Either you don't really understand what feedback and forcing means, or you are trying to imply that we are not the cause of the rise in atmospheric CO2.
False dichotomy. We can be the cause of some measurable rise in atmospheric CO2, without being the only cause of any rise, and without overwhelming other natural climate change factors.
Time for a primer in logic. A implies B is not falsified by its converse.
Go head, present your falsifiable hypothesis on volcanic eruptions being a feedback, rather than a forcing. Show me how it's done:)
Or are you going to throw up your hands and assert there is no scientific way to tell the difference between volcanoes being a forcing of climate, versus a feedback?
Sure you can demonstrate it - God simply uses CO2, right?:)
The problem is that the leap from CO2 absorbing IR, to CO2 being a primary driver of climate, must be held to strict scrutiny. CO2 absorbs IR, but simply increasing the CO2 content in say, my handy airtight glass jar, doesn't inherently raise the temperature. Once you put that molecule into a non-laboratory environment, you lose control of a *bunch* of variables.
You know what Layzej, I enjoy our little chats here on slashdot!
I asked you for a falsifiable hypothesis regarding how to determine whether or not a given factor in climate was a feedback or a forcing. And instead, you dodged slightly to the left and started talking about sources of CO2. Clever, but unpersuasive:)
Let's start with a falsifiable hypothesis regarding how to determine whether or not volcanoes are a feedback or a forcing.
"Volcano eruptions cause global temperature drops. This is a forcing. This would be falsified if temperature drops are followed by increased numbers of volcanic eruptions."
And yes, you can estimate the size of various things affecting climate. And the reality is that for recent decades, the changes from human greenhouse gas emissions are an order of magnitude larger than the net forcing from other changes.
Those are assertions, not facts. Given a complex system, like climate, with a myriad number of external and internal forcings and feedbacks (both positive and negative), you simply cannot assume your estimates are truth - you need to be ruthlessly skeptical of your base assumptions.
Put another way, what concise falsifiable hypothesis statement would you make regarding human CO2 forcing impact? What observations would make you question your your estimate? Despite your interest in helping me learn, it doesn't seem as if you're trying to learn anything new yourself:)
Best of luck to you nonetheless, and thank you for an entertaining exchange! Hope you enjoyed reading Popper's essay, and spend some time contemplating how it relates to your beliefs!
So why do you keep asking me to differentiate between feedbacks and forcings as if that has some bearing on the hypothesis that the rate of increase of GHG is sufficient to cause global temperatures to rise by a couple of degrees by the middle of the next 21st century?
Dessler's critique of Spencer is that clouds are feedbacks, never forcings. This is an assertion, not a fact.
Your assertion was "You may need to look up feedback and forcing since your understanding here seems a little muddled."
However, you're unable (either for clouds or carbon), to make a clear statement of a falsifiable hypothesis that would distinguish between whether or not either clouds or carbon are feedbacks, or forcings (or when they might be one or the other).
The problem is that any factor, be it cosmic rays, dust, ocean currents, undersea volcanic eruptions, plant growth, or human activity, is practically impossible to comb out of the data.
Case in point, the long term temperature trend over the past 15 or so years has been flat, even as CO2 levels have increased.
For your #2 you simply don't have any sort of long term cloud formation data across the globe, and for #3 we don't have nearly the weather data to assert we understand the climate impacts from that long ago.
The challenge to any hypothesis which asserts that any given factor is a dominant force is that you simply don't have a falsifiable hypothesis - ad hoc special pleadings for any variation from your prediction are the *norm* rather than the exception.
The challenge Spencer is making, that hasn't been adequately refuted, is that you cannot simply *assert* that clouds are always caused by weather systems. Dessler can certainly claim that it is true (while saying in the same breath that it isn't true in the "long term"), but unless you can avoid special pleading every time your prediction is shown wrong, you're not really doing science.
So wait, if I show that clouds are caused by anything besides weather systems, you'll concede the hypothesis "clouds occur mainly because of weather systems" as falsified?
Ah, so whenever we have a question as to whether or not someone is worthy to conduct science, or even procreate, we simply ask you to adjudicate with your divine wisdom?
Sounds like the start of a religion, don't you think?:)
We have particular predictions - e.g. a rise of CO2 concentration will yield a certain increase in average temperature. If the CO2 conc. does rise that much and the temperature does not increase, clearly, the prediction was falsified.
Do you *really* believe that? Put another way, we have say, several dozen different climate models, that vary significantly. Some predict different increases in average temperature based on rises in CO2. Do you care to identify any of those models that you will agree have been falsified by failed prediction? Can we now dispense with those models as falsified, and concentrate only on those models that have fit our observations, to say, within +/- 5% of their original predictions?
Of course not. The ad hoc special pleading comes in when a model fails - "our model was correct, except for this one fudge factor that we now know must be changed". There is no limit to the number of corrections that can be made, and special pleadings that can be made, to fit the model to new observations. If things warm too fast in the real world compared to the model, we'll assert that it was because of some other force, preserving the attribution we've given to CO2. If things warm too slowly in the real world compared to the model, we'll assert that it was because of aerosols, or solar activity dropping, or some novel oceanic thermal circulation, in order to preserve the attribution we've given to CO2.
It's like astrology - I say you're a Capricorn, and because of that you'll behave a certain way. You behave in a different way, so I blame it on the fact that you were actually in Pluto rising as well as Capricorn. You behave in a new different way, so I then assert that that was caused by a confounding Saturn eclipse at your date of birth. Any behavior can be explained with the theory of astrology - any observation can be made to fit into the framework.
Any observation of CO2 and temperature can be made to fit into the framework of AGW or CAGW. Rising CO2 and falling temperature? Aerosols and lower solar activity. Rising CO2 and rising temperature? CO2 driving temperature. Falling CO2 and falling temperature? CO2 driving temperature. Falling CO2 and rising temperature? Oceanic upwelling of heat and increased solar activity.
When *any* observation can be explained, it's left the realm of science.
We see how much of the CO2 increase is anthropogenic, given the isotopic ratios of 12C to 14C
I can stipulate to an increase in CO2 being anthropogenic without agreeing to a specific H2O feedback effect caused by increased CO2 (of any origin). Take the complexities of the other forcings that drive climate (solar activity, internal planetary heat, cosmic rays, ocean currents), and it becomes less and less plausible that a single gas, measured in parts per million, could be the dominant driver of any period of warming (or cooling).
I understand that the AGW (or CAGW) hypothesis is built on a number of very well established sub-hypotheses, from the greenhouse effect, to spectral irradiance, to the isotopic ratios of CO2 -> the problem is that these simply don't hold together just because we come up with a reasonable set of logical leaps between them. Those leaps may seem compelling, but unless they're treated with the same scrutiny as the fundamental hypotheses we're leaning on, they can't be justified.
Case example - the hypothesis has been long held by nutritionists that eating fat makes you fat. This is a fairly reasonable assumption, given that fat has the highest caloric density (compared to protein or carbohydrate). From what we know of the laws of thermodynamics, calories in - calories out = weight gain, so we can jump from the fundamental law, and the caloric density facts, to what might seem as a perfectly justifiable and non-controversial conclusion that eating fat makes you fat.
Except there's a catch - it's simply not true. The human body is not simply a
I'm an atheist who lost his faith on the 1st grade playground contemplating the question of evolution, driving back to whatever that first life form was, asserting it was created by God, and then asking the question, "then what created God?" It was a missionary school, so it was also moderately christian.
What puzzles me is that I've always clearly understood the problem with ID as being a lack of falsifiability - "God did it" is always a perfectly accurate answer for anything, even if both you and I know intuitively that its ability to explain all phenomena doesn't show a *strength*, in fact, as Popper points out, this kind of "heads I win, tails you lose" hypothesis is inherently weak.
I could never have imagined, in a thousand years, that otherwise perfectly rational atheists would embrace something unfalsifiable (say, like astrology, reflexology, or in our current discussion, an irrefutable hypothesis of anthropogenic global warming). I could also never have imagined, in a thousand years, that otherwise completely goofy deists would be stalwart defenders of the scientific method and falsifiability. It boggles the mind.
Which leads me to this perhaps odd question -> are there any beliefs that you hold that you recognize as being of a unscientific nature? Knocking on wood superstitions? Other non-falsifiable beliefs?
So to paraphrase, some silly beliefs are unforgivable but others are given a pass? Literal creation in 7 days is beyond the pale, but say, a virgin birth and human sacrifice to cleanse the world of its sins is okay for scientists?
As for ID, doesn't it have more in common with the unfalsifiable hypotheses of CAGW or AGW? If we're going to do science, should we be playing by the rules of the scientific method?
Isn't that *exactly* the complaint Spencer is making for all models? That they're tuned to produce a particular result, and therefore confuse cause with effect?
Put another way, what is the falsifiable hypothesis statement of "clouds occur mainly because of weather systems" (glossing over the weasel word "mainly")? What observation would show that this hypothesis statement is incorrect?
Funny thing, both ID and CAGW (or its lesser cousin AGW) are notoriously unfalsifiable:) Just remove the word "CO2" from your assertions and replace it with "God", and you've got essentially the same thing:)
You may need to look up feedback and forcing since your understanding here seems a little muddled.
Wasn't that Spencer's point in the first place? And isn't that the challenge that you've been unable to meet (come up with a falsifiable hypothesis that will discern between a feedback and a forcing)?:)
Did you get a chance to read Popper's essay? I'll assert that it's not nearly the garbage that the IPCC or Dessler have put out thus far:)
In his own words, Wagner's reason for resignation was publishing a paper which was "problematic in both aspects" of "fundamental methodological errors or false claims" and "fundamentally flawed".
Don't forget this gem from Wagner:
"In other words, the problem I see with the paper by Spencer and Braswell is not that it declared a minority view (which was later unfortunately much exaggerated by the public media) but that it essentially ignored the scientific arguments of its opponents."
Wagner apparently wanted Spencer and Braswell to rebut any rebuttal of their work before publishing. I'm not sure how else you can parse his words.
but based on the research I've seen (IPCC AR4 chapters 2 & 3, economic reviews by Stern, Weitzman, and others), mitigating the climate change will be both cheaper and (by various measures) less painful than adapting to it.
Speculation at best. Put another way, how would you falsify the hypothesis "mitigating climate change will be cheaper and less painful than adapting to it"? What observations would invalidate that hypothesis?
Yes; climate's usually taken to encompass a longer term (I believe the World Meteorological Organization goes with 30 years).
Which only emphasizes my point - nobody ever experiences the average weather over 30 years. Taken worldwide, that's an average of an average that has even less relevance to human experience. Put another way, what kind of clothes would you wear outside today if someone told you what the next 30 years of climate were going to be? What possible decisions could you make?
But if you want to argue about the relative effects of global temperature drivers (such as solar irradiance and carbon dioxide concentration) then you have to consider global averages.
False implied dichotomy. I'm happy to argue about the relative effects of global temperature drivers as an interesting field of study, while insisting that is is not a particularly useful field of study. Much like Russian literature from the 1700s.
You are neglecting the rather crucial point that I'm talking about the next 200 years, whereas you are talking about the previous 100 years.
How different do you think the next 200 years is going to be? 70m of sea level rise? Even in the most dramatically exaggerated claims of sea level rise, you're not going to see anything that would interfere with say, a specific building lasting for 200 years.
"Basically there is a very specific range of wavelengths that will interact with Carbon and other greenhouse gasses. So basically anything other than exactly what we are seeing would be consistent with Tyndall gas not being a forcing."
You made the statement that the specific range of wavelengths that will interact with greenhouse gases is sufficient observation to say Tyndall gases are always forcings, never feedbacks. As I stated, this may be *necessary* for your hypothesis to be true, but it is not *sufficient*.
Maybe you're just not qualified to understand what you quoted from John Nielsen-Gammon? You could always try reading the comments on his post more carefully, especially the ones from Roger Pielke Jr.:
Because it makes absolutely no sense. Honestly, I have no idea what you are talking about.
My apologies if you're having difficulty understanding what I'm trying to convey. Let me see if I can explain it in more explicit terms.
You've made the claim that the value of a certain constant is sufficient to validate your hypothesis. This can be trivially true in some simple cases, for example, you could have the hypothesis, "X + 2 = 4", which would be falsified by X != 2. In this case, the value of the constant is in fact logically connected to the hypothesis.
This is clearly not true in the case of your assertion. Simply claiming that because Tyndall Gases have a specific wavelengths of absorption X, Y and Z, that humans have caused measurable, significant and dangerous impacts to global average temperature, is a logical leap that is unjustified. If the wavelengths of absorption were say, X+.01, Y and Z, one can hardly argue that this would change CO2 into a non-greenhouse gas, or suddenly stop any sort of feedback effect with H2O, or make an increased average global temperature a beneficial rather than harmful thing. There are dozens of logical leaps that you are simply asserting, rather than showing.
Perhaps this is a difficult thing for you to understand, but there are two lists you need to think of - those things that are *necessary* for your hypothesis to be true, and those things that are *sufficient* for your hypothesis to be true. At the very best, wavelengths of absorption may be *necessary* for your hypothesis to be true -> but then again, so is the existence of the earth (if the earth didn't exist, your hypothesis would be moot). You cannot take something that is simply *necessary* (the existence of the earth), and then make the bold statement that it is *sufficient* to prove your hypothesis. Read the paragraph over again, and see if you can follow how the next statement would be silly:
The earth exists, therefore AGW is true.
Yes, the earth *must* exist for AGW to be true, but its existence is not nearly sufficient for AGW to be true.
Suffice it to say that even the most skeptical scientists do not doubt that CO2 is a forcing and that adding CO2 will warm the planet.
The problem here is with the quantity of whatever forcing. There is a big difference between accepting that CO2 is a forcing, and that adding CO2 will warm the planet by 0.1C per 500ppm, and accepting that CO2 is a forcing, and that adding CO2 will warm the planet by 10C per 500ppm.
Realistically, CO2 from any source has some effect on temperature, but is overwhelmed by other drivers of climate.
Slashdot Mirror
False dichotomy. We can be the cause of some measurable rise in atmospheric CO2, without being the only cause of any rise, and without overwhelming other natural climate change factors.
Go head, present your falsifiable hypothesis on volcanic eruptions being a feedback, rather than a forcing. Show me how it's done :)
Or are you going to throw up your hands and assert there is no scientific way to tell the difference between volcanoes being a forcing of climate, versus a feedback?
Sure you can demonstrate it - God simply uses CO2, right? :)
The problem is that the leap from CO2 absorbing IR, to CO2 being a primary driver of climate, must be held to strict scrutiny. CO2 absorbs IR, but simply increasing the CO2 content in say, my handy airtight glass jar, doesn't inherently raise the temperature. Once you put that molecule into a non-laboratory environment, you lose control of a *bunch* of variables.
You know what Layzej, I enjoy our little chats here on slashdot!
I asked you for a falsifiable hypothesis regarding how to determine whether or not a given factor in climate was a feedback or a forcing. And instead, you dodged slightly to the left and started talking about sources of CO2. Clever, but unpersuasive :)
Let's start with a falsifiable hypothesis regarding how to determine whether or not volcanoes are a feedback or a forcing.
"Volcano eruptions cause global temperature drops. This is a forcing. This would be falsified if temperature drops are followed by increased numbers of volcanic eruptions."
Now, your turn for clouds or CO2 :)
Those are assertions, not facts. Given a complex system, like climate, with a myriad number of external and internal forcings and feedbacks (both positive and negative), you simply cannot assume your estimates are truth - you need to be ruthlessly skeptical of your base assumptions.
Put another way, what concise falsifiable hypothesis statement would you make regarding human CO2 forcing impact? What observations would make you question your your estimate? Despite your interest in helping me learn, it doesn't seem as if you're trying to learn anything new yourself :)
Best of luck to you nonetheless, and thank you for an entertaining exchange! Hope you enjoyed reading Popper's essay, and spend some time contemplating how it relates to your beliefs!
Dessler's critique of Spencer is that clouds are feedbacks, never forcings. This is an assertion, not a fact.
Your assertion was "You may need to look up feedback and forcing since your understanding here seems a little muddled."
However, you're unable (either for clouds or carbon), to make a clear statement of a falsifiable hypothesis that would distinguish between whether or not either clouds or carbon are feedbacks, or forcings (or when they might be one or the other).
Does that help you understand?
The problem is that any factor, be it cosmic rays, dust, ocean currents, undersea volcanic eruptions, plant growth, or human activity, is practically impossible to comb out of the data.
Case in point, the long term temperature trend over the past 15 or so years has been flat, even as CO2 levels have increased.
For your #2 you simply don't have any sort of long term cloud formation data across the globe, and for #3 we don't have nearly the weather data to assert we understand the climate impacts from that long ago.
The challenge to any hypothesis which asserts that any given factor is a dominant force is that you simply don't have a falsifiable hypothesis - ad hoc special pleadings for any variation from your prediction are the *norm* rather than the exception.
The challenge Spencer is making, that hasn't been adequately refuted, is that you cannot simply *assert* that clouds are always caused by weather systems. Dessler can certainly claim that it is true (while saying in the same breath that it isn't true in the "long term"), but unless you can avoid special pleading every time your prediction is shown wrong, you're not really doing science.
Obligatory popper ref: http://www.stephenjaygould.org/ctrl/popper_falsification.html
So wait, if I show that clouds are caused by anything besides weather systems, you'll concede the hypothesis "clouds occur mainly because of weather systems" as falsified?
Done: http://public.web.cern.ch/public/en/research/CLOUD-en.html
Ah, so whenever we have a question as to whether or not someone is worthy to conduct science, or even procreate, we simply ask you to adjudicate with your divine wisdom?
Sounds like the start of a religion, don't you think? :)
Do you *really* believe that? Put another way, we have say, several dozen different climate models, that vary significantly. Some predict different increases in average temperature based on rises in CO2. Do you care to identify any of those models that you will agree have been falsified by failed prediction? Can we now dispense with those models as falsified, and concentrate only on those models that have fit our observations, to say, within +/- 5% of their original predictions?
Of course not. The ad hoc special pleading comes in when a model fails - "our model was correct, except for this one fudge factor that we now know must be changed". There is no limit to the number of corrections that can be made, and special pleadings that can be made, to fit the model to new observations. If things warm too fast in the real world compared to the model, we'll assert that it was because of some other force, preserving the attribution we've given to CO2. If things warm too slowly in the real world compared to the model, we'll assert that it was because of aerosols, or solar activity dropping, or some novel oceanic thermal circulation, in order to preserve the attribution we've given to CO2.
It's like astrology - I say you're a Capricorn, and because of that you'll behave a certain way. You behave in a different way, so I blame it on the fact that you were actually in Pluto rising as well as Capricorn. You behave in a new different way, so I then assert that that was caused by a confounding Saturn eclipse at your date of birth. Any behavior can be explained with the theory of astrology - any observation can be made to fit into the framework.
Any observation of CO2 and temperature can be made to fit into the framework of AGW or CAGW. Rising CO2 and falling temperature? Aerosols and lower solar activity. Rising CO2 and rising temperature? CO2 driving temperature. Falling CO2 and falling temperature? CO2 driving temperature. Falling CO2 and rising temperature? Oceanic upwelling of heat and increased solar activity.
When *any* observation can be explained, it's left the realm of science.
I can stipulate to an increase in CO2 being anthropogenic without agreeing to a specific H2O feedback effect caused by increased CO2 (of any origin). Take the complexities of the other forcings that drive climate (solar activity, internal planetary heat, cosmic rays, ocean currents), and it becomes less and less plausible that a single gas, measured in parts per million, could be the dominant driver of any period of warming (or cooling).
I understand that the AGW (or CAGW) hypothesis is built on a number of very well established sub-hypotheses, from the greenhouse effect, to spectral irradiance, to the isotopic ratios of CO2 -> the problem is that these simply don't hold together just because we come up with a reasonable set of logical leaps between them. Those leaps may seem compelling, but unless they're treated with the same scrutiny as the fundamental hypotheses we're leaning on, they can't be justified.
Case example - the hypothesis has been long held by nutritionists that eating fat makes you fat. This is a fairly reasonable assumption, given that fat has the highest caloric density (compared to protein or carbohydrate). From what we know of the laws of thermodynamics, calories in - calories out = weight gain, so we can jump from the fundamental law, and the caloric density facts, to what might seem as a perfectly justifiable and non-controversial conclusion that eating fat makes you fat.
Except there's a catch - it's simply not true. The human body is not simply a
I'm an atheist who lost his faith on the 1st grade playground contemplating the question of evolution, driving back to whatever that first life form was, asserting it was created by God, and then asking the question, "then what created God?" It was a missionary school, so it was also moderately christian.
What puzzles me is that I've always clearly understood the problem with ID as being a lack of falsifiability - "God did it" is always a perfectly accurate answer for anything, even if both you and I know intuitively that its ability to explain all phenomena doesn't show a *strength*, in fact, as Popper points out, this kind of "heads I win, tails you lose" hypothesis is inherently weak.
I could never have imagined, in a thousand years, that otherwise perfectly rational atheists would embrace something unfalsifiable (say, like astrology, reflexology, or in our current discussion, an irrefutable hypothesis of anthropogenic global warming). I could also never have imagined, in a thousand years, that otherwise completely goofy deists would be stalwart defenders of the scientific method and falsifiability. It boggles the mind.
Which leads me to this perhaps odd question -> are there any beliefs that you hold that you recognize as being of a unscientific nature? Knocking on wood superstitions? Other non-falsifiable beliefs?
Spencer's paper had nothing to do with carbon, it dealt with clouds.
I think you need to go back and re-read what you think you understood.
What, you begrudge a fellow for not stalking your posts on a daily basis? :)
Are you disappointed in yourself that you didn't take screen caps when you could have? :)
State your falsifiable hypothesis, and we can let Popper's words rest.
Fail to, and you're playing a game of religion, not science.
So to paraphrase, some silly beliefs are unforgivable but others are given a pass? Literal creation in 7 days is beyond the pale, but say, a virgin birth and human sacrifice to cleanse the world of its sins is okay for scientists?
As for ID, doesn't it have more in common with the unfalsifiable hypotheses of CAGW or AGW? If we're going to do science, should we be playing by the rules of the scientific method?
http://www.stephenjaygould.org/ctrl/popper_falsification.html
And this is different from the models produced by the natural climate change deniers...how?
Isn't that *exactly* the complaint Spencer is making for all models? That they're tuned to produce a particular result, and therefore confuse cause with effect?
Put another way, what is the falsifiable hypothesis statement of "clouds occur mainly because of weather systems" (glossing over the weasel word "mainly")? What observation would show that this hypothesis statement is incorrect?
But being religious, we should exclude them from engaging in any scientific endeavors? Really?
Pics or it didn't happen.
Just for the record, are you an atheist?
If so, did you lose your faith, or did you never have any?
Funny thing, both ID and CAGW (or its lesser cousin AGW) are notoriously unfalsifiable :) Just remove the word "CO2" from your assertions and replace it with "God", and you've got essentially the same thing :)
Obligatory Popper reference: http://www.stephenjaygould.org/ctrl/popper_falsification.html
Wasn't that Spencer's point in the first place? And isn't that the challenge that you've been unable to meet (come up with a falsifiable hypothesis that will discern between a feedback and a forcing)? :)
Did you get a chance to read Popper's essay? I'll assert that it's not nearly the garbage that the IPCC or Dessler have put out thus far :)
Don't forget this gem from Wagner:
"In other words, the problem I see with the paper by Spencer and Braswell is not that it declared a minority view (which was later unfortunately much exaggerated by the public media) but that it essentially ignored the scientific arguments of its opponents."
Wagner apparently wanted Spencer and Braswell to rebut any rebuttal of their work before publishing. I'm not sure how else you can parse his words.
Speculation at best. Put another way, how would you falsify the hypothesis "mitigating climate change will be cheaper and less painful than adapting to it"? What observations would invalidate that hypothesis?
Which only emphasizes my point - nobody ever experiences the average weather over 30 years. Taken worldwide, that's an average of an average that has even less relevance to human experience. Put another way, what kind of clothes would you wear outside today if someone told you what the next 30 years of climate were going to be? What possible decisions could you make?
False implied dichotomy. I'm happy to argue about the relative effects of global temperature drivers as an interesting field of study, while insisting that is is not a particularly useful field of study. Much like Russian literature from the 1700s.
How different do you think the next 200 years is going to be? 70m of sea level rise? Even in the most dramatically exaggerated claims of sea level rise, you're not going to see anything that would interfere with say, a specific building lasting for 200 years.
Are you denying not only natural climate change, but what you actually *wrote*? :)
A few pertinent links for you:
http://webcache.googleusercontent.com/search?q=cache:IrMArI7oZ44J:boards.straightdope.com/sdmb/showthread.php%3Ft%3D521245+global+warming+falsifiable&cd=1&hl=en&ct=clnk&gl=us&client=safari
http://www.stephenjaygould.org/ctrl/popper_falsification.html
Read with an open mind, you might actually learn something! :)
Here, re-read this:
"Basically there is a very specific range of wavelengths that will interact with Carbon and other greenhouse gasses. So basically anything other than exactly what we are seeing would be consistent with Tyndall gas not being a forcing."
You made the statement that the specific range of wavelengths that will interact with greenhouse gases is sufficient observation to say Tyndall gases are always forcings, never feedbacks. As I stated, this may be *necessary* for your hypothesis to be true, but it is not *sufficient*.
Maybe you're just not qualified to understand what you quoted from John Nielsen-Gammon? You could always try reading the comments on his post more carefully, especially the ones from Roger Pielke Jr.:
http://blog.chron.com/climateabyss/2011/08/roger-pielke-jr-s-inkblot/
My apologies if you're having difficulty understanding what I'm trying to convey. Let me see if I can explain it in more explicit terms.
You've made the claim that the value of a certain constant is sufficient to validate your hypothesis. This can be trivially true in some simple cases, for example, you could have the hypothesis, "X + 2 = 4", which would be falsified by X != 2. In this case, the value of the constant is in fact logically connected to the hypothesis.
This is clearly not true in the case of your assertion. Simply claiming that because Tyndall Gases have a specific wavelengths of absorption X, Y and Z, that humans have caused measurable, significant and dangerous impacts to global average temperature, is a logical leap that is unjustified. If the wavelengths of absorption were say, X+.01, Y and Z, one can hardly argue that this would change CO2 into a non-greenhouse gas, or suddenly stop any sort of feedback effect with H2O, or make an increased average global temperature a beneficial rather than harmful thing. There are dozens of logical leaps that you are simply asserting, rather than showing.
Perhaps this is a difficult thing for you to understand, but there are two lists you need to think of - those things that are *necessary* for your hypothesis to be true, and those things that are *sufficient* for your hypothesis to be true. At the very best, wavelengths of absorption may be *necessary* for your hypothesis to be true -> but then again, so is the existence of the earth (if the earth didn't exist, your hypothesis would be moot). You cannot take something that is simply *necessary* (the existence of the earth), and then make the bold statement that it is *sufficient* to prove your hypothesis. Read the paragraph over again, and see if you can follow how the next statement would be silly:
The earth exists, therefore AGW is true.
Yes, the earth *must* exist for AGW to be true, but its existence is not nearly sufficient for AGW to be true.
The problem here is with the quantity of whatever forcing. There is a big difference between accepting that CO2 is a forcing, and that adding CO2 will warm the planet by 0.1C per 500ppm, and accepting that CO2 is a forcing, and that adding CO2 will warm the planet by 10C per 500ppm.
Realistically, CO2 from any source has some effect on temperature, but is overwhelmed by other drivers of climate.