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Post by icefisher on Feb 24, 2019 1:39:11 GMT
Fatjohn, I deleted an earlier post concerning your 0.67K calculation for direct climate sensitivity due to doubling of CO2. This is a rephrasing of the question with a suggested answer. In looking at your calculations, you calculate the total radiation at the surface by adding the 3.7 w/m^2 from a doubling of CO2 to the current surface radiation. The question that’s been bothering me is how can anyone provide a universal number like 3.7 that is appropriate for all cases since there are many variables like other greenhouse gases, clouds, where (elevation and temperature) of the emissions sources, etc. which affect the determination of this number. Then it occurred to me that the value (forcing) may be just for the blackbody case. To use it for the calculations you are making, you would need to divide the number by the emissivity so it would apply the specific case. Instead of 396 +3.7 w/m^2 it should it be 396 + 3.7 divided by emissivity. Your warming value then would be more like 0.67K/.6 or 1.1K which is consistent with other estimates I have seen. The 3.7w/m2 is a pretty solid number. One just has to be aware of what it represents. What it represents is the amount of additional absorption experienced in the atmosphere from a doubling of CO2. As I understand it this additional absorption isn't subtracted from the atmospheric window but simply estimates an additional layering within the atmosphere of multiple absorptions by CO2. In other words doubling of CO2 probably makes light spend something around a microsecond longer in the atmosphere before it heads off for parts unknown in the universe. Ontop of which the more distant from the surface it is absorbed in the atmosphere the greater the warming effect. Folks I didn't make this up. Its just when one cannot imagine any other explanation that becomes the explanation.
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Post by fatjohn1408 on Feb 24, 2019 11:16:04 GMT
Fatjohn, I deleted an earlier post concerning your 0.67K calculation for direct climate sensitivity due to doubling of CO2. This is a rephrasing of the question with a suggested answer. In looking at your calculations, you calculate the total radiation at the surface by adding the 3.7 w/m^2 from a doubling of CO2 to the current surface radiation. The question that’s been bothering me is how can anyone provide a universal number like 3.7 that is appropriate for all cases since there are many variables like other greenhouse gases, clouds, where (elevation and temperature) of the emissions sources, etc. which affect the determination of this number. Then it occurred to me that the value (forcing) may be just for the blackbody case. To use it for the calculations you are making, you would need to divide the number by the emissivity so it would apply the specific case. Instead of 396 +3.7 w/m^2 it should it be 396 + 3.7 divided by emissivity. Your warming value then would be more like 0.67K/.6 or 1.1K which is consistent with other estimates I have seen. I have a hard time following your reasoning why you would apply the emissivity value again. The earth's surface is pretty much behaving as a blackbody. The combo earth surface and atmosphere is behaving as a greybody with emissivity = 0.6. So to extrapolate the 3.7 to the top of the atmosphere you need to multiply by 0.6 so you get 3.7*0.6 = 2.22. That said, yesterday I engaged in a twitter discussion with some people See here: And they pointed out that the definition of radiative forcing is the energy delta at TOA. See en.wikipedia.org/wiki/Radiative_forcingQuite interesting chart attached here: Purple normal, blue 1st doubling, green second doubling This gives 3.275 W per doubling on a 303.5 baseline. But at the poles this would be significantly more apparently. So now I think my whole argument is flawed since I did not think of the fact that they quantify it as delta radiation at TOA.
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Post by duwayne on Feb 24, 2019 21:34:16 GMT
Fatjohn, let me try to explain my point again and hopefully, this is clearer.
The 396 w/m^2 number you use in your formula is not a TOA value.
Excluding albedo, (the solar radiation that is reflected and not absorbed by the earth), the current TOA value for incoming Solar radiation is around 239 w/m^2, the same as theoutgoing radiation net of albedo. If there was a change at the TOA of 3.7 w/m^2, then the percentage change would be 3.7/239 or 1.55%.
What you have done is use an emissivity factor to convert the 396 to an equivalent TOA number. But your formula also applies the same emissivity factor to the 3.7 value even though it is already a TOA number.
After doubling of CO2 you say at the TOA
Forcing = (396+3.7)*emissivity
instead of
Forcing = 396*emissivity + 3.7
I realize you have used slightly different emissivity values for the before doubling and after doubling cases , but the difference does not make up for the error because the emissivity you use is applied to the 3.7 TOA number.
The percentage forcing increase is actually 3.7/239 or 1.55% versus about 0.94% for the method you use. As a result you calculate a 0.67K temperature increase instead of 1.11K
Like you, I have an engineering degree, but after I moved on to Sr VP of Technology and then onto a career in investments I haven’t used those skills much lately. So my rusty thinking can be off. Where am I going wrong?
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Post by duwayne on Feb 25, 2019 17:20:08 GMT
Fatjohn, let me try to explain my point again and hopefully, this is clearer. The 396 w/m^2 number you use in your formula is not a TOA value. Excluding albedo, (the solar radiation that is reflected and not absorbed by the earth), the current TOA value for incoming Solar radiation is around 239 w/m^2, the same as theoutgoing radiation net of albedo. If there was a change at the TOA of 3.7 w/m^2, then the percentage change would be 3.7/239 or 1.55%. What you have done is use an emissivity factor to convert the 396 to an equivalent TOA number. But your formula also applies the same emissivity factor to the 3.7 value even though it is already a TOA number. After doubling of CO2 you say at the TOA Forcing = (396+3.7)*emissivity instead of Forcing = 396*emissivity + 3.7 I realize you have used slightly different emissivity values for the before doubling and after doubling cases , but the difference does not make up for the error because the emissivity you use is applied to the 3.7 TOA number. The percentage forcing increase is actually 3.7/239 or 1.55% versus about 0.94% for the method you use. As a result you calculate a 0.67K temperature increase instead of 1.11K Like you, I have an engineering degree, but after I moved on to Sr VP of Technology and then onto a career in investments I haven’t used those skills much lately. So my rusty thinking can be off. Where am I going wrong? What skills are you using for investing if not math? I do use some math in investing, but it's mainly high school math and not calculus. I think my best skill is pattern recognition supplemented by logic. That's the basis for my global warming prediction. I've explained here exactly how I derived the prediction and you can judge the accuracy. I could also tell you how I use pattern recognition in investing, but, of course, I would use just successful examples and it would sound like bragging and who wants to hear that? I use pattern recognition in both cases because I don't trust anyone's ability to accurately predict the future of the stock market or weather (climate) with models.
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Post by duwayne on Feb 28, 2019 21:47:02 GMT
There’s broad agreement that CO2 causes global warming. There is no agreement on how much. Every model gives a different result. The IPCC uses these innaccurate models to predict likely global warming per doubling of CO2 of 1.5 to 4.5C. And they admit there is a possibility that the warming could be less than that. Amongst all this uncertainty there seems to be 1 number that is viewed as a near certainty, i.e., the increase in TOA radiative forcing for a doubling of CO2. It is given as 3.7 watts per square meter. This causes 1.1C of direct warming per doubling of CO2. According to the IPCC and others the only uncertainty is the indirect warming or feedback which by difference varies from 0.4 to 4.4C with the high number being 1100% of the low number. This sacred CO2 radiation forcing of 3.7 w/m^2 forcing value is derived from the equation Forcing = 5.35*ln (2) where 2 is the ratio of beginning atmospheric CO2 concentration to the ending concentration, in this case a doubling. The question I have is just how much faith should we have in this 5.35 number which seems to form the basis for all warming models? This number appears to be the findings of one man, Gunnar Myhre, and his staff reported in 1998. He says he believes it is accurate to plus or minus 5%. Due to its importance I had always wondered why I couldn’t find articles corroborating or questioning this number. Recently I did find a paper by Antero Ollila , (Department of Civil and Environmental Engineering (Emer.), School of Engineering, Aalto University, Espoo, Finland) to which I provided a link to earlier. Ollila claims he attempted to duplicate Myhre’s 5.35 number using the same spectral analysis technique and got a value of 3.12. Here is the link which I’ve given before. www.emeraldinsight.com/doi/full/10.1108/IJCCSM-05-2017-0107If the 3.12 number is true, then it seems to me that the climate sensitivities of 1.5 to 4.5C from the climate models should all be ratioed down by 3.12/5.35 making the sensitivity 0.9 to 2.6C which gives a middle estimate 1.8C. It’s interesting that if the net warming from 1850 through 2018 is due to CO2, then the climate sensitivity using the Hadcrut4 anomalies coincidentally works out to be 1.8C per doubling of CO2. I know several of you are active on other sites and constantly peruse the internet. Are you aware of anything which would shed more light on the veracity of spectral analysis studies which generate the conflicting numbers from Myhre and Ollila?
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Post by Ratty on Mar 1, 2019 11:31:21 GMT
While we worry about how much warming there will be from increasing CO2 and despite all the discussions of greenhouse science, I still fail to be convinced that what we are seeing is not from a natural cause/cycle. The causation/correlation thinggy still worries me. This Chris Scotese graph doesn't address CO2 but ....
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Post by duwayne on Mar 2, 2019 17:56:27 GMT
While we worry about how much warming there will be from increasing CO2 and despite all the discussions of greenhouse science, I still fail to be convinced that what we are seeing is not from a natural cause/cycle. The causation/correlation thinggy still worries me. This Chris Scotese graph doesn't address CO2 but .... Ratty, can you be a little more specific about why the "causation/correlation thinggy" worries you? By the way, if I am reading it right, the chart above shows a drop in global temperatures of 4.5C from natural causes over the past 15 million years. That is 0.0000003C per year.
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Post by Ratty on Mar 2, 2019 23:47:56 GMT
While we worry about how much warming there will be from increasing CO2 and despite all the discussions of greenhouse science, I still fail to be convinced that what we are seeing is not from a natural cause/cycle. The causation/correlation thinggy still worries me. This Chris Scotese graph doesn't address CO2 but .... Ratty, can you be a little more specific about why the "causation/correlation thinggy" worries you? By the way, if I am reading it right, the chart above shows a drop in global temperatures of 4.5C from natural causes over the past 15 million years. That is 0.0000003C per year. Duwayne, the conventional wisdom - though not universally accepted - is that a rise in CO2 causes temperature to rise. "0.0000003C per year": Are you sure?
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Post by duwayne on Mar 3, 2019 17:29:35 GMT
Ratty, can you be a little more specific about why the "causation/correlation thinggy" worries you? By the way, if I am reading it right, the chart above shows a drop in global temperatures of 4.5C from natural causes over the past 15 million years. That is 0.0000003C per year. Duwayne, the conventional wisdom - though not universally accepted - is that a rise in CO2 causes temperature to rise. "0.0000003C per year": Are you sure? Ratty, did you find an error in my calculation?
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Post by Ratty on Mar 3, 2019 23:37:23 GMT
Duwayne, the conventional wisdom - though not universally accepted - is that a rise in CO2 causes temperature to rise. "0.0000003C per year": Are you sure? Ratty, did you find an error in my calculation? No Duwayne. Just asking if you were sure.
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Post by IB DaMann on Mar 10, 2019 13:36:15 GMT
I’ve started this thread to discuss the “Greenhouse Effect” since it is viewed as being off topic on the Astro thread. Greenhouse Effect is best discussed in theology forums. Greenhouse Effect is a religious myth. It is not real. Try asking for the Greenhouse Effect formula. Let's see how long it takes before you never see it.
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Post by duwayne on Mar 10, 2019 16:51:33 GMT
I’ve started this thread to discuss the “Greenhouse Effect” since it is viewed as being off topic on the Astro thread. Greenhouse Effect is best discussed in theology forums. Greenhouse Effect is a religious myth. It is not real. Try asking for the Greenhouse Effect formula. Let's see how long it takes before you never see it. Ibdamann, do you have a degree in science?
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Post by IB DaMann on Mar 10, 2019 18:36:02 GMT
Greenhouse Effect is best discussed in theology forums. Greenhouse Effect is a religious myth. It is not real. Try asking for the Greenhouse Effect formula. Let's see how long it takes before you never see it. Ibdamann, do you have a degree in science? I'm elated to discuss any science you wish. If you are asking about refuting the absurd physics-violating claims of the Global Warming Congregation then, well, only an eighth grade education is required, which I certainly have. What would you like to discuss?
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Post by fatjohn1408 on Mar 11, 2019 0:00:18 GMT
I have done another back of the envelope calculation concerning this topic for anyone who's interested. 1) The IPCC claims a climate sensitivity of 1.5 - 4.5 degrees. 2) The IPCC claims CO2 doubling causes 3.7 W/m^2 of radiance forcing. 3) The IPCC claims that by 2011 anthropogenic forcings amounted to 2.29W wrt 1750 reference period. 4) Warming between 1850 and 2011 has been about 1.06 degrees if we go by the five year average of the BEST dataset (a very generous dataset for warming enthousiasts), 1.16 degrees if we cherrypick our starting point to account for the most possible warming: berkeleyearth.lbl.gov/auto/Global/Land_and_Ocean_complete.txtAssumptions: Change in anthropogenic forcings were negligible between 1750 and 1850 and therefore the increase in anthropogenic forcings between 2011 and 1850 is also 2.29W. Anthropogenic forcings was the sole factor for all of the warming. 2.29W is 61.8% of 3.7W. Or in other words, 61.8% of a equivalent effect of CO2 doubling had taken place by 2011. Radiance forcing and temperature response are nonlinear and therefore this constitutes to a 69.4% increase in temperature expected from a doubling. For the IPCC doubling range of 1.5 - 4.5 degrees this then effectively becomes a range of 1.04 - 3.12 degrees. So my question becomes why does the IPCC even entertain the notion that the sensitivity might be as high as 4.5 degrees if actual temperature data shows it to be right at the bottom of their range. Do they think that solar activity has had a cooling effect since 1850? Do they think we're in a volcanically active period and that had a net cooling effect since 1850? Do they think that it is possible that if the atmospheric CO2 values had come to a standstill in 2011 that the temperature would have increased another 2 degrees out of momentum, feedback etc prior to reaching a steady state? Do they think those three combined can explain the 2 degree gap between their most alarming predictions and reality? Do they think we're stupid?
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Post by missouriboy on Mar 11, 2019 0:33:29 GMT
I have done another back of the envelope calculation concerning this topic for anyone who's interested. Do they think we're stupid?Yes.
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