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Post by poitsplace on Mar 25, 2009 7:58:29 GMT
I've been in debates elsewhere and something that's come up recently is that people just don't seem to get the fact that since CO2 is already absorbing most of the radiation it can...the entire system is pre-stressed. Radiative equilibrium already has the vast majority of radiation escaping AROUND the wavelengths that CO2 absorbs.
Suggesting that additional CO2 would cause pronounced warming is like suggesting to a cold man wearing nothing but several hats...that putting on yet another hat would make him significantly warmer.
He's not cold because he doesn't have enough insulation on his head, he's cold because he hasn't got enough insulation elsewhere
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Post by steve on Mar 25, 2009 9:58:51 GMT
All the energy that leaves the earth has to get through the greenhouse gas containing atmosphere. It's not like a man with lots of hats and no trousers, where he can lose heat from "elsewhere".
Further, I can recall one time when I was wearing 6 layers of clothing and removed one when I got too warm, so the analogy fails anyway.
Finally, the existing greenhouse effect is keeping temps at the earth's surface about 30 degrees warmer than they would be. People don't seem to get the fact that the "pronounced" warming we're talking about is only another 2 or 3 degrees for a doubling of the second strongest greenhouse gas. The science is hardly claiming that it's the difference between eskimo clothing and nudity!
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Post by nautonnier on Mar 25, 2009 11:44:50 GMT
All the energy that leaves the earth has to get through the greenhouse gas containing atmosphere. It's not like a man with lots of hats and no trousers, where he can lose heat from "elsewhere". Further, I can recall one time when I was wearing 6 layers of clothing and removed one when I got too warm, so the analogy fails anyway. Finally, the existing greenhouse effect is keeping temps at the earth's surface about 30 degrees warmer than they would be. People don't seem to get the fact that the "pronounced" warming we're talking about is only another 2 or 3 degrees for a doubling of the second strongest greenhouse gas. The science is hardly claiming that it's the difference between eskimo clothing and nudity! Steve, Hypothesis, the existing 'green house effect' is both due to water vapor and mediated by water vapor and its other states as droplets, ice crystals, precipitation, water in the oceans and in the soil, and latent heats of evaporation, condensation etc., All of which vary dependent on the local heat fluxes and temperatures. CO 2 has a small forcing effect which is dwarfed by the mediating negative feedbacks from the hydrologic cycle which continue to keep the earth in relative balance despite the solar grand maximum. Now show experimental proof in the real world, that CO2 does in fact have sufficient forcing to overwhelm the natural feedbacks in the hydologic cycle to falsify the above hypothesis. To the extent that the global temperatures will increase by "another 2 or 3 degrees" C.
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Post by FurryCatHerder on Mar 25, 2009 12:31:04 GMT
Hypothesis, the existing 'green house effect' is both due to water vapor and mediated by water vapor and its other states as droplets, ice crystals, precipitation, water in the oceans and in the soil, and latent heats of evaporation, condensation etc., All of which vary dependent on the local heat fluxes and temperatures. CO 2 has a small forcing effect which is dwarfed by the mediating negative feedbacks from the hydrologic cycle which continue to keep the earth in relative balance despite the solar grand maximum. Now show experimental proof in the real world, that CO2 does in fact have sufficient forcing to overwhelm the natural feedbacks in the hydologic cycle to falsify the above hypothesis. To the extent that the global temperatures will increase by "another 2 or 3 degrees" C. Absolutely NO ONE in the AGW debate is claiming that HO2 plays no role in the current long-term warming trend. One major difference between CO2 and H2O is that CO2 is not "washed out" of the atmosphere to the same extent that the hydrologic cycle "washes out" water. So, it's like adding additional H2O that sticks around even longer. If you agree that water vapor is a major forcing, you have to agree that CO2 -- which doesn't rain out the way water does -- is an incremental forcing. Or put another way -- for some range of water vapor in a local climate region, adding more CO2 is like increasing both the lower and upper concentrations of water vapor. If you agree that increased water vapor would increase temperatures (and there is a HUGE body of evidence it does), you logically have to agree that a persistent increase in CO2 will have the same effect.
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Post by poitsplace on Mar 25, 2009 13:52:44 GMT
Or put another way -- for some range of water vapor in a local climate region, adding more CO2 is like increasing both the lower and upper concentrations of water vapor. If you agree that increased water vapor would increase temperatures (and there is a HUGE body of evidence it does), you logically have to agree that a persistent increase in CO2 will have the same effect. AGAIN, CO2 is not like a full blanket, it's like a partial blanket. It's hard for normal people to wrap their heads around the concept because the CO2 covers the whole planet. Since we know it wraps around the whole planet, let's forget about those other pesky dimensions and just look at it as the spectrum. Thinking of it in terms of spectrum you can see that CO2 is already absorbing essentially everything it can. Off to the sides of the CO2 spectrum, however...long wave radiation is pouring off into space COMPLETELY unchecked. About 75% of the energy just leaves the earth. Of that which the CO2 grabs it's either re-emitted at CO2's wavelengths, having never contributed to additional warming or converted into heat in the atmosphere or surface where...oops...once again it's emitted as standard black-body radiation and 75% of it promptly leaves unchecked. The time for this is just a few minutes. Most of the remaining heat is due to the specific heat capacity of our atmosphere or...phase changes with water, the biggest moderator of temperature on earth. Saying extra CO2 is going to allow extra energy is absurd because CO2's already essentially opaque. The REAL limiting factor for CO2's warming is the fact that within minutes of it grabbing energy...it's re-emitted in some frequency CO2 can't touch. Once again I point out, saying CO2 will cause significant warming is like a nudist trying to stay warm by wearing additional hats. The problem isn't the total amount of insulation, it's the distribution of the insulation. The barn doors of the atmosphere are wide open across most of the spectrum that keeps earth's energy in balance. Any time the CO2 converts long-wave radiation back into heat...most of it immediately (minutes) gets re-radiated and leaves.
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Post by steve on Mar 25, 2009 13:53:02 GMT
Nautonnier,
I'm glad that at least you agree with me that the "hat" analogy is wrong!
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Post by icefisher on Mar 25, 2009 14:10:16 GMT
Hypothesis, the existing 'green house effect' is both due to water vapor and mediated by water vapor and its other states as droplets, ice crystals, precipitation, water in the oceans and in the soil, and latent heats of evaporation, condensation etc., All of which vary dependent on the local heat fluxes and temperatures. CO 2 has a small forcing effect which is dwarfed by the mediating negative feedbacks from the hydrologic cycle which continue to keep the earth in relative balance despite the solar grand maximum. Now show experimental proof in the real world, that CO2 does in fact have sufficient forcing to overwhelm the natural feedbacks in the hydologic cycle to falsify the above hypothesis. To the extent that the global temperatures will increase by "another 2 or 3 degrees" C. Absolutely NO ONE in the AGW debate is claiming that HO2 plays no role in the current long-term warming trend. One major difference between CO2 and H2O is that CO2 is not "washed out" of the atmosphere to the same extent that the hydrologic cycle "washes out" water. So, it's like adding additional H2O that sticks around even longer. If you agree that water vapor is a major forcing, you have to agree that CO2 -- which doesn't rain out the way water does -- is an incremental forcing. Or put another way -- for some range of water vapor in a local climate region, adding more CO2 is like increasing both the lower and upper concentrations of water vapor. If you agree that increased water vapor would increase temperatures (and there is a HUGE body of evidence it does), you logically have to agree that a persistent increase in CO2 will have the same effect. The fact it might be an incremental forcing is unremarkable. Huge quantities of kinetic energy is transported to the upper atmosphere by the water cycle through evaporation and condensation. CO2 could well be a 1/4" pebble on the kinetic highway being traveled by Mack-built water trucks and just coming along for the ride embedded in the treads. With the hockey stick discredited and the pipeline empty where is all this supposed building heat?
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Post by socold on Mar 25, 2009 14:11:57 GMT
The effect of co2 isn't saturated in the atmosphere. For every doubling of co2 there's an additional ~4wm-2 less energy that reaches space. And that is taking water vapor absorption, etc into account.
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Post by tacoman25 on Mar 25, 2009 18:42:04 GMT
The effect of co2 isn't saturated in the atmosphere. For every doubling of co2 there's an additional ~4wm-2 less energy that reaches space. And that is taking water vapor absorption, etc into account. Purely hypothetical and unproven. I would especially like to see exactly how water vapor absorption is so cleanly and simply figured out. Assumptions cannot be treated as facts...and over-simplifying a very complex system to get model output is not going to work accurately 99% of the time. That, to me, is the biggest problem with popular AGW theory...it falls into a common trap of science: thinking we know enough to come to certain conclusions, when that is not at all the case.
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Post by nautonnier on Mar 25, 2009 19:34:53 GMT
Hypothesis, the existing 'green house effect' is both due to water vapor and mediated by water vapor and its other states as droplets, ice crystals, precipitation, water in the oceans and in the soil, and latent heats of evaporation, condensation etc., All of which vary dependent on the local heat fluxes and temperatures. CO 2 has a small forcing effect which is dwarfed by the mediating negative feedbacks from the hydrologic cycle which continue to keep the earth in relative balance despite the solar grand maximum. Now show experimental proof in the real world, that CO2 does in fact have sufficient forcing to overwhelm the natural feedbacks in the hydologic cycle to falsify the above hypothesis. To the extent that the global temperatures will increase by "another 2 or 3 degrees" C. Absolutely NO ONE in the AGW debate is claiming that HO2 plays no role in the current long-term warming trend. One major difference between CO2 and H2O is that CO2 is not "washed out" of the atmosphere to the same extent that the hydrologic cycle "washes out" water. So, it's like adding additional H2O that sticks around even longer. If you agree that water vapor is a major forcing, you have to agree that CO2 -- which doesn't rain out the way water does -- is an incremental forcing. Or put another way -- for some range of water vapor in a local climate region, adding more CO2 is like increasing both the lower and upper concentrations of water vapor. If you agree that increased water vapor would increase temperatures (and there is a HUGE body of evidence it does), you logically have to agree that a persistent increase in CO2 will have the same effect. "One major difference between CO2 and H2O is that CO2 is not "washed out" of the atmosphere to the same extent that the hydrologic cycle "washes out" water. So, it's like adding additional H2O that sticks around even longer. If you agree that water vapor is a major forcing, you have to agree that CO2 -- which doesn't rain out the way water does -- is an incremental forcing."
This is mis-assumption that even Michael 'Hockeystick' Mann pushes and it shows that you are not really thinking of how the hydrological system works. When CO 2 'washes out of the atmosphere' it has zero impact on the 'green-house effect'. It only has any effect while it is in the atmosphere. However, the act of washing out HUGE quantities of water cools the surface as it arrives as rain/snow/hail/sleet etc etc or even as a heavy dew. Rain can drop from a cold upper air into a warm drier layer lower down and evaporate again cooling that warm layer. The 'washout' is the cooling obverse of the hot convection in which warm water vapor convectively lifted as the volume cools due to the adiabatic lapse rate the water condenses out adding the heat it was transporting to the volume of gases around it. Convection and clouds will not happen without the precipitation back to the surface. Even at the surface water in all its states affects the heat flux of the planet by albedo changes and changes of state. CO 2 has no such effect but is required for photosynthesis to work. So the put down that 'water washes out' shows you have not fully understood the cycle of carrying warmth to the tropopause and then returning cold water to the surface. I am sure someone can come up with the figures but the amount of water vapor continually entering the atmosphere is many orders of magnitude higher than CO 2 from all sources. It is CONTINUALLY entering the atmosphere at a similar rate to its precipitation out (which is logical if you think about it). The level of water in the atmosphere is linked to the heat at the surface and the water available at the surface. So as the heat goes up so does water vapor - the difference being that it transports that heat via convection and then forms clouds that can with their albedo reduce the heat of the surface from which they evaporated - one of the many feedbacks. In larger scales the Hadley Cells are formed from such tropical convection and the Coriolis forces on the air being drawn in and upward causes the tradewinds - which in turn are thought to initiate the ENSO events another major feedback which AGW proponents repeatedly refer to as an external event - but the underlying driver for ENSO events is the hydrologic cycle. So "If you agree that water vapor is a major forcing, you have to agree that CO2 -- which doesn't rain out the way water does -- is an incremental forcing."Well actually no. My hypothesis is that water vapor both is a major forcing and a major negative feedback against forcing. The 'rain out' is part of that feedback and it is obviously replaced as fast as it rains out. Any warming due to CO 2 is extremely small comparison to these feedbacks which will be driven by, but more than compensate for, that small CO 2 warming. The point that you miss is that increased water vapor also increases these negative feedbacks as it 'rains out' or forms high-albedo cloud. As I said in my response to Steve: Show experimental proof in the real world, that CO2 does in fact have sufficient forcing to overwhelm the natural feedbacks in the hydologic cycle to falsify the above hypothesis. To the extent that the global temperatures will increase by "another 2 or 3 degrees" C.
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Post by socold on Mar 25, 2009 19:38:29 GMT
It's proven that co2 is not saturated in the atmosphere. You can see in the emission spectrum that not all the co2 regions are saturated.
The calculations from the simple to the complex all show about 4wm-2 extra absorption from doubling co2.
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Post by kenfeldman on Mar 25, 2009 20:36:12 GMT
I think this is one of the biggest misunderstandings of the science out there, and one that the so-called "sceptical scientists" exploit to get people to deny the AGW problem. It simply isn't true. This arguement was first made within a decade of Arrenhius publishing his paper on AGW, and it was disproved in the 1950s by Plass and others. The more greenhouse gases you put in the atmosphere, the more chance there is for a photon of heat to be absorbed and redirected downward toward the earth again, resulting in more warming. Here's a good website explaining the reason the "hat analogy" fails: www.geocities.com/bpl1960/Saturation.html
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Post by poitsplace on Mar 25, 2009 23:13:53 GMT
I think this is one of the biggest misunderstandings of the science out there, and one that the so-called "sceptical scientists" exploit to get people to deny the AGW problem. It simply isn't true. This arguement was first made within a decade of Arrenhius publishing his paper on AGW, and it was disproved in the 1950s by Plass and others. The more greenhouse gases you put in the atmosphere, the more chance there is for a photon of heat to be absorbed and redirected downward toward the earth again, resulting in more warming. Here's a good website explaining the reason the "hat analogy" fails: www.geocities.com/bpl1960/Saturation.htmlThe hat analogy is dead on. You people keep acting as if the ONLY frequencies of IR coming from the earth were those affected by CO2. Were that the case you'd have a leg to stand on. This however is not the case. MOST of the radiation pours out of the atmosphere unchecked. Of the energy captured by CO2...most of that is radiated straight back out of the atmosphere unchecked as well. CO2's only contribution is a pause of a few minutes, not some bottomless pit of energy. Just like the hats...there's no question that putting on another hat will slow the loss of energy. You can even quantify it. You can have long arguments about how at X insulating level it would stop this much heat leaving a body at 36C and at 2X insulating level it would stop that much heat from leaving the body...but the person will still freeze to death if 75% of his body's uncovered, as the atmosphere is. Since CO2 is already stopping the vast majority of all the radiation it can stop...all that energy already skirts around the CO2 wavelengths. People huff and puff about how CO2 traps heat over and over again in the layers of the atmosphere. The problem is that every time it's heat...75% of that heat is radiated away, outside the frequencies of CO2. The mechanism you keep describing isn't a highly efficient method of trapping energy...it's a highly efficient method of converting it into frequencies NOT covered by CO2. The temperature gradient caused by CO2 absorption is NOT equal to the amount of energy absorbed, it's equal to the amount of energy absorbed for however long it's trapped. It doesn't trap a day's energy, it traps minutes worth of the sun's energy. You're talking about a temperature increase from the delay of a couple percent of the energy for just a few minutes total.
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Post by socold on Mar 25, 2009 23:33:14 GMT
The hat analogy is dead on. You people keep acting as if the ONLY frequencies of IR coming from the earth were those affected by CO2. Were that the case you'd have a leg to stand on. This however is not the case. MOST of the radiation pours out of the atmosphere unchecked. Of the energy captured by CO2...most of that is radiated straight back out of the atmosphere unchecked as well. CO2's only contribution is a pause of a few minutes, not some bottomless pit of energy. The 4wm-2 earth emission reduction from doubling co2 is taking into account the fact that co2 doesn't absorb at all wavelengths and some wavelengths co2 does absorb in is already saturated. If that wasn't the case the forcing would be far greater than 4wm-2. The Earth is absorbing about 240wm-2 from the Sun and emitting 240wm-2 IR into space. Doubling co2 reduces the emission into space to about 236wm-2. Ie reduces it by about 4wm-2. Earth's emission is reduced. It is still absorbing 240wm-2 but now is emitting only 236wm-2. Heat builds up, Earth warms. It stops warming once the emission is 240wm-2 again and then remains at the new warm temperature. It doesn't really matter whether the additional emission is coming from water vapor or co2. In both cases you require a warmer atmosphere to do it. And the point of course which cannot be avoided is that to pump out 240wm-2 again after a doubling of co2 the earth has to be warmer.
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Post by steve on Mar 26, 2009 9:05:44 GMT
Poitsplace Essentially, what you are claiming is that the earth emits into space no radiation in the wavebands absorbed by CO2, because it has all been absorbed by the CO2. Do you believe that? Could you dig out a spectrum of the outgoing radiation from the earth which shows this? Is this spectrum incorrect then? www.barrettbellamyclimate.com/page15.htmSee also this paper for evidence of the enhanced greenhouse effect: Volume 16, Issue 22 (November 2003) Journal of Climate Observations of the Infrared Outgoing Spectrum of the Earth from Space: The Effects of Temporal and Spatial Sampling H. E. Brindley and J. E. Harries
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