I received this presentation of the “Bjerknes Lecture” that Dr. James Hansen gave at the annual meeting of the American Geophysical Union on December 17th. There are the usual things one might expect in the presentation, such as this slide which shows 2008 on the left with the anomalously warm Siberia and the Antarctic peninsula:
Source: James Hansen, GISS
Off topic but relevant, NASA has recently “disappeared”updated this oft cited map showing warming on the Antarctic peninsula and cooling of the interior:
There is also some new information in Hansen’s presentation, including a claim about CO2 sensitivity and coal causing a “runaway greenhouse effect”.
Hansen makes a bold statement that he has empirically derived CO2 sensitivity of our global climate system. I had to chuckle though, about the claim “Paleo yields precise result”. Apparently Jim hasn’t quite got the message yet that Michael Mann’s paleo results are, well, dubious, or that trees are better indicators of precipitation than temperature.
In fact in the later slide text he claims he’s “nailed” it:
He adds some caveats for the 2xCO2 claim:
Notes:
(1)
It is unwise to attempt to treat glacial-interglacial aerosol changes as a specified boundary condition (as per Hansen et al. 1984), because aerosols are inhomogeneously distributed, and their forcing depends strongly on aerosol altitude and aerosol absorbtivity, all poorly known. But why even attempt that? Human-made aerosol changes are a forcing, but aerosol changes in response to climate change are a fast feedback.
(2)
The accuracy of our knowledge of climate sensitivity is set by our best source of information, not by bad sources. Estimates of climate sensitivity based on the last 100 years of climate change are practically worthless, because we do not know the net climate forcing. Also, transient change is much less sensitive than the equilibrium response and the transient response is affected by uncertainty in ocean mixing.
(3)
Although, in general, climate sensitivity is a function of the climate state, the fast feedback sensitivity is just as great going toward warmer climate as it is going toward colder climate. Slow feedbacks (ice sheet changes, greenhouse gas changes) are more sensitive to the climate state.
Hansen is also talking about the “runaway” greenhouse effect, citing that old standby Venus in part of his presentation. He claims that coal and tar sands will be our undoing:
Hansen writes:
In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect. If we also burn the tar sands and tar shale (a.k.a. oil shale), I think it is a dead certainty.
That would be the ultimate Faustian bargain. Mephistopheles would carry off shrieking not only the robber barons, but, unfortunately and permanently, all life on the planet.
I have to wonder though, if he really believes what he is saying. Perhaps he’s never seen this graph for CO2 from Bill Illis and the response it gives to IR radiation (and thus temperature) as it increases:
It’s commonly known that CO2’s radiative return response is logarithmic with increasing concentration, so I don’t understand how Hansen thinks that it will be the cause of a runaway effect. The physics dictate that the temperature response curve of the atmosphere will be getting flatter as CO2 increases. Earth has also had much higher concentrations of CO2 in past history, and we didn’t go into runaway then:
Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today (Quaternary Period ).
There’s lots more in this paper to behold in wonderment, and I haven’t the time today to comment on all of it, so I’ll just leave it up to the readers of this forum to bring out the relevant issues for discussion.
I’m sure Steve McIntyre at Climate Audit will have some comments on it, even though his name is not mentioned in the presentation. My name was mentioned several times though. 😉
A few brief comments on the foinavon reply:
“I’m not trying to “nail you” but this highlights a real problem with information, which might be that if you source information from sites designed to misrepresent the science, you are very likely to get the wrong end of the stick more generally.”
How can you make such a vague response to the criticism that the Santer paper you are pointing to as “proof” has been discredited? A highly evasive response…
I wrote: “Could you provide some links please on published criticisms of this data? …”
Your reply: “But surely you can interpret the graphs in the same way that I can.”
Translation: “No, I can’t”
Your reply: “Its a profound problem if you can only assess the science after it’s been “filtered” through some dodgy web site somewhere!”
That “dodgy website” is written by a well respected peer reviewed climate researcher. I suppose you mean it’s “dodgy” if it’s critical of your opinion. Don’t resort to rubbishing people you don’t agree with. Stick to the science please.
You have written many long replies full of opinions but lacking in content or worthwhile referenced links. A reminder of some of the questions put to you that remain outstanding and which you have so far evaded:
1. References to published criticisms of the temperate data in respected journals for the temperature data in which you’ve expressed the opinion that it’s “unreliable.” One wouldn’t want to think you are getting your information from “dodgy” websites. 😉
2. A non-evasive response to the Santer paper and its problems.
3. Links to published papers on atmospheric aerosol effects in relation to past cooling events in the previous century. This is CRITICAL for propping AGW theory. You just can’t tip toe over it…
You’ve made lots of bold proclamations. It’s 500+ postings so far. It’s time to stop posting opinions and provide some links to the key claims you’ve made.
Thanks.
If climate sensitivity is logarithmic as often surmised, then 3 deg C for 2 times CO2 depends on where you are on the graph of CO2. 100 ppm to 200 ppm is a different place to 300 ppm to 600 ppm.
Geoff Sherrington (21:17:32) :
If climate sensitivity is logarithmic as often surmised, then 3 deg C for 2 times CO2 depends on where you are on the graph of CO2. 100 ppm to 200 ppm is a different place to 300 ppm to 600 ppm.
I’m afraid not Geoff, a y=log(x) plot shows the same increase in y for the same ratio change in x.
foinavon
December 29, 2008 4:24 am
Will,
That “dodgy website” is written by a well respected peer reviewed climate researcher. I suppose you mean it’s “dodgy” if it’s critical of your opinion. Don’t resort to rubbishing people you don’t agree with. Stick to the science please.
and
: References to published criticisms of the temperate data in respected journals for the temperature data in which you’ve expressed the opinion that it’s “unreliable.” One wouldn’t want to think you are getting your information from “dodgy” websites. 😉
You’re confused here I think or just haven’t been paying attention. I have no problem with Scotese’s very nice paleogeology site as I’ve said several times. Unfortunately the paleotemperature sketch pulled from there, denuded, and dumped at the top of this thread doesn’t bear much relationship to what we know of paleotemperature. And as you well know, my reference to “dodgy website” refers to wherever you “sourced” the awesomely false interpretation about the time period of Santers tropospheric temperature analysis.
I linked to a more up to date and properly sourced paleotemperature data set here [25.12.08 (16:13:03)]. It’s got all the scientific literature sources cited below.
Your reply: “But surely you can interpret the graphs in the same way that I can.”
Translation: “No, I can’t”
Leaving aside the fact that I’ve linked to some rather more reliable paletemperature data [25.12.08 (16:13:03)], and listed around 10 scientific papers that address the relationship between paleoCO2 and paleotemp [22.12.08 (10:47:01), there must be some point at which you can make an independent judgement of data/arguments. Otherwise you’re hopelessly susceptible to being suckered by those with the most “convincing” propaganda/misrepresentation.
This thread is about Hansens AGU presentation. He’s assessing climate sensitivity (the relation between the earths surface temperature and atmospheric CO2 levels), and the consequences of massive release of CO2 within scenarios that mankind oxidises all the carbon sequestered in coal and tar shale. If we wish to assess Hansen’s analyses reliably we should be considering appropriate CO2 concentrations (not a graph so heavily biased by the completely inappropriate 0-100 ppm range to give the impression that temperatures seem unresponse to CO2 above several hundred ppm); we need to be aware of the truism that Hansens scenarios can only be addressed in the knowledge that 3000 ppm CO2 gives a much higher forcing now than 450 million years ago when the solar constant was 5% weaker; if we want to understand the relationship between paleoT and paleoCO2 we can’t use a crude sketch of paleotemperature that bears little relation to the science, overlaid with a data-free model of paleCO (Berner’s very nice Geocarb model has a time resolution is 1 point every 10 million years). We can only assess the true relationships between paleoT and paleoCO2 in those specific circumstances where we have contemporaneous paleoT and paleo CO2 data [see 22.12.08 (10:47:01)]. And so on…
These are all self-evident aren’t they Will? We don’t need to hunt around the web for some reassurance or “criticism”. We can decide for ourselves. After all that’s what well-informed policymakers and their scientific advisors are doing. We’re going to become increasingly divorced from informed-understanding of these issue if we’re unable to address the science without it first being “filtered” through someone else’s reinterpretation!
A non-evasive response to the Santer paper and its problems.
3. Links to published papers on atmospheric aerosol effects in relation to past cooling events in the previous century. This is CRITICAL for propping AGW theory. You just can’t tip toe over it…
I’m not sure what you mean about Santer’s paper. It’s recently published and seems a rather detailed and considered piece of work. What’s your problem with it? I get the impression that you’ve found something on some dodgy website (that seems to be where you’ve got the wrong end of the stick over its temporal period). But I’m not interested in that. The blogosphere is an awesome fount of self-serving nonsense. Best to stick to the scientific literature. That’s what well-informed opinion that informs policymaking does.
Perhaps if you could put your criticism of Santer in your own words (being careful to look at the papaer first so as not to make elementary errors of fact) we could address that. But I’m not going to waste time addressing nonsense on some website.
There’s a large literature on aerosols. A good starting point in relation to effects on Earth’s temperature during the 20th century is:
J. Hansen et al. (2007) Climate simulations for 1880-2003 with GISS modelE. Clim. Dynam., 29, 661-696. which can be downloaded from here: http://pubs.giss.nasa.gov/abstracts/2007/
See pps 4-6 and Figures (especially Figure 5)
anna v
December 29, 2008 6:57 am
Hansen as a reference is priceless.
We have a proverb in modern Greek : “if you do not believe me, ask my uncle the liar”.
foinavon
December 29, 2008 11:38 am
do you think so Anna?
There’s plenty of papers in the scientific literature that address the effect of aerosols on the pattern of 20th century warming. I’ve cited a further selection below. However, Will wants clickable links apparently, so why not read an example from Hansen (and more than 40 colleagues)? All NASA GISS publications are nicely clickable.
If you (or Will) doesn’t like Hansen (!), you can track down some of the papers below [***].
There is a more serious issue ‘though. It may be dandy to attempt to trash someone that doesn’t suit your fancy, such that you can demonise him and thus dismiss all of his works out of hand. But that’s just a blogosphere practice. Neither scientists nor informed policymakers resort to that sort of nonsense.
[***] here’s some more papers that address the effects of aerosols within the total 20th century Earth (or ocean) warming profile. You can find lots more of you put some effort into it:
Lean JL, Rind DH (2008) How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett. 35, art # L18701
Delworth TL et al (2006) The impact of aerosols on simulated ocean temperature and heat content in the 20th century. Geophys. Res. Lett. 32 art # L24709
Dufresne JL et al. (2006) Contrasts in the effects on climate of anthropogenic sulfate aerosols between the 20th and the 21st century. Geophys Res. Lett. 32 art # L21703
Cai W et al (2006) Pan-oceanic response to increasing anthropogenic aerosols: Impacts on the Southern Hemisphere oceanic circulation. Geophys. Res. Lett. 33, art # L21707
Fyfe JC (2006) Southern Ocean warming due to human influence. Geophys. Res. Lett. 33, art # L19701.
and so on…
PeteM
December 30, 2008 6:25 am
foinavon (and Joel)
Thank you for adding a sense of realism and good practice to this website. I’ve seen a lot of very challengable items added on several discussions before and I’m pleased to see someone respond to the points in such a clear and patient way.
As the discussison has developed I’ve realised I don’t understand the mechanism by which extra absoprtion of IR radiation by CO2 leads to increased temperature.
Is this because the extra absorbed radiation leads to an increase in emitted photons (as the CO2 molecules move back to a lower energy state) which are then reabsorbed by the ground .
Or is it because the CO2 molecules can transfer energy via collisions with other molecules (eg N2 , O2) increasing their ‘vibrational’ energy .
Ben Kellett
January 5, 2009 2:57 am
Foinavon & Joel Shore, I must also congratulate you both on your well reasoned, well informed and objective responses throughout. I particularly like the way you both respond point by point to anyone who challenges your views. A skeptic by nature, I think you are absolutely right Foinavon in suggesting that many of us including myself have been at times a little influenced by the more….” “convincing” propoganda/misrepresentation”.
Like many who use this website, I also dislike the use of assertions such as “the science is settled” and terms such as “nailed” as I think there is a long way to go before we can be so sure of processes with so many variables. However, you have both been successful in moving me a little further towards accepting some of the very good science that is already in place. Thank you both for the excellent links, some of which I had not read as thoroughly as they deserved.
This has been a compelling debate from which you have both emerged holding the ground closest to the truth. I am intrigued though as to your motives. You must have both put in an impressive few shifts in order to respond as comprehensively as you have, leaving no stone unturned.
Also Foinavon – interesting name – mountain in Sutherland (NW Highlands of Scotland) – or Grand National winner!
A quick scan through future topics on this site and I haven’t seen many, if any of your contributions. I for one, certainly look forward to reading your posts on future topics.
Ben
foinavon
January 5, 2009 7:10 am
PeteM
My understanding of the origin of the greenhouse effect at the molecular level is that absorption of long wave infra-red (emitted by the Earth’s surface), by greenhouse gasses, results in the retention of thermal energy within the atmosphere by both of the mechanisms you describe!
So the stimulation of IR vibrational modes is essentially a “capture” of thermal energy which is passed to other molecules of the atmosphere by molecular collisions.
Additionally the greenhouse gasses can re-emit vibrational IR directing some of this back towards the surface. How much of this reaches the surface I’m not sure..presumably much of it is reabsorbed by greenhouse gasses above the surface (which results in additional local warming), but presumably some proportion of the long wave IR emitted by the atmospheric greenhouse gasses does reach the surface.
Joel Shore’s account of the effect on surface temperature from the point of view of atmospheric physics [25:12:08 (08:00:19)] is good.
dohboi
January 12, 2009 12:05 am
Yes, thank you foinavon and joel shore and a very few other for turning a thread that started with a slew of not vey informed or informative knee-jerk reactions into a very informative and civil discussion of an important issue.
Unfortunately, even after you patiently, clearly and repeatedly explained how CO2 is the variable and H2O a passive feedback ghg, most here still just seemed to not be able to understand this basic distincion. There seem to be some fairly strong emotions blocking understanding, here, but it could be something else.
Anyway, thanks again, and best wishes to all for what promises to be an interesting year.
dohboi:
I agree that both Joel and foinavon discuss their views without resorting to name calling or invective. That is very much appreciated, and is in pretty stark contrast to the way many other commenters act when they disagree.
Also, site owners themselves who believe that CO2 will lead to runaway global warming often join in the invective against anyone who thinks otherwise. Or they delete all the vowels from the poster’s comment, turning an opposing point of view into gibberish. Or they arbitrarily censor uncomfortable comments by arbitrarily deleting the post. I think respect for opposing views is a major reason why WUWT is the runaway winner in the “Best Science” category.
Finally, regarding your opinion that most skeptics question the role of CO2 in temperature, this chart and others like it have been repeatedly posted here. If rising CO2 caused rising temps, it would be apparent in the empirical record. It is not, so the role of CO2 is, if anything at all, extremely minor and completely overwhelmed by other factors.
Thanks again for your input and polite post, and come back often.
Frank. Lansner (15:30:44) & Graeme Rodaughan (13:37:57)
The same should be said about the Paleoclimate Reconstruction Challenge.
A few brief comments on the foinavon reply:
“I’m not trying to “nail you” but this highlights a real problem with information, which might be that if you source information from sites designed to misrepresent the science, you are very likely to get the wrong end of the stick more generally.”
How can you make such a vague response to the criticism that the Santer paper you are pointing to as “proof” has been discredited? A highly evasive response…
I wrote: “Could you provide some links please on published criticisms of this data? …”
Your reply: “But surely you can interpret the graphs in the same way that I can.”
Translation: “No, I can’t”
Your reply: “Its a profound problem if you can only assess the science after it’s been “filtered” through some dodgy web site somewhere!”
That “dodgy website” is written by a well respected peer reviewed climate researcher. I suppose you mean it’s “dodgy” if it’s critical of your opinion. Don’t resort to rubbishing people you don’t agree with. Stick to the science please.
You have written many long replies full of opinions but lacking in content or worthwhile referenced links. A reminder of some of the questions put to you that remain outstanding and which you have so far evaded:
1. References to published criticisms of the temperate data in respected journals for the temperature data in which you’ve expressed the opinion that it’s “unreliable.” One wouldn’t want to think you are getting your information from “dodgy” websites. 😉
2. A non-evasive response to the Santer paper and its problems.
3. Links to published papers on atmospheric aerosol effects in relation to past cooling events in the previous century. This is CRITICAL for propping AGW theory. You just can’t tip toe over it…
You’ve made lots of bold proclamations. It’s 500+ postings so far. It’s time to stop posting opinions and provide some links to the key claims you’ve made.
Thanks.
If climate sensitivity is logarithmic as often surmised, then 3 deg C for 2 times CO2 depends on where you are on the graph of CO2. 100 ppm to 200 ppm is a different place to 300 ppm to 600 ppm.
Geoff Sherrington (21:17:32) :
If climate sensitivity is logarithmic as often surmised, then 3 deg C for 2 times CO2 depends on where you are on the graph of CO2. 100 ppm to 200 ppm is a different place to 300 ppm to 600 ppm.
I’m afraid not Geoff, a y=log(x) plot shows the same increase in y for the same ratio change in x.
Will,
You’re confused here I think or just haven’t been paying attention. I have no problem with Scotese’s very nice paleogeology site as I’ve said several times. Unfortunately the paleotemperature sketch pulled from there, denuded, and dumped at the top of this thread doesn’t bear much relationship to what we know of paleotemperature. And as you well know, my reference to “dodgy website” refers to wherever you “sourced” the awesomely false interpretation about the time period of Santers tropospheric temperature analysis.
I linked to a more up to date and properly sourced paleotemperature data set here [25.12.08 (16:13:03)]. It’s got all the scientific literature sources cited below.
Leaving aside the fact that I’ve linked to some rather more reliable paletemperature data [25.12.08 (16:13:03)], and listed around 10 scientific papers that address the relationship between paleoCO2 and paleotemp [22.12.08 (10:47:01), there must be some point at which you can make an independent judgement of data/arguments. Otherwise you’re hopelessly susceptible to being suckered by those with the most “convincing” propaganda/misrepresentation.
This thread is about Hansens AGU presentation. He’s assessing climate sensitivity (the relation between the earths surface temperature and atmospheric CO2 levels), and the consequences of massive release of CO2 within scenarios that mankind oxidises all the carbon sequestered in coal and tar shale. If we wish to assess Hansen’s analyses reliably we should be considering appropriate CO2 concentrations (not a graph so heavily biased by the completely inappropriate 0-100 ppm range to give the impression that temperatures seem unresponse to CO2 above several hundred ppm); we need to be aware of the truism that Hansens scenarios can only be addressed in the knowledge that 3000 ppm CO2 gives a much higher forcing now than 450 million years ago when the solar constant was 5% weaker; if we want to understand the relationship between paleoT and paleoCO2 we can’t use a crude sketch of paleotemperature that bears little relation to the science, overlaid with a data-free model of paleCO (Berner’s very nice Geocarb model has a time resolution is 1 point every 10 million years). We can only assess the true relationships between paleoT and paleoCO2 in those specific circumstances where we have contemporaneous paleoT and paleo CO2 data [see 22.12.08 (10:47:01)]. And so on…
These are all self-evident aren’t they Will? We don’t need to hunt around the web for some reassurance or “criticism”. We can decide for ourselves. After all that’s what well-informed policymakers and their scientific advisors are doing. We’re going to become increasingly divorced from informed-understanding of these issue if we’re unable to address the science without it first being “filtered” through someone else’s reinterpretation!
I’m not sure what you mean about Santer’s paper. It’s recently published and seems a rather detailed and considered piece of work. What’s your problem with it? I get the impression that you’ve found something on some dodgy website (that seems to be where you’ve got the wrong end of the stick over its temporal period). But I’m not interested in that. The blogosphere is an awesome fount of self-serving nonsense. Best to stick to the scientific literature. That’s what well-informed opinion that informs policymaking does.
Perhaps if you could put your criticism of Santer in your own words (being careful to look at the papaer first so as not to make elementary errors of fact) we could address that. But I’m not going to waste time addressing nonsense on some website.
There’s a large literature on aerosols. A good starting point in relation to effects on Earth’s temperature during the 20th century is:
J. Hansen et al. (2007) Climate simulations for 1880-2003 with GISS modelE. Clim. Dynam., 29, 661-696. which can be downloaded from here:
http://pubs.giss.nasa.gov/abstracts/2007/
See pps 4-6 and Figures (especially Figure 5)
Hansen as a reference is priceless.
We have a proverb in modern Greek : “if you do not believe me, ask my uncle the liar”.
do you think so Anna?
There’s plenty of papers in the scientific literature that address the effect of aerosols on the pattern of 20th century warming. I’ve cited a further selection below. However, Will wants clickable links apparently, so why not read an example from Hansen (and more than 40 colleagues)? All NASA GISS publications are nicely clickable.
If you (or Will) doesn’t like Hansen (!), you can track down some of the papers below [***].
There is a more serious issue ‘though. It may be dandy to attempt to trash someone that doesn’t suit your fancy, such that you can demonise him and thus dismiss all of his works out of hand. But that’s just a blogosphere practice. Neither scientists nor informed policymakers resort to that sort of nonsense.
[***] here’s some more papers that address the effects of aerosols within the total 20th century Earth (or ocean) warming profile. You can find lots more of you put some effort into it:
Lean JL, Rind DH (2008) How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006. Geophys. Res. Lett. 35, art # L18701
Delworth TL et al (2006) The impact of aerosols on simulated ocean temperature and heat content in the 20th century. Geophys. Res. Lett. 32 art # L24709
Dufresne JL et al. (2006) Contrasts in the effects on climate of anthropogenic sulfate aerosols between the 20th and the 21st century. Geophys Res. Lett. 32 art # L21703
Cai W et al (2006) Pan-oceanic response to increasing anthropogenic aerosols: Impacts on the Southern Hemisphere oceanic circulation. Geophys. Res. Lett. 33, art # L21707
Fyfe JC (2006) Southern Ocean warming due to human influence. Geophys. Res. Lett. 33, art # L19701.
and so on…
foinavon (and Joel)
Thank you for adding a sense of realism and good practice to this website. I’ve seen a lot of very challengable items added on several discussions before and I’m pleased to see someone respond to the points in such a clear and patient way.
As the discussison has developed I’ve realised I don’t understand the mechanism by which extra absoprtion of IR radiation by CO2 leads to increased temperature.
Is this because the extra absorbed radiation leads to an increase in emitted photons (as the CO2 molecules move back to a lower energy state) which are then reabsorbed by the ground .
Or is it because the CO2 molecules can transfer energy via collisions with other molecules (eg N2 , O2) increasing their ‘vibrational’ energy .
Foinavon & Joel Shore, I must also congratulate you both on your well reasoned, well informed and objective responses throughout. I particularly like the way you both respond point by point to anyone who challenges your views. A skeptic by nature, I think you are absolutely right Foinavon in suggesting that many of us including myself have been at times a little influenced by the more….” “convincing” propoganda/misrepresentation”.
Like many who use this website, I also dislike the use of assertions such as “the science is settled” and terms such as “nailed” as I think there is a long way to go before we can be so sure of processes with so many variables. However, you have both been successful in moving me a little further towards accepting some of the very good science that is already in place. Thank you both for the excellent links, some of which I had not read as thoroughly as they deserved.
This has been a compelling debate from which you have both emerged holding the ground closest to the truth. I am intrigued though as to your motives. You must have both put in an impressive few shifts in order to respond as comprehensively as you have, leaving no stone unturned.
Also Foinavon – interesting name – mountain in Sutherland (NW Highlands of Scotland) – or Grand National winner!
A quick scan through future topics on this site and I haven’t seen many, if any of your contributions. I for one, certainly look forward to reading your posts on future topics.
Ben
PeteM
My understanding of the origin of the greenhouse effect at the molecular level is that absorption of long wave infra-red (emitted by the Earth’s surface), by greenhouse gasses, results in the retention of thermal energy within the atmosphere by both of the mechanisms you describe!
So the stimulation of IR vibrational modes is essentially a “capture” of thermal energy which is passed to other molecules of the atmosphere by molecular collisions.
Additionally the greenhouse gasses can re-emit vibrational IR directing some of this back towards the surface. How much of this reaches the surface I’m not sure..presumably much of it is reabsorbed by greenhouse gasses above the surface (which results in additional local warming), but presumably some proportion of the long wave IR emitted by the atmospheric greenhouse gasses does reach the surface.
Joel Shore’s account of the effect on surface temperature from the point of view of atmospheric physics [25:12:08 (08:00:19)] is good.
Yes, thank you foinavon and joel shore and a very few other for turning a thread that started with a slew of not vey informed or informative knee-jerk reactions into a very informative and civil discussion of an important issue.
Unfortunately, even after you patiently, clearly and repeatedly explained how CO2 is the variable and H2O a passive feedback ghg, most here still just seemed to not be able to understand this basic distincion. There seem to be some fairly strong emotions blocking understanding, here, but it could be something else.
Anyway, thanks again, and best wishes to all for what promises to be an interesting year.
dohboi:
I agree that both Joel and foinavon discuss their views without resorting to name calling or invective. That is very much appreciated, and is in pretty stark contrast to the way many other commenters act when they disagree.
Also, site owners themselves who believe that CO2 will lead to runaway global warming often join in the invective against anyone who thinks otherwise. Or they delete all the vowels from the poster’s comment, turning an opposing point of view into gibberish. Or they arbitrarily censor uncomfortable comments by arbitrarily deleting the post. I think respect for opposing views is a major reason why WUWT is the runaway winner in the “Best Science” category.
Finally, regarding your opinion that most skeptics question the role of CO2 in temperature, this chart and others like it have been repeatedly posted here. If rising CO2 caused rising temps, it would be apparent in the empirical record. It is not, so the role of CO2 is, if anything at all, extremely minor and completely overwhelmed by other factors.
Thanks again for your input and polite post, and come back often.