The Search for a Short Term Marker of Long Term Climate Sensitivity
By Dr. Roy Spencer. October 4th, 2009
[This is an update on research progress we have made into determining just how sensitive the climate system is to increasing atmospheric greenhouse gas concentrations.]
While published studies are beginning to suggest that net feedbacks in the climate system could be negative for year-to-year variations (e.g., our 2007 paper, and the new study by Lindzen and Choi, 2009), there remains the question of whether the same can be said of long-term climate sensitivity (and therefore, of the strength of future global warming).
Even if we find observational evidence of an insensitive climate system for year-to-year fluctuations in the climate system, it could be that the system’s long term response to more carbon dioxide is very sensitive. I’m not saying I believe that is the case – I don’t – but it is possible. This question of a potentially large difference in short-term and long-term responses of the climate system has been bothering me for many months.
Significantly, as far as I know, the climate modelers have not yet demonstrated that there is any short-term behavior in their models which is also a good predictor of how much global warming those models project for our future. It needs to be something we can measure, something we can test with real observations. Just because all of the models behave more-or-less like the real climate system does not mean the range of warming they produce encompasses the truth.
For instance, computing feedback parameters (a measure of how much the radiative balance of the Earth changes in response to a temperature change) would be the most obvious test. But I’ve diagnosed feedback parameters from 7- to 10-year subsets of the models’ long-term global warming simulations, and they have virtually no correlation with those models known long-term feedbacks. (I am quite sure I know the reason for this…which is the subject of our JGR paper now being revised…I just don’t know a good way around it).
But I refuse to give up searching. This is because the most important feedbacks in the climate system – clouds and water vapor – have inherently short time scales…minutes for individual clouds, to days or weeks for large regional cloud systems and changes in free-tropospheric water vapor. So, I still believe that there MUST be one or more short term “markers” of long term climate sensitivity.
Well, this past week I think I finally found one. I’m going to be a little evasive about exactly what that marker is because, in this case, the finding is too important to give away to another researcher who will beat me to publishing it (insert smiley here).
What I will say is that the marker ‘index’ is related to how the climate models behave during sudden warming events and the cooling that follows them. In the IPCC climate models, these warming/cooling events typically have time scales of several months, and are self-generated as ‘natural variability’ within the models. (I’m not concerned that I’ve given it away, since the marker is not obvious…as my associate Danny Braswell asked, “What made you think of that?”)
The following plot shows how this ‘mystery index’ is related to the net feedback parameters diagnosed in those 18 climate models by Forster and Taylor (2006). As can be seen, it explains 50% of the variance among the different models. The best I have been able to do up to this point is less than 10% explained variance, which for a sample size of 18 models might as well be zero.
Also plotted is the range of values of this index from 9 years of CERES satellite measurements computed in the same manner as with the models’ output. As can be seen, the satellite data support lower climate sensitivity (larger feedback parameter) than any of the climate models…but not nearly as low as the 6 Watts per sq. meter per degree found for tropical climate variations by us and others.
For a doubling of atmospheric carbon dioxide, the satellite measurements would correspond to about 1.6 to 2.0 deg. C of warming, compared to the 18 IPCC models’ range shown, which corresponds to warming of from about 2.0 to 4.2 deg. C.
The relatively short length of record of our best satellite data (9 years) appears to be the limiting factor in this analysis. The model results shown in the above figure come from 50 years of output from each of the 18 models, while the satellite range of results comes from only 9 years of CERES data (March 2000 through December 2008). The index needs to be computed from as many strong warming events as can be found, because the marker only emerges when a number of them are averaged together.
Despite this drawback, the finding of this short-term marker of long-term climate sensitivity is at least a step in the right direction. I will post progress on this issue as the evidence unfolds. Hopefully, more robust markers can be found that show even a stronger relationship to long-term warming in the models, and which will produce greater confidence when tested with relatively short periods of satellite data.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Slightly O-T, Loveland Basin, a ski resort in Colorado, just opened today, earliest in 40 years; and A-basin will open in two days, earliest ever.
Leif Svalgaard (19:20:58) :
Richard (18:45:01) :
“If there is a strong correlation, then somewhere there must be a cause and effect.”
Not necessarily
Isn’t it amazing that it is necessary to state that?
Please read more carefully. I did not say that correlation implies causation,
nor did I say that one factor is necessarily in any way responsible for the other, by way of direct cause and effect, only that it is very likely that there is a cause and effect SOMEWHERE in the situation that explains the correlation.
When two things correlate, there are two possiblities. There is some real underlying mechanism that is responsible for the correlation or the correlation is happenstance, sheer coincidence, with no explaination other than chance.
When you are faced with a STRONG correlation, supported by a reasonable amount of data, the likelyhood of coincidence becomes very slight, and the assumption must be that there is a real physical explaination that explains the correlation.
Both of the “things” that correlate may be effects of some third factor that is unknown or unidentified. Every year in the fall, I hear people talking about the temperature going down and the leaves changing color and falling off the trees. Certainly there is a correlation between the two, but many people believe that the leaves falling are a direct result of the colder weather. Actually the trees are reacting to the decreasing length of daylight, which is also responsible for the cooler temps. Neither is the cause of the other, both are effects of a third factor. Regardless, there are real causes and effects SOMEWHERE in the situation, that are responsible for the correlation.
If you gentleman when faced with a strong correlation, based on a reasonable amount of data, choose to assume that the situation is driven by coincidence, rather than a real relationship, feel free, after all anything is possible. On the other hand, nobody is going to be betting on you to push the envelop of human understanding either. Strong Correlations correlate strongly to underlying mechanisms
If you look at my statement in context, I was saying that if Dr. Spencer determines that there is a short term index that correlates strongly with the long term warming behavior, then it will be quite enlightening to attempt to understand why that is the case. Unless the index is entirely coincidental, there will be a real cause and effect SOMEWHERE in the situation that can further understanding.
Perhaps the index is a ratio of the anomoly of LW radiation to the anomoly of SW radiation (or vice versa), during a cool down after rapid warming. The models don’t cool down by rejecting heat the same way AQUA sees it in the real world.
Perhaps it is also the case that Dr. Roy is looking for a short term indicator for long term behavior, but having run out of ideas, he has hit on a clever way to get us to do some brainstorming for him. He’ll try out our ideas before he gets back to us, and let’s us know who managed to “guess” what he was thinking.
Just jokin’ Roy.
Steve Keohane says:
I don’t think I do. (Note that if the relative humidity drops slightly as temperatures rise, the absolute humidity will still increase…It will just increase slightly less fast with temperature than the saturation vapor pressure is.)
DGallagher (09:00:35) :
When you are faced with a STRONG correlation, supported by a reasonable amount of data, the likelyhood of coincidence becomes very slight, and the assumption must be that there is a real physical explaination that explains the correlation.
I actually agree with that, with emphasis on STRONG rather than just strong. Everybody who is peddling a correlation always says it is ‘strong’ [why peddling it, if it wasn’t]. In the case with the models that prompted this, I don’t think there is or can be a STRONG correlation, simply because our models are not very good. In fact, I would distrust anybody you claimed a PERFECT correlation with what the models say.
Piece of cake.
The gobal water balance move heat from low latitudes to higher latitudes.
That is why the poles are warmer than the radiation balance equotation would show.
The heat is released where the vapor condens.
But this water balance also move heat from low altitudes to high altitudes.
Heat is “dragged” into where vapor is forming clouds
What make vapor condensate? Ask Mr Svalgaard.
With high solar activity is the magnetic fields pole oriented and generates more condensation at high latitudes. With low solar activity is the cosmic rays equally formed which is more at low altitudes. In the atmosphere where the condensations occur heats is that marker which tells us where we are going.
We are now going from a pole condensation regime to a more tropic regime.
Less heat is mowing towards the poles it is also a wetter climate at lower latitudes and by that less total incoming solar radiation.
It is not a coincident that the glacier at Mt kilimanjaro was formed AFTER the high latitudes glacier melted. The new heat distribution cooled the tropic and heated the poles.
Warmer tropics make colder poles. It is a matter of heat distribution.
So mr Spencers sensivity marker is probably MSU 2 and AMSU 5 that with a higher value at tropical latitudes is a marker of a cooling earth.
Waith here: that is precisly what happends right now.
Svalgaard and Spencer are two side of the same coin.
Something changing where clouds is formed and that i our sun.
The correlation here certainly isn’t PERFECT. Apparently, it can only explain about 1/2 the variation among the models. I assume the index(s) from the AQUA data is simply plotted along the line that was fit to the model data. I don’t think that UAH can plot the long term climate feedback parameter directly from satellite data (yet).
If this measureable index reveals itself during rapid warming and then cooling events in the short term, then there is a difference between the way that the models reflect and radiate heat and the way nature does (assuming that the index comes from the satellite data). This would indicates that the models are not accurate in the short term, particularly around the time of rapid warming and cooling. It is possible that the models are inaccurate in the short term and in the long term, but for entirely different, unrelated reasons. I accept that possibility, I’d even believe that they don’t get mid term right either for several reasons unrelated to the others.
That said, it’s seems likely that an error in how models deal with warming and cooling in the short term would lead to errors in the long term simply by being propagated by subsequent inerations.
Until Dr. Spencer reveals the nature of the index, it is difficult to do anything but speculate on the significance. It is never the less intrigueing that there could be some significant parameter that is revealed in the short term, that could determine the accuracy of models and provide insight into nature.
DGallagher (14:38:41) :
Until Dr. Spencer reveals the nature of the index, it is difficult to do anything but speculate on the significance.
Which is partly why I criticized him for not revealing it.
“”” DGallagher (09:00:35) :
When you are faced with a STRONG correlation, supported by a reasonable amount of data, the likelyhood of coincidence becomes very slight, and the assumption must be that there is a real physical explaination that explains the correlation. “””
Would you consider a theory that agrees with the best experimental measured data to about a couple of parts in 10^8; well to within less than half of the standard deviation of the very best experimental measurement; to be indicative of the validity of the theory.
The fine structure constant which is 1/137.0359895 (+/-) 0.045 ppm was theoretically calculated accurate to less than half of that standard deviation back in the mid 1960s.
You should try to find the letters on that; probably in Applied Optics or some similar peer reviewed Journal. Really exciting reading.
The fine structure constant has the exact value 2.h.c.(epsilon-0)/e^2, and measurments were actually used at one point to determine the value of (c).
The mathematical theory deriving it contained absolutely no observational input data from the physical universe. Quite remarkable to then arrive at a function of some of the most fundamental Physical constants; but yet it had to be right to get the answer so accurately.
Too bad it was quite fictional; and computer programmers quickly derived other expressions of exactly the same form, that were within the standard deviation, and a couple of those were better than that obtained by the first charlatan.
I think you need better than even good correlation to establish a theory; like some causal mechanism maybe.
“”” In fact, while the climate models tend to disagree somewhat on the strength of the positive water vapor feedback and negative lapse rate feedback, the ones with a larger magnitude water vapor feedback tend to have a larger lapse rate feedback and vice versa, because these feedbacks are essentially controlled by the same convective processes. “””
Joel can you point to some peer reviewed papers where somebody has actually made real world measurments of the water vapor feedback resulting from CO2 increases. Perhaps something like:-
d(H2O)/d(CO2) = k +/- e%
Maybe (k) is a function of latitude or some other geographical variable; so one would have to measure it in a number of locations.
How would one separate d(H2O)/d(CO2) from say d(H2O/d(H2O), or
d(H2O)/d(O3) or any other GHG water feedback coefficient.
I just can’t figure out why it is that water vapor doesn’t have any climate effect, until it is “stimulated” by CO2; that is really remarkable.
Leif says: Any ‘theory’ that ignores the facts [as ID does] cannot be called science, and someone adhering to it does not show good scientific judgment.
You make a very good point. But isn’t this entire debate characterized by an absence of ‘facts?’ After all, everyone is talking about global temperature as if there were such a thing as a meaningful global temperature.
How does one come up with such a number in the first place? Where does the accurate data come from in the first place? First, Anthony has shown with his audit that the US historical climate network stations are biased by a very large amount. That makes any numbers produced by the network very questionable. But at least the US has data that may be questionable and incomplete. From what has been disclosed by Phil Jones, there is no raw data for the global temperature set. He claims to have lost it during office moves or such other nonsense. Of course that happened after he tried to prevent access for nearly a decade, perhaps more, by outsiders who wanted to see how complete the data was and how it was adjusted to make up for discontinuities, station moves, urbanization, and other material factors. Some people would be willing to trust that Dr. Jones did everything correctly but I am not certain that such a trust would be wise. After all, Dr. Jones wrote a paper that came up with a ridiculously low UHI effect based on data that was incomplete and discontinuous. (Anyone with a thermometer and a vehicle can do a number of runs and come up with a much better estimate than Dr. Jones produced.)
So what we are left with is a global data trend that cannot be verified and an American data set that shows that the 1990s were cooler than the 1930s. So where exactly is this warming that everyone is arguing about again? I may not be as smart about these issues as many on this board but my training was very specific about getting the real fundamentals right. That leaves me with two questions”
1. Where are you getting independently verified temperature data that you can trust?
2. How does one exactly use this data to come up with a meaningful global planetary average that adequately accounts for atmosphere, ocean and land temperatures at different altitudes and latitudes?
RR Kampen (02:05:57) :
At moderators… Please leave away previous post, it contains a dumb error!
——-
It sure does – yet again you talk about volume (to the power 3) and link to maps of area (to the power 2). Do you not know the difference ?? Please answer with sentences that contain numbers.
danappaloupe (00:59:28) :
Also, must I explain why surface area of ice is a weak indicator of total volume of ice?
——————-
Go for it – with sentences that contain numbers please.
George E. Smith (17:12:14) :
—————
George – were you in the news just recently ??
George E. Smith (17:12:14) :
I just can’t figure out why it is that water vapor doesn’t have any climate effect, until it is “stimulated” by CO2; that is really remarkable.
———————–
It’s the Shore Uncertainty Principle. If everything he wished for were true, he wouldn’t be here to argue it !!!!
Vangel (17:20:58) :
as if there were such a thing as a meaningful global temperature.
But there is. It may be hard to measure [especially on the ground with a flawed network of poorly sited thermometers], but there is such a thing. Here is a thought experiment to prove it. Place in space around the Earth a large number of satellites distributed all around the Earth. Have radiometers on these satellites measure the radiation they receive from the Earth. Integrate over all radiometers and determine the total irradiance of the Earth. There is an ‘effective’ temperature that would give just that irradiance. This is a meaningful global temperature.
Leif Svalgaard (17:56:11) :
Vangel (17:20:58) :
as if there were such a thing as a meaningful global temperature.
But there is. It may be hard to measure [especially on the ground with a flawed network of poorly sited thermometers], but there is such a thing. Here is a thought experiment to prove it. Place in space around the Earth a large number of satellites distributed all around the Earth. Have radiometers on these satellites measure the radiation they receive from the Earth. Integrate over all radiometers and determine the total irradiance of the Earth. There is an ‘effective’ temperature that would give just that irradiance. This is a meaningful global temperature.
Thus the satellites give us a more meaningful picture than the so called “surface” temperatures of Hadley and NASA.
Even if the temperatures were evenly and accurately measured, which they are not, how meaningful is it to measure air temperatures over land and sea water temperatures over the sea and then combine them for the “Global” temperature?
Richard (22:31:58) :
Thus the satellites give us a more meaningful picture than the so called “surface” temperatures of Hadley and NASA.
Even if the temperatures were evenly and accurately measured, which they are not, how meaningful is it to measure air temperatures over land and sea water temperatures over the sea and then combine them for the “Global” temperature?
For the time before the satellites, all we’ve got are the ground-based measurements, so we have to learn to live with them as at least an approximation to a ‘global temperature’. There is a difference between saying that we only have an approximation to the ideal and to say that the very concept is meaningless.
Re: philincalifornia (17:34:41) :
“It sure does – yet again you talk about volume (to the power 3) and link to maps of area (to the power 2). Do you not know the difference ?? Please answer with sentences that contain numbers.”
—
Do you really expect me to post a three (3) dimensional object??
I posted a map. Those who know the first things about arctic sea ice will also know the very first thing: older ice is thicker.
” Leif Svalgaard (17:56:11) :
Vangel (17:20:58) :
as if there were such a thing as a meaningful global temperature.
But there is. It may be hard to measure [especially on the ground with a flawed network of poorly sited thermometers], but there is such a thing.”
That is one point out of the way. You have a flawed network of poorly sited thermometers that are biased by a number of factors (as demonstrated by Anthony’s audit). The network is missing data and does not properly account for such things as the UHI effect, station moves, instrument error, etc.
This means that we do not have a valid measure of average global temperature even if we could come up with a way to come up with such a construction and that construction could be made meaningful. That brings me back to my point. If the temperature data is not good, how can we be arguing about what has actually happened? How is any of this valid science when it resembles an ideological and political debate that tells us far less about what is rather than what we are?
It is my contention that most of the warmers actually believe the snake oil they are peddling because they bought the made up temperature profile as real and never bothered to ask the important questions about the fundamentals. I maintain that without the original global data set there is no way to accept the huge divergence between the US data, which shows that the 1930s were the warmest decade, and the global temperature construction.
Of course, this provides many in the AGW crowd a ready made excuse. They can say that they used the data provided to them and did not believe it to be invalid so they are not to blame for ignoring the scientific evidence that has clearly debunked the AGW myth.
“Here is a thought experiment to prove it. Place in space around the Earth a large number of satellites distributed all around the Earth. Have radiometers on these satellites measure the radiation they receive from the Earth. Integrate over all radiometers and determine the total irradiance of the Earth. There is an ‘effective’ temperature that would give just that irradiance. This is a meaningful global temperature.”
But here is the problem. First, you cannot have enough satellites to be sure that your data is sufficient. Second, the earth is not some uniform black body
that gives off consistent radiation depending on the temperature of a particular area. Third, the integration can be done in a number of ways that produce slightly different results.
But even if I were to dismiss the points above, it is impossible to assign meaning to the composite number that we come up with. If we were to create a scenario in which we had the polar regions warm up substantially during the long hot summer days elsewhere we could wind up with a number that did not change but had a substantial effect on the ability of the biosphere to support much more biodiversity. The climate could be much better but would not show up in the average number. We could also go the other way by having days become much hotter and nights much colder. The average would remain the same but life would be much harsher. This means that the number is not meaningful and that the changes to the average global temperature that are being reported are meaningless to individuals.
Of course, you can try to make the old statist argument that the individual is not very important because it is humanity itself that matters but that argument has never had much intellectual merit to begin with. It has simply been a convenient argument for those seeking political power to use in order to justify forcing individuals to do what they would not choose to do on their own. Sorry Leif, but while I appreciate your ability and willingness to debate these topics I see a very weak position because the fundamentals that are necessary to have a meaningful argument are not in place. Until you can come up with a global average temperature trend that is both accurate and meaningful the entire debate is just a political exercise. Note that science is on the side of the sceptics because they do not have to make an assertion that they cannot support. All they need to do is to point out that the temperature data that would be required to have a meaningful dialogue has not been provided by the AGW proponents.
George E. Smith says:
The correct question to ask is what is d(H2O)/dT. You are correct that the water vapor feedback is not expected to depend significantly on the mechanism causing the change in temperature. And, here are two papers that discuss the moistening (focusing on the upper troposphere, which is most important for the radiative effects): http://www.sciencemag.org/cgi/content/summary/sci;323/5917/1020 and http://www.sciencemag.org/cgi/content/abstract/sci;310/5749/841
You are creating a strawman. It is not that water vapor needs to be “stimulated” by CO2. It is that water vapor needs to be in the atmosphere (and especially the upper troposphere) to have its greenhouse effect. And, the concentration of water vapor in the atmosphere is controlled by the temperature.
“For the time before the satellites, all we’ve got are the ground-based measurements, so we have to learn to live with them as at least an approximation to a ‘global temperature’. There is a difference between saying that we only have an approximation to the ideal and to say that the very concept is meaningless.”
But you do not have an approximation. As many have pointed out, Phil Jones claims to have lost the original data that was used to make the adjustments that provide us with the temperature profile. That isn’t real science, particularly when the global data diverges so much from the American data, which shows that the 1930s were warmer.
You are probably familiar with the Hansen, Ruedy, Glascoe and Sato admission that, “The U.S. has warmed during the past century, but the warming hardly exceeds year-to-year variability. Indeed, in the U.S. the warmest decade was the 1930s and the warmest year was 1934.” (http://www.giss.nasa.gov/research/briefs/hansen_07/)
The link shows a major divergence between the US and Global temperatures that cannot be taken at face value without examination. I suggest that we go with the results that can be supported by actual data and that isn’t the global temperatures. The bottom line is that we can’t trust the global construction and have to go back to the original country data and reintegrate the whole thing into a new calculation of we are to assume that the ‘approximation’ is good enough.
And let me point out that shedding light on the methodology has not exactly been kind to the AGW proponents. First, the ice cores showed that changes in temperature trends drove CO2 levels, not the other way around. Second, the hockey stick studies were shown to be incorrect; when the statistical errors were corrected there was no hockey stick to be found. Third, the dendro data fell apart. The NAS, NRC, and other organizations clearly made the point that stripbark proxies were improper because they measured CO2 content and moisture changes in addition to temperature changes. After that the dendro community dropped the Polar Urals data because it did not confirm the expected temperature profile. That left the infamous Yamal proxies, which kept the battle going during the decade in which the data was kept from reviewers. When the editors at Philosophical Transactions of the Royal Society Journal enforced the rules and forced Briffa to release the Yamal data it took a few hours to show that the sample was too small according to Briffa’s own written standards and that when the entire data set was used the warming went away. What is worse is the fact that most of the ‘warming’ signal could be traced to YAD06, a single tree that shows a profile that is very different from the mean.
So where does this leave us? We have an American record showing no appreciable temperature changes other than the PDO driven variability. We have NO global data to show us anything one way or another. We have satellite readings showing warming that began when the PDO went into its warm phase and end when the PDO flipped back into a cool phase. We have discredited dendro data that cannot be used in any way to show warming if proper statistical methods are used. We have historical records that show that most highs took place quite some time ago in most locations. We have studies that show that the UHI effect overestimates warming and biases modern readings. We have Anthony’s audit that shows that 89% of the USHCN stations have a bias of 2C or more, a number that is substantially higher than the claimed warming since the end of the Little Ice Age.
We also have the inconvenience of the official record showing that most of the warming since the depth of the LIA took place before man had a substantial effect on CO2 emissions. And if you are looking at meaningful estimates let us not forget the fact that the MWP and Holocene Optimum were warmer. (We can tell this by looking at plant growth and do not need thermometers.) The fact that most of England still can’t produce much of a wine industry as it did during the MWP, or that Chinese orange orchards are still hundreds of miles south of their previous range during the RW tells us that the modern temperatures are not very high and that the warming scare driven by an irrational fear of CO2 is not to be taken very seriously by objective observers of the data.
“Do you really expect me to post a three (3) dimensional object??
I posted a map. Those who know the first things about arctic sea ice will also know the very first thing: older ice is thicker.”
Yes it is. But the AGW proponents have had a big problem measuring thickness of the ice. The Polar 5 measurements showed that the satellites were off slightly–by 100%.
http://motls.blogspot.com/2009/04/north-pole-ice-100-thicker-than.html
As Anthony has argued, the ice conditions are not all that unusual.
http://wattsupwiththat.com/2009/04/26/ice-at-the-north-pole-in-1958-not-so-thick/
And we have plenty of evidence that the natural variability in the Arctic is driven by decadal AO and multidecadal LFO.
http://www.google.ca/url?sa=t&source=web&ct=res&cd=1&url=http%3A%2F%2Fwww.frontier.iarc.uaf.edu%2F~igor%2Fresearch%2Fpdf%2F50yr_web.pdf&ei=CvfNStbNIcrh8Qb4n93wAw&usg=AFQjCNF1qlqHofR6kllNTG4OF3WzSjZhVw&sig2=j6bKK52MUNDoV_YdV1BYbQ
We also need to keep in mind that this planet has ice at both poles and that the SH has shown less melting and greater ice cover than usual. Just looking at one side makes one appear to be biased.
RR Kampen (01:02:20)
Do you really expect me to post a three (3) dimensional object??
I posted a map. Those who know the first things about arctic sea ice will also know the very first thing: older ice is thicker.
—————-
I asked you to post numbers that support your theory that Arctic sea ice volume is declining.
I think we can agree on the fact that you can’t.
In other words, you have reached the conclusion you wanted to reach with zero experimental data.
Worse still, you don’t even know what I’m talking about do you ??
Re: Vangel (07:34:48) :
“We also need to keep in mind that this planet has ice at both poles and that the SH has shown less melting and greater ice cover than usual. Just looking at one side makes one appear to be biased.”
The reason for this separation is that north and south have opposite land/sea-distributions. They show different phenomena that need different local explanations. One thing is certain: it is not cooling in or around Antarctica, rather contrary so particularly around, so temperature change sec cannot explain the increase of sea ice around the south continent.
“But the AGW proponents have had a big problem measuring thickness of the ice.”
Correct. But there is eighty years of pinpoint measurements and there is a relation between thickness and age of the ice from which tentative conclusions may be drawn.
Thickness measurements are on the increase as countries are investigating the Arctic for commercial reasons.
“And we have plenty of evidence that the natural variability in the Arctic is driven by decadal AO and multidecadal LFO.”
Thanks for that article, I’ll study it first. As a first impression I’ll submit that maybe variability may be driven by large scale fluctuations, including the past couple of years, but these drivers seem to be superposed over the sharp downward trend of decade – a trend which in itself cannot be explained from AO/LFO. Also, the trend of the Arctic does not exist by itself; most of the globe shows physical evidence of warming which cannot be explained solely by global fluctuations.
Vangel (07:17:36) :
But you do not have an approximation.
This is different from the statement that a global temperature does not make sense. It does make sense even if we don’t have a good measure of it. A long time ago, there was great debate about the distance to the Sun and the estimates [measurements] varied greatly. Yet, the real distance did not, of course. So the concept of a global temperature makes sense. That we don’t have a good measure of it is another matter and is not even worth discussing. If you want to point out to people that we don’t have a good measure of the global temperature, the wrong way of doing that is to deny that the concept makes sense. That tunes them out right there and you are labeled a crank.
Re: philincalifornia (07:36:28) :
“I asked you to post numbers that support your theory that Arctic sea ice volume is declining.
I think we can agree on the fact that you can’t.”
‘Think’? O well, I think we can agree on the fact that you cannot produce numbers to show the Artic ice has increased over this century – see what I mean!
I guess you can find the database containing e.g. the Soviet measurements as from about 1930 somewhere…
Well, I posted a more serious reply above.
As for the relation between thickness and age of Arctic sea ice, it is enough to corroborate my statement. Literature on this abound.