Relationship between CO2 and Global Warming

  • Thread starter Andre
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Relationship of CO2 with global temperature

  • is the primary driver

    Votes: 0 0.0%
  • is an important factor

    Votes: 9 52.9%
  • There is only a weak correlation, if at all

    Votes: 6 35.3%
  • Global temperature is the driver of CO2

    Votes: 2 11.8%

  • Total voters
    17
  • #26
Hi Reasonmclucus,

If the use of maxima and minima on ground sites were a factor that significantly impacted the accuracy of temperature, then this should be apparent in variance between MSU and ground readings. Indeed there is a small unaccounted for difference. See the IPCC Third Assessment Report Chapter 2 Observed Variability and Change for an in depth account of the science up to 2000. I’ve never heard this point raised before, do you have any references to it?

The study I refer to Soden et al does not need to address “the actual energy being radiated” in order to demonstrate the good agreement between the model predictions and the observed reality. You argue with regards the agreement claimed by the authors, and indeed there is a small variance, see fig 2. But if there were NO variance I would be very suspicious of such a result. Due to the complexity of the atmosphere exact agreement is not likely. Soden et al was peer-reviewed and as it stands against the sceptics case you can bet there’ll be a small army of them working to attempt to undermine it’s support for the model’s ability to predict the water vapour amplification of temperature shifts.

Water does indeed impact air temp close to the dew point. But above the dew point the factor you state is not a major factor. Furthermore the energy balance mechanism you allude to is a short-term localised factor. And it cannot account for the globally observed increase in temperatures. With an atmospheric residency time of around 3.6 years against water’s 11 days, CO2 remains a long term forcing that can account for the recent observed warming when amplified by water vapour increases.
 
  • #27
Hi Andre :(

Looks like you got me here....

"And yes Pinatoba is clearly preceeding a trophosphere temperature dip. No surprise there but we see similar sort of dips in 1982, 1984, 1989. This makes it very clear that without the Pinatoba eruption a similar dip could have occured. So comparing the dip with average values has no meaning as we don't know what the real driver behind this cyclic behavior is. So, we don't know which part of the post-Pinatoba cooling is Pinatoba related and which part is natural cycle. Conclusion, the water vapor feedback is based on very shallow observations and cannot be considered proven. "

Oh the logic! or lack of it. ;)

1) Is there an increase in strato temps associated with "1982, 1984, 1989." No? See http://www.metoffice.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif So we have an indication of mechanism, unique to events like Pinatubo ElChihin etc. This allows the authors of that paper to use the event as they state.

2) "Conclusion, the water vapor feedback is based on very shallow observations and cannot be considered proven."

Using the same logic I will prove that nights are being overlooked and those of us paid on a daily as opposed to an hourly basis are beeing conned by a conspiracy!

When it's dark outside it's night, we ALL know that. Now I remember what 'the scientists' called an eclipse some years back. And it did indeed go dark. Now they try to tell us that this was not a night, they'll say things like 'it was by a different mechanism', 'it only lasted for about 5 minutes'. But I know their game, they're just trying to diddle me out of a days pay! They should have counted the day before this eclipse thingy as one day and the day after as another, so you see one day lost!!!

These 'scientists' with their logical deduction and big words they're all in it together.


Got any more thoughts on the Global Temperature trends displayed in all measuring systems - as I showed under our Stratosphere debate? It really is amazing how we can see the temperature rising, we can see the effects of this in global pattern of glacial retreat, the warming seas, changes in climate observed. And at the same time we see an increase in CO2, which as shown in Soden et al produces a variation in water vapour that is correctly modelled. And it's all just a coincidence, not a syndrmoic pattern.

What a puzzle. ;)
 
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  • #28
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Nice try but look again:

http://home.wanadoo.nl/bijkerk/El-chichon-Pinatobo.JPG [Broken]

So:
Is there an increase in strato temps associated with "1982, 1984, 1989." No?
Indeed, no

Check also:
http://volcano.und.edu/vwdocs/Gases/chichon.html [Broken]

A puzzle indeed why the atmospheric reaction on both eruptions is so different.
 
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  • #29
Hi Andre,

My analogy stands.

1982 and 1991 were incidents of volcanic aerosol injection, yet El Chichon, as you indicate occurred during an ongoing background dip in temperature - as you kindly demonstrate in your graph http://home.wanadoo.nl/bijkerk/El-chichon-Pinatobo.JPG [Broken]. So I'd have agreed with Soden et al that this does not represent a good clean effect to study, whatever cooling it caused was added to another effect already underway due to another process. So it is tricky to draw conclusions. Yet with Pinatubo the cooling appears during a peak and thus the effect is most likely to be arguably due to Pinatubo's aerosol injection. Indeed the models show good agreement with the physical understanding of the processes involved, although that is not the main point of the study.

Why were the two eruptions different? Well how long is a piece of string? In essence it is not for the report author's to address such issues. As I describe above they have chosen a good alternate scenario to critically analyse the response of the models in predicting water vapour levels in response to a forcing. In this case a reduction in temperature, but it still shows a positive feedback (reinforcing the original perturbation).

You also stated 1984 and 1989, a propo of what? As I pointed out, whilst these were cooling incidents they were not associated with strato warming at all. Such a warming is on a theoretical and observational level assoc with stratospheric aerosol injection. The 1984 coincides with the tail end of the warming from El Chichon - as again shown in your graph.

So once again you are referring to the normal cycles (night) due to effects other than an atypical event with it's own cause and characteristics (eclipse) and trying to refute claims made on a reasonable basis that the event was atypical (eclipse darkness) and thus not comparable with a typical event (night time period of darkness). In Chichon we have the equivalent of a solar eclipse just before nightfall. With Pinatubo it's at midday.

Soden et al's paper supports the models ability to model water vapour reaction to a change in forcing.
 
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  • #30
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How bold to persist with all the evidence shouting something else.

So what to we see, the lower stratosphere temperature (MSU-4) apparently reacting on the two (three) major aerosol producing volcanic eruptions. But the lower trophosphere MSU-2 is following it's own logic, warming after one event and cooling after another. Yet, you happily persist in a 100% relationship of Volcanoes and the lower troposphere.

We may have to go over the scientific method again; in particular the part that covers the reproducability.
 
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  • #31
I stand by what I state.

Your graph http://home.wanadoo.nl/bijkerk/El-chichon-Pinatobo.JPG [Broken]. And the Hadley Centre Graphs I refer to http://www.metoffice.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif both show that what I state in my post above, that both El Chichon and Pinatubo produced a clear stratospheric warming. Furthermore the Hadley Centre graph shows that in the recorded period roughly 1960 to present, there are three incidents of vulcanism that produced a strato injection leading to strato warming. This is the marker that shows they are associated with volcanic aerosol injection (or is this 3 more coincidences to add to the list of global changes I refered to earlier in this thread?). The tropo cooling periods you state in 1984 and 1989 do not have a strato warming, therefore they were not due to stratospheric injection of volcanic plumes. So my point stands, citing them does not in any way undermine the conclusions of Soden et al.

Re your introduction of the MSU records. I quote from the IPCC Third Assesment Report, Chapter 2; (co authored by a Mr Christy if I recall correctly - see TAR appendix) http://www.grida.no/climate/ipcc_tar/wg1/059.htm

“The three temperature products that are commonly available from MSU are: the low to mid-troposphere (MSU 2LT, surface to about 8 km), mid-troposphere (MSU 2, surface to about 18 km, hence including some stratospheric emissions) and the lower stratosphere (MSU 4, 15 to 23 km, hence including some tropical tropospheric emissions) (Christy et al., 2000).”

So you are attempting to draw simple conclusions from a data set that requires complex analysis to avoid contamination. MSU-2 is contaminated by the stratosphere, as stated above. So without the analytical techniques needed to remove that contamination your conclusion is specious. I wouldn't even trust MSU-4 supporting my contention re strato warming without such adjustment to remove the effect of the tropical troposphere - despite it supporting my contention, as I say drawing conclusions from direct data is risky, best to rely on professionally derived data. PS if you have carried out the adjustments I refer to above can you advise me what procedure you used? TIA.

Yet again I assert: Soden et al's paper supports the model’s ability to model water vapour reaction to a change in forcing.
 
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  • #32
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I stand by what I state.
Hmm. Luckily enough that’s not a scientific dogma, otherwise the Earth would still be flat.

there are three incidents of vulcanism that produced a strato injection leading to strato warming.
Exactly and since there are no other clear spikes in the known statistics, the causality seems pretty strong. No doubt about it.

The tropo cooling periods you state in 1984 and 1989 do not have a strato warming, therefore they were not due to stratospheric injection of volcanic plumes. So my point stands, citing them does not in any way undermine the conclusions of Soden et al.
Here is where the troubles start. There are several sudden lower troposphere cooling events not associated with major volcano aerosol injections. There are two counts of distinct volcanic aerosol injections not associated with cooling. This lack of reproducibility simply falsifies any distinct correlation between aerosol injection, stratospheric warming versus troposphere cooling.

Check http://home.wanadoo.nl/bijkerk/reproduceability.jpg [Broken], three thumbs ups for three volcanic events for the lower stratosphere (lower graph), no thumbs down. Rather convincing. For the lower troposphere there is only one thumbs up for the Pinatubo, one count of undetermined for Agung to say the best and fat thumbs down for El Chichon as well for all the other unrelated clear cooling events. No wonder that IPCC makes no suggestion of a correlation.

MSU-2 is contaminated by the stratosphere, as stated above. So without the analytical techniques needed to remove that contamination your conclusion is specious.
The contamination is only a minor fraction, hardly enough to change anything in the trends. I would concur that this contamination introduces some larger error bars in the spikes but it would not remove the spikes and shape them into nicely reproducing aerosol effects.

Yet again I assert: Soden et al's paper supports the model’s ability to model water vapour reaction to a change in forcing.
No doubt the paper does, nicely omitting adverse evidence, however the reality does not. The question seems to be if the models are right and reality is wrong?
 
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  • #33
“There are several sudden lower troposphere cooling events not associated with major volcano aerosol injections.” Yes, and so what? There are also warming events, but the key here is the strato warming spikes which do pick out certain tropo cooling events as assoc with volcanic aerosol injections into the strato. http://www.metoffice.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif The importance of this strato warming is that it allows us to see a pattern associated with such eruptions as discussed here http://www.cru.uea.ac.uk/cru/info/volcano/. And I quote from the closing para of that paper:

“Impact apart, the importance of volcanic events is that forecasts can be tested relatively quickly over the subsequent few years. Other natural (e.g. solar output changes) and anthropogenic (increases in greenhouse gases and sulphate aerosols) operate on decadal-to-century timescales and any changes over short timescales are very difficult to distinguish from the natural variability of the climate system. Volcanic-induced forcing is sufficiently large to be clearly seen and provides a good test of climate model performance.”

So Soden et al can pick out the event they use as probably being caused by Pinatubo and not being one of the other non-volcanic cooling events that you seem to be obsessed with.

You say, “But the lower trophosphere MSU-2 is following it's own logic, warming after one event and cooling after another. Yet, you happily persist in a 100% relationship of Volcanoes and the lower troposphere.”

Perhaps it would help you to understand if I were to explain that vulcanism is not the only effect that can cause changes in Global Average Temperature. Not every cooling is due to vulcanism and sometimes the signature of vulcanism is lost because of other factors in the climatic system. Again it is you, having grabbed the wrong end of the stick, who are obsessed with every wiggle in the tropo temp record. I am only concerned with Pinatubo and it’s utility in the examination by Soden et al. In that respect you have failed to invalidate it.

As is seen in the El-Chichon eruption where, as I point out above, the cooling period was already underway thus undermining it’s utility as a scenario for this study.

According to the graph I have always been relying on, http://www.metoffice.gov.uk/research/hadleycentre/CR_data/Monthly/upper_air_temps.gif , there is a CLEAR drop associated with Agung. But as it’s before 1979 when the MSU record began (again see the earliest period that the graph I link to). So being before the MSU record it’s not as good a study as Mt Pinatubo, because the observational evidence against which to test the model performance is not as comprehensive.

Why on earth would the IPCC make any suggestion of a correlation in this case? IPCC may well address Soden et al in the Fourth Assessment report, but this issue is not relevant to the SAR or TAR.

Soden et al's paper supports the model’s ability to model water vapour reaction to a change in forcing.
 
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  • #34
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“There are several sudden lower troposphere cooling events not associated with major volcano aerosol injections.” Yes, and so what?
So what??
Not every cooling is due to vulcanism and sometimes the signature of vulcanism is lost because of other factors in the climatic system
You answer the question yourself. Due to the other factors in the climatic system the signature of volcanism is lost. This also goes for the pinatubo event. You cannot switch off those other factors at your own convenience. Yet that is what you do:
I am only concerned with Pinatubo
Would the term obsessed be applicable here too? I'm obsessed only to let the scientific method prevail instead of your data mining: "The data of Pinatubo is convenient so let's use that and skip the rest".

According to the graph I have always been relying on, http://www.metoffice.gov.uk/researc...r_air_temps.gif , there is a CLEAR drop associated with Agung.
You are looking at identical http://home.wanadoo.nl/bijkerk/reproduceability.jpg [Broken] A copy paste job, with only some excess data removed.

Immediately after Agung the UKMO 2LT rose slighly for well over year before the dip started. There are many more dips like that. Why would Agung have caused it after such a delay? Nevertheless I gave it an undetermined. thumbs horizontal.

As is seen in the El-Chichon eruption where, as I point out above, the cooling period was already underway thus undermining it’s utility as a scenario for this study
Look again, why is El Chichon appartly causing a rise with the cooling already on its way? Isn't that exactly the opposite effect of the expected reaction?

Now with two cases of non compliance with the models, why are we so sure that Pinatubo is spot on all of a sudden with no influence of other factors in the climatic system, other than that we want it to be spot on?
 
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  • #35
You state ”Now with two cases of non compliance with the models, why are we so sure that Pinatubo is spot on all of a sudden with no influence of other factors in the climatic system, other than that we want it to be spot on?”

Firstly, you have clearly not demonstrated “non compliance with the models” What models are you referring to??? The study we are discussing only addresses Pinatubo, it is not concerned with the cases you are raising. Soden's models do not model vulcanism - they account for it's effects using forcings calculated from observation.

Secondly nothing in a system as complex as the climate can be 'spot on'. But for the reasons I have already repeatedly stated Pinatubo gives a good clean response. AND the models reproduce it well. Indeed it is not only in the case of Soden et al that Pinatubo shows a good response. Figure 4 of the IPCC SPM is one other example (don't ask for more I haven't got time to waste on that).

Thirdly your attempt at (what I see as) obfuscation has demonstrably failed. It is simply not reasonable for you to expect me to account for every possible climatic influence on Agung and El Chichon. I have provided you with a link to a paper written by the CRU http://www.cru.uea.ac.uk/cru/info/volcano/. Do you disagree with their final statement? If you do then research it and publish.


I have indulged you for long enough Andre. Now I have a question for you:

Given that other factors may be involved and that you are seeking to cast doubt on their work: How is it that the models used in Soden et al reproduce, to a good degree, the short wave and long wave radiation anomalies (fig 1). The temperature, total column water vapour, and upper tropo water vapour (fig2). And the 6.7um brightness (fig 3)?


I've spent enough time on this issue. Have you any substantive points to make on the issue at hand? That being that Soden et al demonstrates the ability of their GCMs to accurately model the response of atmospheric water vapour to a change in forcing.
 
  • #36
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Firstly, you have clearly not demonstrated “non compliance with the models”
That sounds like a conclusion but I seem to miss the elaborated reasoning to underscore it; the lack thereof reduces that statement to have the same merit as “Firstly, you have clearly not demonstrated that 1+1=2”

The study we are discussing only addresses Pinatubo, it is not concerned with the cases you are raising.
Exactly! And that’s the reason why it is fundamentally flawed (to use a popular partisan term in the global warming circles), Why? The selective use of data and implicitly discarding the data that falsify it.

Soden's models do not model vulcanism - they account for it's effects using forcings calculated from observation.
Straw man, we are talking about that all the time. Why do those models not account for Agung and La Chichon. Two against one is not an impressive score.

Secondly nothing in a system as complex as the climate can be 'spot on'. But for the reasons I have already repeatedly stated Pinatubo gives a good clean response.
And repeatedly excluding other factors that influence the troposphere temperature. Repeating things does not make them right. You cannot exclude that the post Pinatubo dip would also have occurred without the eruption.

AND the models reproduce it well.
Circular reasoning / aka begging the question. The clean dry effect of aerosols was supposed to be to small to account for all the cooling so, if the remainder is assumed to be water vapour feedback, then the models reproduce it well based on the same assumption that was to be proved. Circular reasoning.

Now what if the cooling was natural whilst in reality -equal to Agung and La Chchon- the real effect of Pinotuba was not only radiative warming of the Stratosphere but also radiative warming of the Troposphere that happened to be superseded by a large natural cooling?

Thirdly your attempt at (what I see as) obfuscation has demonstrably failed.
There you are again: Thirdly your attempt at (what I see as) 2+2=4 has demonstrably failed.

It is simply not reasonable for you to expect me to account for every possible climatic influence on Agung and El Chichon.
Why not? Why give Pinatubo a privileged accounting?

If you do then research it and publish.
Fallacy of the restricted choice. In reality I have a lot more choices, none of which, by the way would have any influence on the failure of the troposphere to react consistently with the same trend on Volcanic induced aerosol forcing like the Stratosphere does.

Anyway, Viner Jones address only Pinatubo, meaning that the paper does not exceed the scientific level of Soden. Restricted data, restricted scope.

I have indulged you for long enough
Absolutely, quite happy to take the candy and expose the fallacies. Appreciate it.

How is it that the models used in Soden et al reproduce, to a good degree, the short wave and long wave radiation anomalies (fig 1)
As I said, begging the question. To put it bluntly: the models are developed empirically to fit reality. They fit reality hence they are right. That is, until reality decides to come up with yet another big unknown.

But now another question. Where do models belong in the scientific method?

I've spent enough time on this issue.
Hmm not enough time to go over whatever I produce and yet spend enough time? But why is it of importance to tell it here? To use it as a emotional appeal fallacy? (The master has no time for the obnoxious pupil and implying that the master is right and the pupil is wrong) I have not forgotten about your opening statement about James Lovelock and my assumed lack of knowledge.

I’d love to have you around some more and give me a chance to expose some more of those abundant fallacies that the global warming hype needs, missing real evidence of the assumed GHG-water vapour effect..

Have you any substantive points to make on the issue at hand? That being that Soden et al demonstrates the ability of their GCMs to accurately model the response of atmospheric water vapour to a change in forcing.
Now if those models are so accurate, why not a reality check and do the same exercise for Agung and La Chichon? Isn’t that how the scientific method works?
 
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  • #37
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I wonder over and over again why good news in climate studies never hits major news channels. With this kind of research you'd expect: "Detailed Research Ends Global Warming Myth, World Leaders Consider Abandoning Kyoto":

http://www.nasa.gov/vision/earth/lookingatearth/warmer_humidity.html

....like carbon dioxide, the Earth warms, more water evaporates from the ocean, and the amount of water vapor in the atmosphere increases. Since water vapor is also a greenhouse gas, this leads to a further increase in the surface temperature. This effect is known as "positive water vapor feedback." Its existence and size have been contentiously argued for several years.
...

They found the increases in water vapor were not as high as many climate-forecasting computer models have assumed. "Our study confirms the existence of a positive water vapor feedback in the atmosphere, but it may be weaker than we expected"
Obviously, the same saturation effect that causes the greenhouse effect to be rather stable with various concentations, the same is true for water vapor. Larger changes in humidity seem to have not much impact on it's greenhouse effect. The first ppms are doing the trick. Water vapor feedback is a very small change (greenhouse gas) of a very small change (temperature) of a very small change (humidity) of a very small change (temperature).
 

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