UPDATE#2 I finally found a graph from Professor Akasofu that goes with the text of his essay below. I’ve added it above. You can read more about Akasofu’s views on climate in this PDF document here. (Warning: LARGE 50 megabyte file, long download) The two previous graphs used are in links below.
UPDATE: Originally I posted a graph from Roger Pielke Jr. see here via Lucia at the Blackboard because it was somewhat related and I wanted to give her some traffic. As luck would have it, few people followed the link to see what it was all about, preferring to question the graph in the context of the article below. So, I’ve replaced it with one from another article of hers that should not generate as many questions. Or will it? 😉 – Anthony
THE IPCC’S FAILURE OF PREDICTING THE TEMPERATURE CHANGE DURING THE FIRST DECADE
Syun Akasofu
International Arctic Research Center
University of Alaska Fairbanks
Fairbanks, AK 99775-7340
The global average temperature stopped increasing after 2000 against the IPCC’s prediction of continued rapid increase. It is a plain fact and does not require any pretext. Their failure stems from the fact that the IPCC emphasized the greenhouse effect of CO2 by slighting the natural causes of temperature changes.
The changes of the global average temperature during the last century and the first decade of the present century can mostly be explained by two natural causes, a linear increase which began in about 1800 and the multi-decadal oscillation superposed on the linear increase. There is not much need for introducing the CO2 effect in the temperature changes. The linear increase is the recovery (warming) from the Little Ice Age (LIA), which the earth experienced from about 1400 to 1800.
The halting of the temperature rise during the first decade of the present century can naturally be explained by the fact that the linear increase has been overwhelmed by the superposed multi-decadal oscillation which peaked in about 2000.*
This situation is very similar to the multi-decadal temperature decrease from 1940 to 1975 after the rise from 1910 to 1940 (in spite of the fact that CO2 increased rapidly after 1946); it was predicted at that time that a new Big Ice Age was on its way.
The IPCC seems to imply that the halting is a temporary one. However, they cannot give the reason. Several recent trends, including the phase of the Pacific Decadal Oscillation (PDO), the halting of sea level increase, and the cooling of the Arctic Ocean, indicate that the halting is likely to be due to the multi-decadal change.
The high temperatures predicted by the IPCC in 2100 (+2~6°C) are simply an extension of the observed increase from 1975 to 2000, which was caused mainly by the multi-decadal oscillation. The Global Climate Models (GCMs) are programmed to reproduce the observed increase from 1975 to 2000 in terms of the CO2 effect and to extend the reproduced curve to 2100.
It is advised that the IPCC recognize at least the failure of their prediction even during the first decade of the present century; a prediction is supposed to become less accurate for the longer future.
For details, see http://people.iarc.uaf.edu/~sakasofu
* The linear increase has a rate of ~ +0.5°C/100 years, while the multi-decadal oscillation has an amplitude of ~0.2°C and period of ~ 50-60 years, thus the change in 10 years is about ~ -0.07°C from the peak, while the linear change is about ~ +0.05°C.
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Re: Chris V. (22:45:27) :
I was really hoping someone else would take this up before I got back tonight. You will recall that in my earlier post I cited three reservations:
1. It is not presenting any new data or clarification of methods;
2. It was written specifically to reconcile their earlier publications with the IPCC 2007 report;
3. They appear to be claiming that their results are consistent with the instrumental record, which Anthony Watts’ Surface Station Project seems to be showing is badly flawed, and various proxy records which have been criticized in great detail on their own merits (e.g. bristlecone pines).
1. It is not presenting any new data or clarification of methods
I may have been a bit too (unjustifiably) emphatic here, however, none of the data is new and a full page of their five page paper is dedicated to a restatement of their papers HPS97 and HPS00, essentially telling the readers of this paper what they should have been able to deduce from the previous papers.
Of 18 cited references, 11 of them are to their own papers. I do not know if that large a percent of self-citations is unusual, but it does indicate that much of the argument is addressed in more detail there. You can accept their current interpretation or go back and read the original sources and judge for yourself.
The Integrated Reconstruction section does not appear to provide enough information to reproduce their work One would have to go back to their earlier work to understand the methodologies e.g.
“The century long trends from HPS00 were based on 616 borehole temperature profiles from six continents. As the T-z database has grown, updated century long trends have been estimated by others [e.g., Pollack and Smerdon, 2004; Huang, 2004], but for the purposes of this paper the small differences are inconsequential.”
“q(z) is the empirically determined variation of heat flux with depth z as reported in HPS97,”
I would also suggest that if the “small differences” are consequential enough to be mentioned in the paper, it would have behooved the authors to discuss why they were inconsequential.
I should point out that this discussion in no way impugns or invalidates their methodology or conclusions. They may have gotten it right. I’ll have to defer to others on the scientific merits.
2. It was written specifically to reconcile their earlier publications with the IPCC 2007 report;
One can often judge the true intention of an author by simply noting the number of lines he devotes to a topic. 25% of this paper was spent addressing the controversy generated by the IPCC reports and the MWP in particular. The following selections give the flavor of that 25%:
The reconstruction of past climate provides a useful context for discussions of contemporary climate change. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Intergovernmental Panel on Climate Change, 2007, chapter 6] addresses this topic … We have contributed to the development of the paleoclimate record as reconstructed from geothermal data in many publications [e.g., Shen and Beck, 1991; Huang et al., 2000; Huang, 2004; Pollack and Smerdon, 2004] including the discussion by Intergovernmental Panel on Climate Change [2007]…. The reconstruction of climate over the past one to two millennia has not been free of contention, because of its relevance to assessing the significance of 20th century global warming … We did not anticipate that a comparison of late 20th century and Medieval Warm Period temperatures would later become a contentious issue.
3. They appear to be claiming that their results are consistent with the instrumental record, which Anthony Watts’ Surface Station Project seems to be showing is badly flawed, and various proxy records which have been criticized in great detail on their own merits (e.g. bristlecone pines).
“The transient anomaly to a depth of 300 m is generated with a forward model that drives the surface with the 20th century instrumental record (land only) and the 16th through 19th century temperature trends from HPS00”
If I read that sentence correctly, much of the reconstruction is based on a model that uses 20th century surface temperatures…. Exactly the issues we are documenting here. I also get the impression that those same 20th century surface temperatures are being used to calibrate the model, which would explain the high degree of correlation. To suggest, as you did, that
“I haven’t seen any quantitative analysis showing the temperature reconstructions (eg GISSTEMP) to be “badly flawed”. Perhaps we will have that once Anthony W. does his analysis using only the best stations. But right now the only attempt (that I am aware of) was by John V. over at CA a couple of years ago, and he got the same results as GISSTEMP”
is merely disingenuous.
What I am suggesting is that when another study comes along to validate or confirm models and hypotheses that are being shown to be flawed, it is the new paper that should be regarded with a certain amount of suspicion.
Regarding Soylent Green: it is a common convention in the movies, or was, to inject some topical humor. John Ford, for example was always doing that. I saw Soylent Green shortly after it came out. The audience laughed at Robinson’s remark. You see, we KNEW that a new Ice Age was on its way.
As for that [self-snipped] chart. It would have been a lot better to let Dr. Akasofu supply his own chart. Lucia’s chart was used to illustrate a point that Lord Monkcton had been trying to make. Lucia is not a rabid admirer of his Lordship.
By the way, Anthony, where did Dr. Akasofu’s post come from? Is this a guest post?
Ron de Haan:
That link disgusts me. I commented on it, wondering how long my comment will stay there.
I despise these self-righteous idiots who actually believe they stopped the destruction of the ozone layer. These are the same chest-thumping neanderthals who believe that things we do now will “save the world” from gobal warming… watch for it, because you’re going to see a lot of it.
Yet another thing I used to believe in until I learned something about it.
Excellent deconstruction, rephelan.
The authors still cling to the current inbred, outdated and corrupt peer-review process, rather than daring to slug it out online — where it’s obvious they’d get demolished for their zero-sum paper.
What new knowledge have they added? It’s pretty clear the answer is zero. Yet they still get published simply because they’re in the good ol’ boy clique, and they wrote all the right buzz words.
Olimpus Mons (09:07:08) :
It’s fair to postulate the inverse. What can happen in the next 5-10 years, to make me an AGW believer?
Note: we live a pivotal time: PDO is negative, sun is quite, and something seems to be stabilizing temps…
a. If in the next 5 years Artic Ice depletion reaches a value between or less the 2007and 2008 values…
Olimpus Mons, I think you are setting the Arctic ice depletion goalpost much too to the current minima as the satellite record does not appear to go back before 1979 ( a short 30 years). Anecdotal evidence shows the Arctic ice extents to go through cycles with historical ice extents quite possibly as low as present minima.
Eric (15:43:45) :
Robert Austin (08:41:10) :
wrote,
Eric (18:21:50) :
“The reason this has been observed in the Malinkovich cycles, was because periodic changes in orbital tilt kicked off a warming cycle in the northern hemisphere due reduction in albedo.
The CO2 emissions were of increased temperature, and but also produced a further increase in temperature, based on the evidence of the 400,000 year Vostock Ice core data, and modeling of these effects.”
Eric mistakes hypothesis for fact in making this assertion. The fundamental forcing of CO2, possibly modifed by an unknown feedback factor, is still unknown. So the role of CO2 in ice age cycles is still in the realm of conjecture.”
The greenhouse theory explains why the earth is 32C cooler than its radiation temperature. Without it, the nightime temperatures would be much colder. The basic explanation is 150 years old, and since the late 1950’s spectroscopic measurements have refined it to be one of the most accurately understood mechanisms that acts to set the atmospheric temperature. This makes it more than a conjecture, it is a scientific theory accepted by climate researchers.
A 2008 survey by Roger Pielke et. al. of climate scientists who published in the past year showed that ,
Your stating that the mechanism is most accurately understood is just plain wrong. Not only is there a range of thought on the warming effects of atmospheric CO2 by itself (the amount of warming hypothesized by the doubling of CO2), there even less agreement, and by that token, solid science to show what feedback would be engendered by the presence of the major greenhouse gas, H2O. Sorry, you can pile up your scientists like cordwood but we are still at the hypothesis stage.
http://climatesci.org/2008/02/22/is-there-agreement-amongst-climate-scientists-on-the-ipcc-ar4-wg1/
“4. Almost all respondents (at least 97%) conclude that the human addition of CO2 into the atmosphere is an important component of the climate system and has contributed to some extent in recent observed global average warming.”
Appeal to authority. You should know by now that skeptics have been whacked with the cudgel of authority many times and just bounce back. Just let us look at the data and the science.
When there is that level of unanimity about a scientific theory, it is more than a mere conjecture or a hypothesis.
Unanimity does not make hypothesis into theory. Hypothesis becomes theory by being repeatedly challenged scientifically and standing the test of time. AGW most certainly does not fit this criteria. On the contrary, there seems to be a concerted effort to prevent the challenging of the hypothesis.
Smokey (19:16:58) :
Thank you. I agree with you that the peer-review process has become dysfunctional… as for the Huang et al paper, I don’t know whether it would be demolished or not. It needs to be replicated and analyzed, just like the two Jeffs have been doing to the Steig et al Antarctic paper. What I am tired of is having posters hype some paper as being “The One” – the skeptic crowd is latching on to
Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics
Authors: Gerhard Gerlich, Ralf D. Tscheuschner
as being “The One” as well. I’m paying a high price for my youthful disinterest in science and have a very steep learning curve to to overcome. The context and structure of the Huang et al paper tell me that it is probably not a block-buster that I have to research to finally reach enlightenment.
The de-politicization of science and restoration of ontellectual integrity would be a wonderous thing.
that was supposed to be “intellectual integrity” …. I suppose ontological integrity would be a nice thing, too
Smokey: “You’re quoting something I don’t think I ever said.”
The quote included your quote of foinavion. Check back to my (22:08:52) and you will see that I have included the time of your previous quote, namely Smokey (17:25:43). My apologies if that wasn’t clear.
Ohioholic: “So…..the heat goes directly into the ocean? No pipeline? Which is it?”
The term “pipeline” is clearly a metaphor which refers to the fact that the oceans warm up more slowly than the atmosphere. I’m no climate scientist, but as I understand it, the oceans are warmed by the sun and will keep warming until an equilibrium point with the atmosphere is reached.
Clearly, if the atmosphere is also warming, the atmosphere/ocean equilibrium point will be higher than if atmospheric heat were stable or declining, and because the atmosphere acts as a blanket, a warmer atmosphere helps the oceans to retain more heat.
In that case, the phrase “in the pipeline” would refer to a process of delayed warming.
rephelan (18:30:36) wrote:
I may have been a bit too (unjustifiably) emphatic here, however, none of the data is new and a full page of their five page paper is dedicated to a restatement of their papers HPS97 and HPS00, essentially telling the readers of this paper what they should have been able to deduce from the previous papers.
In scientific papers, it’s pretty standard to discuss the results/methods of previous work in the same area. I don’t see what that has to do with the accuracy of their current research.
Of 18 cited references, 11 of them are to their own papers.
Reconstructing atmospheric temperatures from borehole temperatures is a bit of a niche field- there just aren’t many other scientists doing it.
The Integrated Reconstruction section does not appear to provide enough information to reproduce their work One would have to go back to their earlier work to understand the methodologies e.g.
They provide the source of all their data (it took me less than a minute to find the borehole records on the web), and they provide the references where their methods are described. There’s more than enough information in that paper for anyone who understands terrestrial heat flow to redo their work. Why turn a 5 page paper into a 20 page paper, when all the relevant methodology is easily available in their references?
I should point out that this discussion in no way impugns or invalidates their methodology or conclusions. They may have gotten it right. I’ll have to defer to others on the scientific merits.
Agreed.
One can often judge the true intention of an author by simply noting the number of lines he devotes to a topic. 25% of this paper was spent addressing the controversy generated by the IPCC reports and the MWP in particular. The following selections give the flavor of that 25%….:
What do you think their true intentions are?
They appear to be claiming that their results are consistent with the instrumental record, which Anthony Watts’ Surface Station Project seems to be showing is badly flawed, and various proxy records which have been criticized in great detail on their own merits (e.g. bristlecone pines).
ALL proxies have to be calibrated against modern temperatures in some way, so your criticism is equally valid for those proxy reconstructions that show a MWP that is warmer than today. If you think that the modern temperature record is significantly flawed, then you have to throw out all the proxy temperature reconstructions.
Or maybe you would prefer they compare their results to UAH, rather than HADCRU?
http://cce.890m.com/giss-vs-all.jpg
Not much difference between them- certainly not enough to change the conclusions of this study.
“The transient anomaly to a depth of 300 m is generated with a forward model that drives the surface with the 20th century instrumental record (land only) and the 16th through 19th century temperature trends from HPS00”
If I read that sentence correctly, much of the reconstruction is based on a model that uses 20th century surface temperatures…. Exactly the issues we are documenting here. I also get the impression that those same 20th century surface temperatures are being used to calibrate the model, which would explain the high degree of correlation.
See previous response.
To suggest, as you did, that
“I haven’t seen any quantitative analysis showing the temperature reconstructions (eg GISSTEMP) to be “badly flawed”. Perhaps we will have that once Anthony W. does his analysis using only the best stations. But right now the only attempt (that I am aware of) was by John V. over at CA a couple of years ago, and he got the same results as GISSTEMP”
is merely disingenuous.
Maybe- but it is also correct. Showing pictures of some poorly sited temperature stations is one thing; demonstrating that those poorly sited stations are significantly skewing the global temperature anomalies is another.
What I am suggesting is that when another study comes along to validate or confirm models and hypotheses that are being shown to be flawed, it is the new paper that should be regarded with a certain amount of suspicion.
I don’t agree that the other proxy reconstructions are necessarily significantly flawed (though they certainly might be). Remember, there are 2 sides to that particular argument.
Besides, I believe the criticism of the bristlecones is that they are not good temperature indicators, not that they indicate some other temperature trend. If that criticism is correct, then you would have to throw out the bristlecone studies because they don’t tell you anything about temperature, and can’t be used as positive or negative evidence for any particular trend. In that case, you are left with judging the borehole temperature stuff on it’s own merits.
But if you think that the surface temperature records (along with the satellite temperatures, since they agree pretty well with the surface temperatures), are flawed, you really have no way of judging the accuracy of ANY proxy.
For the record, I have no idea whether Huang et als temperature reconstruction is right or wrong. I just know that it uses a completely independent methodology, and is in agreement with the others that show a MWP cooler than today.
CodeTech (18:40:41) : said
“Ron de Haan:
That link disgusts me. I commented on it, wondering how long my comment will stay there.
I despise these self-righteous idiots who actually believe they stopped the destruction of the ozone layer. These are the same chest-thumping neanderthals who believe that things we do now will “save the world” from gobal warming… watch for it, because you’re going to see a lot of it.
Yet another thing I used to believe in until I learned something about it.”
I used to just accept we have saved the ozone layer until a few things happened last year that made me contact Cambridge University and the Max Planck institute. There is obviouisly some concern and disbelief that things havent been fixed. Have you any other information you can link me to so we dont hijack this thread?
tonyb
You can propergandaall you like radicals BUT YOU ARE LIARS ,PROF WANG WHO WAS DOING THE STUDY FOR THE IPPC HAS BEEN FOUND TO BE FRAUDULANT IN HIS REPORT AND IS BEING INVESTIGATED ,ITS A BIT LIKE THE 500,000 SQ KM OF MELTED “ICE REPORTED BUT WAS FOUND AFTER IT WAS CHECKED ON GOOGLE ,A SCAM IS A SCAM ,NO MODEL CAN PREDICT THE FUTURE WEATHER CYCLES ITS IMPOSSIBLE ,C02 IS NOT EVEN A POLLUTANT YOU MORONS ,ITS ALL ABOUTTRYING TO CONTROL US AN CHARGE US A FORTUNE FOR POWER WHICH THEY WILL OWN BUT MAKE US PAY TO BUILD ITS A JOKE ,THERE IS NOT ONE BIT OF EVIDENCE THAT PROVES C02 HAS ANYTHING TO DO WITH WEATHER ,IN FACT IT HAS A 800YR LAG BEHIND IT IN MODELS AND IT TAKES THOUSANDS OF YRS FOR YCLES TO CHANGE ,NOTHING YOU CAN DO WILL CHANGE ANYTHING YOU NITWITS ,WASNT IT FLANNERY WHO SAID PUMP SULPHER INTO THE ATMOSPHERE WITH JET FUEL?SURE WAS ,I MEAN WHAT KIND OF IDIOT WOULD SUGGEST THAT ?? KEEP UP THE GOOD WORK AND EXPOSE THESE FRAUDS .
Reply: Your comments are appreciated, but there is no need to use all caps. Thanks. ~dbstealey, mod.
Brendan H (21:35:40) :
‘In that case, the phrase “in the pipeline” would refer to a process of delayed warming.’
Ohioholic: It’s like saying the “check” is in the mail.
Re: Update #2
Anthony, instead of Akasofu-san’s
http://people.iarc.uaf.edu/~sakasofu/pdf/recovery_little_ice_age.pdf
report, he has a newer variant that is only 50 MB and is date 3/19/2009, see
http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdf
(1) The Recovery from the Little Ice Age
(A Possible Cause of Global Warming)
and
(2) The Multi-decadal Oscillation
(The Recent Halting of the Warming)
(2) is PDO.
It has the same image that you used, see figure 2b. I haven’t compared the two closely, but did print out the new one to read in my copious free time. 🙂
REPLY: Thanks I kept trying to download the first one and got timeouts. I don’t know why his PDF’s are so large. – Anthony
More Malthusian junk science from the Guardian today relying heavily on James Lovelock and eugenics. It is so full of factual errors that I don’t know where to begin.
http://www.guardian.co.uk/world/2009/mar/22/environment-population-conference-britain
The subtext of the whole article can be summed up like this “Cut your carbons, accept population control and Green politics otherwise lots of coloured people will be living next door to you!!”
Talk about exploiting xenophobia to advance a political agenda.
The article then ends with a bunch of numbers to make people feel that we are exploiting the planet’s resources well past sustainable levels.
TonyB (00:59:55) From this article: Journal of Physical Chemistry, 2007, DOI: 10.1021/jp067660w
“scientists can no longer account for 60 percent of the observed ozone depletion. Although it is still thought that chlorine based catalytic reactions are the major cause of ozone depletion, we no longer have a strong link between theory, experiment, and observation.”
This question is for foinavon and anyone who’d like to reply:
Why have we been relying on climate models for policy before those models have been proven?
Ie. if today we’re debating whether the IPCC scenario-casts are coming true or not, then even if they are, why did we start making policy in Kyoto back in 1997? I thought the whole point about science was that you rely on evidence, like evidence that your models’ predictions come true.
Regarding this article again
http://www.guardian.co.uk/world/2009/mar/22/environment-population-conference-britain
Note the eugenicist creed, only young healthy foreigners should be allowed into a country. All the rest should be sent away.
I can’t help but raise a Godwin here but the Nazis treated Jews like that. Healthy ones in the factories, and the rest…
foinavon (12:09:15)
“We know very well why the Earth cam out of the ice age between 15,000-10,000 years ago. Google “Milankovitch cycles.”
While I’m somewhat of a novice that doesn’t seem very likely, particularly the first part about “We know very well”. It sounds to me like hand waving and more “Trust me, I’m right on this.”, and “the science is settled”.
See http://en.wikipedia.org/wiki/Milankovitch_cycles#Problems , especially the part about Effect Exceeds Cause.
If the Malinkovitch Cycles are so well know, perhaps you can predict the start of the next Ice Age for me. Will it start in the next 100 years, 1000 years, or 10,000 years?
MikeEE
I neglected to remark about this at The Futre at the bottom of the Wikipedia article on Milankovitch Cycles. This seems to say it all!
“Two caveats are necessary: that anthropogenic effects and that the mechanism by which orbital forcing influences climate is not well understood.”
MikeEE
” tallbloke (11:49:13) :
Here he is posing next to a mock grave in the bombed out cathedral…
What is it with this guy and his morbid fascination with death and WWII? ”
This keeps puzzling me, too, all those creepy references to “deniers’ and death trains and so on. I couldn’t see any connection whatsoever.
I presume Hansen’s preferred association of imagery is supposed to go like this: WWII – fighting fascism – I am fighting the good fight – therefore anyone who disagrees with me is a fascist.
Or something.
Chris V (13:22:40)
Re the new graph at the top of the post-
does anyone know which temperature anomaly is plotted on that graph? Is it some sort of composite of the “big four” (GISS, HADCRU, UAH, RSS)?
As I read the paper, it says the data is HadCRUT3: referencing http://www.metoffice.gov.uk/research/hadleycentre/obsdata/HadCRUT3.html.
On checking the link, I find it has been moved to:
http://www.metoffice.gov.uk/climatechange/science/monitoring/hadcrut3.html
On a quick eyeball, the graph given by Dr Akasofu and copied to the head of this post agree with the source data.
Ric Werme (16:29:40) :
foinavon (10:50:33) :
Yes, “exponential decay climbing…” is more explicit. But it’s difficult to describe a rising exponential decay in a single word, and an exponential recovery looks quite like a hyperbola. So I said “broadly hyperbolic”.
The point is that a hyperbola (or a rising exponential decay) tends to an asymptote but appears linear in its early stages. If, according to Akasofu, we are still in the linear phase of the recovery form the LIA (and Akasofu is quite explicit about this as can be seen by reading page 2 of the document that is linked to in the top article of this thread), then the Earth has (according to Akasofu) an extremey slow response to a change in forcing. That would support a very large climate sensitivity to enhanced [CO2], likely much larger than the 3 oC of warming per doubling that is the mid range of likeihood from a load of other analyses.
It’s not obvious what the asymptote is since Akasofu doesn’t give us any indication of what the relevant forcings are that gave us the LIA. If one takes the assumption (for example) that the LIA was a combination of reduced solar output combined with a suppression of the Meridonal Overturning Circulation that resulted in reduced heat transfer to the high Northern latitudes (there’s evidence for each of these), then the asymptote would be the surface temperature that accrues at equilibrium under conditions where the solar output isn’t suppressed and neither is the MOC.
“I’m no climate scientist, but as I understand it, the oceans are warmed by the sun and will keep warming until an equilibrium point with the atmosphere is reached.”
When do we reach the equilbirium point? Temperature is constantly in flux. This is sort of like looking at supply and demand, and deducing that since supply outstrips demand, prices should go down. That is the general concept, but since the economy as a whole is constantly in flux, such neat scenarios are hardly ever realistic. Is the price of the good being driven up by outside forces? Is the temperature of the ocean tending towards the atmospheric temperature, or the other way around?
Ohioholic (17:11:03) :
Sometimes it does, and sometimes it doesn’t. Of course, since CO2 is a greenhouse gas, a temperature rise always follows a CO2 rise, all else being equal. Some of the catastrophic warming events in the deep past were the result of temperature rises that resulted from massive release of CO2 (and other greenhouse gases) into the atmosphere.
Not quite sure what you mean. Obviously, if one wants to assess the effects of ocean oscillations on global temperature, then one really needs to consider the oceans en masse. For example if the Gulf Stream is suppressed somewhat (as seems to have happened during the LIA), there will be a reduction in heat transfer to the high Northern latitudes. However that doesn’t mean that the cooling of the northern oceans constitues “global cooling”, because the Southern oceans will warm somewhat since less heat is being carried to the high Northern latitudes. In other words without independent evidence that changes in the PDO (say) can themselves result in significant global scale temperature changes, one can’t make acceptable interpretations about its influence on global temperature. After all, if we were to choose the AMO record (say) to interpret global temperature changes we’d come to a completely different conclusion. It’s a bit like trying to assess the global temperature from the record of temperature in Central England…
That’s quite well understood. The saturation level of air as a function of temperature and pressure is known. When the water content exceeds the saturation level, the water will condense in the form of clouds and perhaps rain/snow. Supersaturation effects might apply and nucleating species (e.g aerosols or ocean salt) can affect the saturation levels.