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Post by jimcripwell on Oct 15, 2009 0:27:18 GMT
socold writes "How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous?"
The earth is not gaining an addiyional 3.7 mm-2. This is a purely hypothetical number which can never be measured experimentally, and so can never be validated. It is merely the output of non-valididated computer programs.
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Post by sigurdur on Oct 15, 2009 2:12:45 GMT
socold writes "How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous?" The earth is not gaining an addiyional 3.7 mm-2. This is a purely hypothetical number which can never be measured experimentally, and so can never be validated. It is merely the output of non-valididated computer programs. I am going to have to dig deep and find the paper written last year that shows that earth's radiation budget is actually running negative right now. We are losing more heat than we are gaining. Anyone remember who the author's were of this? Used ONLY satillite info and not tried to model etc.
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Post by sigurdur on Oct 15, 2009 2:15:17 GMT
How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous? Socold: I have been searching for validation of that "3.7 wm-2" for years and can't find ONE source. Being you are familiar with it, can you show me the base source for that figure?
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Post by poitsplace on Oct 15, 2009 4:19:48 GMT
How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous? You don't know how much it will do. If the absorption at the tropopause is actually caused more by water vapor intercepting and reemitting CO2's spectrum before that altitude...then it won't do much at all because its just emitting whatever it can. If the warming occurs in the tropopause...you know, the region of low thermal mass but which is likely the only place limiting radiation...then there will be very little warming on the ground because the atmospheric "window" will be opened up for those frequencies. Let's see, there's mixing of all the air in the troposphere but no mixing at the tropopause. If you had to pick which part of the atmosphere was likely to develop a hot spot, which do you think it would be? The low thermal mass of the tropopause where the additional absorption would actually take place...or the well mixed troposphere where water vapor dominates the lapse rate and where water vapor both bypasses and lowers the impact of CO2's absorption? Of course, it's an extremely chaotic system...so it's hard to know what it would do. But, since we're not warming at a rate that would indicate there's an imbalance of even that suggested by CO2 absorption...its a pretty safe bet to assume the climate has a fairly low sensitivity. It will probably be some time before we work out what sensitivity (if its even detectable) CO2 actually has. In the mean time...let's just imagine how much of an impact on US food production this recent cold snap would have had if temperatures were initially in the ranges of the 60s and 70s.
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Post by socold on Oct 15, 2009 18:32:48 GMT
socold writes "How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous?" The earth is not gaining an addiyional 3.7 mm-2. This is a purely hypothetical number which can never be measured experimentally, and so can never be validated. It is merely the output of non-valididated computer programs. 3.7wm-2 is based on lab and atmospheric experiments to determine the absorption properties of gases. This is used to calculate how much extra IR will be absorbed if there were twice as much co2 molecules in the atmosphere. And in turn that tells you how much less energy will reach space. The climate system must respond to this forcing by reconfiguring temperature, clouds, etc.
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Post by socold on Oct 15, 2009 18:34:13 GMT
How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous? Socold: I have been searching for validation of that "3.7 wm-2" for years and can't find ONE source. Being you are familiar with it, can you show me the base source for that figure? The figure is derived from radiative models. It's essentially based on calculating how much extra IR would be absorbed if there was double the number of co2 molecules in the atmosphere.
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Post by socold on Oct 15, 2009 18:39:42 GMT
How can Earth gaining an additional 3.7wm-2 only cause 0.01C warming? Isn't it that which sounds the most preposterous? You don't know how much it will do. Yes I do. Science shows it's 3.7wm-2. This is the amount of energy 750 billion additional tons of co2 in the atmosphere would absorb. Complex calculations, but the basis is simple. So doubling co2 in the atmosphere will cause Earth's energy loss into space to reduce by 3.7wm-2. The question is, how would that not cause warming?
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Post by jimcripwell on Oct 15, 2009 20:53:52 GMT
socold writes "The figure is derived from radiative models."
You can go on repeating this as often as you like, but it still will not alter the fact that radiative transfer models have not been validated as suitable computer programs to estimate the value of radiative forcing. Unless a number can be actually measured, there is no way to validate any computer program. 3.7 wm-2, I repeat, is a purely hypothetical number with no practical use whatsoever. You have not, and cannot, produce a reference that shows that radiative transfer models are capable of estimating radiative forcing.
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Post by sigurdur on Oct 15, 2009 21:46:46 GMT
socold writes "The figure is derived from radiative models." You can go on repeating this as often as you like, but it still will not alter the fact that radiative transfer models have not been validated as suitable computer programs to estimate the value of radiative forcing. Unless a number can be actually measured, there is no way to validate any computer program. 3.7 wm-2, I repeat, is a purely hypothetical number with no practical use whatsoever. You have not, and cannot, produce a reference that shows that radiative transfer models are capable of estimating radiative forcing. Thank you Socold. And Jimmy......you stated what I have found so very well. I understand that the 3.2W proposed is a slab model. But in reality, the h2o cycle seems to have deminished the 3.2W as climate is never in a slab state.
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Post by socold on Oct 15, 2009 22:42:00 GMT
socold writes "The figure is derived from radiative models." You can go on repeating this as often as you like, but it still will not alter the fact that radiative transfer models have not been validated as suitable computer programs to estimate the value of radiative forcing. It won't alter the fact that they are sufficient to estimate radiative forcing. Radiative forcing doesn't involve the response. It's the amount of extra radiation 750 billion tons more co2 in the atmosphere would absorb, all other things being equal. Therefore it is of practical use because we know 3.7wm-2 X other things not being equal = temperature response The skeptic argument that doubling co2 causes hardly any warming relies on "other things not being equal" meaning negative feedback. But just how you get only a 0.01C temperature rise from a 3.7wm-2 perpetuation in earth's energy balance is a good quesiton.
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Post by socold on Oct 15, 2009 23:03:38 GMT
socold writes "The figure is derived from radiative models." You can go on repeating this as often as you like, but it still will not alter the fact that radiative transfer models have not been validated as suitable computer programs to estimate the value of radiative forcing. Unless a number can be actually measured, there is no way to validate any computer program. 3.7 wm-2, I repeat, is a purely hypothetical number with no practical use whatsoever. You have not, and cannot, produce a reference that shows that radiative transfer models are capable of estimating radiative forcing. Thank you Socold. And Jimmy......you stated what I have found so very well. I understand that the 3.2W proposed is a slab model. But in reality, the h2o cycle seems to have deminished the 3.2W as climate is never in a slab state. The 3.7wm-2 figure takes into account the radiative properties of water vapor. It's a comparison between two atmospheres A and B where: A) Is identical to our atmosphere B) Is identical to our atmosphere but for one difference - double the co2. Temperature is the same as A, cloud amount is the same as A, humidity is the same as A. But B has twice as much co2 in the atmosphere than A. One way of looking at it is that B is our atmosphere if co2 level was instantly doubled, before the surface temperature, clouds, etc can change in response. Calculating the difference in outgoing radiation between A and B only requires calculating the radiative changes caused by the presence of the extra co2. It doesn't require needing to knowing how the climate will respond - ie how clouds will change, how water vapor will change, ie feedbacks. This is why the 3.7wm-2 figure can be pinned down. How the climate responds to the 3.7wm-2 reduction in outgoing radiation determines the temperature change that will cause. But the 3.7wm-2 figure is a significant imbalance caused by doubling co2, therefore the climate response must be significant whether or not temperature increases much.
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Post by jimcripwell on Oct 16, 2009 0:49:00 GMT
socold You still have not given a reference that proves that radiative transfer models are suitable to provide a quantitative estimate of radiative forcing.
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Post by icefisher on Oct 16, 2009 0:58:03 GMT
Yes I do. Science shows it's 3.7wm-2. This is the amount of energy 750 billion additional tons of co2 in the atmosphere would absorb. Complex calculations, but the basis is simple. The carney barker cries out step right into my tent of smoke and mirrors and be amazed!! Its simple and complex at the same time!! But the man with many feathers in his hat can interpret them for you!!! Shake a lodestone here, a frog head there, a couple of spiders and viola. . . . It'll only cost a little!
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Post by sigurdur on Oct 16, 2009 1:13:23 GMT
Thank you Socold. And Jimmy......you stated what I have found so very well. I understand that the 3.2W proposed is a slab model. But in reality, the h2o cycle seems to have deminished the 3.2W as climate is never in a slab state. The 3.7wm-2 figure takes into account the radiative properties of water vapor. It's a comparison between two atmospheres A and B where: A) Is identical to our atmosphere B) Is identical to our atmosphere but for one difference - double the co2. Temperature is the same as A, cloud amount is the same as A, humidity is the same as A. But B has twice as much co2 in the atmosphere than A. One way of looking at it is that B is our atmosphere if co2 level was instantly doubled, before the surface temperature, clouds, etc can change in response. Calculating the difference in outgoing radiation between A and B only requires calculating the radiative changes caused by the presence of the extra co2. It doesn't require needing to knowing how the climate will respond - ie how clouds will change, how water vapor will change, ie feedbacks. This is why the 3.7wm-2 figure can be pinned down. How the climate responds to the 3.7wm-2 reduction in outgoing radiation determines the temperature change that will cause. But the 3.7wm-2 figure is a significant imbalance caused by doubling co2, therefore the climate response must be significant whether or not temperature increases much. Ok, so it is a theoretical value, verses an emperical value. And the theoretical value is done using a slab. I understand the reasoning behind unsing a slab to obtain the 3.7W, but it would appear in reality that the 3.7 will not hold up to scrutiny. So, that gets us to sensativity......right? And the best paper I have read on that to this point is Lindzen's paper......which indiates what... .3C? potential realisitically?
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Post by poitsplace on Oct 16, 2009 6:46:02 GMT
Reality tells us sensitivity is low. Otherwise we'd still be warming. (especially since the previous warming was unprecedented")
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