Spotting the AGW fingerprint

“The AR4 authors are careful to refer to “natural external factors” that have been ruled out as potential causes, like those seen in the above figure”.
“I can only assume this is was deliberate attempt to cover themselves just in case most warming eventually gets traced to natural internal changes in the climate system, rather than to that exceedingly scarce atmospheric constituent that is necessary for life of Earth – carbon dioxide.”
The voice of truth!
Also….they finally mention “Natural External Factors”.
With many more pressing scientific issues vexing our species and our planet…how much more scientific energy will be wasted on the AGW scare??
Chris
Norfolk, VA, USA

I can see your point about the presence or absence of the hotspot not implicating AGM, but I thought that the tropical hotspot conjecture had been disproved by thousands of radiosonde balloons.

As you mention, the Models do not work correctly. If the models are wrong, it matters not whether there is a Hot Spot.
It DOES matter what would cause PROBLEMS in the climate system. If corrected, the models might be able to show this. Until then, all the spending and reorganisations of society are contraindicated as we DO NOTKNOW HOW THINGS HAPPEN AND THEREFOR WE DO NOT KNOW HOW TO CORRECTLY IMPLEMENT SOLUTIONS!!
Actions we take could, instead of improving the situation, actually exacerbate it through our ignorance.
Thank you for sticking with your excellent work and also taking the time to clarify issues for us .

Could someone lead me please to a baloon data that falsifies the formation of tropical stratosphere hot spot ?

May I ask someone another favor.
My source of the UAH satellite data is limited to low- and mid-troposphere data on the Junkscience site.
Where should I go to watch similar data for troposphere/stratosphere interfacial region (TTS) and for mid-stratosphere (TLS) ?

Friday, October 9, 2009 BBC News: What happened to global warming?
BBC News climate correspondent, Paul Hudson, declares “For the last 11 years we have not observed any increase in global temperatures. And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise.”
More at http://news.bbc.co.uk/2/hi/science/nature/8299079.stm

We need to demonize CO2 and destroy the economy of the world because the models predict such disastrous consequences that billions of people will die by the end of the century if we don’t. They’re right of course, at least 8 to 10 billion people will die by 2100, if we don’t stop using fossil fuels immediately. Of course, 8 to 10 billion people will die by 2100 no matter what we do and judging by the resounding success of all the green initiatives of the past 40 yrs, DDT ban, biofuels etc., if we follow their demands, the number of dead will be far larger than if we do absolutely nothing. The fact that most everything the models have predicted to be increasing rapidly is occurring slower than predicted, except for everything that’s happening far faster than expected. But, if you put it all together, couldn’t we all just agree that when it comes to predicting the climate, the models just plain suck!

John F. Hultquist (22:07:40)
A prolonged cooling appears to be what we are going to experience. While this will not convince alarmists, as the goal posts will simply be moved, it may change the thinking of billions of others. The political machinations and scientific malfeasance of AGW supporters only have the ability to affect human beliefs, they cannot affect nature. Just as King Canute could not stop the tide, AGW promoters cannot stop natural global cooling. It is disappointing that the AGW hoax will be stopped by nature rather than good science, but I am thankful that skeptics have managed to at least delay the AGW train long enough for cooling to begin. I’m guessing there may not be too may outdoor photo opportunities with Al or the Teleprompter Reader in Chief at Copenhagen this December.

anna v (22:49:44) :
fuzzy myself 🙂
If there were in the data a hotspot, I would agree with the author that it would not be enough/sufficient to demonstrate its origin: it would have been another confirmation/fit to the data showing consistency/sufficiency but not necessity.
“constistency/sufficiency” should of course be only “consistency” . No slash. Sufficiency would mean it were sufficient to prove CO2 the culprit, which is not possible with so many “forcings” entering in the problem.

I agree that there would be almost certainly many other mechanisms that would lead to the same fingerprint. But is this question relevant at all if this fingerprint is actually found not to exist according to the observations? In my opinion, it does exclude the greenhouse effect as the “predominant” driver – and it does exclude all other mechanisms with the same fingerprint, too.
Consistency is not enough as a proof but inconsistency is enough for a negative proof, isn’t it? By Bayesian inference, consistency may be a more or less strong circumstantial evidence that a hypothesis is correct – except that the consistency doesn’t seem to exist here so the question how strong evidence it would be seems immaterial.
Cheers
LM

kuhnkat (21:36:06) :
Actions we take could, instead of improving the situation, actually exacerbate it through our ignorance.
That is a huge problem with AGW. They are transfixed on taking drastic (and probably irreversible) actions against something that might be, not knowing what the consequences are due to the inability to understand how it works.
And even if it were true, not knowing how much correction to apply and what to apply makes the chances of getting it right slim indeed.
Uncertainty of lagtimes translates to a high chance of overdoing it.
How can the Earth be warmed if it is cooled too much? No exit strategy.
Sucking vast quantities of carbon out of the atmosphere and sucessfully sequestering it sound dangerous, and it likely is. Agriculture could teeter or simply fail, propelling stronger nations to attack thier neighbors in a desperate struggle for dwindling resources.
It can be done from a single nation, and doing so may hit the panic button of other nations and ignite open warfare.
Next up are the economic weakenings as the energy tax saps all recovery efforts, which are puny to begin with. Faltering nations are the playground of every anarchist.
All that risk for so poor of a calculation.
Reads like a Sci-Fi thriller with a very bad ending.

In any other case, such a disparity between theory and observation would lead to dismissing the theory, or reworking it. Not in this case.

M White – the media have been speculating about how badly security failed in allowing so many demonstrators to gain access to Westminster. It doesn’t take a rocket scientist to work out that security turned a blind eye. I figure it’s just an escalation of the Government’s pathetic anti-sceptic (ha ha) propaganda offensive.

P.S.
There is no such thing as a “global” temperature. So how does one measure something that is non-existent???

Truth and action an uncomprendable
S/B “action are” uncomprendable

It has always been the case in the scientific method that while a theory can never be proved, a single falsification can render it invalid (Popper). As several posters have already remarked, the fact of the matter is, not only would the “fingerprint” not be unique to greenhouse gases, but the fact that it doesn’t exist, would count as a falsification.
Of course, we don’t know that it doesn’t exist, and therein lies the rub. It may simply have escaped detection. This is the favoured explanation from the warmists, and have led to attempting to use windspeeds as a proxy for temperature, with some degree of success, if the results are to be believed.
But there are no more reasons to believe that windspeed proxies indicate higher temperatures than there is to believe that radiosondes and satellite data indicate no higher temperature. In fact less so, since the windspeed proxies and another layer of uncertainty.
However, if the windspeed proxies are in fact correct, indicating a net positive radiative imbalance, then the heat must be accumulating in the system, but this too has escaped detection. Roger Pielke snr. has already shown that the warming theory predicts that the ocean energy anomaly should now be showing (since 2003) somewhere between 10^22 tor 10^23 joules. But according to Argo based data, no ocean warming has been observed since 2003. So each predicition leads in turn to more and more contradicitory observations.
Of course, the missing heat could have gone below the 750m Argo floor. It could have, maybe . . . just maybe.

Bob Tisdale (01:42:58) :
Real Climate writes, “Whether the warming is from greenhouse gases, El Nino’s, or solar forcing, trends aloft are enhanced. For instance, the GISS model equilibrium runs with 2xCO2 or a 2% increase in solar forcing both show a maximum around 20N to 20S around 300mb (10 km):”
—
I am constantly amazed that people (climate “scientists”) actually use AOGCMs as poorly written and undocumented as Model E as proof of anything. For those who want to see how bad Model E is, please go here:
http://www.giss.nasa.gov/tools/modelE/modelEsrc/

michel (01:09:57) :”By the way, these rants people are indulging in about socialism, world government, plans to wreck the economy, they add nothing whatever to our understanding of climate and the evidence.”
Unfortunately, Michel, this is also a political debate. The IPCC is a political entity. It stands for “Intergovernmental Panel on Climate Change”. It’s organizational statement claims: “Because of its scientific and intergovernmental nature, the IPCC embodies a unique opportunity to provide rigorous and balanced scientific information to decision makers”
http://www.ipcc.ch/organization/organization.htm
Note the wording, “to provide rigorous and balanced information to decision makers”. That means the decisions makers will use the information, correctly or incorrectly, to inflict their policies on us. When Al Gore, a political figure, makes statements like “the science is settled” and wants us all to follow him without question, that is political. But the bigger question is why do they want to stifle open debate? Certainly not to increase our understanding of climate. No, the politicians have hijacked the scientific debate to force their agenda on us. The institution of cap and trade policies do nothing to further the science. It only redistributes wealth.
Using a scientific agenda to force taxation on us is always political.
michel (01:09:57): “It must be quite probable (moderators please note) that these are in fact trolls. I have long suspected that the most plausible explanation for some of the wilder and more frenzied postings on Tamino and RC is that those who appear the most fanatical proponents of AGW are in fact trolls seeking to undermine it. ”
May I suggest that it appears the pot is calling the kettle black!
I have been reading this site for almost 2 years. I have learned such a great deal. But also, I always question government and their authority over us. Being forced to do anyting by anyone goes against my nature. Especially when I am told by our “leaders” to simply trust and not to question. This is how freedoms are lost and dictators win. So as long as the stated solution to climate change involves government control and taxation it will remain political and we need to remain vigilant.

Roy – I came to the same conclusions in my book ‘Chill’. As a scientist, but an outsider in relation to climate, I simply could not believe the simplistic stance of the IPCC – they had a graph of their computer validation showing no increase in global temperatures from 1950 to 2000 if there had been no CO2 (and hence only natural variability – they did not really highlight the existence of ‘cycles’) – and then a match to the observed temperatures when CO2 was factored in. Yet in another section, they admit that their knowledge of natural cycles is very poor!
Yet – this has been called ‘mainstream’ and ‘consensus’ and ‘authoritative’ by huge numbers of commentators as well as science institutions.
It seems the BBC is turning and looking at the arguments instead of the ‘authority’. Hopefully, other TV channels will follow. But many are afraid to put their toes in the water – for fear of repeating Channel4’s mistakes and getting the backlash.
There has been absolutely NO coverage of the Yamal controversy here.
The grip of authority in the UK is really very disturbing – but more so because it now includes Friends of the Earth, Greenpeace, WWF, Oxfam and even the lowly Royal Society for the Protection of Birds. These organisations have all jumped on the bandwagon and colluded with authorities they would have historically been very wary or critical of. I know that WUWT readers tend to take a somewhat jaundiced view of the ‘green’ movement – but it consists very largely of decent folk concerned about their environment, and who rely upon the campaign offices to do a decent job of monitoring government actions and justifications. This ‘rank-and-file’ have been seriously let down and misled – but they get virtually no dispassionate analysis – all the normal channels of communication are subject to the collective spin of global warming and its deniers.

From Santer (G. Schmidt) et al 2005
Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere
“Tropospheric warming is a robust feature of
climate model simulations that include historical
increases in greenhouse gases (1–3). Maximum
warming is predicted to occur in the middle and upper tropical troposphere.”
Nowhere in the entire article is mention made of solar amplification. In fact, the crux of the article is the likelihood of observational error, not “warming can be from any source”.
Wasn’t the whole purpose of Santer 08 to support the GCM “hot spot”?

Climate science needs to get back to basics — observe the real world, make an hypothesis, test, revise and repeat. Take the emphasis away from computer models and go back to working in the physical world.

Your RSS feed is fixed … Thanks.
It would appear that the last refuge of the UN IPCC is to use the ruse of correlation to show causation. That and very careful weasel wording — Most people will not understand the lies that can be told using that method.
One fact is the upper atmosphere CO2 measurements destroy the models credibility.

RW (06:12:35) If not, what exactly is your problem with the term ‘consistent with’?
How about that it is a meaningless term, that amounts to ‘might be correlated with, but no causal attribution can be made’. They don’t use ‘proof’ because they have none. Their use of language exposes their tenuous grasp of climate.

There is one item, mentioned in Bob Tisdale first post that I think needs clarifying.
As RC states, the FINGERPRINT is made up of at least 3 components. The first 2 are the Hot Spot and the increase in the altitude of the Tropopause. Both of these items are common to most warming as they are mostly very basic physics of more heat causing more rising and expanding gasses especially in the tropics.
The third part of the FINGERPRINT is the decrease in Stratospheric Temperatures. This is specifically caused by the increase in GHG’s. With more GHG’s in the Stratosphere to radiate away the heat, it cools due to the inability of the system to move the extra heat across the tropopause from the Hot Spot area into the Strat.
WITH this third item we complete a real fingerprint. As the Stratospheric temps appear to have been flat for about 15 years with no measurable Hot Spot or increase in the Tropopause height, we also have the confirmation of no AGW!!!!!
The RC claim is that we have all these items but our measurements are so poor that they do not show up.
As the Hot Spot should be warming at a rate FASTER than the surface, possibly as much as 3x, according to the models, and the surface has alledgedly warmed about .5c in the last 30 years, I find their claims to be specious.
If the actual warming was on the order of .2c then I might believe it. Of course, then we would STILL NOT HAVE A PROBLEM!!!!
HAHAHAHAHAHAHAHAHAHAHAHAHA

Maybe this is the hot spot they are looking for:
http://www.breitbart.tv/mystery-halo-over-moscow-spooks-residents/

Scientists Rebut Claim That Man Causes Climate Change
http://www.cnsnews.com/news/article/55278

tarpon (07:15:48) :
It would appear that the last refuge of the UN IPCC is to use the ruse of correlation to show causation
UN IPCC it is just one version, the other version is from UN’s FAO:
http://www.giurfa.com/fao_temps.jpg
Which relates temperatures with LOD (Length of the day and fish catches.
http://www.fao.org/docrep/005/y2787e/Y2787E04.HTM

Moderators, stay the course, please. The two parts of the parcel should not be exclusive. There are reasons the IPCC came into existence and formulated/advanced the AGW theory and they are not scientific, or so most here believe.

@Roy Spencer…
Thanks a lot for this article which Phil. had been needing urgently for update his physics. I would like to bring the attention of bloggers on the next assertions from your article:
“The AR4 authors are careful to refer to “natural external factors” that have been ruled out as potential causes, like those seen in the above figure. I can only assume this is was deliberate attempt to cover themselves just in case most warming eventually gets traced to natural internal changes in the climate system, rather than to that exceedingly scarce atmospheric constituent that is necessary for life of Earth – carbon dioxide.”
As I have said in other threads at WUWT, most AGWer authors praise the accuracy of their models after some A Posteriori “adjustments” to their models. Mostly, they fail in their predictions, like this one on the heat spots and fingerprints.
There is another good example when they refer to the effects of the warming of the troposphere on the middle and upper troposphere and in the stratosphere. I remember they were saying some years ago that the fingerprint of the anthropogenic global warming will be the warming of the middle and upper troposphere, which never in the last 20 years happened.
You say at the end of your very explicit article:
“…rather than to that exceedingly scarce atmospheric constituent that is necessary for life of Earth – carbon dioxide.”
This assertion is absolutely true. Carbon dioxide is essential for life on Earth. Photosynthetic plants and phytoplankton depend absolutely on the current (and higher than current) concentrations of carbon dioxide, as in the atmosphere as in the oceans.
Now this party of green activists pretends to eliminate the food for plants from the world’s atmosphere.
On the other hand, the carbon dioxide at its current concentration wields a very low pressure in the atmosphere, which makes it to be a very inefficient greenhouse gas. For the absorptivity-emissivity (erroneously or purposely handled by AGWers) of around 0.3, the carbon dioxide would have to be at a concentration of 100%, at a uniform temperature, and with a partial pressure of 1 atmosphere. This is not the case in nature. The carbon dioxide barely reaches a 0.038% of the atmosphere, which means a Pp of 0.00038 atm, so it is impossible that this gas, at its current concentration in the atmosphere, could have a high thermal (or spectral, or monochromatic) absorbency-emittancy capacity higher than 0.001.
Congratulations for your article, Roy…
🙂

For those who haven’t seen this entry (or same elsewhere), now Department of Energy’s Oak Ridge National Laboratory and the National Center for Atmospheric Research have published in the current issue of Biogeosciences, “Key new ingredient in climate model refines global predictions”. Link at Brightsurf.Com for press release: http://www.brightsurf.com/news/headlines/49366/Key_new_ingredient_in_climate_model_refines_global_predictions.html

Sceptics welcome BBC report on ‘global cooling’
http://www.telegraph.co.uk/earth/environment/globalwarming/6300329/Sceptics-welcome-BBC-report-on-global-cooling.html

Pascvaks (10:23:07) :
For those who haven’t seen this entry (or same elsewhere), now Department of Energy’s Oak Ridge National Laboratory and the National Center for Atmospheric Research have published in the current issue of Biogeosciences, “Key new ingredient in climate model refines global predictions”. Link at Brightsurf.Com for press release: http://www.brightsurf.com/news/headlines/49366/Key_new_ingredient_in_climate_model_refines_global_predictions.html
Models, simulations. They think their models are more real than reality…

Was snowing at 4AM when the cats got me up. Still snowing but now tapering to flurries. Snowed Saturday but only stuck on the grass as now. Damned warmening, where are ye?

michel:
“By the way, these rants people are indulging in about socialism, world government, plans to wreck the economy, they add nothing whatever to our understanding of climate and the evidence.”
————-
I completely agree. If everyone thinks that the only people questioning AGW are rabid right-wingers (of a type which would make most UK conservatives wince) and/or the paranoid then everyone else (which includes, for example, most of the opinion-formers in Europe) will tend to ignore the message and shy away from the messenger.
It’s far too easy for warmists to point at the strident right-wing rhetoric of some sceptics in the US and put all sceptics in the same boat as creationists.
If anyone wants to have any credibility in Europe they certainly don’t want to be seen as similar to a creationist.
Not a single party of any size of the left or right in the UK is publicly sceptical of AGW and I think that’s true over most of Europe. That isn’t going to change as long as being sceptical is seen as a knee-jerk right wing political position rather than a considered opinion based on a disinterested examination of the evidence.

RW,
The observed stratospheric cooling is a fingerprint of ozone depletion.

Global warming hooey
Worries about climate are being manufactured by the international left
By MICHAEL COREN
http://www.torontosun.com/comment/columnists/michael_coren/2009/10/10/11363661-sun.html

“kuhnkat (08:42:43) :
The third part of the FINGERPRINT is the decrease in Stratospheric Temperatures. This is specifically caused by the increase in GHG’s. With more GHG’s in the Stratosphere to radiate away the heat, it cools due to the inability of the system to move the extra heat across the tropopause from the Hot Spot area into the Strat.”
I may be missing something, but this explanation does not make a lot of sense. It looks like the argument is that there is an impediment to conduction and convection transferring heat into the stratosphere and that the added CO2 in the stratosphere makes it a more efficient radiator. But heat also radiates from the lower layers of the atmosphere into the stratosphere, and the added CO2 in the stratosphere would capture more of that radiation. (And how does the CO2 get into the stratosphere absent convention)
Also, I question the other premise; the stratosphere should not become a more efficient radiator because of a higher CO2 concentration. If that were true, then why do the lower atmospheric layers not become more efficient net radiators with higher greenhouse gas concentrations. My understanding is that CO2 and other GHGs are absorbers of IR radiation and thus, to re-radiate the absorbed heat, they have to increase in temperature according to the equation R(out) = kT^4. If I add more CO2 to a balloon that is held in an environment that receives all radiative energy from bands outside its absorbtion spectrum, it should not cool.
One way that stratospheric cooling with more GHG emissions might make sense is to start from the premise that the radiation leaving the outer boundary of the stratosphere is unchanged with GHG emissions, under the equilibrium assumption that radiation into the earth equals radiation out, and if radiation in is unrelated to CO2 concentrations then the net radiation leaving the earth also must remain unchanged with CO2 concentration. If CO2 concentrations in the lower layers of the atmosphere grow at a faster rate than that in the stratoshpere, due to convention constraints, the large warming below produces more of an outbound (upward) radiation increase than can be captured by the stratosphere. Therefore, of the fixed amount of radiation exiting the atmosphere’s boundary into space, more of it becomes pass-through radiation from the lower atmoshpere, through the stratosphere, as opposed to radiation captured by the stratosphere and re-radiated into space. For the stratosphere to radiate less into space, it has to cool. But this is not a function of higher GHG concentrations in the stratosphere, it is a function of the stratosphere losing ground in relative CO2 concentration to lower levels of the atmosphere.

All of this makes for a very interesting discussion. But yet, no one contributing to this blog has published any of these refutations to AGW warming in a reputable peer review journal. If all of this is so obvious and easy to prove then who here is going to write and publish the refutation?
Until that is done, then what we have here is people expressing their opinions and everyone has one of those. I look forward to the published article.
Shiny
William

Until that is done, then what we have here is people expressing their opinions and everyone has one of those. I look forward to the published article.
Shiny
William
William,
In case You haven’t noticed, I can read the published words right before my very eyes, right here at WUWT, on Climate Audit, and other non biased places right before my very eyes right now.

Adolfo,
Isn’t the total volume of available air, much larger than the total volume of water?

Smokey
1) I don’t believe there will be “runaway” global warming, but I do believe there will be warming caused by the CO2 we are dumping into the atmo. There are consequences for putting that CO2 into the air and we should not ignore those consequences the same way we did not ignore the consequences of polluting our waters until the clean air and water acts were enacted.
2) So the peer review process is gamed? So it’s like a big “left wing conspiracy”? Let’s use Occam’s razor, skeptical articles don’t get published because there are so few skeptics, so few valid skeptical arguments and som many scientists across dozens of disciplines that do not agree with the skeptical argument. I’d suggest that it’s more likely that the skeptical argument does not “hold water”.
3) Much as I love this site, CA, the Air Vent and the Pielke’s blog sites, that is not where science is being published and distributed to the rest of the world. Until skeptics can meet the AGW head to head in the journals these sites will just be nipping at the heels of what gets published and what the IPCC compiles next time around.
As I have stated before, I’m a warmer in that I believe CO2 will cause some warming and the level of that warming will depend on feedbacks. If cloud feedbacks turn out to be positive then it will be game over for the skeptical argument. I do trust Dr. Spencer to get to the bottom of it but don’t be surprised if his findings in the long run validate the GCM’s and increases in temps over the next century.
Shiny
William

rbateman (13:57:11) :
Michael (11:00:51) :
“Should we entitle that “The Return of the MSM”??
The ideal situation in the debate is for ordinary people to be prepared, not scared.”
Never let your guard down when it comes to the MSM. They do not have your best interest at heart.
The (BSM) Blog Stream Media is the new authority, even though you have to pick through it to find the nuggets of truth and intricate details the MSM does not have to offer.

Here is something most people don’t know – the use of fingerprints to prove guilt… is not a science. So when they say they have the fingerprint of Man Made Global Warming, they are not conducting science. 🙂

tallbloke (15:20:15):
Downward mixing well below the thermocline, which is seldom found much deeper than 100m anywhere before disappearing completely at high latitudes , is a very sluggish process, quite inconsequential in its climatic effect. Widespreasd subduction of surface waters is a red herring, accepted only by ignoranti in physical oceanography, such as Al Gore. What little sinking occurs is due purely to density differences developed in limited areas, under rather special conditions. The wind-driven circulation is orders of magnitude more important than the thermohaline in redistributing near-surface heat poleward, rather than downward.

O’s Peace Dividend Report (formerly Goreacle Report) from the GWN, the Land of the Broken Hockey Stick. (Go, Steve.)
The frost moves up the window pane, Canuck Ned Pratt said.
The “expert'” has more: Goreacle is “”shattering” them,”.
…..
“Cold snap grips B.C., sets dozens of records again on Thanksgiving
The early-morning reading of 0.9 degrees Celsius was a low for Oct. 12 since weather records began being kept decades ago.
“I’ve counted in excess of 80 cold-temperature records set throughout the long weekend [across the province],” said Environment Canada meteorologist and Global BC weather expert Mark Madryga on Monday.
In many cases, the lows aren’t just slipping slightly below old records but “shattering” them, he said.
He cites Williams Lake, where the morning low of minus 13 broke the old 2002 record of minus 6.5.
“And most of these weather stations go back 50 or 60 years or more,” he notes.”
http://www.calgaryherald.com/technology/Cold+snap+grips+sets+dozens+records/2092744/story.html

Smokey, just to remind you, here is the link: http://magee.vsb.bc.ca/dsheldan/climate/pdf/Laut_2003.pdf It is worth noting that one of the original co-authors of the paper containing the data that you showed (Lassen) was on the new paper that updated that data in 2000 ( http://www.uwmc.uwc.edu/geography/globcat/globwarm/solar-00.htm ) and his co-author on that new paper notes, “The curves diverge after 1980 and it’s a startlingly large deviation. Something else is acting on the climate.” And, although he says they can’t be sure what is responsible, he says, “It has the fingerprints of the greenhouse effect.”

William,
“If cloud feedbacks turn out to be positive then it will be game over for the skeptical argument.”
What if cloud feedbacks turn out to be negative? What would that mean to “the skeptical argument”? You are implying that the determination of the value of “the skeptical argument” lies in the future. WRONG! The skeptical argument is directed towards the lack of scientific method of today, regardless of what will be (scientifically) proven in the future.

Joel Shore (17:50:05) :
“I think it is great that the side which the real science is on should attempt to take back the use of the word “skeptic” or “skeptical”, which has been badly misappropriated by those who are just dead-set against entertaining the possibility that AGW is real.”
Joel – “real science” eh? I’m a skeptic when I see garbage like this:
http://www.giss.nasa.gov/tools/modelE/
passed off as “proof” of AGW for policy makers (i.e. our government), so they can fool the public into passing confiscatory taxes and burdensome regulations as a way to “fix” the global warming problem.
But I really can’t blame the people in the climate industry for advancing the AGW meme – it has proven to be very lucrative for those involved…

The nominal conclusion of the above is that ice cores indicate a 30% increase today, whereas pre (and post) 1957 back to 1810 measurements by chemical and spectroscopic methods show similar figures, or excessive figures of today

Smokey: I think thou dost protest too much. Having been caught red-handed using the same deceptive graph a day after I last shot it down, you have now gone off on a tangent!
As for your post, I count 4 links to what you call “peer-reviewed” papers. Two of them are really links to the same paper (one a version that was apparently not peer-reviewed published in a conference proceedings and the other version published in a hydrology journal that I don’t think normally publishes on climate science). One is a link to something at ICECAP that comments on Hansen’s 1988 paper but I see no evidence of being peer-reviewed.
And, the final one is a link to Caillon et al published in the journal Science no less. The problem, however, with the Caillon article is that it does not contradict AGW in any way. It just shows that temperature started to rise before CO2 levels did in the ascent out of the glacial period ~240,000 years ago. Since it has been understood since the mid-1970s that the trigger of the glacial – interglacial cycles is orbital oscillations, this was not really very surprsing. The last paragraph in their paper is worth quoting in full:

Finally, the situation at Termination III differs from the recent anthropogenic CO2 increase. As recently noted by Kump (38), we should distinguish between internal influences (such as the deglacial CO2 increase) and external influences (such as the anthropogenic CO2 increase) on the climate system. Although the recent CO2 increase has clearly been imposed first, as a result of anthropogenic activities, it naturally takes, at Termination III, some time for CO2 to outgas from the ocean once it starts to react to a climate change that is first felt in the atmosphere. The sequence of events during this Termination is fully consistent with CO2 participating in the latter ~4200 years of the warming. The radiative forcing due to CO2 may serve
as an amplifier of initial orbital forcing, which is then further amplified by fast atmospheric feedbacks (39) that are also at work for the presentday
and future climate.

“Skeptics” are in the awkward position of having to say, “Look at this paper but make sure you ignore the final paragraph!”

Scott Mandia (17:12:24)
“Today’s warming climate is doing so at rates that ‘natural’ forcings seem not to be able to explain.”
These few words describe my picture. Consider the (non-Mann!) hockey stick graphs. Not only is the blade higher, it is also STEEPER than for other warmings in the past 2000 years.
This would seem to reduce “the possibility that warming might have been simply part of a natural, internal fluctuation (cycle, if you wish) in the clilmate system.”

P Wilson (19:30:24) :
Jan veizer was published in science mag – how he got through the peer reviewing / censorship process is a mystery.
Perhaps he didn’t put the AGW disclaimer in the final paragraph to get past the censors, which they all seem to do!
I cannot find Jan Veizer published in Science Magazine, but only a mention by Richard Kerr. Would you be so kind as to tell me the title of Veizer’s article?

“Scott Mandia (20:42:45) :
I do not believe we can afford to “gamble” that the science and the models are incorrect.
I suggest you watch the lengthy video series by Greg Craven which is pure common sense.”
I’m assuming your referring to the Oregon science teacher who laid out a case for the precautionary principal. I did watch that, and it was so full of logical holes that I cringed that this guy was teaching our children. Basically, his point was that the nightmare scenarios of global warming were so, so awful that we just had to take action against it because no matter how small the risk, the consequences of being wrong were just, well, so so awful.
The first logical flaw in that is that if you can’t asses the risk of the consequence occurring in the first place, you can’t rationally act on it. By his logic, the only rational choice of all mankind is to fervently believe in God, because the ultimate risk of not doing so is spending an etermity in purgatory, if not hell, which is well, too, too awful to take a chance on. That drive we all take to go out to eat rather than have the food in the refrigerator -stupid move given that the consequences of dying in a car wreck is simply not worth the transitory and insignificant satisfaction of having the food you crave at the moment. When making these kinds of decisions you simply cannot ignore the step of assessing the risk of a consequence occurring.
Second, he failed to evaluate the nightmare consequences of curbing CO2 emissions. Burning energy does have its benefits in economic growth, standards of living etc. Preventing the third world from economic development using cheap, abundant fossil fuels is essentially condemning them to a perpetual existence of disease, etc. Using the same logic of ignoring risks and just looking at the worst imaginable scenarios, anyone could come up with some pretty good nightmares on the other side.
Finally, about every nightmare scenario of global warming has an opposite possibility. Hurricane intensity could decrease in a warmer world due to the reduction in the temperature differential between the sea surface and the air aloft. Increased evapration could speed up the hydrogeological cycle and reduce droughts, and let us feed the world. By counteracting global warming, we could be preventing all these so, so wonderful things from happening. Again, under Craven’s logic, assesment of the probability of global warming lessening the occurrence of natural disasters is a no-no. We just look at the consequences and ask whether it is worth the gamble.
But, of course this just proves how silly it all is because the analysis just boils down to how creative you can get in stringing together a sequence of events without regard to their plausibility.

Scott Mandia (20:42:45):
I do not believe we can afford to “gamble” that the science and the models are incorrect.
India and China are doing exactly that, wagering that the greater disaster will be for them to not modernize, using fossil fuel energy sources.
The ipcc actully made the same “gamble” by not requiring countries containing ~5 billion of the Earth’s ~6.5 billion people to adhere to its own Kyoto Protocols.
Apparently, the alleged cure to GW is taken to be worse than the alleged disease – the Precautionary Principle must also be applied to the “precautions”.
The idea that GW, regardless of cause, will be a net disease has not been established: no one has spent billions of dollars having scientists “prove” the likely and wildly optimistic benefits of GW.
The planetary experiment which the Models suggested to prove AGW resulted in the failure of the Models – the predicted “hot spot” did not materialize.

********
kurt (18:39:49) :
I largely agree with this except for the last couple sentences. As long as positive feedback is less than 1, you have a stable system. Having said that, feedback is not a constant function and in the real world is subject to a limited source of the feedback. In a cold climate, e.g. an ice age, there are lots of sources for positive feedback to warm the climate, but not cool it. Take albedo for example. If 45% of the earth is covered with ice, that’s a huge source of potential warming feedback as the ice slowly melts and exposes all that bare earth or water underneath it. But ice isn’t infinite. As you move into the interglacial and most of the ice has melted, the warming feedback from that mechanism slows down considerably. When the earth moves back into an ice age, all that bare earth is now a source of positive feedback to reinforce a cooling signal until the ice age is in full swing at which point there isn’t much more bare earth that can change to reflective ice. My own personal opinion is that since we are well into an interglacial, whatever positive feedback might exists to reinforce further warming should have mostly depleted itself already. But again, while that’s just an opinion I don’t think that it would be surprising at all if at the end of an interglacial the balance had shifted to net negative feedback.
Kurt, your thoughts are similar to mine. The dominate positive feedback is the ice/albedo effect — especially in the temperature “mid-range” of the glacial periods. Right now there’s practically no ice except at the highest latitudes where the effect is minimal due to low solar input in those areas, so the positive feedback is mostly absent. This shows up in the ice-cores as our relatively “stable” interglacials. Once glacial conditions return & snow/ice advances into lower latitudes, temp swings are much greater (the drastic temp swings of 1500 yr period in Greenland’s cores). What causes the apparent “cap” at the bottom like the LGM (last glacial max)? This is unclear to me, but conditions could reach a point where summer snow/ice cannot survive into lower latitudes no matter how much winter snow/ice occurs — too much sun. But the essence should be the same — running out of positive feedback.
This raises a point — tho negative feedback dominates overall, especially at the high and low “caps”, positive feedback dominates in the middle temp ranges during glacials. Some positive water-vapor feedback seems to add to the ice/albedo feedback — glacial periods are also much drier than interglacials & even tropical rainforests recede to mere localized patches compared to today. During the LGM conditions were exceedingly dry & dusty.
As to what triggers transitions to/from glacial periods, the only thing I can think of to cause such rapid, global changes are ocean-current changes (atmospheric changes follow that). Milanchovich forcings are just too slow and gradual to do it by themselves. I don’t think we’ve seen in modern history the range of possible ocean-current changes — they could be dramatic.

kurt says:

As you move into the interglacial and most of the ice has melted, the warming feedback from that mechanism slows down considerably. When the earth moves back into an ice age, all that bare earth is now a source of positive feedback to reinforce a cooling signal until the ice age is in full swing at which point there isn’t much more bare earth that can change to reflective ice. My own personal opinion is that since we are well into an interglacial, whatever positive feedback might exists to reinforce further warming should have mostly depleted itself already.

Yeah, this might be so…However, the problem is, as James Hansen has pointed out, the calculation that gives you a climate sensitivity of ~0.75 C / (W/m^2), which translates to a sensitivity of ~3 C per CO2 doubling, considers the land ice and vegetation changes to be a forcing and not a feedback. What this means is that essentially the 3 C sensitivity in fact assumes no changes in land ice or vegetation that further lower the albedo.

Proving that mechanisms for positive feedback still exist (and I do think there are positive feedbacks still around), but without quantifying them, gains little ground in what is essentially the ultimate question.

True enough…but that’s what looking at the climate’s response to different events and also that numerically modeling the feedbacks (and testing those models in various ways, such as against satellite data for upper tropospheric humidity in the case of the water vapor feedback) helps us to determine.

I could easily make a case that a warmer world will be a boon for mankind, causing a decrease in hurricane intensity, less drought, more food, and less energy consumption. And this is coming from someone who actually prefers colder climates to warmer ones.

There could be some winners, especially for small changes. However, as a general rule, change…especially quite rapid change…tends to be bad because both we and the other species that inhabit the planet are adapted to the current climate and especially the current sea levels. Also, the other species have stresses on them and limitations on them from us (due to habit fragmentation, for example) that will likely limit their abilities to adapt.
Finally, the modeling suggests that you are not correct, for example, on your hopes for less drought. In fact, drought is expected to increase in many places (especially the American Southwest). This is true due both to changes in weather patterns and due to increasing drying out from the higher temperatures. At the same time, there is also expected to be increasing in the highest magnitude precipitation events, which can lead to more flooding too.

P Wilson: Every time I think you can never say anything sillier than what you have already said, you prove me wrong. You don’t even have to plot that data to see that there has been a strong cooling trend. And, any least-squares fit through the data would confirm it.
I would say that you can’t just eliminate data that you don’t like but what you are doing is actually much worse than that. In fact, if you just eliminated data around 1991 and didn’t include it in the fit, you would still get a significant negative trend. What you are doing is presumably eliminating the whole drop by shifting the data up after 1991 or down before 1991 or something like that.

kurt (18:39:49):
My last two sentences point to the quintessential features of bona fide feedback: the need for an INDEPENDENT source of of power for physical implementation and the RUNAWAY instability of positive feesback in all cases. It appears that both of you (and you are not alone) harbor the analytically unsupported notion that finite accumulation of energy, such as a capacitor acquiring a charge, or some step-wise process expressed by the sum of the binomial series, constitutes “feedback” in a system. This is simply a vague misappropriation of the term from rigorous system analysis.
Genuine feedback requires 1) a transducer to sense the system output signal without disturbing it, 2) external power to replicate it (with or without filtering) , and 3) a loop feeding the replicated signal to the system input for algebraic addition to the driving input signal. Nothing in the climate system is capable of doing that. It would lead to violation of energy conservation principles. There simply are no power plants or operational amplifiers in the sky. Only redistribution and/or storage of energy ultimately received from the Sun is possible. Nothing on Earth can change the TSI; thus no genuine feedback (positive or negative) is possible. But the climate system can affect insolation.
What you’re calling “feedback” appears to be little more than a simplified version of the response characteristic of the system. That characteristic is generally frequency dependent, thus not reducible to the simple notion of “sensitivity” or “gain.” It indeed changes with changing albedo due to clouds and snow/ice distributions on the globe. But, if one hopes to analyze the climate system rigorously, using the well-developed mathematics of system analysis, then such changes and their consequences should not be confused with feedback.

Joel Shore:
Even Roy Spencer says in this post, “the hotspot is not a unique signature of manmade greenhouse gases. It simply reflects anomalous heating of the troposphere — no matter what its source.” If you don’t want to believe me, maybe you can believe him.
What Dr. Spencer says and the ipcc said are two different things.
As Richard directed above: For a more complete discussion/ explanation see here
a link to Lucia’s discussion.
The issue was also discussed at Climate Audit a while back, but I can’t access CA’s search engine right now.

Richard says:

Joel Shore if the blasted Aerosols are a result of the anthropogenic production process of CO2 then it becomes a feedback. And if that feedback works in opposition to the effect of CO2 it becomes a negative feedback – can you understand this simple concept?

There are several reasons why they should be considered a separate forcing even though many of the same processes that produce CO2 also produce aerosols and vice versa:
(1) The ratio of aerosols to CO2 produced can vary considerably. For example, biomass burning essentially produces no net CO2 (if you grow the biomass that you burn) but can produce a lot of aerosols. And, in Western countries, we have used technologies to significantly cut aerosols but not CO2 so our aerosol emissions have been dropping significantly while our CO2 emissions continue to increase.
(2) Even if the emission of aerosols and the emission of CO2 were directly proportional, the forcing due to each would not remain proportional over time. This is because CO2 accumulates in the atmosphere whereas aerosols wash out quickly, so the forcing due to CO2 depends mainly on the cumulative emissions (with some dependence on how fast they are being emitted) whereas the forcing due to aerosols only depends on total emissions. (The forcing also probably has a different dependence on concentration for aerosols and CO2…For CO2 it is roughly logarithmic in concentration whereas I think for aerosols it is closer to linear.)
The basic point is that, assuming that we want reasonable air quality, we are not going to want to keep increasing our aerosol emissions at the rate necessary to try to counterbalance the warming due to our CO2 emissions. There have been some proposed geo-engineering schemes where we inject aerosols into the stratosphere, where they will remain longer and have much less impact on near-surface air quality; however, there are various difficulties with this as a realistic solution.

So whereas a moron would understand from this that GHG’s would produce a tropospheric “hotspot”, solar “forcing” would not, you, who are not a moron, understands from this that what they in fact mean is solar forcing WILL produce a tropospheric hotspot, indistinguishable from the CO2 “forcing”. How very brilliant you are Joel Shore.

They don’t directly say that the tropospheric hotspot for the two will be indistinguishable but they certainly don’t say or imply that it won’t. Their statement is quite clear on what the difference is: “but in contrast to the response to greenhouse warming, the simulated solar-forced warming extends throughout the atmosphere”. So, we have one forcing where the warming extends throughout the atmosphere, i.e., warms both the troposphere and the stratosphere and another where the troposphere warms and the stratosphere cools.
You basically come up with the most convoluted interpretation of what the IPCC says as possible, ignoring all the evidence to the contrary. Maybe the IPCC could have been a little clearer but most people try to interpret statements in the way that seems most sensible; you simply do so in the way that suits you. I have noticed this trend in a lot of “skeptics”…To make the most uncharitable possible interpretation of what some scientific source says, no matter how convoluted, and then attack that statement as you have interpreted it as if no other interpretation…in fact a much better interpretation…exists.

The GHG graph shows a tropospheric hotspot whereas the solar one doesnt. Maybe they think this is clear enough to not warrant further discussion?

Which part of my previous discussion of this, which I will repeat here, are you having trouble understanding? Which part of Gavin’s figure are you having trouble understanding? I said:

You can’t tell from looking at the graph how similar the pattern is because the pattern is not very well-resolved for the forcings like solar that don’t contribute very much. It is as simple as that. If they replotted the solar forcing with a spacing between contour levels of, say, 0.04 C instead of 0.2 C, I expect it to look very much like the one for GHGs except without the cooling in the stratosphere. And, in fact, Gavin made this sort of plot here http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends/ , except instead of changing the contour levels between the two, he adjusted the two forcings so the magnitude of the temperature effects are about the same. (This may in fact be better for detecting the spatial structure due to a forcing since I am not sure how small you can have a forcing by before noise tends to overwhelm the spatial structure.)

Richard says:

The final appeal to authority? I have pointed out that THE IPCC SAYS THAT THE HOTSPOT SHOULD EXIST DUE TO ANTHROPOGENIC WARMING and ANTHROPOGENIC WARMING ALONE.

No, what you have shown is that you can come up with an interpretation of what the IPCC says that you think suggests this. The problem with said interpretation is it doesn’t really make sense when you look closely at what they actually said and the context in which they were saying it.
As for the figure, why do you think that Roy Spencer looks at that same IPCC figure and does not seem to think that it shows that the “hotspot” is a unique signature of the GHG mechanism? Could it be that he understands the issue of resolution in contour plots, like I do, but apparently you do not?

@Dr. Shore,
Joel, here is a little exercise for you:
It’s fairly well accepted that there was a rather sudden Arctic warming from 1930-1940. Bengtsson et al (2004) surmised that the warming was due to the NAO and other atmospheric and oceanic circulation changes…

During the peak period 1930–40, the annually averaged temperature anomaly for the area 60°–90°N amounted to some 1.7°C. Whether this event is an example of an internal climate mode or is externally forced, such as by enhanced solar effects, is presently under debate. This study suggests that natural variability is a likely cause, with reduced sea ice cover being crucial for the warming.
[…]
By analyzing climate anomalies in the model that are similar to those that occurred in the early twentieth century, it was found that the simulated temperature increase in the Arctic was related to enhanced wind-driven oceanic inflow into the Barents Sea with an associated sea ice retreat.
[…]
Observational data suggest a similar series of events during the early twentieth-century Arctic warming, including increasing westerly winds between Spitsbergen and Norway, reduced sea ice, and enhanced cyclonic circulation over the Barents Sea. At the same time, the North Atlantic Oscillation was weakening.

A decadal Arctic anomaly of +1.7°C and a global anomaly of about 0.4°C during a 30-year warm PDO phase totally not cause by CO2.
McConnel et al (2007) presented a fairly solid case for black carbon soot as the main driver of the early 20th century Arctic (and by extension global) warming…

Black carbon (BC) from biomass and fossil fuel combustion alters chemical and physical properties of the atmosphere and snow albedo, yet little is known about its emission or deposition histories. Measurements of BC, vanillic acid, and non–sea-salt sulfur in ice cores indicate that sources and concentrations of BC in Greenland precipitation varied greatly since 1788 as a result of boreal forest fires and industrial activities. Beginning about 1850, industrial emissions resulted in a sevenfold increase in ice-core BC concentrations, with most change occurring in winter. BC concentrations after about 1951 were lower but increasing. At its maximum from 1906 to 1910, estimated surface climate forcing in early summer from BC in Arctic snow was about 3 watts per square meter, which is eight times the typical preindustrial forcing value.

If the NAO and black carbon can both be modeled to have accounted for the early 20th century Arctic warming… Which was it? The Arctic only wamed as much as it warmed… Yet there is strong evidence that two different things caused all of the observed warming,
And… If black carbon could have driven the early 20th century Arctic warming, how can this IPCC chart be accurate? It shows black carbon to have accounted for about 1/9 of the radiative forcing as CO2 from 1750-2005. If CO2 didn’t drive the early 20th century warming or prevent the mid 20th century cooling, how could it possibly have been the dominant radiative forcing mechanism since 1750?
How could it even be the dominant radiative forcing mechanism since 1978, when there is ample evidence that cloud cover and albedo changes can account for most, if not all, of the observed warming of the late 20th century?
Palle et al (2004)

Recent analysis of monthly mean cloud data from the International Satellite Cloud Climatology Project uncovered a strong correlation between low cloud and the cosmic ray flux for extensive regions of the Earth. Additional data have been recently released covering the period up to September 2001 with which we have made a new study of the geographical variation of the correlation between low cloud and predicted ionization level from cosmic rays at an altitude of 2 km. When analysed globally, we find that the correlations do not correspond to the latitude variation of cosmic ray flux and they are not field significant. Nonetheless they appear to be marginally field significant over broad latitude and longitude bands with a peak positive correlation at 50 degrees North and South and a tendency to negative correlation at lower latitudes. The correlation is strongest over the North and South Atlantic. Several of these features are consistent with the predictions of the electroscavenging process. We use a simple model to calculate the climatic impact should the correlation be confirmed. We show that, under the most favorable conditions, a reduction in low cloud cover since the late 19th century, combined with the direct forcing by solar irradiance can explain a significant part of the global warming over the past century, but not all. However, this computation assumes that there is no feedback or changes in cloud at other levels.

Courtillot found a strong correlation between geomagnetism and climate up until the mid-1980s (Courtillot et al. (2006)) and a strong correlation between solar activity and climate in (Le Mouël et al. (2008)).
If there are multiple other radiative forcing mechanisms that can account for most, if all, of the observed climate change… CO2 cannot be as powerful of a climate driver as the IPCC says it is.
Of course, the fact that the Medieval Warming and Roman Warming Periods were as warm or warmer than today means one of two things: Modern CO2 levels aren’t warming the planet. Or, CO2 levels in the MWP and RWP must have been a lot higher than the ice cores indicate. The same thing applies to the Sangamon Interglacial (~125 KYA)… Either the Earth wasn’t really warmer back then than it is now… Or CO2 levels were higher back then than the ice cores indicate. The Mid-Pliocene Warm Period (~3.2 MYA) was also significantly warmer than today; yet there’s no evidence of CO2 levels being much higher than today’s levels.
The Earth doesn’t suddenly start doing things that it has never done before just because James Hansen makes a computer model and Al Gore gets a Nobel Peace Prize and an Oscar.

John S. says:

My last two sentences point to the quintessential features of bona fide feedback: the need for an INDEPENDENT source of of power for physical implementation and the RUNAWAY instability of positive feesback in all cases.

There is a confusion between how the net feedback is often discussed in climate and how it is apparently discussed in control theory / system analysis. If you want to define the net feedback in a way where positive feedbacks lead to an outright instability, then you have to include the strong negative feedback that occurs on the radiative imbalance as described by the Stefan-Boltzmann Equation. I.e., an increase in temperature causes an increase in outgoing radiation, which reduces the radiative imbalance.
However, in climate science, people have often described the rise in temperature that the Stefan-Boltzmann Equation implies without any other changes in the climate system as the first-order effect and then talked about the net feedbacks beyond this and how they change the first-order effect. By this definition, a negative feedback reduces the temperature response relative to what the S-B Equation predicts (without feedbacks due to other changes in the atmosphere) and a positive feedback that is less positive than the feedback due to Stefan-Boltzmann is negative will result in a magnification of the first-order temperature response. However, only if the positive feedback due to these other factors is more positive than the feedback due to Stefan-Boltzmann is negative would you get a net positive feedback in the sense that you are talking about and hence outright instability.
To see a discussion in which the response given by the S-B Eq is considered as a negative feedback, see Dennis Hartmann, “Global Physical Climatology”. You can read part of the relevant section on the web here: http://books.google.com/books?id=Zi1coMyhlHoC&pg=PA231&lpg=PA231#v=onepage&q=&f=false This way of talking about the climate system and its feedbacks is apparently more closely aligned with the control theory / system analysis way of talking about things (at least as far as I can judge from the comments of you control theory / system analysis people).

It appears that both of you (and you are not alone) harbor the analytically unsupported notion that finite accumulation of energy, such as a capacitor acquiring a charge, or some step-wise process expressed by the sum of the binomial series, constitutes “feedback” in a system. This is simply a vague misappropriation of the term from rigorous system analysis.

Well, in the common sense of the word, something like the water vapor feedback is called a feedback because the rise in temperature causes an increase in water vapor which feed back on the temperature, causing it to rise more. Not being familiar enough with system analysis lingo, I don’t know exactly how this compares, but it seems like a reasonable use of the term “feedback” from just a basic English language standpoint.

But, if one hopes to analyze the climate system rigorously, using the well-developed mathematics of system analysis, then such changes and their consequences should not be confused with feedback.

The problems are ones of translating terminology between different disciplines. They are not problems with the actual mathematical calculations themselves.

There is one aspect of climate feedback caused by water vapor that I have not seen mentioned anywhere. This is the consideration of the relative contribution of the two most important greenhouse gases, namely water vapor and CO2. It seems intuitively obvious that the greatest impact of CO2 on the temperature is in the regions where it is the dominant GHG, namely in the polar regions and really dry deserts. Conversely, in the tropical regions, where vater vapor is dominant GHG, the effect of CO2 increase on the temperature would so small that would not be detectable. This presents a problem in postulating a water vapor caused positive feedback. In the regions where the CO2 caused temperature increase is the greatest – polar and desert regions – there is no water to evaporate. Conversely, in the tropical regions, where there is plenty of water vapor generated, the CO2 contribution is so small in relative terms that it would not be noticeable. There are the intermediate temperate regions where both water vapor generation and CO2 caused temperature increase co-exist, so such a simplified argument cannot be used, but the amount of water vapor created positive feedback is likely to be much smaller if the two most important regions – the regions responsible for the most water vapor generation, the tropical regions and regions experiencing the greatest temperature increase due to CO2 increase – are not contributing to it.

What I really really need to recognize is that it is impossible to teach people who don’t want to learn. It is simply impossible. When a person’s whole world-view is dependent on thinking about things in a certain way, you can’t break them out of it.

Joel Shore (10:49:09):
It’s not just a matter of terminology, but of something much more fundamental. The concepts and mathematical methods of system analysis, which indeed have their historical roots in electrical circuit analysis, have been successfully adapted and assimilated quite intact in wide variety of studies of both inaminate and animate real-world systems. The singularly peculiar exception is “climate science,” whose misguided use of system science terminology (and oversimplified equations) indicates a failure to grasp the basic concepts. This often leads to erudite-sounding, unscientific gobbledygook in explaining system behavior that cannot withstand analytic scutiny. Hartman’s equations and your hand-waving notions of endless chains in explaining “water-vapor feedback” are but two such examples of analytic cluelessness. Increases or decreases of global thermalization relative to the simplistic S-B formulation have nothing to do with feedback, in any scientific sense of the word.
There is a universality to good science that “climate science” does not partake in. It will not advance far beyond its primitive stage in understanding the complexities of climate by standing far apart from the rigorously analytic mainstream.

Joel Shore (16:19:48) :
You may be right that if the models had more of the warming occurring in the tropical areas, the water vapor feedback would be even stronger. I’m not sure.
———-
If I’m interpreting Tom’s comment correctly, your interpretation is 180 degrees off.
It appears to me that Tom is saying that there is very little or zero anthropogenic CO2-mediated warming occurring in the tropical areas because there is so much water vapor there. The additional CO2 is not capable of additional forcing. Ergo, if there is no warming, there can be no local feedback, either positive or negative, so there is nothing new to incorporate into the “complex atmospheric dynamics” that existed pre-anthropogenic CO2.
I think that passes the sanity check as evidenced by data from one site, at least, in the tropics, as shown:
http://img162.imageshack.us/img162/6073/timcurtintempandco2char.jpg
You said “How that radiative balance is distributed in terms of the location of temperature rises involves more complex atmospheric dynamics. And, then it is those temperature rises that will lead to the water vapor feedback.”
It would follow from Tom’s argument then that any temperature rise and feedback in the tropics would be driven by “complex atmospheric dynamics” from the temperate zones to the tropics. I find that concept somewhat ridiculous on its face.
I’m not suggesting that you said that, or think that, but if Tom is correct, then I for one think that you need a new explanation.
Lastly, surely it is known mathematically what ppms 285 – 385 of CO2 can do in the face of typical water vapor concentrations in the tropics at local temperatures of 80 – 90 F ??

Richard says:

““The simulated responses to natural forcing are distinct from those due to the anthropogenic forcings” do they mean it?

Yes, they mean it. And, from the context in which that statement is imbedded it is clear that they are talking about the fact that the solar forcing warms both troposphere and stratosphere while the anthropogenic forcings warm only the troposphere and cool the stratosphere. Hence the statement, “Solar forcing results in a general warming of the atmosphere (Figure 9.1a) with a pattern of surface warming that is similar to that expected from greenhouse gas warming, but in contrast to the response to greenhouse warming, the simulated solar-forced warming extends throughout the atmosphere.”
To believe your interpretation, one has to believe that a hotspot in the troposphere is incompatible with the description “warming extends throughout the atmosphere”, which makes no sense at all. The correct interpretation is that cooling of the stratosphere is what is incompatible with the description “warming extends throughout the atmosphere”.

Because, whereas the IPCC could have been “a little clearer”, there is no difference between the GHG Hotspot and the Solar “Hotspot”, despite the fact that the graphs show that the GHG hotspot is well defined over tropics and the solar is not and the GHG hotspot is at least 0.2C warmer than the solar “hotspot”.

The IPCC estimates that most of the warming that has occurred is due to GHGs, so the GHG response is larger than the solar response EVERYWHERE, i.e., at the surface, in the mid and upper troposphere, etc. What is important for looking at whether the pattern of warming is different is, however, the RELATIVE warming, e.g., by what factor does the mid-upper troposphere warm relative to the surface in the tropics. For GHGs, the graph shows 0.4-0.6 C warming at the tropical surface and 0.8-1.0 C further up in the troposphere…Hence, the amplification factor is somewhere around 2. For solar, the graph shows 0.0-0.2 C warming at the tropical surface and 0.2-0.4 C further up in the troposphere…Alas, this doesn’t tell us much about the amplification factor. It says it is at least 1 but is compatible with any number greater than that. If the surface actually warmed only 0.06 C and the mid- and upper-troposphere warmed 0.30 C, that would be an amplification factor of 5, which is much larger than is seen for GHGs, and such a scenario is compatible with the figure. (In reality, because Gavin has been kind enough to provide a contour plot that is better designed to distinguish the patterns of solar and GHGs, we know that the amplification factor is really about the same for GHGs and solar.)
By the way, if this still confuses you, go to Fig. 9.1 and imagine that you replot the GHG panel but use a contour spacing of 0.6 C instead of 0.2 C. I think you can then see that the GHG panel will look very much like the solar one does now (except for the behavior in the stratosphere, of course). In other words, the reason for the apparent difference between the patterns in the troposphere is that the solar has a lower total magnitude of response and hence the contour intervals are such that the pattern is not well-resolved. This is what can make contour plots a little subtle. You can’t just look at the pretty picture. You have to look closely at the contour interval and think about what the picture means.

To the uninitiated the above might seem as if they are saying the the spatial and vertical pattern of the GHG hotspot is different to the Solar one but then again you would be horribly naive and foolish to assume so.

It says that they are different but that sentence alone does not say how they are different. When you read the previous discussion in the chapter and when you look at Fig. 9.1 and you are able to understand contour plots, you understand that the difference is in the stratospheric response.

This again you might assume to be saying that the vertical pattern of change as given in Figure 9.1 between Solar and GHG forcings is different. If they were the same how could the responses be said to be more consistent with one rather than the other.

They are not the same. The solar forcing shows warming throughout the atmosphere. The anthropogenic forcings (GHGs alone but even moreso in the case when combined with stratospheric ozone depletion) show a warming in the troposphere and a cooling in the stratosphere. The latter is also what the data show.

philincalifornia says:

It appears to me that Tom is saying that there is very little or zero anthropogenic CO2-mediated warming occurring in the tropical areas because there is so much water vapor there. The additional CO2 is not capable of additional forcing.

And, I am saying that I don’t think this statement about the forcing is correct. In fact, I pointed to a figure (unfortunately not available online as far as I know) that shows that in fact the calculated radiative forcing due to increasing CO2 is larger in the tropics than near the poles. (Since the forcing was latitudinally-averaged in the figure, I don’t know how the forcing compares in dry vs moist areas of the tropics though.)
And in addition to this calculation, I think the logic for arguing that the CO2 is not capable of additional forcing is weak. For one thing, CO2 absorbs at some wavelengths where water vapor is not as major a player. For another, the issue for the greenhouse effect ends up being not whether the absorption is saturated near the surface where the atmosphere is dense but rather what happens high up in the atmosphere where it is much less dense.

Ergo, if there is no warming, there can be no local feedback, either positive or negative, so there is nothing new to incorporate into the “complex atmospheric dynamics” that existed pre-anthropogenic CO2.

Even if tom is correct on the distribution of the forcing, it simply does not follow that the pattern of warming in the atmosphere is proportional to the local forcing. The troposphere is a strongly coupled system. So, even if there is little forcing in the moist part of the tropics, it does NOT follow that there is little warming there and hence little water vapor feedback.

I think that passes the sanity check as evidenced by data from one site, at least, in the tropics, as shown:
http://img162.imageshack.us/img162/6073/timcurtintempandco2char.jpg

It’s a huge mistake to use a graph from someone like Tim Curtin. First of all, one station does not represent the whole tropics. For another, Tim has not plotted the temperature but rather the change in temperature from one year to the next, so a graph of temperature that showed a steady linear rise (nonzero first derivative but zero second derivative) would be flat on Tim’s graph. For a graph of the temperature anomaly itself at Mauna Loa, see here: http://rabett.blogspot.com/2009/09/first-krammed-then-curtained-one-of.html You will see that there is indeed an upward temperature trend. In fact, the trend is ~0.22 C/decade over 30 years, which is a bit larger than the global trend (although I am sure that there are large errorbars for such an individual station record).

It would follow from Tom’s argument then that any temperature rise and feedback in the tropics would be driven by “complex atmospheric dynamics” from the temperate zones to the tropics. I find that concept somewhat ridiculous on its face.

I don’t see why changes in the temperate zone would not tend to affect the flow of energy from the tropics into those zones. However, I also noted that the whole chain of reasoning is incorrect, starting with the assumption that the forcing is lower in the tropical zones.
And, of course, this whole line of argument is basically mute unless you can show that the climate models are getting an aspect of this incorrect. I.e., even if it were true that the pattern of the warming means that there is less feedback from water vapor than if the pattern of the warming were different (which probably is true, in fact), what does it matter as long as the climate models are correctly estimating the pattern of the warming? I.e., if they show less warming in the tropics, then they will naturally have less water vapor feedback occurring there.

Sandy: I am not sure what your post has to do with system analysis.
At any rate, there are errorbar estimates given for the global temperature anomaly trend in the IPCC report. The errorbars can be smaller than the precision in each measurement because non-systematic errors will tend to average out. Furthermore, the reason that you don’t need that high a density of stations is that temperature anomalies tend to be correlated over a fairly large reason, which is why it is much better to use the anomalies than the absolute temperatures themselves. (See discussion here: http://data.giss.nasa.gov/gistemp/ )

Terms get used differently in different fields. I’ve meandered through 7 different fields and people have challenged me to a lot of unnecessary, pedantic discussions. Clear & careful communication is the work-around; people with different mother-tongues find a way. If someone wants to argue that one language should dominate all others on the grounds of universality, that is also a discussion I might evade in favor of more practical pursuits (particularly if all involved parties already appear to understand each other perfectly-well and disagree only on semantics).
Thank you John S. for heightening my awareness of the ‘anomalous’ application of the term “feedback” in Climatology.

Joel Shore (6:56:48):
A clear example of misguided sysytem reasoning is provided by the imputed “positive water-vapor feedback.” For water vapor to enter the atmosphere, evaporation has to take place to begin with, which is invariably a cooling process that correspondingly reduces the surface LW radiation. Once in the atmosphere the vapor does increase the thermal capcitance (though not necessarily the content) of the atmosphere. But it cannot lead to an endless chain of increases, simply because vapor content is physically limited by saturation. And cloud formation invariably reduces the effective insolation, while blocking the return path to the surface for any inceases in atmospheric LW radiation due to the release of latent heat during condensation aloft. Ultimately, precipitation returns the condensation to the surface as cool rain or snow. This, the common hydrological cycle viewed in its entirety, is far from the myopic cry of “tipping points” and “runaway greenhouse.”
For those who might be more familiar with differential equations than with the formal methods of system analysis, an elementary example suffices to illustrate an important point about genuine feedback systems. Let the system be an ideal integrator responding to a forcing signal f(t). It’s output Q(t) then is governed by
dQ(t)/dt = af(t) +bQ(t)
where a is some characteristic response constant and b is the feedback gain. It is readily shown that, for any bounded forcing, the output is bounded only if b is negative. That’s the reason DE texts treat only that case. Positive-feedback control systems are man-made and invariably incorporate artificial limiters. Such systems are nowhere to be found in nature, which operates by its own design.
I hope this puts to rest the present debate, to which I cannot devote more time.

Paul Vaughn (17:56:11):
Thank you for the precis of Barkin’s work. I must confess that its relationship to analysis of climate variations escapes me at the moment, unless you’re thinking of n-order effects of geomagnetism upon the solar wind etc.
I’m also acquainted with different jargon in different disciplines. The deliberate reliance of AGWers upon the inapplicable runaway instability of positive feedback, however, goes well beyond the scientific pale. It reminds me of the Queen in “Alice in Wonderland” who claimed that “words mean what I want them to mean.”

John S.: I don’t think the problem is the scientists lack of understanding of some aspects of system theory but is instead your lack of understanding of some aspects of climate science.

A clear example of misguided sysytem reasoning is provided by the imputed “positive water-vapor feedback.” For water vapor to enter the atmosphere, evaporation has to take place to begin with, which is invariably a cooling process that correspondingly reduces the surface LW radiation.

True, although this is really just a transfer of energy from the surface to further up in the troposphere where the water condenses and releases latent heat. At the end of the day, what matters is how much energy is transferred out of the earth-atmosphere system into space and this can only happen by radiation. That said, the fact that the mid- and upper-troposphere is expected to warm more than the surface does introduce a negative feedback called the “lapse rate feedback” (because to restore radiative balance, what is important is the rise in temperature in the upper troposphere and because that area is expected to warm more than the surface, the surface doesn’t have to warm as much as the upper troposphere in order to restore radiative balance). This negative feedback is included in all of the climate models…and, in fact, because much of the same convective physics controls it and the water vapor feedback, the sum of these two feedbacks tends to vary less from model to model than the strength of each of these feedbacks individually.

Once in the atmosphere the vapor does increase the thermal capcitance (though not necessarily the content) of the atmosphere. But it cannot lead to an endless chain of increases, simply because vapor content is physically limited by saturation.

I’m confused. In what way do you think that the scientists don’t recognize the limits imposed by saturation? They understand this very well.

And cloud formation invariably reduces the effective insolation, while blocking the return path to the surface for any inceases in atmospheric LW radiation due to the release of latent heat during condensation aloft.

Now you are getting into the cloud feedback issue, which is quite complex. As both the amount of water vapor increases and the temperature (and hence the saturation vapor pressure) increases, it is not entirely clear from first principles what clouds will do. You are correct that increases in clouds tend to reduce insolation although they also reduce the transfer of of infrared radiation to space. (I suppose that they might block some of the infrared radiation coming at them from above as you suggest, although there will be less of this because of the decrease in temperature with height.) In general, low clouds block more energy from the sun than they reduce infrared radiation from leaving the earth whereas high clouds block less energy from the sun than the amount by which they decrease infrared radiation leaving the earth.

Ultimately, precipitation returns the condensation to the surface as cool rain or snow. This, the common hydrological cycle viewed in its entirety, is far from the myopic cry of “tipping points” and “runaway greenhouse.”

I don’t actually hear very many cries of “runaway greenhouse”. It can occur in theory (with Venus as a likely example) but in practice it is not the regime we are likely to be in. Tipping points are a different story and involve issues of nonlinear dynamics and hysteresis. For example, the process of building up land ice sheets and breaking apart land ice sheets is not reversible because the ice sheets don’t just decrease by melting but can break up and disintegrate or slide into the sea. There are also possible tipping points involving ocean currents and the release of stores of carbon into the atmosphere (e.g., due to melting permafrost).

Positive-feedback control systems are man-made and invariably incorporate artificial limiters. Such systems are nowhere to be found in nature, which operates by its own design.

I don’t think this is really correct. There are in fact lots of cases in nature of positive feedbacks that lead to instabilities. Pretty much whenever you see an interesting pattern such as a snowflake, sand dunes, a “washboard” effect on a dirt road, or the stripes on a zebra, what you are seeing is the result of a linear instability leading to pattern formation. (Of course, nonlinear terms come in and eventually restabilize the system so it doesn’t run off forever. Even Venus did not rise to infinite temperature!) Here is a rather famous review article on the subject within the field of crystal growth from the physics literature, circa 1980: http://prola.aps.org/abstract/RMP/v52/i1/p1_1
Anyway, this is pretty much irrelevant for the question of current climate change because we are not talking about instabilities. As I noted, in what is apparently the system theory lingo, the net feedbacks in the climate system are expected to be negative when the radiative feedback described by the Steffan-Boltzmann Equation is included in the sum of feedbacks (and, indeed, it is very much a feedback on the original radiative perturbation). However, the net feedbacks excluding the radiative feedback due to the S-B Equation can be positive, which means that the temperature change due to a change in CO2 can be larger than that predicted solely by applying the S-B Equation to the radiative effect of the change in CO2 alone.

I hope this puts to rest the present debate, to which I cannot devote more time.

In fact, I don’t think you have shown any evidence that climate scientists do not understand their system because they don’t understand system theory.

” it is not entirely clear from first principles what clouds will do”
It is entirely clear when you look at ITCZ Cu-Nims and consider the vertical wind-speeds within them.
Evaporation removes heat from the surface of the water very effectively due to the latent heat of vaporization, this damp air is flung 15 miles upward where it reflects incoming radiation as it radiates away its extra heat. While the reflection of incoming heat stops at sundown surface evaporation and stratospheric radiation continue into the night.
Thus logic and observation of those living in the tropics confirm that Cu-Nims have an important cooling effect, and hence strong negative feedback. That this is an inconvenient truth to alarmists, like the MWP, does not entitle it to be ignored for their convenience.
“In fact, I don’t think you have shown any evidence that climate scientists do not understand their system because they don’t understand system theory.”
The evidence that the modellers have no idea is in the fact that their predictions fail. That they cannot model the effects of Cu-Nims so they ignore them shows they don’t actually take science seriously.
I don’t understand how anyone claiming to be a scientist can support these charlatans.

By the way, the irony in all this, as I have noted before, is that those people who are arguing that “the hot spot doesn’t exist” in the tropical troposphere are essentially arguing against the negative lapse rate feedback that Sandy was describing.