation changes the energy balance at the surface so that there is more incoming energy Z, and the equilibrium has to change to increase radiation (or thermals, but their magnitude is secondary), meaning increase in temperature of the surface.[/QUOTE]I have seen that too many times, it stings my eyes. If the atmosphere would give 333W it would have to have an average temperature of 4√(333/0.0000000567)=276KWe can be very sure that it doesn`t.And since surface T is Tsun=εδT^4 and atmosphere is T-surface=εδT^4. The atmosphere would have to heat the sun if it heats the earth surface because it always is a one way process.The number of 161 hitting the earth is ridicolous, we can measure it to 1000. Why use such a misleading number, of course you will get a conclusion that is way off.I have still not seen a calculation including the whole chain that can explain how a cold atmosphere can heat a warm surface. Back radiation is about photons from single molecules and that is not possible to calculate at this scale. We should stick to what we know works, heat transfer and thermic radiation. That tells us that a body radiaties only according to its own temperature.[QUOTE]So, looking at the atmosphere as a heat sink is faulty reasoning – it is an insulator.[/QUOTE]Insulators is a specific thing, it does not have steep gradients, it has very low gradients.[QUOTE]But all you really needed, in order to know that the atmosphere is raising the surface temperature, is to do the calculations for the blackbody equilibrium temperature for an airless barren planet at 1 AU around the Sun. Since that is lower than what we've got here, it is a clear indication that the atmosphere is responsible for raising the temp. All that remains is to figure out how (which the paper linked above does nicely).[/QUOTE]I think they calculate with average watts, not what is hitting earth in reality, 1370W. That is almost 400K. Look at the moon, above 100C.[QUOTE]The Stefan-Boltzman law concerns only radiative energy transfer from a black body. You can't use it for thermals.[/QUOTE]It´s the base for heat transfer, there is no process that can change it in an open system. And earth surface is cooling to space with a ΔT to 3K, the stuff in between is details that can´t change that without a boundary with conduction.And the whole base for greenhouse theory is about radiation, so where does that leave us?And please tell us what to use then. A chart with numbers of Watt is a mockery of thermodynamics without calculations. And the numbers is clearly wrong, the atmosphere is not that warm. Even though you claim S-B is not correct for the transfer, it IS correct for the temperature.[QUOTE]No! The violation would be if there was colder atmosphere heating up hotter surface, whereas what we've got is the hot Sun heating up the surface.When considering the Earth+atmosphere system, you don't get any NET heat flow inward. Heat is always flowing away from the hot source (surface) to colder surroundings (including space). But there is extra energy coming inward from the atmosphere that wouldn't be there without air, which means that the NET heat flow is lower and the equilibrium temperature at the surface has to self-adjust to re-emit that extra energy.[/QUOTE]But heat transfer is a process where the energy in the colder body does not influence the hot body in any way. The hot body radiates only according to it´s own temperature, and as you said, that comes from the sun. There is not a single observation in nature or in experiments where we can see such a process.[QUOTE]You should forget everything you wrote about GR there and there on after, since it's completely misappropriated, and just wrong.Forget about the c^2 in the equation, it's confusing you. It's just a unit conversion factor, and you can freely choose units in which it's equal to 1, so that all the equation says is that mass of a body at rest has some associated energy.[/QUOTE]Now you just make me more interested, that was a sore toe.[QUOTE]You're mostly talking about energy conservation anyway, which is not violated when putting CO2 into the atmosphere (because the mass was already there, only not in the atmosphere) nor when increasing temperature, because the system is not closed – i.e. the Sun provides energy. If you would design a rather implausibly good insulation system for the planet, you could raise its temperature as high as the temperature of the Sun's surface, and it wouldn't violate any conservation nor thermodynamic laws.[/QUOTE]Absolutely not. Give me the calculations. You are ignoring the distance. Please, up the level.[QUOTE]YWhy would CO2 on Earth heat the Sun? It doesn't make any sense..[/QUOTE]Because it is a chain of δT^4 that goes only in one direction, and you are putting in energy at the end exhaust.[QUOTE]No, that is a tell-tale sign of a good insulator.This might be another significant issue – what you seem to consider 'cooling' is just heat transfer from hot to cold. Remember that we're talking about systems in thermal equilibrium with their surroundings, which include heat sinks and heat sources. In such a system there will always be temperature gradients, but this doesn't necessarily mean there is cooling[/QUOTE]Well then, show me a good insulator in an example that has a steep gradient from a hot surface.[QUOTE]E.g. if you put on a sweater in winter, a steep gradient from your skin to the air will set up. By your usage of the term, the sweater is 'cooling' your skin, because you're loosing heat through it.[/QUOTE]You have to buy new sweaters. The sweater is not hot if it keeps you warm.[QUOTE]For something to be cooling a body heated by an external source, it has to increase energy transfer from the body, so that more net heat is removed than without it, and the equilibrium temperature drops as a result.E.g., if you put a radiator on your processor, it'll remove more energy by increasing surface area in contact with air, reducing its temperature – i.e. a cooling effect. Conversely, if you glue a block of fibreglass to the processor, it'll slow down heat transfer, heating it up. The second case will have a steeper temp gradient than the first, but it will be undoubtedly heating.[/QUOTE]So, youre saying that the atmosphere is like fiberglass?It really is a big problem with the comparisons using sweaters, blankets and fiberglass. It shows you have a hard time yourself to validate the theory.Can you show me an open system without fiberglass that gets warmer by being in contact with a much cooler gas… that is in contact with an optimal heat sink?The claim has to be confirmed by an observation in natural setting in scale. Why is it not possible to demonstrate in experiments?There is no proof of the concept. You say that a hot body surrounded by 3K is insulated by a lowdensity, low heat capacity gas. Why cant we design that and make it work then?
[QUOTE="haruspex, post: 5517249, member: 334404"]Interception and reradiation back to the source is a slowdown in transfer but not a slowdown in primary emission. You are confusing the two.[/QUOTE]While I am very confused about what "re-radiation" is about, a constant emission from the surface is exactly my point. If emission is constant, nothing more is absorbed than what it gets from the sun. A surface emits according to it´s own temperature only, if emission is constant, that is -not slowed down-, then the "re-radiation" has not addedd anything. What you are saying is that the atmosphere gets heated, nothing else. According to Kirchoff, what is emitted is absorbed, so constant emission is a sign of nothing absorbed from the atmosphere.And "re-raditation" only happens if there are two surfaces. Heat and radiation are waves, light is a wave, you cannot interfere a wave in an open system with a gas receiving heat from a hot body without a boundary or surface, right?[QUOTE]As you should know, the temperature gradient is a consequence of the adiabatic cooling as air rises. This puts a brake on convection, requiring a minimum gradient before convection can occur. Yes, the air cools, but not as a result of heat transfer..[/QUOTE]I´m not sure about that brake, how do you mean? How big is the restriction? The speed is pretty constant, but how about pressure?[QUOTE]No, it's quite patchy. One reason CO2 is important is that it plugs some holes in the H2O spectrum. Each absorption band is somewhat spread by Doppler and other effects. You may have read that the greenhouse impact of a gas rises logarithmically with concentration. That is because, typically, the main consequence of increased concentration is a broadening of the bands. In the centre of the band absorption is fairly total, so it is the broadening of the band shoulders that is of interest.[/QUOTE]Not the whole spectrum, over the whole spectrum. And strongly at shorter wavelenghts. The doppler is at higher altitude, I think. By logartihmically you mean less effect with higher concentration, right? Not the other way around. [QUOTE]I have no idea how you conclude that. Have you considered how Venus has such a high surface temperature?[/QUOTE]Yes, it´s a strange thing. Almost no sunlight reaches the surface. But the pressure of 90+ atmospheres and co2 at 63kg per m^3 is more like a solid than a gas, and as far as i know co2 is considered to be a supercritical fluid at the circumstances. Things I don´t know that much about…yet.What really is the interesting question is why venus has almost the same temperature at 1atm pressure, at around 50km altitude, as earth? That is a really good sign that co2 has very little to do with surface temp.[QUOTE]So when you wear a sweater, as opposed to simply a windcheater, it only makes the sweater warm, not you?[/QUOTE]No no, a sweater keeps air in place in a structure, and air is a good insulator when it is not allowed to leave with the heat. And it conducts poorly. But look what happens when you get to hot, water takes over wetting your sweater making conduction easier and cools by evaporation.
[QUOTE="rbelli1, post: 5517213, member: 315621"]So you are saying that radiative cooling is impossible? Then how does this work? https://spaceflightsystems.grc.nasa.gov/print/cooling_prt.htm BoB[/QUOTE][QUOTE="rbelli1, post: 5517213, member: 315621"]So you are saying that radiative cooling is impossible? Then how does this work? https://spaceflightsystems.grc.nasa.gov/print/cooling_prt.htm BoB[/QUOTE] I think I saw liquid ammonia in there somewhere;)We can design forced cooling systems, we´re really good at it. Radiative cooling is very possible, that is the main cooling function in the universe(I think). In a natural, unforced, heat transfer between two bodies, the rate of transfer changes only at the cooler body, the hotter one doesn´t take notice of what is riding on it´s wave.
Much of that 80 watts of latent heat gets deposited above 80% of the greenhouse gas [ATTACH=full]103078[/ATTACH]where its transport mechanism changes from convection to radiation, both upward and downward of course,[ATTACH=full]103079[/ATTACH]i've not been able to figure whether they model it that wayDownward bound has to get back through the ghg layer., upward doesn'tfrom last page[QUOTE]Thus, the downwellingLW flux exists as one of the principle uncertainties inthe global surface energy budget. (page 6)In our analysis, the biggest uncertainty and biascomes from the downward longwave radiation. Thissource of uncertainty is likely mainly from clouds. (page 10)[/QUOTE]old jim
Sorry for the late response to my part of the conversation. I didn't want to make this a wall of quotes (and kinda hoped haruspex would take over my bit as well), but I couldn't figure out any other way to go about it. I'll try to summarise the crux of the issue as what I think it is first, and then address some of the particular misconceptions in the spoiler.[QUOTE="Reality Is Fake, post: 5516436, member: 598755"]Of course all energy leaves as radiation and it leaves from the top of atmosphere. As far as I can see it doesn´t matter that the gas is distributing the heat by cooling the surface at any location to all the volume of the atmosphere. That is a process that maximize the atmospheres capacity to radiate to space.[/quote]The last sentence here seems to be the culprit here. You're seeing the atmosphere as an additional heat sink – i.e., the idea seems to be that since for a set amount of incoming radiation Z, surface radiates X energy to space, then if we add a medium that will remove extra Y energy from the surface, and carry it away where it will then escape into space, it should mean that we've added another sink, so that the energy escaping is X+Y, meaning the radiative emissions have to go down, meaning the equilibrium temperature at the surface must become lower.The issues with this picture are:- the atmosphere is for the most part not transparent to the outgoing radiation, so it can't just escape into space – it gets absorbed and reradiated in all directions, including downwards. The actual atmospheric window for escaping radiation is just about 40 W/m^2.- the thermal heat transfer (conduction, convection, evaporation) from the surface is 1. small when compared with radiative transfer, and 2. ends up being reradiated in upper parts of the atmosphere, again including back to the surface.This could still be a valid objection if the energy balance at the surface was a net removal of energy, and would require quantifying – if it hasn't been done many times already. E.g. see the following paper (with its inforgraphic reproduced below):http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2634.1
All that energy that was removed from the surface and then returned in the form of back radiation changes the energy balance at the surface so that there is more incoming energy Z, and the equilibrium has to change to increase radiation (or thermals, but their magnitude is secondary), meaning increase in temperature of the surface.So, looking at the atmosphere as a heat sink is faulty reasoning – it is an insulator.But all you really needed, in order to know that the atmosphere is raising the surface temperature, is to do the calculations for the blackbody equilibrium temperature for an airless barren planet at 1 AU around the Sun. Since that is lower than what we've got here, it is a clear indication that the atmosphere is responsible for raising the temp. All that remains is to figure out how (which the paper linked above does nicely).I'll put the rest into spoilers, since it's all a bit tangent to the main issue, I believe.[spoiler][quote]Black body radiation is a beutiful concept and S-B law is the reason that we can use space as a heat sink. Because it defines the energy leaving the boundary of a system that transfers heat to the surroundings as an effect only depending on temperature. It is true for the transfer of heat no matter if it is in the state of radiation or heat as kinetic energy. It is used for heat transfer and thermic radiation.[/QUOTE]The Stefan-Boltzman law concerns only radiative energy transfer from a black body. You can't use it for thermals.[QUOTE="Reality Is Fake, post: 5516436, member: 598755"]According to theory of heat transfer, the rate of transfer is defined by the difference in temperature, and it shrinks as the difference gets smaller. So that makes a transfer of energy from atmosphere to surface a violation of the concept black body and even more for grey body.[/QUOTE]No! The violation would be if there was colder atmosphere heating up hotter surface, whereas what we've got is the hot Sun heating up the surface.When considering the Earth+atmosphere system, you don't get any NET heat flow inward. Heat is always flowing away from the hot source (surface) to colder surroundings (including space). But there is extra energy coming inward from the atmosphere that wouldn't be there without air, which means that the NET heat flow is lower and the equilibrium temperature at the surface has to self-adjust to re-emit that extra energy.[QUOTE="Reality Is Fake, post: 5516436, member: 598755"]Another interesting thing is that I always had a hard time visualizing Einsteins theory of relativity, E=mc^2, but the greenhouse theory solved that for me.[/QUOTE]You should forget everything you wrote about GR there and there on after, since it's completely misappropriated, and just wrong.Forget about the c^2 in the equation, it's confusing you. It's just a unit conversion factor, and you can freely choose units in which it's equal to 1, so that all the equation says is that mass of a body at rest has some associated energy.You're mostly talking about energy conservation anyway, which is not violated when putting CO2 into the atmosphere (because the mass was already there, only not in the atmosphere) nor when increasing temperature, because the system is not closed – i.e. the Sun provides energy. If you would design a rather implausibly good insulation system for the planet, you could raise its temperature as high as the temperature of the Sun's surface, and it wouldn't violate any conservation nor thermodynamic laws.And yes, that means that a hotter Earth has more energy stored, i.e., is more 'massive', i.e., curves space-time more.[QUOTE="Reality Is Fake, post: 5516436, member: 598755"]And a calculation of radiation balance at any point has to relate to the source, the sun. I f co2 heats the surface as the last passive body in the chain, then it has to heat the sun as well if it is true.[/QUOTE]Why would CO2 on Earth heat the Sun? It doesn't make any sense.[QUOTE="Reality Is Fake, post: 5516436, member: 598755"]That is also confirmed by observation of energy as temperature in the atmosphere, steep gradients an very low temperatures that is averaged much below surface, is the tell-tale sign of something acting cooling on the surface.[/QUOTE]No, that is a tell-tale sign of a good insulator.This might be another significant issue – what you seem to consider 'cooling' is just heat transfer from hot to cold. Remember that we're talking about systems in thermal equilibrium with their surroundings, which include heat sinks and heat sources. In such a system there will always be temperature gradients, but this doesn't necessarily mean there is cooling.E.g. if you put on a sweater in winter, a steep gradient from your skin to the air will set up. By your usage of the term, the sweater is 'cooling' your skin, because you're loosing heat through it.For something to be cooling a body heated by an external source, it has to increase energy transfer from the body, so that more net heat is removed than without it, and the equilibrium temperature drops as a result.E.g., if you put a radiator on your processor, it'll remove more energy by increasing surface area in contact with air, reducing its temperature – i.e. a cooling effect. Conversely, if you glue a block of fibreglass to the processor, it'll slow down heat transfer, heating it up. The second case will have a steeper temp gradient than the first, but it will be undoubtedly heating.I might have skipped a few points, but this response is already way too bloated.[/spoiler]
[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]slowdown in heat transfer is something that only happens at the receiving end. The source don´t care about what is licking up the waste it´s putting out in radiation.[/QUOTE]Interception and reradiation back to the source is a slowdown in transfer but not a slowdown in primary emission. You are confusing the two.[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]The air cools so fast with height that it´s clear that there is a cooling effect all the way up there.[/QUOTE]As you should know, the temperature gradient is a consequence of the adiabatic cooling as air rises. This puts a brake on convection, requiring a minimum gradient before convection can occur. Yes, the air cools, but not as a result of heat transfer.[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]co2 and water absorbs over the whole spectrum from 700nm to way up in far-IR.[/QUOTE]No, it's quite patchy. One reason CO2 is important is that it plugs some holes in the H2O spectrum. Each absorption band is somewhat spread by Doppler and other effects. You may have read that the greenhouse impact of a gas rises logarithmically with concentration. That is because, typically, the main consequence of increased concentration is a broadening of the bands. In the centre of the band absorption is fairly total, so it is the broadening of the band shoulders that is of interest.[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]From S-B law applied in heat transfer and thermic radiation it is clear that there is no point in adressing the re-emission from a certain gas at this scale in an open system[/QUOTE]I have no idea how you conclude that. Have you considered how Venus has such a high surface temperature?[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]A warming would not show at the surface, it would show at the other end of transfer. At the tropopause[/QUOTE]So when you wear a sweater, as opposed to simply a windcheater, it only makes the sweater warm, not you?
[QUOTE="Reality Is Fake, post: 5516725, member: 598755"]A slowdown in heat transfer is something that only happens at the receiving end. The source don´t care about what is licking up the waste it´s putting out in radiation. It is only cooled when another way of transfer is added to radiation, like conduction or convection.[/QUOTE]So you are saying that radiative cooling is impossible?Then how does this work? https://spaceflightsystems.grc.nasa.gov/print/cooling_prt.htmBoB
[QUOTE="haruspex, post: 5516530, member: 334404"]Only up to the tropopause. Going any further depends almost entirely on radiation.[/QUOTE]But it does it really well all the way up to the tropopause. From about 300K down to about 200K in 10km. The air cools so fast with height that it´s clear that there is a cooling effect all the way up there. Observed temperatures shows a cooling in the troposphere at any altitude. I can´t figure out how we can interprete such a steep gradient as anything but poweful cooling. That type of gradient is what we want when we design a device that cools by convection, why would a troposphere that shows such a gradient be a heating element?And wher it´s hotter than else, we see a higher troposphere, at the equator. So there seems to be a regulating mechanism that keeps the temperature constantly at the same level at tropopause. Funny enough, co2 shows it´s imprint in spectral intensity of OLR at the same temperature as the tropopause. The sign of co2 in spectral is that of a massive reduction in intensity att the peak wavelength of surface radiation at 300K.I feel like someone is making fun of me, all the signs that we observe in the atmosphere, and from co2 especially, is the signs of cooling. From earth to space. But everyone says it´s warming. Some even point to that decrease in intensity of radiation from co2 distinct absorption at 15μ. As far as I know, an increase in temperature must show as an increase in total intensity. The argument that it shows trapped heat doesn´t add up. Heat doesn´t hide.[QUOTE="haruspex, post: 5516530, member: 334404"]It depends what you mean by "trapping". Infrared Radiation is absorbed from either direction (up or down) and reradiated equally in both directions. Since the Earth reradiates absorbed visible and IR as IR, there is more IR coming from below than from above. The net effect of the greenhouse gas is therefore to slow the transfer of heat into space. That is all that is meant by trapping in this context.[/QUOTE]Yeah, I know, I´ve seen that explanation everywhere. But mostly with the addition that it heats the surface as well. I´m totally agreeing with earth heating the atmosphere, that is clear. And co2 and water absorbs over the whole spectrum from 700nm to way up in far-IR. With much more intense radiation in near-IR. I have not managed to clarify how many watts the atmosphere absorbs in near-IR compared to far-IR. But it looks like about the same, maybe more in the shorter wavelenghts from insolation.From S-B law applied in heat transfer and thermic radiation it is clear that there is no point in adressing the re-emission from a certain gas at this scale in an open system. We get the best result when we consider difference in temperature as the rate of transfer. And when that rate is calculated we cannot se any change the rate of emission or the temperature at the warmer surface. And I think that is supported by observation as well. A warming would not show at the surface, it would show at the other end of transfer. At the tropopause, since all transfer of heat to other altitudes below must be less. Even if the atmosphere is slowing the rate of transfer into space, that is only from the atmosphere. The surface emits only according to it´s own temperature, and of course that is according to the suns temperature.Some people seems to approach this "trapping" of radiation in the atmosphere as resistance in an elecrical circuit, or as a resistance in the flow. While it´s not totally wrong, it doesn´t say anything about the surface temperature. Electrical circuit resistance does not heat the source, it heats the resisting medium for the flow. A resistance in a flow is more like a stone in a waterfall, it doesn´t change the flow at the source.One more point, in heat transfer, an atmospheric gasmixture at 1 atm of pressure, it is said that for a temperature of 300K radiation is absorbed, and for higher temps, like 1000K, it is absorbed and emitted. I think that it is not until we see the spectral sign of co2 emitting radiation, which would be seen as a rising spike, that we can come to the conclusion that we are observing a rise in temperature that is signed by co2. It should also show up as a smaller gradient and/or a higher overall troposphere.
[QUOTE="haruspex, post: 5516640, member: 334404"]Below that, convection carries the heat up.[/QUOTE]A lot of it by water vapor.If this number is goodhttp://www.superstrate.net/pv/illumination/irradiation.html[QUOTE]The solar energy irradiated to the Earth is 5.10[SUP]24[/SUP] Joule per year.[/QUOTE]it would seem that in short-circuiting the insulating layer, hurricanes and thunderstorms provide a goodly part of a 1% energy trim mechanism to keep the tropical oceans cool.
[QUOTE="jim hardy, post: 5516626, member: 327872"]Once air reaches tropopause it's above most of the greenhouse gas so radiation has a shorter hop to make[/QUOTE]Sure, but that is the bit where it matters. Below that, convection carries the heat up.