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Post by socold on Jul 25, 2009 14:35:39 GMT
Another strawman. The models do incorperate H2O well. Not perfectly. But well. By their own admission, the IPCC states that is has a very poor understanding of h2o vapor. You are thinking of clouds or aerosols or something, not h2o vapor. The IPCC also states it is "very likely" that recent warming is due to human activity.
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Post by sigurdur on Jul 25, 2009 15:05:47 GMT
By their own admission, the IPCC states that is has a very poor understanding of h2o vapor. You are thinking of clouds or aerosols or something, not h2o vapor. The IPCC also states it is "very likely" that recent warming is due to human activity. Yes, they state it is likely, but not a certainty at all. From 15 years of studying this as a layman, I think humans have contributed to warming, however; not nearly as much as some would infer. The cycles still predominate and always will.
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Post by slh1234 on Jul 25, 2009 15:30:26 GMT
Edit: I have to come back for this one after reading this from Steve: I know I spend a lot of time pointing out how easily someone will accept arguments that support what they want to believe, and will spend all their energy arguing against things that do not support what they want to believe, but this one surprised even me. No questions? No professional skepticism? No questioning of the fallacy that can develop from two people comparing results for accuracy? Not even a clarification of the meaning of "errors" as used in the statement? Just a wholesale swallowing of the line. OK almost my last word. In what way is your comment relevant to my criticism of icefisher's arguing technique and his abject failure to prove his absurd allegations that climate modeller developers are fraudulent and incompetent. Just once it would be nice for someone to at least acknowledge "yes it appears they might have done as good a job as possible of building a model" even if you then go on to argue that building a useful model is an impossible task. When that is done, perhaps a more civilised conversation might ensue about whether models might reasonable represent an earthlike climate and whether models subjected to a forcing from greenhouse gases, aerosols or solar effects might reasonably represent an earth-like response. If you read my posts you will find me discussing the unreasonably good results from 20th century hindcasts (implying that something, probably inadvertent, is up), the fact that models do not fully represent solar cycle variation, and the fact that models do not agree on feedbacks or even the relative causes of different sources of feedbacks. I will even accept that the apparent overlap of the models and satellite data when you take into account natural variability and uncertainty in the observations, is not yet good enough - though it is as much a question for the satellite data as the models. But when you get down to it. CO2 warms the climate, so the initial expectation really ought to be that more CO2 might just warm it more. My point is that you also believe what you want to beleive and argue against anything that disagrees with that point. Of course, everybody wants to believe they don't do that and that theirs is a correct method of debate. I think the modellers do the best job possible to build climate models. I do not think it is possible to model the climate accurately. How accurate they can get remains to be seen. That's great. Let's ackoowledge the models for just that. In that case, there is NO WAY that guideance should be given to political systems based on those models. They are still in development, and have not yet shown that they can accurately predict the climate 20 years out. Hindcasting is not the same thing as forecasting. An example of a model I think is useful is the one used to project the path of a tornado. But the interesting thing about that: The path is projected in a wedge shape out from the current position of the tornado. The farther out in time it goes, the more margin for error there is, and this is reflected in the wedge shape. Truth be told, the meteorologists can see the hook in the doppler radar, and see that there might be a tornado there, but until spotters see the tornado, they can't be sure there really is a tornado, and certainly can't see if it is on the ground. In their model projections, they likewise cannot tell if the tornado will still be on the ground in 10 minutes. I think that is an ethical use of modelling. They recognize and acknowledge the limitations and recommend action based on that. The limitations are not acknowledged in climate models. We know that all factors are not known, and in fact, it is probably not possible to accurately model the climate on as long a scale as they are trying to do - especially not with the data types we have to work with in modern computing. If they want to develop these models, then great, let's recognize that development for what it is - development. It is not something we should be basing political decisions on.
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Post by sigurdur on Jul 25, 2009 15:46:47 GMT
aye sir. Very truthful post about models
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Post by nautonnier on Jul 25, 2009 16:29:32 GMT
Socold The very DEFINITION of radiative forcing is using a static slab atmosphere specifically WITHOUT ANY CONVECTION this is why they call it RADIATIVE forcing You are confusing radiative forcing with climate response. How the climate changes when a forcing is applied is the response. Changes to convection are part of the response, not part of the forcing. The forcing is a measure of the energy inbalance caused by a change. The climate will respond to reduce that energy inbalance, including changes in convection. But those changes in convection don't alter the initial amount of energy inbalance caused. How convection changes doesn't alter the initial forcing. Why is it called a "radiative" forcing? Because the Earth can only gain and lose energy by absorbing radiation from space and emitting radiation to space. The Earth cannot gain or lose energy by convection and conduction because it's surrounded by a vacuum. Therefore any change to the Earth's energy balance can be described entirely in terms of the change in radiation out vs in. For example if the sun increases output by 2% that causes the Earth to gain 4wm-2 more radiation than it emits. The Earth will respond in a way that reduces this inbalance back to zero. How it responds to do this (increased convection, warmer surface, whatever) doesn't alter the fact of the 4wm-2 initial inbalance. Another example if co2 in the atmosphere is doubled that also causes the Earth to be gaining 4wm-2 more radiation than it emits. Again the Earth will respond in a way that reduces this inbalance back to zero. How it does so doesn't alter the fact of the 4wm-2 initial inbalance. Both cases highlight an important use of radiative forcing - they allow seperate causes to be compared, because generally the overall climate response to a forcing is pretty much the same irregardless of the cause. They aren't starting, they've been doing it for decades and the laws governing it are not extremely complex, they are just computationally intensive. The modelling is accurate. No we are describing the change in energy in vs out caused by a change, such as a 2% increase in solar output or a doubling of co2. We can for example see that a 2% decrease in solar output would roughly cancel out a doubling of co2. Without the concept of radiative forcing such a comparison between solar output and greenhouse gas changes would be made far more difficult. Radiative forcing isn't used to "quantify the total heat energy transport from the surface to the tropopause". It's used to quantify the initial change in energy in vs energy out of the Earth system due to a forcing event. After the intial change there will of course be internal changes to reduce the forcing, such as changes in convection, clouds, etc, but that is response not forcing. Everything else isn't disregarded, models calculate how convection responds to the forcing, but that is not the forcing, it's the response "You are confusing radiative forcing with climate response. How the climate changes when a forcing is applied is the response"Lets take this a step at a time I model a building where I put a stack of kindling down against the wooden wall. Then set light to it. Keeping everything else static in the building my model shows it burns down in 1 hour. I then repeat the modeling with a different type of wall and again keeping everything else invariant find it takes 90 minutes to burn down. Thus the flammability can be compared. REALITY I put some kindling down against the wooden wall. Then set light to it and the sprinkler system and halon flooding extinguish the kindling in less than 60 seconds - the wall doesn't even catch fire. I may have a coefficient of flammability - but I CANNOT use it as the sole metric for the fire safety of the building The moral of the story (if you haven't managed to understand) is that FORCING cannot be allowed its full effect INSTANTANEOUSLY as if there are no feedbacks. In reality the feedbacks - the sprinkler system and halon flooding, start almost as soon as the input forcing is sensed and immediately modify its effect. You can live in an unreal world and use it to develop pretty hypotheses but do NOT confuse those hypotheses with reality. The very fact that radiative forcing is considered without the modifying effect of the convective and hydrologic effects makes it totally unreal. As soon as heating however minor exists the feedbacks start and they modify the input forcing - that is what a feedback does in a system, there is no pause to await full effect before feedback starts. The values that have been calculated against a frozen unperturbed atmosphere can never be reached because in reality the atmosphere does not remain frozen and unperturbed and feedbacks immediately start. If you want to tax/govern/change the behavior of - people in the real world then it is only ethical to actually model the real effects in the real world. To do that a real-world metric is required that is not limited solely to one parameter in a chaotic system with complex feedbacks between multiple parameters.
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Post by socold on Jul 25, 2009 20:00:28 GMT
Lets take this a step at a time I model a building where I put a stack of kindling down against the wooden wall. Then set light to it. Keeping everything else static in the building my model shows it burns down in 1 hour. I then repeat the modeling with a different type of wall and again keeping everything else invariant find it takes 90 minutes to burn down. Thus the flammability can be compared. I am not in favor of using analogies as there are always differences. But in this case so far the kindling is analogous to the forcing. Whether the building burns down in 1 hour or sprinklers save it is analogous to the response. However that response doesn't alter the concept or value of the forcing which is the same irregardless of how the system responds to it. As soon as you try to calculate the effect you are calculating the response, not the forcingResponse is not part of the forcing. The forcing is equivalent to the kindling being put against the wall. Of course that doesn't take into account the response. It's not supposed to. The simple act of putting kindling next to the wall or increasing solar output by 2% or doubling co2 knock the system out of balance and the system will respond to get back into balance. Same with the climate models. There are instantaneous doubling experiments of course, but also experiments with gradual increases in co2 (like 1% a year). It makes little difference to the final state whether you gradually increase the forcing to doubled-level or instantly change it. Convection and hydrological effects are considered - in the response. Take the kindling again. Putting flaming kindling up against a wall doesn't take into account the response. Yet it's certainly not "totally unreal". It's the input into what the system is about the respond to. That's the response. Of course the response alters the forcing, otherwise how would the system return to energy balance? But that doesn't alter the intial forcing. A solar output increase of 2% creates a 4wm-2 radiative forcing, meaning that if the Earth is in energy balance and solar output increases 2%, 4wm-2 more energy will be aborbed by the Earth than emitted. In response the Earth warms up, convection alters until many years later the forcing relative to the start point is now 0wm-2. That however doesn't mean the forcing from a 2% solar output is zero. That's why the forcing doesn't take into account the response, it would be meaningless if it did.
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Post by icefisher on Jul 25, 2009 23:39:22 GMT
Lets take this a step at a time I model a building where I put a stack of kindling down against the wooden wall. Then set light to it. Keeping everything else static in the building my model shows it burns down in 1 hour. I then repeat the modeling with a different type of wall and again keeping everything else invariant find it takes 90 minutes to burn down. Thus the flammability can be compared. However that response doesn't alter the concept or value of the forcing which is the same irregardless of how the system responds to it. Value? Thats kind of like saying there are a billion checkbooks in the world and a billion pens and a billion bank accounts; but not many are going to write you a check. Value is from what one expects to be realized. If you are on the looney tune express perhaps values are a little altered for you. A solar output increase of 2% creates a 4wm-2 radiative forcing, meaning that if the Earth is in energy balance and solar output increases 2%, 4wm-2 more energy will be aborbed by the Earth than emitted. In response the Earth warms up, convection alters until many years later the forcing relative to the start point is now 0wm-2. That however doesn't mean the forcing from a 2% solar output is zero. That's why the forcing doesn't take into account the response, it would be meaningless if it did. The earth warms up? How do you know that? Perhaps just the upper atmosphere warms. Language is a funny thing. Someone tests the heat of boiling water by touching their fingertip to it. Can you then say you were boiled? I guess for the black and white only no grey crowd you were. . . .or you weren't; depending upon your political outlook.
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Post by socold on Jul 26, 2009 1:28:07 GMT
Value as in 4wm-2 forcing from a 2% increase in solar output. That's true irrespective of how the Earth responds to 4wm-2 additional solar energy.
"The earth warms up? How do you know that? Perhaps just the upper atmosphere warms"
The upper atmosphere is part of the Earth. Is the idea of the Earth warming up in response to absorbing more energy controversial?
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Post by icefisher on Jul 26, 2009 6:44:10 GMT
The upper atmosphere is part of the Earth. Is the idea of the Earth warming up in response to absorbing more energy controversial? Silly me. . . .! Must be getting paranoid about a bunch of loons trying to double the cost of filling up my pickup.
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Post by nautonnier on Jul 26, 2009 11:31:26 GMT
Lets take this a step at a time I model a building where I put a stack of kindling down against the wooden wall. Then set light to it. Keeping everything else static in the building my model shows it burns down in 1 hour. I then repeat the modeling with a different type of wall and again keeping everything else invariant find it takes 90 minutes to burn down. Thus the flammability can be compared. I am not in favor of using analogies as there are always differences. But in this case so far the kindling is analogous to the forcing. Whether the building burns down in 1 hour or sprinklers save it is analogous to the response. However that response doesn't alter the concept or value of the forcing which is the same irregardless of how the system responds to it. As soon as you try to calculate the effect you are calculating the response, not the forcingResponse is not part of the forcing. The forcing is equivalent to the kindling being put against the wall. Of course that doesn't take into account the response. It's not supposed to. The simple act of putting kindling next to the wall or increasing solar output by 2% or doubling co2 knock the system out of balance and the system will respond to get back into balance. Same with the climate models. There are instantaneous doubling experiments of course, but also experiments with gradual increases in co2 (like 1% a year). It makes little difference to the final state whether you gradually increase the forcing to doubled-level or instantly change it. Convection and hydrological effects are considered - in the response. Take the kindling again. Putting flaming kindling up against a wall doesn't take into account the response. Yet it's certainly not "totally unreal". It's the input into what the system is about the respond to. That's the response. Of course the response alters the forcing, otherwise how would the system return to energy balance? But that doesn't alter the intial forcing. A solar output increase of 2% creates a 4wm-2 radiative forcing, meaning that if the Earth is in energy balance and solar output increases 2%, 4wm-2 more energy will be aborbed by the Earth than emitted. In response the Earth warms up, convection alters until many years later the forcing relative to the start point is now 0wm-2. That however doesn't mean the forcing from a 2% solar output is zero. That's why the forcing doesn't take into account the response, it would be meaningless if it did. "As soon as you try to calculate the effect you are calculating the response, not the forcing
Response is not part of the forcing. The forcing is equivalent to the kindling being put against the wall. Of course that doesn't take into account the response. It's not supposed to."This is your major logic flaw SoCold. Anthropogenic Global Warming is being pushed as something that WILL destroy mankind unless CO 2 output from anthropogenic action is stopped. This is based on hypothetical numbers showing the INPUT FORCING to the system WITHOUT REGARD to the response of the system. But the system RESPONSE must be considered as if it were to immediately overwhelm the input then the input whatever its magnitude is unimportant. So we need a metric for the EFFECT of the input, ideally one that accepts that the effect could be inversely proportionate to the input. So if the response to a rise in outgoing heat absorption is an increase in convection and the hydrologic cycle and heat escapes to the stratosphere in any case and albedo increases reducing heat input, then the the absorption may have altered the way the heat is transported but the reaction of the system means that the actual heat content of the atmosphere remains stable. You have GOT to look at both sides of the equation as it is the feedbacks that make it the SYSTEM that we live in. You cannot start proselytising the severe impact on the SYSTEM based on only considering an input - you must consider the entire system. Therefore, 'radiative' forcing is a one sided and incorrect metric for measuring the heat budget of the earth By all means if you feel you must then use it - but its a totally meaningless metric as it assumes instantaneous increase in a greenhouse gas with no tropospheric response. So yes its a nice hypothetical mathematical coefficient but NOT something a physicist would use. This is why Jim Cripwell is correct in his assertion that there is no experimental evidence for radiative forcing - there can never be as its an unreal construct. We NEED a real. physically measurable metric for the 'green house effect' of gases on the climate and a methodology for its real world quantification. Radiative forcing is not it.
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Post by nautonnier on Jul 26, 2009 11:41:25 GMT
Value as in 4wm-2 forcing from a 2% increase in solar output. That's true irrespective of how the Earth responds to 4wm-2 additional solar energy. "The earth warms up? How do you know that? Perhaps just the upper atmosphere warms" The upper atmosphere is part of the Earth. Is the idea of the Earth warming up in response to absorbing more energy controversial? "Value as in 4wm-2 forcing from a 2% increase in solar output. That's true irrespective of how the Earth responds to 4wm-2 additional solar energy."Well actually no. If the Earth response to the "2% increase in solar output" is the formation of a huge amount of high albedo cloud with a negative-100WM -2 effect and torrential rain to the surface - then the Earth could actually cool. (such cloud albedos have been measured in the tropics by ERBE) The system response must be known - as I have just said in another post on this thread, Radiative Forcing is not a metric for the actual climatic effect.
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Post by steve on Jul 26, 2009 14:16:26 GMT
As I see it, the purpose of this thread is to try and negate the usefulness of the concept of radiative forcing by saying the concept is useless because whatever the forcing is, it is the response that is important.
I think that the reason why people are trying to negate it is because they accept that it is something that is easily calculated, and therefore it is quite a strong argument.
If I were to argue that it is unreasonable to assume that a 2% increase in total solar irradiation would have a significant effect on the climate, I'd probably be laughed at. That is why the debate on forcing seems so false to me.
The underlying implication is that somehow climate science rests purely on this concept and doesn't properly address the responses.
But the implication is false. Of course there are uncertainties in the responses. But that is why it is researched in many ways (including using observation evidence).
Using the tornado analogy (and similar issues relate to hurricane track forecasting):
When do you secure your windows and plan a trip to the cellar or out of town? When the forecast of 10% chance of being hit is delivered? 20%, 50%? Or do you wait for certainty? At what point does the cost of mitigating the risk (eg. just by getting ready to board your windows, or by shutting your business for a day or two to give people time to leave town) outweigh the risk to life and property? How much are you concerned about your own wealth, and how much are you concerned about the welfare of your employees?
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Post by socold on Jul 26, 2009 14:17:31 GMT
This is your major logic flaw SoCold. Anthropogenic Global Warming is being pushed as something that WILL destroy mankind unless CO 2 output from anthropogenic action is stopped. This is based on hypothetical numbers showing the INPUT FORCING to the system WITHOUT REGARD to the response of the system. On both counts you are wrong. First just to nitpick, AGW is not pushed as something that will destroy mankind. Second it is based on calculations of the response of the system. What do you think GCMs do if not calculate the response? Noone is simply taking the 4wm-2 co2 forcing alone, but in context of the response to such a forcing.
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Post by socold on Jul 26, 2009 14:31:39 GMT
If the Earth response to the "2% increase in solar output" is the formation of a huge amount of high albedo cloud with a negative-100WM -2 effect and torrential rain to the surface - then the Earth could actually cool. (such cloud albedos have been measured in the tropics by ERBE) The system response must be known - as I have just said in another post on this thread, Radiative Forcing is not a metric for the actual climatic effect. How does any of that contradict the sentence of mine you were quoting? For refresh here is my sentence and a key part is bolded: "Value as in 4wm-2 forcing from a 2% increase in solar output. That's true irrespective of how the Earth responds to 4wm-2 additional solar energy."
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Post by icefisher on Jul 26, 2009 16:41:48 GMT
As I see it, the purpose of this thread is to try and negate the usefulness of the concept of radiative forcing by saying the concept is useless because whatever the forcing is, it is the response that is important. I think that the reason why people are trying to negate it is because they accept that it is something that is easily calculated, and therefore it is quite a strong argument. If I were to argue that it is unreasonable to assume that a 2% increase in total solar irradiation would have a significant effect on the climate, I'd probably be laughed at. That is why the debate on forcing seems so false to me. The underlying implication is that somehow climate science rests purely on this concept and doesn't properly address the responses. But the implication is false. Of course there are uncertainties in the responses. But that is why it is researched in many ways (including using observation evidence). Using the tornado analogy (and similar issues relate to hurricane track forecasting): When do you secure your windows and plan a trip to the cellar or out of town? When the forecast of 10% chance of being hit is delivered? 20%, 50%? Or do you wait for certainty? At what point does the cost of mitigating the risk (eg. just by getting ready to board your windows, or by shutting your business for a day or two to give people time to leave town) outweigh the risk to life and property? How much are you concerned about your own wealth, and how much are you concerned about the welfare of your employees? Isn't a 2% increase in insolance at TOA be about 27watts Steve?
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