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Post by magellan on Apr 27, 2009 0:36:30 GMT
The last challenge thread got hijacked so let's try this one.
1) Provide evidence that Greenland and the Arctic are influenced by increases or decreases in atmospheric CO2. 2) More specifically, provide evidence that the 2007 "record" ice loss was due to increased levels of atmospheric CO2.
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Post by steve on Apr 27, 2009 11:27:29 GMT
The last challenge thread got hijacked so let's try this one. 1) Provide evidence that Greenland and the Arctic are influenced by increases or decreases in atmospheric CO2. As shown in previous threads, a number of lines of evidence demonstrate that a doubling of CO2 is very likely to lead to warming of at least 1.5C. Evidence from the last interglacial is that it was about this much warmer then, and then they had sea levels of 6 metres higher. This was due to a reduced-size Greenland and/or West Antarctic Ice Sheet. Since 1979 there has been a downward trend of Arctic sea ice that is reasonably well correlated with observed Arctic warming. That more warming means less ice makes sense of those of us who like ice in our drinks. The record loss was on account of a number of things. Not just the warming due to CO2.
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jtom
Level 3 Rank
Posts: 248
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Post by jtom on Apr 27, 2009 14:10:45 GMT
"As shown in previous threads, a number of lines of evidence demonstrate that a doubling of CO2 is very likely to lead to warming of at least 1.5C. "
Once again, the 'evidence' you claim did not DEMONSTRATE that a doubling of CO2 led to a warming of 1.5C. An assumption of the research was that the correlation between increased CO2 and temperature was due to CO2 causing warming.
If they started with the assumption that warming caused an increase in the level of CO2, they would conclude that an increase of 1.5C led to a doubling of CO2 WITHOUT CHANGING A WORD OF THE RESEARCH. Thus, nothing was demonstrated, they only theorized a possibility based upon a set of assumptions.
Secondly, that kind of an analysis can be done with ANYTHING that shows a correlation (atmospheric CO2 has been increasing 5 ppm every year since my house was built. Obviously, we can stop the increase by burning down my house. Please don't tell anyone). It does not demonstrate cause and effect.
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Post by steve on Apr 27, 2009 14:29:39 GMT
"As shown in previous threads, a number of lines of evidence demonstrate that a doubling of CO2 is very likely to lead to warming of at least 1.5C. " Once again, the 'evidence' you claim did not DEMONSTRATE that a doubling of CO2 led to a warming of 1.5C. An assumption of the research was that the correlation between increased CO2 and temperature was due to CO2 causing warming. If they started with the assumption that warming caused an increase in the level of CO2, they would conclude that an increase of 1.5C led to a doubling of CO2 WITHOUT CHANGING A WORD OF THE RESEARCH. Thus, nothing was demonstrated, they only theorized a possibility based upon a set of assumptions. Secondly, that kind of an analysis can be done with ANYTHING that shows a correlation (atmospheric CO2 has been increasing 5 ppm every year since my house was built. Obviously, we can stop the increase by burning down my house. Please don't tell anyone). It does not demonstrate cause and effect. Happy to change "demonstrate" to "in line with". My reading of the paper I assume you are referring to differes from yours, and it's just one of the lines of evidence. The paper's main assumption was that the CO2 weathering rate was influenced by temperature and CO2 concentration, not that temperature drove CO2 or vice versa. There are other papers that do look at temperature vs CO2 forcing estimates. While people may choose to assume that it must be because temperature drives CO2 but CO2 cannot drive temperature, I'm going to choose to believe the basic physics of CO2 forcing (Myrhe 1998 etc) on which such papers are based.
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Post by magellan on Apr 27, 2009 16:41:27 GMT
"As shown in previous threads, a number of lines of evidence demonstrate that a doubling of CO2 is very likely to lead to warming of at least 1.5C. " Once again, the 'evidence' you claim did not DEMONSTRATE that a doubling of CO2 led to a warming of 1.5C. An assumption of the research was that the correlation between increased CO2 and temperature was due to CO2 causing warming. If they started with the assumption that warming caused an increase in the level of CO2, they would conclude that an increase of 1.5C led to a doubling of CO2 WITHOUT CHANGING A WORD OF THE RESEARCH. Thus, nothing was demonstrated, they only theorized a possibility based upon a set of assumptions. Secondly, that kind of an analysis can be done with ANYTHING that shows a correlation (atmospheric CO2 has been increasing 5 ppm every year since my house was built. Obviously, we can stop the increase by burning down my house. Please don't tell anyone). It does not demonstrate cause and effect. Happy to change "demonstrate" to "in line with". My reading of the paper I assume you are referring to differes from yours, and it's just one of the lines of evidence. The paper's main assumption was that the CO2 weathering rate was influenced by temperature and CO2 concentration, not that temperature drove CO2 or vice versa. There are other papers that do look at temperature vs CO2 forcing estimates. While people may choose to assume that it must be because temperature drives CO2 but CO2 cannot drive temperature, I'm going to choose to believe the basic physics of CO2 forcing (Myrhe 1998 etc) on which such papers are based. I asked for evidence, not lectures about "basic physics" or your belief system.
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Post by jimcripwell on Apr 27, 2009 16:53:32 GMT
steve writes " I'm going to choose to believe the basic physics of CO2 forcing (Myrhe 1998 etc) on which such papers are based. "
This is, of course, the problem. There is no basic physics in Myhre et al. It starts by using the word "calculations". My idea of "calculations" is where you have an exact formula, like I can calculate how much money I owe on income tax each year. There is no exact formula for the radiative forcing (RF) of CO2, so a better word is "estimate". The best word is "guess". The authors state they have used 3 radiative transfer models. Nowhere do they show that such models are suitable to guess at the value of the RF of CO2. Conduction, convection and the latent heat of water also transfer heat in the atmosphere, and these could easily influence the value of the RF of CO2. Where is the proof that radiative transfer models can be used to estimate the value of the RF of CO2? However, the main problem is that it is impossible to carry out the experiment that, when you add CO2 to current levels in the atmosphere, measures how much the world temperatures actually rises. Such an experiment is impossible to do. This must have been known ab initio, yet the proponents of AGW have perpetuated this hoax about AGW to the present day. With no experimental data, there is no physics. Any calculations may be subject ot the Kelvin Fallacy, and so cannot be trusted. All in all, Myhre et al is merely smoke and mirrors.
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Post by steve on Apr 27, 2009 17:53:30 GMT
steve writes " I'm going to choose to believe the basic physics of CO2 forcing (Myrhe 1998 etc) on which such papers are based. " This is, of course, the problem. There is no basic physics in Myhre et al. It starts by using the word "calculations". My idea of "calculations" is where you have an exact formula, like I can calculate how much money I owe on income tax each year. There is no exact formula for the radiative forcing (RF) of CO2, so a better word is "estimate". The best word is "guess". The authors state they have used 3 radiative transfer models. Nowhere do they show that such models are suitable to guess at the value of the RF of CO2. Conduction, convection and the latent heat of water also transfer heat in the atmosphere, and these could easily influence the value of the RF of CO2. Myrhe 1998 calculates the forcing *before* the changes in convection and the hydrological cycle. The forcing is the change in the outgoing long wave radiation that occurs when CO2 is increased instantaneously. I'm prepared to believe that that is reasonably calculable (based on a reasonably accurate atmosphere profile) because I've used other sorts of radiation models to good effect, because radiation models aren't uniquely used by climate scientists, and because observational evidence matches the models reasonably well. There *is* an exact formula, for the radiative forcing. The fact that it can be estimated reasonably accurately doesn't affect matters. If you believe only science that can be calculated exactly, then you are limiting yourself somewhat.
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Post by jimcripwell on Apr 27, 2009 20:08:41 GMT
steve writes "There *is* an exact formula, for the radiative forcing. "
Fair enough. What is it?
And you have not addressed the fact that there is no experimental data to measure radiative forcing.
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Post by steve on Apr 27, 2009 21:10:31 GMT
steve writes "There *is* an exact formula, for the radiative forcing. " Fair enough. What is it? What's the calculation of your tax return? There is experimental measurement of the electromagnetic spectra of the earth that can be compared with the model. There are measurements taken a number of years apart that can confirm the effects of increasing CO2.
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Post by jimg on Apr 27, 2009 22:42:39 GMT
Steve said:
There are measurements taken a number of years apart that can confirm the effects of increasing CO2.
Isn't that with the caveat: All other things being equal?
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Post by jimg on Apr 27, 2009 22:45:23 GMT
Steve. Were you claiming that tropospheric CO2 or stratospheric CO2 has the greater effect?
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Post by jimcripwell on Apr 28, 2009 0:01:34 GMT
steve writes "There is experimental measurement of the electromagnetic spectra of the earth that can be compared with the model. There are measurements taken a number of years apart that can confirm the effects of increasing CO2."
steve, you are avoiding my questions. I am specifically talking about Myhre et al, which you started. This deals with the estimation of the radiative forcing (RF) of CO2. That is all I am talking about. First, do you agree that there is no experimental data that measures the RF of CO2 directly? Second, where is the reference, or the exact formula, from which the RF of CO2 can be calculated exactly? Third, where is the discussion that shows that radiative transfer models are suitable to be used to estimate the RF of CO2?
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Post by magellan on Apr 28, 2009 0:27:04 GMT
Ok folks, we are descending into hypothetical scenarios again. Earth is not an enclosed box in a laboratory. No evidence, experimental or otherwise, has been presented linking CO2 to Arctic ice melt (or even warming), as I suspected there wouldn't be.
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Post by nautonnier on Apr 28, 2009 3:37:09 GMT
Yes hypotheticals and totally unreals...
"Myrhe 1998 calculates the forcing *before* the changes in convection and the hydrological cycle. The forcing is the change in the outgoing long wave radiation that occurs when CO2 is increased instantaneously."
A really realistic system. Only a mathematician would think that this approach could be anything like normal. As soon as the first CO2 molecule gets excited and starts colliding with other molecules then then convection starts. When convection starts all sorts of other feedbacks both positive and negative start some of them reacting to the various states of the others. Not only that but much of the heat leaves the surface as sensible and latent heat carried by water vapour and does not become radiation until far higher in the atmosphere and is ignored by a radiation only model.
So we have an imaginary world with no feedbacks, no hydrological cycle (until afterward - why not before??) and then instantaneously raise the level of CO2 to an unreal level. Then on the outcome of that base the formula for calculating the effect of CO2 being increased steadily in a real atmosphere with a multiplicity of interrelated feedbacks to an unreal level over a century?
This is a scientific approach?
The <bow> models' </bow> assumptions are built around formulae from this unreal slab atmosphere with an instantaneous jump in CO2 to unreachable levels?
Then on the basis of these models of 'physical laws' politicians are persuaded to tax industries into bankruptcy?
There are cases when assumptions can be overly simplistic to a level that they are unreliable. I think that this is one of them.
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Post by steve on Apr 28, 2009 14:37:26 GMT
Steve said: There are measurements taken a number of years apart that can confirm the effects of increasing CO2. Isn't that with the caveat: All other things being equal? This is just one of three reasons for trusting the analysis. The "all things being equal" relates to average changes to the climate that may have additional effects. By measuring decades apart and by picking two similar atmosphere profiles (usually a profile with clear sky) you are measuring two atmosphere columns with different, known, amounts of CO2, and can confirm that the models used to calculate the radiation produce the correct results in both scenarios. That is additional confirmation that the radiation model is sufficiently accurate.
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