Is Stratospheric Cooling Proof of CO2-Induced Global Warming?

[heldervelez]

Officially there is no global warming

(NOAA ,October 8, 2008, National Weather Service
JetStream - Online School for Weather)

http://www.srh.noaa.gov/srh/jetstream/atmos/ll_gas.htm

quote
It has been thought that an increase in carbon dioxide will lead to global warming. While carbon dioxide in the atmosphere has been increasing over the past 100 years, there is no evidence that it is causing an increase in global temperatures.

In 1997, NASA reported global temperature measurements of the Earth's lower atmosphere obtained from satellites revealed no definitive warming trend over the past two decades. In fact, the trend appeared to be a decrease in actual temperature. In 2007, NASA data showed that one-half of the ten warmest years occurred in the 1930's with 1934 (tied with 2006) as the warmest years on record. (NASA data October 23, 2007 from http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt )

The 1930s through the 1950s were clearly warmer than the 1960s and 1970s. If carbon dioxide had been the cause then the warmest years would have understandably been in the most recent years. But that is not the case.

The largest differences in the satellite temperature data were not from any man-made activity, but from natural phenomena such as large volcanic eruptions from Mt. Pinatubo, and from El Niño.

The behavior of the atmosphere is extremely complex. Therefore, discovering the validity of global warming is complex as well. How much effect will the increase in carbon dioxide will have is unclear or even if we recognize the effects of any increase.
end-quote

El Niño is a consequence, not a cause, and in that web page the reference to Venus is absolutely inappropriate and misleading.
Yes, the clime is always changing, as always.

Lets talk about other models?

 

[heldervelez]

Do you remember the dinosaurs?
HUGE, requiring an habitat RICH in LIVE, rich in CO2 and warmer weather?
Nowadays the live is little (Lilliputian), CO2 starving.
Today, if we want bigger vegetable life we have to administer artificially CO2, as we really do.
The global trend from distant past to the present day is the opposite of Global Warming.
The future will be colder with CO2 famine.
Oh don’t claim about the theory of the past ‘Frozen Earth’. This model is not supported by evidence.
Geologists and geologic evidence are stronger against the theoretical model of ‘Frozen Earth’.
The glaciations are just variations on the details.

 

[Gokul43201]

Officially there is no global warming
...
Lets talk about other models?

No, let's first talk about everything that's wrong with that page you've quoted. Honestly, I'm quite shocked by it. It looks like some hacker got through and snuck in a little propaganda piece.

In 1997, NASA reported global temperature measurements of the Earth's lower atmosphere obtained from satellites revealed no definitive warming trend over the past two decades.

Lower "atmosphere"? What exactly is that? The lower troposphere or mid-troposphere or the stratosphere? The surface temperatures would be expected to correlate strongest with the lower troposphere data, not with the lower stratosphere, where a cooling trend is expected.

http://www.atmosphere.mpg.de/enid/20c.html

Second, why talk about the trend until 1997 when we are in 2008? Could it be because the UAH analysis in 1997 is now known to have errors in it that have since been corrected? Currently, the UAH analysis of the lower troposheric temperature record from 1978 to 2008 shows a warming trend of +0.13C/decade.

Source: http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt (trends at page bottom)

In fact, the trend appeared to be a decrease in actual temperature.

If this is talking about lower troposphere, it is nonsense. If it's about the lower stratosphere it is at least factually correct, but nevertheless misleading: the Earth's surface is at least 20km below the Stratosphere, and there are satellite records for much lower altitudes (like the mid troposphere and the lower troposphere).

In 2007, NASA data showed that one-half of the ten warmest years occurred in the 1930's with 1934 (tied with 2006) as the warmest years on record. (NASA data October 23, 2007 from http://data.giss.nasa.gov/gistemp/graphs/Fig.D.txt )

I thought we were talking about Global temperatures, but without the merest mention of it, the author switches to a discussion about US temperatures (as does the link provided to the GISS data). Since when did the US (accounting for less than 2% of the Earth's surface area) become equivalent to the globe? The unwitting reader thinks this is still about Global temperatures, but the author instead uses data from US temperatures to make the case for cooling. That's just plain deception.

Now, if you do look at Global temperatures, then NASA data shows this:

The eight warmest years in the GISS record have all occurred since 1998, and the 14 warmest years in the record have all occurred since 1990.

Source: http://www.nasa.gov/centers/goddard/news/topstory/2008/earth_temp.html

The 1930s through the 1950s were clearly warmer than the 1960s and 1970s. If carbon dioxide had been the cause then the warmest years would have understandably been in the most recent years. But that is not the case.

Another deception here.

Why compare the 30s and 40s with the 60s and 70s, instead of with the most recent decade? The 70s are clearly not "in the most recent years."

Could it be because 1940 lies near the peak of a multi-decadal oscillation, while 1970 lies near the bottom of that oscillation? Well, they most certainly do. So, it is hardly surprising that the 40s could be warmer than the 70s. The next peak in the oscillation is near 2000, and the 40s were certainly not warmer than the 90s or the 2000s.

Here's a picture showing the Atlantic Multidecadal Oscillation over the last 150 years:

Image created from NOAA data.

Sources:
http://en.wikipedia.org/wiki/Atlantic_Multidecadal_Oscillation#Climate_impacts_worldwide
http://www.cdc.noaa.gov/Correlation/amon.us.long.data

 

[heldervelez]

The web page I’ve pointed http://www.srh.noaa.gov/srh/jetstream/atmos/ll_gas.htm is a TURN in the official trend.
It was revised on October 8, 2008, and its contents are a notorious patch over the previous contents.
A page for OFFICIAL education revised so recently is more pertinent than years of documents that anyone can advocate to the opposite cause.
They cannot simply erase all the millions of pages already written.
They have to start by changing some OFFICIAL page.
And we have to get used to this shift in the direction.
Science is not a static issue (it never was) and nowadays it is politically biased. If you are shocked with the contents is not my problem.
You can confirm with the authorities that are responsible for the site.
The actual contents of that page, in my perspective, are somewhat incorrect, but I do not comment that.
What I stress, according to the OFFICIAL source, is that now we are allowed to speak in other terms.
Let’s do it here.
You use NOAA data, but if you search the net you will easily find a lot of issues that concerns the validity and credibility of those data.
This post is to talk about ‘NO Global Warming’. Can we?
-------------
Why the word ‘SUN’ is not present in the whole page we are reading?
The tricky SUN gave us a much colder 2008 then anyone was expecting.
Just find the official USA site about SUN and read about.
-------------

 

[LURCH]

This post is to talk about ‘NO Global Warming’. Can we?

What can be said about "NO Global Warming"? Your OP seemed to present a case against GW. If this is to be a discussion or debate about the validity of GW, then both sides must be allowed to speek; the case for and the case against.

If it's not a discussion about the validity of GW, then what is it about? What "other models" did you want to talk about?

 

[vanesch]

I think the statements on the page linked in the OP warrant for a verification. In the mean time, I lock this thread.

(as heldervelez proposed, we are checking with NOAA)

 

[vanesch]

Ok, I re-opened the thread. I didn't get any reply, but at least the page can be reached from the official NOAA site:

On http://www.noaa.gov you go to:

NOAA Organizations

Then on National weather service

Down under, on Jetstream (in the column Education/Outreach)


Then on (left band) "Lesson plan overview"

and there in "the atmosphere", number 10: "it's a gas, man"

So the page seems not to be a hoax.

 

[Gokul43201]

The web page I’ve pointed http://www.srh.noaa.gov/srh/jetstream/atmos/ll_gas.htm is a TURN in the official trend.
It was revised on October 8, 2008, and its contents are a notorious patch over the previous contents.
A page for OFFICIAL education revised so recently is more pertinent than years of documents that anyone can advocate to the opposite cause.
They cannot simply erase all the millions of pages already written.
They have to start by changing some OFFICIAL page.
And we have to get used to this shift in the direction.
Science is not a static issue (it never was) and nowadays it is politically biased. If you are shocked with the contents is not my problem.
You can confirm with the authorities that are responsible for the site.
The actual contents of that page, in my perspective, are somewhat incorrect, but I do not comment that.
What I stress, according to the OFFICIAL source, is that now we are allowed to speak in other terms.
Let’s do it here.
You use NOAA data, but if you search the net you will easily find a lot of issues that concerns the validity and credibility of those data.
This post is to talk about ‘NO Global Warming’. Can we?

I see that you have chosen to not directly address any of the errors and deceptions that I pointed out. Would you?

Also, I'm curious how you happened to find this page.

 

[heldervelez]

here http://wattsupwiththat.com/2008/07/...se-in-total-disagreement-with-nasa-satellite/ I found a review of recent issues about NOAA data.
Also here [PLAIN]http://wattsupwiththat.com/2008/07/16/latest-noaa-press-release-in-total-disagreement-with-nasa-satellite/[/URL]
I found that web page by chance.
I am not a climatologist. Instead of talking about data records with problems I’d like to hear about new models.
Look for the SUN factor, the long past record climate data (dinosaurs era, for ex.).
Look for the geological evidence on the past hot Earth against the theoretical model of ‘Frozen Earth’.

 

[Andre]

http://ambio.allenpress.com/perlserv/?request=get-abstract&doi=10.1579%2F0044-7447-37.sp14.483&ct=1 may be interesting too,

...Greenland ice core data yield well-dated information about climate over an extended period that, seen together with other data series, indicates that large, probably global scale changes have occurred at numerous times in the past. The warming during the past 100 y is not likely to be unique.

 

[vanesch]

I have to say that I find the "educative experience" on that page totally strange. In as much as it even does something (after all, the heat capacity of the gas is minuscule as compared to that of the bottle and the water and everything), it would only demonstrate some spectral properties of CO2. There would be no "greenhouse" effect in the bottle due to the CO2. You could just as well add some black ink to the water, and that would work much better.

 

[vanesch]

Concerning the lower stratospheric cooling, this is usually seen as a proof for CO2-induced global warming. The simple explanation is that as more IR radiation is withhelt by the lower troposphere, less of it reaches the stratosphere so this one cools.

Now, the problem is that there is indeed a cooling trend of the lower stratosphere since there are reliable satellite observations of this (1979), but that the overall "linear fit" which gives a downward slope is not a continuous trend, but actually comes about because of a few dramatic steps, and that in between there is rather a small "rise" (recovery ?).

Another element which plays a role in the lower stratosphere is that it is influenced by the ozone concentration: less there is ozone, less radiation is absorbed in the ozone bands. As we know that there has been an ozone depletion, this also influences the tendency.

When we look at the data http://www.ssmi.com/msu/msu_data_description.html
(look at the TLS plot 3/4 down the page), then we see indeed that there is an overall "cooling" trend of -0.33 K per decade, but that this comes about in steps related to volcanic eruptions which give first a rise, and then a dramatic fall in lower stratospheric temperatures.

However, when one looks at the "pieces of data" in between these steps, there is no discernable continuous "cooling" tendency (it rather looks flat, or even slightly rising).

So the "stratospheric cooling" is quite a complicated phenomenon, and the overall "straight line fit" is a bit a cheap argument.
People are still investigating what is the exact dynamics of that temperature:
http://www.publicaffairs.noaa.gov/releases2006/feb06/noaa06-025.html

“The unusual manner in which the cooling of the lower stratosphere evolved between 1979 and 2003 is very likely unique and unprecedented, and has not previously been well understood,” Ramaswamy said. “Climate model simulations show that human influences, namely stratospheric ozone depletion and greenhouse gas increases, and natural factors, namely volcanic aerosols and variations in the sun's energy output, combined to produce two step-like decreases in the lower stratospheric temperatures, one in the 1980s and the other in the 1990s.”

So stratospheric cooling is not simple, and it is not even clear whether it is cooling right now.

 

[heldervelez]

I have to say that I find the "educative experience" on that page totally strange.

I agree with your comment. Thats why I said that the page appears to be a 'patch' over the previous content and it is not properly done.

In the post #9 I've intended to make a link to this revue
http://www.nowpublic.com/environment/cooking-books-global-warming-are-numbers-fudged

As I'm not an expert in clime it's hard to me to discuss data reliability, credibility of sources and so on.

I saw that web page when I was looking for other subject. I am only reporting what is there.

Of course I have an opinion as anyone is entitled to have, more or less an informed one.

I read in the past the report made by a young girl that is called Ponder the Maunder http://home.earthlink.net/~ponderthemaunder/index.html that poses a lot of questions.

The SUN this year of 2008 gave us too little power compared with the expected in previsions.

The Artic and Antarctic cores are in fact growing in ice content (recent sattelit mesures)

I think that also ice cores have shown that CO2 grow up only after temperature grow up.

But the more important is that we must look back to ancient weather to find the real global trend. I'm convinced that in the past the Earth was hotter.

Of course the air polution is not good to clime stabylity.
Of course there is a need to save natural resources to use in the future.

The fact that USA did not signed Kyoto protocol and the fact that the White House as a new guy and the need to redirect funds from some issue to other more important issues could be the cause for the change in the contents of that web page.

We have to broaden our perspective and listenning in a lot of directions, not only the 'official' or 'funded' currents of research.
If we don't do that we can miss a lot of important ideas or evidence.
We can not be blind. It costs money to everyone.

But I have to leave the discussion of this issue to others with more expertise.

 

[Gokul43201]

Of course I have an opinion as anyone is entitled to have, more or less an informed one.

Informed by what? Experts that work in the field, or blogs written by lay-people?

For instance, where did you get this - see quote below - information from?

The Artic and Antarctic cores are in fact growing in ice content (recent sattelit mesures)

The plots below show the actual Arctic ice cover from satellite data.

Source: M. C. Serreze et al, Science, v315, p1533 (2007) [http://sciencemag.org/cgi/content/abstract/315/5818/1533 ]

 

[heldervelez]

In fact in this moment I can’t find the web page were is shown the actual positive net mass balance of ice over Antarctic and Greenland (not the all Arctic as I've written in the post). There exists a positive overall net mass balance with thickening in the interior and thinning in the periphery.

But this recent dissertation about Ice Sheets
ASSESSMENT OF GLACIER MASS BALANCES FROM SMALL TROPICAL GLACIERS TO THE LARGE ICE SHEET OF GREENLAND By TODD H. ALBERT
Found at:
http://etd.lib.fsu.edu/theses/available/etd-04092007-174614/unrestricted/dissertation.pdf

is clear in relation to Greenland :
pag 58 (70 pdf) Map of GreenLand and enlarged detail of the positions of measuring stations
pag 66 (78 pdf) Mass balance between 1995 to 2005 by station
pag. 67 (79 pdf) Graph of Mass balance with accumulation and ablation detail
it clearly shows a net mass balance largely positive on West Greenland
pag 112 (124 pdf) Conclusions on MODELING MASS BALANCE ON ICE SHEETS
models PDD and SNTHERM were put to test against real data
pag 114 (126 pdf) SUMMARY AND FUTURE WORK
quote
Finally, this dissertation takes a critical look at melt modeling on the Greenland Ice Sheet.Several models were assessed, including the statistical Positive Degree-Day (PDD) model, a numerical model called SNTHERM, and a new analytical model, SOSIM, developed as part of this research. The assumptions of the PDD model were tested and found to be tenuous at best, despite the popularity of the model and its overall performance in the study area. SNTHERM was unable to adequately model snow melt over a cold ice surface, so a third model was developed. The new model, SOSIM, performed better than the other models tested, but its heavier data requirements limit its utility and in many cases the simpler PDD model would suffice
end-quote

beeing so, when I compare these results with data and graphs from http://www.eoearth.org/article/Glaciers_and_ice_sheets_in_the_Arctic
section Projected changes
figure
http://www.eoearth.org/imag/Figure6.18_time_series_of_greenland_melt.JPG
As they do not fit, makes me wonder about the model capability to project changes

 

[heldervelez]

We are talking about two different things ‘Arctic sea ice cover’ and ‘Net mass balance of ice over Arctic and Antarctic ice cores’

 

[heldervelez]

in another way
The Ice Caps are Growing By David J. Ameling
http://icecap.us/images/uploads/The_Ice_Caps_are_Growing.pdf
quote
This means since 1999 to the present the Earth's rate of rotation has increased. There are two possible (but not mutually exclusive) causes for this. 1. Some of the Earth's mass has moved closer to the Earth's axis of rotation similar to a spinning skater bringing his arms closer to his sides, and thus spinning faster.
end-quote
(the other possible cause is only a small EMF effect)

 

[Andre]

In fact in this moment I can’t find the web page were is shown the actual positive net mass balance of ice over Antarctic and Greenland (not the all Arctic as I've written in the post). There exists a positive overall net mass balance with thickening in the interior and thinning in the periphery.

Thanks for the link, actually during periods of warming, one would expect that, the summit of the ice sheet gets warmer, hence the amount of water vaper can increase. There can be a lot more snow at -20C than at -40C, which are normal temperatures for the Greenland Ice sheet summits.

Why it's warming over there is a different story of course.

 

[latecommer]

In fact the very idea of "global warming" is deceptive, and if valid, is more so in the Northern hemisphere than in the Southern. The Southern hemisphere has different conditions to measure, (for instances the predominence of land in the north, sea in the south). In this modern "optimum" the Northern H. has warmed more than the Southern by everyones measurments
As a geologist it is very evident that in former eons there were periods much warmer and much colder.
Yes, the general trend, subtracting the extremes, has been a steady gentle warming since the last glacial, but that is the pattern of all interglacials. Most of the warming of our present interglacial is believed to have happened in the first third of the period with resultant sea level rise and general warming. As interglacials are understood this is the norm.

The point is that dispite the studies of Mann, Hansen, and others, unless we are totally wrong in our evaluation of paleo-climates, greenhouse gases have only a small part to play on the stage of climate. Granted the effect of greenhouse gas is a necessary part of our livable world, but the effect of negative feedback have strong constraining effects on control and argue against a tipping point or runaway warming.

It seems obvious to me that we are in one of the many warming cycles we have had in the past, and sooner or later we will once again enter a cooling period. The debate is on about if we are doing that at present, and if this is just another optimum followed by a minimum or if this is the cusp of this interglacial and the beginning of the next glacial.

Statements about consensus or "settled science" are foolish at best, since science is never settled and consensus also means everyone could be wrong, as as happened many times in the past. "Consensus" science is stagnent, and produces little. Most breakthroughs in historic science have been made by those who thought outside the box. Something consensus science prohibits.

I must agree with heldervelz, who is I suspect, like me much more impressed with observational data than with model projections.
As I understand it, the consensus model requires positive feedback in excess of 1, which in my experience leads to unstable run-away systems...one which the climate clearly has never experienced.

In my opinion the climate is a self balancing system, always attempting, but never succeeding, to achieve an energy balance. This indicates a self correcting process of negative and positive feedbacks of less than 1.

Adressing the CO2 agrument in terms of AGW must include the facts that CO2 does not care where it comes from, and acts in the same way no matter its source. It must also take into account that we have very good evidence that CO2 has been much higher in other times...far higher than all the fossile fuel known reserves could achieve even if we were to release it all at once.
This alone should give pause to anyone reading or hearing that we only have a few years to correct what will become a catastrophe.

In terms of paleo-geolgy and paleo-climatology... prove it has happened before and then we can discuss if it will happen again. Until then, IMO, it remains in the realm of social political discussion and not in science.

We do not know enough about most of the complex systems that makeup our climate to base life changing economic stratagy on. It is pretty obvious that we know more about what the "cure" will cause and cost, than we do about the possible problem we face.

My personal opinion, as can be deduced from the above, is that; yes we have contributed to the levels of CO2, but no, we have no data that shows it has anymore than a small and transitory effect on climate, some of it perhaps benificial.
Nothing unusual has happened in the last century that hasn't happened many times before without human aid. Just as we havn't caused anything unusual, we can not create anything unusual.

 

[mheslep]

Informed by what? Experts that work in the field, or blogs written by lay-people?

For instance, where did you get this - see quote below - information from?
The plots below show the actual Arctic ice cover from satellite data.

Source: M. C. Serreze et al, Science, v315, p1533 (2007) [http://sciencemag.org/cgi/content/abstract/315/5818/1533]

Curious. I am having trouble matching those monthly artic ice extents from Serreze with this NSIDC data published at the Univ of Ill. The NSIDC twenty year graph never shows maximum ice area greater than 14.5, 15 million sq km, where as the Serreze March graphs (peak month?) show many years greater the 16 million sq km.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

 

[heldervelez]

The history of atmospheric CO2 http://earthguide.ucsd.edu/virtualmuseum/images/CO2History.jpg
Shows a general global trend of declining, aproching the limiar of life survival,
About 300My ago life (and us) was endangered, and no explanation to such a low CO2 value at that time.
Do you know what is the level bellow what we can say life is CO2 starving or extinguishing?
Biology has some numbers calculated.
It scares me to know that there are some guys trying to trap CO2.
Do we have to pay to become extinguished?
CO2 is the most rare gas in the atmosphere, more rare than Argon.
60 Mys ago life was Huge, clima was good.
now life is liliputian, clima is colder.
Tens of years are nothing, nothing, nothing in the geological timescale.
Wont we stop talking on the details? We don't understand the general drivers of clima but pretend to model the picodetail.

 

[latecommer]

I agree, prove there is really a problem then work on the response to it.
Until then I will do my best to release as much trapped carbon as possible in hopes of increasing the tillable acres of the world and help stave off the starvation that is sure to follow what I believe will be the next 60 years of cooling.
Even in the hottest of year in our life time, 1998, there were nearly 10 times more deaths attributed to cold than to heat.
In thirty years this global warming BS will be as laughable as as the alarming predictions of those scared of global cooling in the 70's. The ironic thing is that the cooling, if you recall, had a simple cause in the minds of the alarmists...fossile fuel burning. Hum... is there a common factor here?

 

[Evo]

Even in the hottest of year in our life time, 1998, there were nearly 10 times more deaths attributed to cold than to heat.

Any statement of fact needs to be backed up by a credible source.

 

[vanesch]

Curious. I am having trouble matching those monthly artic ice extents from Serreze with this NSIDC data published at the Univ of Ill. The NSIDC twenty year graph never shows maximum ice area greater than 14.5, 15 million sq km, where as the Serreze March graphs (peak month?) show many years greater the 16 million sq km.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

That's indeed an interesting remark

That said, their lowest numbers also go below the ~ 6 million square kilometer (although that's less of a contradiction, given that the Serreze graphs are only for certain months).

 

[heldervelez]

Any statement of fact needs to be backed up by a credible source.

Mr. latecommer referred 10x more deaths? I bet that number is underestimated
In Portugal a mid-latitude country, official number of 2001-2006 found at pag. 65 (66 pdf)
here http://www.ine.pt/ngt_server/attachfileu.jsp?look_parentBoui=16223900&att_display=n&att_download=y
quote
Mortalidade por meses
Em 2006, em média, faleceram por dia 279 indivíduos
residentes em Portugal. Contudo, o número de óbitos
flutua ao longo do ano e tende a atingir valores mais
elevados nos meses de Inverno (317 óbitos diários, em
média, entre 1 de Dezembro de 2005 e 31 de Março de
2006) e mais reduzidos nos meses de Verão (258 pessoas
faleceram em cada dia, em média,entre 1 de Junho e 30
de Setembro de 2006)
end-quote

It means :
Monthly mortality (2006)
In 2006, on average, each day 279 individuals dieded, ...,
maximum 320 daily during winter (Dec,Jan,Feb,Mar) (317 is error, it is not a leap year)
inbetween 261 daily warm weather (Apr, May,Out,Nov)
minimum 258 daily during summer (Jun, Jul, Aug,Sep)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
10052 9260 9337 8057 8053 7330 8774 7957 7414 7824 7888 10044

hot make us live more. deadly cold.
in countries with severe weather it will be worst.

 

[heldervelez]

The history of atmospheric CO2 http://earthguide.ucsd.edu/virtualmuseum/images/CO2History.jpg
Shows a general global trend of declining, aproching the limiar of life survival,
About 300My ago life (and us) was endangered, and no explanation to such a low CO2 value at that time.
Do you know what is the level bellow what we can say life is CO2 starving or extinguishing?
Biology has some numbers calculated.

about photosynthesis and CO2, some data
google this ""AGRICULTURE is basically a system of exploiting solar energy through photosynthesis"" and download
you will get this paper from agronomy.ifas.ufl.edu
http://www.google.pt/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fagronomy.ifas.ufl.edu%2Fclass_sites%2FAGR4512%2Fclassnotes%2FCHAPTER1bRev2008.ppt&ei=9X9CSYSnOYb00AW7i4yzBg&usg=AFQjCNE7euFi-p3z9zIRHfVh7lpNjODb7Q&sig2=Wy35LZa2kf5s_jF3cMJEUQ

inside document find "Response of Leaf PS to Increasing [CO2]"
watch the left graph carefuly below 200 ppm (a dark area) it is danger
the amplified graph on the right we see that bellow 100 ppm CO2 is extinction

if not satisfied we check other sources.

 

[latecommer]

Evo,

Sorry, my oversight, I agree and it won't happen again, I hope.

There are many sites that show this information, but the one I took it from is from a study by doctors in Europe that covered several nation's official statistics. It also links to studies in about 20 other nations. This study stated that 5 to 15 times as many annual deaths are due to cold vs warm.
It can be found at:

http://sharpgary.org/Warm Vs Cold Deaths.html

Let me know if this link doesn't work because for some reason it wouldn't copy and paste and I had to hand do it.

Doug

 

[BoomBoom]

This study stated that 5 to 15 times as many annual deaths are due to cold vs warm.

I don't think the concerns with global warming are that people will perish in the heat, I think it is more to do with the lives that may be lost from famine as a result of widespread drought, and flooding due to sea level rise.


But then again, as you mentioned earlier, receding glaciers open up new tillable land.

 

[Gokul43201]

Curious. I am having trouble matching those monthly artic ice extents from Serreze with this NSIDC data published at the Univ of Ill. The NSIDC twenty year graph never shows maximum ice area greater than 14.5, 15 million sq km, where as the Serreze March graphs (peak month?) show many years greater the 16 million sq km.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg

Forget that for a second (if you will bear with me). You should first have trouble matching the ice extents plotted in two different graphs supposedly plotted from the same NSIDC data on that page you linked. The figures are all found if you go up one level from the url you linked. (I'm not crazy about urls that only give you a figure.)

Here's the url: http://arctic.atmos.uiuc.edu/cryosphere/

Here are the other images on that page:

1. Northern Hemispheric Sea Ice Extent (the picture you attached)

2. Seasonal Sea Ice Extent (sorry for the large pic)

The maxima in 1 are lower, and so are the minima. I don't know what the deal is with that. Plot 2, however, showing seasonal averages closely matches Serreze's plots, from the brief checking I did. For instance, compare the Winter (JFM) average data from 2 with the average of the Jan and Mar plots from Serreze.

Does that fix the problem?

Also, there's a third graph on your page.

3. Northern Hemisphere Sea Ice Anomaly

From that, I eyeball a linear trend of at least -1.5 mill. sq. km. over 3 decades, or about -0.5 mill sq km per decade. From 2, the average extent is about 12 mill sq km, so this is nearly -5% per decade. An average of the linear trends from Serreze (6 alternate months) gives me -4.53% per decade.

Looks to me like the data matches alright.

 

[Andre]

I wonder about the relevancy of sea ice with this thread, after all, the variation in sea ice is attributed to changes in wind patterns.

https://www.physicsforums.com/showthread.php?t=263921

 

[Gokul43201]

Is there evidence of a trend showing growing strength in Artcic winds over the last few decades? This is, after all, not about a single year.

 

[Gokul43201]

Yes, the general trend, subtracting the extremes, has been a steady gentle warming since the last glacial, but that is the pattern of all interglacials. Most of the warming of our present interglacial is believed to have happened in the first third of the period with resultant sea level rise and general warming. As interglacials are understood this is the norm.

Surely, you know this is not about the 10^-2K/decade warming out of a glacial, but the 10^-1K/decade warming of the last century or so.

The point is that dispite the studies of Mann, Hansen, and others, unless we are totally wrong in our evaluation of paleo-climates, greenhouse gases have only a small part to play on the stage of climate.

Who are "we", how small is "small" and how about some references?

Granted the effect of greenhouse gas is a necessary part of our livable world, but the effect of negative feedback have strong constraining effects on control and argue against a tipping point or runaway warming.

Without any reference to the gain or time constants of an effective negative feedback mechanism, this is a pointless "point". Interglacial swings are of the order of 10K, with periods on the order of 10⁵ years. A negative feedback mechanism with a time constant in the several thousands of years could be quite extraordinarily useless over timescales of 10² years.

Adressing the CO2 agrument in terms of AGW must include the facts that CO2 does not care where it comes from, and acts in the same way no matter its source. It must also take into account that we have very good evidence that CO2 has been much higher in other times...far higher than all the fossile fuel known reserves could achieve even if we were to release it all at once.
This alone should give pause to anyone reading or hearing that we only have a few years to correct what will become a catastrophe.

How many technologically advanced civilizations were around during these higher CO2 periods?

Nothing unusual has happened in the last century that hasn't happened many times before without human aid. Just as we havn't caused anything unusual, we can not create anything unusual.

All good reasons to overturn the Montreal Protocol and start producing and emitting CFCs as well.

 

[Andre]

Is there evidence of a trend showing growing strength in Artcic winds over the last few decades? This is, after all, not about a single year.

Please do check out the links, I'm merely showing the message. It's what the researchers say.

http://www.nasa.gov/vision/earth/lookingatearth/quikscat-20071001.html
http://www.sciencemag.org/cgi/content/summary/sci;322/5898/33

You can follow the daily development of the ice here.

http://ocean.dmi.dk/arctic/plots/icecover/icecover_2008.png

 

[Gokul43201]

Both seem to talk about the effect of winds on ice extent over the last few years. It seems to me like it may be possible that there is some wind related effect that is the dominant reason for the last three decades of trend, but right now there isn't enough data to support such a hypothesis.

 

[Andre]

Both seem to talk about the effect of winds on ice extent over the last few years. It seems to me like it may be possible that there is some wind related effect that is the dominant reason for the last three decades of trend, but right now there isn't enough data to support such a hypothesis.

As far as I recall, the full article of Richard Kerr in Science talks about a gradual process in the last century. I'm not at home and I can't see it from here to quote it, I'm afraid. Will get back to it later.

 

[Gokul43201]

As far as I recall, the full article of Richard Kerr in Science talks about a gradual process in the last century. I'm not at home and I can't see it from here to quote it, I'm afraid. Will get back to it later.

Me neither. Will have to look at it later.

Edit: I just read it now. It says that in the Greenland shelf, there was a lot of ice loss from an influx of warm water in 1997. That seems to be directly connected to the NAO. Similar loss of ice from shifting wind and water patterns is expected from modeling of the equivalent effect in the Antarctic. What doesn't seem to be well known is if, and to what extent, the changes in the winds are affected by changes in air temperature.

 

[heldervelez]

To those of us that are especially concerned with details:

The Netherlands’s people have a lot to loose with the rising sea.
Most probably they will loose ALL their land, assuming GW.
I've no notice of alarmism between them. This is a gross detail.
My oldest son bought a house there, this year. This a fine detail.

In physics a detail data mismatch becomes important if we have a model that is generally aligned with data, but in some points the model fails.
It was the case with the finding of planet Uranus, for instance. And physics has a lot of such good examples.
In this case of GW we lack the knowledge, the expertise to model with success.
Do we have a consensual model that agrees with past data?
I suppose that we have several models that doesn’t coincide in previsions.
Do we agree how data is collected, worked, massaged and interpreted? No.

I think that Phil Jones is monitoring the thermometric values used by IPCC and I have reasons to believe that he said that he will not make public neither the algorithm nor the database that he is using.
That’s ok I’m not indicating the source. Enlighten me if I’m wrong and someone considers it relevant.
Does someone finds and write here the previsions on sea level in the successive IPCC reports? It could be helpful.
Those last two paragraphs to me are non important at all because they are just peculiarities. I wrote them only to say that those kind of ‘facts’ are unimportant to the clime evolution. At most are important to understand why we are distracted from main facts.

 

[heldervelez]

But what cannot be considered a detail is the fact, which is not denied even by AGW believers, that ice cores indicate that temperature rise lead by (+-) 800ys the CO2 rise.

and it means:

1. Time t0 : Temperature start to raise
2. ​
   T0 + 800ys : CO2 start to raise
3. ​
   T0 + 5000ys : Temperature lowers (and CO2 still high)
4. ​
   T0 + 5000yrs+ xxx CO2 lowers

Physically the cause-effect relation cannot be inverted.

An explanation on this site of AGW believers (climate science from climate scientists):
http://www.realclimate.org/index.php/archives/2004/12/co2-in-ice-cores/

My understanding of this page is :

CO2 does not start, but ..maybe maybe not amplifies the temperature rise, and the explanation ..maybe maybe not is…

---- in the page contents I made a few translations such as:

… could in fact have been… translates …maybe maybe not…
… CO2 could have caused… translates …maybe maybe not…
…the probable sequence of events… translates …maybe maybe not…
… Some (currently unknown) process causes…translates …unknown…
… But it may give us a… translates …maybe maybe not…
… So CO2 might be stored… translates …maybe maybe not…

Well apart from all that maybe maybe not a pertinent question is in my mind is:
After 4200 yrs of amplifying cause, the CO2 gets tired of its amplifying role. CO2 is not in the mood.

Again can someone make a comment to this updated content?
http://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2/

-----------------
In this site some points againts AGW of "Atmospheric CO2 Levels Follow Temperature, Data Clearly Shows..." Nov/2007

http://petesplace-peter.blogspot.com/2007/11/atmospheric-co2-levels-follow.html

Craig James is a Michigan meteorologist and here he explains his reasoning as to why atmospheric carbon dioxide does not drive, or control global warming.
...
...
Also, never once mentioned in the mainstream media is the fact that the southern hemisphere sea ice extent was at a record MAXIMUM this year
-----

 

[Gokul43201]

I had left this part for later, because I wasn't sure what exactly to make of it.

In my opinion the climate is a self balancing system, always attempting, but never succeeding, to achieve an energy balance.

I have no idea what you mean by this. Is it a scientific statement that you are writing metaphorically, or is the statement itself based on some philosophy other than empiricism.

This indicates a self correcting process of negative and positive feedbacks of less than 1.

I don't understand why that is so, but I also don't understand whether that is the feedback ratio, or the open loop gain, or the product of the two, or the closed loop gain. Which is it (I'm guessing it is the third, but need to be sure)?

Also, why would you expect this gain to be frequency (or timescale) independent? If not, do you imagine the system has the same gain at a timescale of 10⁶ or more years as it has on a timescale of 10² years?

 

[Andre]

But what cannot be considered a detail is the fact, which is not denied even by AGW believers, that ice cores indicate that temperature rise lead by (+-) 800ys the CO2 rise.

...
Again can someone make a comment to this updated content?
http://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2/

You are linking to a blog, which is not peer reviewed and which would make some mentors frown here.

Anyway, positive feedback is considered here as a rock solid theory whilst it is only a idea/hypothesis, rougly like: first something is causing warming which causes the oceans to release more CO2 as it's capacity to store CO2 decreases with temperature. The extra CO2 in the atmosphere causes more warming, which causes more CO2 to be released, positive feedback.

But, if you diagose feedback, you have to play it by the physical rules of feedback with a lot of complications and up until now I have not found any paper testing that hypothesis by mimmicking/modelling the "temperature"/CO2 graphs of the Pleistocene ice ages with positive feedback. Actually when you attempt that, the result is failure, refutal, like this:

Complete documentation in this thread.

We are looking at the combined graph of the isotopes (considered paleothermometer) and CO2 concentrations as measured in the newest EPICA Dome C ice core during the last Glacial Transition between 20,000 and 10,000 years ago. The lack of persistency demonstrates that positive feedback cannot be discerned. It seems that we're merely looking at open loop master - slave behavior.

 

[heldervelez]

Mr. Andre tanks for the link to your post on the subject
"The positive feedback factor of CO2"
https://www.physicsforums.com/showthread.php?t=162192
I congratulate you for your work on the "lead or lag problem".
I stay with "Temperature leads and CO2 lags without any amplification factor".
Any doubts must be addressed in that thread.

About the issue raised on post #39 we can be enlightened reading on the 2nd page post #21 of that thread where Mr Vanesch details on feedback math, with some more words of Mr mheslep on 1st page post #15, and I do not see the need to bring that discussion to this thread.

I was not prepared to discuss the AGW in detail, and so, I’m sorry not to address information based on proper papers. I ask anyone to correct me if I say something that is incorrect. I like to address issues based on information and reasoning.
I was surprised by the position of NOAA on that web page.

Any idea on the why NOAA has that content?
Hypothesis 1: the CO2 cause of temperature rising is untenable.
Hypothesis 2: the page was ‘pirated’ from inside or outside NOAA
Hypothesis 3: ?

Unless better information I bet on the first hypotesis.

 

[Gokul43201]

Physically the cause-effect relation cannot be inverted.

When you have systems of coupled differential equations, all the variables involved become "cause" as well as "effect". Which is the cause and which is the effect, in a predator-prey system?

CO2 does not start, but ..maybe maybe not amplifies the temperature rise, and the explanation ..maybe maybe not is…

---- in the page contents I made a few translations

Those translations are good. There is always some uncertainty in the understanding. At the early stages of development of any new science, these uncertainties are always large.

When Quantum Electrodynamics was invented in the 20s, it made some terribly nonsensical predictions: infinite energies and masses, vanishing charge ... all kinds of nonsense. It took a couple decades to fix all the problems, and then quickly become one of the most accurate physical theories around.

But speaking of translation, let me try one, for fun. Here's an earlier post of yours:

I am not a climatologist. Instead of talking about data records with problems I’d like to hear about new models.
Look for the SUN factor, the long past record climate data (dinosaurs era, for ex.).
Look for the geological evidence on the past hot Earth against the theoretical model of ‘Frozen Earth’.

My translation: I am not an expert in the field, but as a lay person, I believe I can still tell the experts how to go about their research.

I recently saw some news about a large number of deaths in a nearby hospital. It was just after some big accident or something like that, but that's not important. What's important is that the surgeons in that hospital are obviously incompetent. I think I should just go there and teach those lousy surgeons how to do their job. Of course, I didn't take Biology beyond High School, but at least I have never had a dozen dead people in my house.



This is not to say that one shouldn't question the work done by professionals, but to point out that one ought to recognize the limitations of being not an expert in the field. One of those limitations is that one probably does not have the understanding or knowledge of the field necessary in order to tell the experts how they should be doing things.

 

[Gokul43201]

Actually when you attempt that, the result is failure, refutal, like this:

Let me make sure I'm not misunderstanding this. Are you saying you have proved that there can not be any positive feedback mechanism from CO2 (i.e., you have refuted the hypothesis of positive feedback from CO2)? And this proof involves eyeballing turning points, and not noticing an acceleration in T when CO2 is rising?

 

[Andre]

Let me make sure I'm not misunderstanding this. Are you saying you have proved that there can not be any positive feedback mechanism from CO2 (i.e., you have refuted the hypothesis of positive feedback from CO2)? And this proof involves eyeballing turning points, and not noticing an acceleration in T when CO2 is rising?

Not exactly Gokul, all that I said was that the lack of typical characteristics of positive feedback (persistency) do not support (refute) the positive feedback claim here. Actually there could be a slight positive feedback, but it's not detectable and it cannot account for the bi-stable seesaw as assumed like this:

http://www.realclimate.org/epica.jpg

since a bistable system (flip flop) by positive feedback requires a total gain >=1 in the loop and you will find it rather hard to model a momentary reversal halfway in such an oversteered positive feedback loop.

Actually, should you test both the IPCC radiation hypothesis for the atmosphere with 2-4 degrees warming for doubling and the Chilingar et al 2008 convection hypothesis, you would probably conclude that the latter is much better explaining the isotope temperature versus CO2 relationship.

But all is on the presumption that the graph indeed accurately depict temperature and CO2 concentration. There is a lot more to say about that.

 

[Gokul43201]

Not exactly Gokul, all that I said was that the lack of typical characteristics of positive feedback (persistency) do not support (refute) the positive feedback claim here.

There is a huge difference between an observation that does not support a hypothesis and an observation that refutes it. I hope you note the difference.

Actually there could be a slight positive feedback, but it's not detectable and it cannot account for the bi-stable seesaw as assumed like this:

http://www.realclimate.org/epica.jpg

First[/URL] of all, your first figure is over a timescale that is 2 orders of magnitude smaller than that of the second figure. There is no reason I've seen from your posts, that one should assume that the loop gain is frequency independent, and it looks to me like you are trying to extract a signal from a region that is so small, that it is dominated by noise. Moreover, if the closed loop gain is indeed large, there may be good reason to believe that it comes with a pretty small bandwidth. Third, why should it be necessary that the system can be modeled using a single feedback loop? There may very well be dozens of different feedback mechanisms, some negative others positive, with different gains, different bandwidths, poles all over the place, all kinds of non-linearity, and who knows what. And finally, there is the question of noise, which I shall come to in the next paragraph.

since a bistable system (flip flop) by positive feedback requires a total gain >=1 in the loop and you will find it rather hard to model a momentary reversal halfway in such an oversteered positive feedback loop.

I don't know what an "oversteered" positive feedback loop is. I can easily imagine halfway reversals if indeed there is more than one feedback mechanism (and they are all not positive). And even in a single feedback loop, I can very easily imagine such reversals, if you have significant noise in the system. And guess what: your figure shows that the noise amplitude is on the order of 10% of the rail-to-rail difference - that's huge. Why should it be impossible for noise - what looks like "noise" within a single feedback model may just turn out to be the result of a much different feedback mechanism operating at a much smaller time scale; you might not know until you analyze the noise spectrum - and I imagine people have done such things - to trigger turnarounds in the signal, especially when it is this big?

Actually, should you test both the IPCC radiation hypothesis for the atmosphere with 2-4 degrees warming for doubling and the Chilingar et al 2008 convection hypothesis, you would probably conclude that the latter is much better explaining the isotope temperature versus CO2 relationship.

Actually, I doubt I'm likely to conclude anything, unless I see obvious mistakes in one or the other that I am capable of judging from within my areas of relative expertise.

Moreover, to my knowledge, op-amp circuits with positive feedback are bistable (usually not even that - if the noise level is sufficiently low, they just hit one of the two rails and stay there) only because they are limited by the supply voltage (that itself should be treated as a negative feedback mechanism). In the absence of such limits^*, the output signal should just diverge, shouldn't it? I guess if you are at a pole, then you have an unstable system, but that will probably produce an oscillatory output (rather than the bistable signature in your figure). If you do have an oscillator with severe clipping (again, I believe that is itself a consequence of strong negative feedbacks), it could possibly look like a bistable system, but a different kind of one, if you can picture what I mean.

In any case, I know next to nothing about control systems and only the tiniest bit about feedback circuits. If there exists a Thevenin/Norton kind of theorem that let's you find a single loop equivalent for a jumble of different loops (I would be very surprised, but) I am not the person that would know about it. You should take my post as one one that is expressing a lot of questions and doubts about your conclusions. It would be best if someone more versed in these matters gives an opinion.

One more thing: your "refutation" seems to be an attempt at refuting a claim from a blog, not from a peer-reviewed paper. Even if your refutation is perfectly good, you will only have achieved a refutation of a claim in a blog. I think it would be better, if we want to show that the science is badly done, to go after the source, rather than the layman popularization of it.

 

[Eric_meyers]

I have a question about the realclimate blog posting: if CO2 lags temperatures by 800 years is explained by the fact that the CO2 is the mechanism that continues the warming from that point forward, then how come the temperature goes down while the CO2 remains high for xxx years after the cooling? If the CO2 is acting as an amplifier, then shouldn't the temperature at that point be locked with CO2 levels and not permitted to drastically reduce until AFTER CO2 levels drop?

 

[Andre]

There is a huge difference between an observation that does not support a hypothesis and an observation that refutes it. I hope you note the difference.

Let's see, positive feedback processes are persistant, the graphs don't show persistancy, hence the processes do not show a predominance of positive feedback. Olavi Kärner uses the term: http://www.aai.ee/~olavi/2001JD002024u.pdf in a such a case.

One more thing: your "refutation" seems to be an attempt at refuting a claim from a blog, not from a peer-reviewed paper. Even if your refutation is perfectly good, you will only have achieved a refutation of a claim in a blog. I think it would be better, if we want to show that the science is badly done, to go after the source, rather than the layman popularization of it.

That's the essence, there is no peer reviewed paper that I know of, which presents model results that demonstrates that the isotope signal could be caused by a positive feedback effect of CO2. There are just several studies, which show that CO2 lags "temperature" and speculate that this must be positive feedback, no math, no models, just a sentence or two of suppositions. This hypothesis simply has never been tested. The http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf is built on this speculation. Note that there is no reference to any study that explicitely demonstrates that the ice core reflect the system response characteristics for positive feedback.

But I fully agree, the link to realclimate was tongue in cheek and I fully agree that we should never look there and link again (which is also )

Anyway, another thing to do is trying to reproduce data with other sources. So what would happen if we compare Antarctica with Greenland?

So if we would picture that sudden reversal to "cold" around ~14,500, as this has opposed the alleged warming feedback of the ever increasing CO2 concentration then that cold should show up somewhere. However this is the Greenland compilation of Ulf Erlingsson 2008

So no cooling at all around 14.500 calendar years ago, instead we see the Bolling warming and an complete different picture overall. No trace of a cooling input to force the Antarctic temperature reconstruction down against the feedback, on the contrary.

Hence I keep saying, we are on the wrong way and we should start from scratch instead of building global warming theories on blatantly conflicting reconstructions.

 

[Gokul43201]

Let's see, positive feedback processes are persistant, the graphs don't show persistancy, hence the processes do not show a predominance of positive feedback.

Do you believe you have shown that your demonstration of "no persistance" is rigorous? It looks to me like it could be completely meaningless - you are trying to eyeball a signal buried in noise and you are looking at the response in the wrong frequency window. Moreover, I think the thing you are searching for may itself be a strawman of kinds: there could be positive feedback in the system away from saturation, but not near it.

Olavi Kärner uses the term: http://www.aai.ee/~olavi/2001JD002024u.pdf in a such a case.

Olavi Kärner makes a case for a lack of persistence (in the short term temperature record) based on spectral analysis, all kinds of clever statistical examination and some sophisticated math tricks for dealing with non-linear systems with fractal structure. I know nothing of these methods, but they don't look very much like your visual estimate analysis.

That's the essence, there is no peer reviewed paper that I know of, which presents model results that demonstrates that the isotope signal could be caused by a positive feedback effect of CO2. There are just several studies, which show that CO2 lags "temperature" and speculate that this must be positive feedback, no math, no models, just a sentence or two of suppositions. This hypothesis simply has never been tested.

So basically, all this comes down to is your experience that there are no good mathematical models in place that produce the right feedback necessary to reproduce the paleoclimate record. I think we could have left things at that without trying to perform a refutation based on eyeball analysis. These systems are incredibly complex, and very hard to analyze. Don't you think we should leave such things to folks like Olavi Kärner, who seem to have the expertise necessary to do a serious analysis of the temperature records and various forcing mechanisms? Or else I recommend you send your refutation to J. Geophys. Res., and have some real experts look at it, rather than us laypeople who can't tell a banana from a hockey-stick.

The http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter6.pdf is built on this speculation. Note that there is no reference to any study that explicitely demonstrates that the ice core reflect the system response characteristics for positive feedback.

I don't care much for IPCC reports as a scientific source - they are not peer-reviewed, and some parts that I have read use some terribly unscientific language that I can only describe as "Business School talk". So let me tell you that I'm not keen to read any part of that chapter to see what they are saying there.

But I fully agree, the link to realclimate was tongue in cheek and I fully agree that we should never look there and link again (which is also )

I'm sure this gives you indescribable joy!

That's all I've got time for now.

 

[Gokul43201]

I have a question about the realclimate blog posting: if CO2 lags temperatures by 800 years is explained by the fact that the CO2 is the mechanism that continues the warming from that point forward, then how come the temperature goes down while the CO2 remains high for xxx years after the cooling? If the CO2 is acting as an amplifier, then shouldn't the temperature at that point be locked with CO2 levels and not permitted to drastically reduce until AFTER CO2 levels drop?

No, what triggers the start of the rise and fall is likely to be something other than CO2 (maybe the Milankovitch cycles, or maybe something else). Typically, it takes some kind of perturbation or noise to take an amplifier out of saturation, and this noise can be entirely independent of the feedback mechanism.

 

[vanesch]

Gokul, I agree with everything you write here. The data point to a more complicated dynamics than just the "well, and then the CO2 rises, and this gives then positive feedback which enhances the heating". That can be part of it, but there must be other things. I think that what Andre is pointing at is that it cannot be a simple, direct positive feedback and that's it.

Now, the problem is that this verbal statement is all I've ever read as a support for the core claim of the paleo indications of positive feedback mechanisms, which by itself is one of the basic supports for the higher temperature increases in the IPCC predictions. Let's not forget that the essence of the "dramatic" AGW resides in the existence, or not, of these strong positive feedback mechanisms (and not in the basic greenhouse effect of CO2 itself).

So my question is: is there some paper, where a model is described (essentially a set of dynamical equations with or without free parameters) which can successfully retrodict these paleo data, with the features Andre points out, and if so, what are the dynamical equations used, and what free parameters have been fitted ?