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Discussion > (A)GW Lite

Chris M

Thank you for your kind words. In order for me to be to begin to understand your comment, I need clear examples of the following from my comments above:

pseudish nonsense
specious argument used for deception
obscure words and complicated sentence constructions in order to intimidate
manipulating the opponent's prejudices and emotions to overcome their logical faculties

Jun 3, 2012 at 4:05 PM | Unregistered CommenterBBD

Logico

Thanks. I downloaded this. I haven't read it yet, but I was expecting to find Hansen's explanation of how AGW impacts on blocking highs and the jet stream. So I did a search in this paper for "blocking high" - no result. "Jet stream"? No result.) Hansen's certainty on current catastrophic effects (definitely not a "consensus" view) are an example. So I read the paper carefully, and I note that temp and CO2 do not appear on the same graph. The detailed comparison is not easy to make.

This is to miss the point. The study demonstrates that the frequency of extreme summer hot weather events is increasing by investigating the GISTEMP gridded temperature data. The focus is on NH land temperatures as that is where most of the land is.

The average June-July-August land surface temperature anomaly for for each NH gridcell (250km^2) is calculated from the 1951 - 1980 JJA average for that cell. The normal (gaussian) distribution of frequency of extremes is compared:

Fig P1

JJA summer temperature anomalies over the baseline have increased (hence the shift to the right), but the *frequency* of extreme high temperature episodes has *also* increased (hence the widening of the curve). The abstract, with emphasis added:

Should the public be able to recognize that climate is changing, despite the notorious variability of weather and climate from day to day and year to year? We investigate how the probability of unusually warm seasons has changed in recent decades, with emphasis on summer, when changes are likely to have the greatest practical effects. We show that the odds of an unusually warm season have increased greatly over the past three decades, but also the shape of the frequency distribution has changed so as to enhance the likelihood of extreme events. A new category of hot summertime outliers, more than three standard deviations (3σ) warmer than climatology, has emerged, with the occurrence of these outliers having increased 1-2 orders of magnitude in the past three decades. Thus we can state with a high degree of confidence that extreme summers, such as those in Texas and Oklahoma in 2011 and Moscow in 2010, are a consequence of global warming, because global warming has dramatically increased their likelihood of occurrence.

The detail (emphasis added):

A more important change is the emergence of a subset of the hot category, extremely hot outliers, defined as anomalies exceeding +3σ. The frequency of these extreme anomalies is about 0.13% in the normal distribution, and thus a typical summer in the period of climatology would have only about 0.1-0.2% of the globe covered by such hot extremes. We show that during the past several years the portion of global land area covered by summer temperature anomalies exceeding +3σ has averaged about 10%, thus an increase by about a factor of 50 compared to the period of climatology. Recent examples of summer temperature anomalies exceeding +3σ include the heat wave and drought in Oklahoma, Texas and Mexico in 2011 and a larger region encompassing much of the Middle East, Western Asia and Eastern Europe, including Moscow, in 2010.

The question of whether these extreme hot anomalies are a consequence of global warming is commonly answered in the negative, with an alternative interpretation based on meteorological patterns. For example, an unusual atmospheric "blocking" situation resulted in a long-lived high pressure anomaly in the Moscow region in 2010, and a strong La Nina in 2011 may have contributed to the heat and drought situation in the southern United States and Mexico. However, such meteorological patterns are not new and thus as an "explanation" fail to account for the huge increase in the area covered by extreme positive temperature anomalies. Specific meteorological patterns help explain where the high pressure regions that favor high temperature and drought conditions occur in a given summer, but the unusually great temperature extremities and the large area covered by these hot anomalies is a consequence of global warming.

This attribution is important, because we can project with a high degree of confidence that the area covered by extremely hot anomalies will continue to increase during the next few decades and even greater extremes will occur. The decade-by-decade shift to the right of the temperature anomaly frequency distribution (Fig. P1) will continue, because Earth is out of energy balance, more solar energy absorbed than heat radiation emitted to space, and it is this imbalance that drives the planet to higher temperatures.

We might be sceptical of modelled projections, but this is an empirical analysis of what has already happened.

Jun 4, 2012 at 12:16 AM | Unregistered CommenterBBD

BBD: I'd rather continue this elsewhere [?]

Hansen uses 1951 - 1980 base period. Michaels and Balling 2009 reproduce Kunkel 2006 using 1900 onwards - huge difference. Recent not special. Note in Hansen that 61 - 71 is less extreme than 51 - 61; he just catches part of the earlier variation.

Jun 5, 2012 at 12:24 PM | Unregistered Commenterlogicophilosophicus

Logico

Altering the baseline doesn't alter trend. It just moves the curve up and down the y-axis. You can try this yourself. Here's GISTEMP with Moyhu Climate Plotter's default 1979 - 2000 baseline.

Here again, with the GISS 1951 - 1980 baseline.

Here again with the UAH 1981 - 2010 baseline.

I get the strong impression that you still haven't understood the Hansen study, and that minor sub-issue of baselines has only added to the confusion.

Michaels and Balling are contrarians with a long record of errors and misrepresentations behind them. I do not share your confidence in their output. Nor could I find the paper you reference - was it published in a mainstream reviewed climate journal? Or just something the Heartland Institute put out?

It would have been nice if, rather than a constant stream of weak, often entirely spurious 'objections' to the points I've raised on this thread, you had shown some evidence of reflection. Of genuinely weighing the evidence. Of real scepticism rather than the reflexive contrarianism on show here.

Good luck.

BBD

Jun 5, 2012 at 6:56 PM | Unregistered CommenterBBD

For some reason MCP has not retained the changed base year settings. To see the example work, check the box by GISS in the plot list, enter the desired values in the Base Yrs fields (eg 1951 1980) and click the Base Yrs button to re-baseline the curve. Repeat using different (but equal length) baseline periods and watch the curve move up/down the y-axis.

Jun 5, 2012 at 7:21 PM | Unregistered CommenterBBD

BBD

1) The baseline issue concerns what happened PRIOR to 1951. Hansen's paper concerns the Northern Hemisphere; Kunkel's work relates to the USA in particular, which is the greatest region in the NH with a reliable climate record for a the whole of the last century. The point is that there was a more major spate of extreme heatwaves throughout the 1930's, which a) raise the baseline, making the last decade less extreme than Hansen suggests, and b) show that a decade of heatwaves occurred just 20 years before his reference/study period. See the CCSP SAP on extreme climate events:

http://downloads.climatescience.gov/sap/sap3-3/sap3-3-final-all.pdf

2) I understand the thrust of the Hansen paper very well. It is designed to make the most of the trivial finding that if you raise the average temperature by a fraction of a degree, then all those warm spells which failed to reach heatwave status by a fraction of a degree will now be heatwaves. I believe you will find no evidence in the literature for the suggestion that "more extreme" means anything more than that in respect of heatwaves.

3) I was well aware that the Kunkel presentation to a meteorological convention might not be readily available on a search, hence the helpful Michaels and Balling link, which I could have omitted of course. I expressed no particular confidence in their work, beyond the charitable assumption that they had not doctored Kunkel's graphs. However, it behoves you to give examples if you impute "a long record of errors and misrepresentations" to them.

4) But you can see Kunkel's points (i.e. the basis for (1) above) are uncontroversial, and can be seen in the CCSP SAP (page 3, and in detail pages 129-30). The 1930's were more extreme in terms of heatwaves than the recent period.

5) The ENTIRE point of introducing this information was to show that James Hansen is an extremist and - apparently like yourself - systematically avoids addressing the early 20th century natural variability of the climate. Your position is that Hansen's views are mainstream and orthodox (you have not answered any of the examples of his disgraceful public outbursts). Well, if so, no doubt in 180 pages of SAP the United States CCSP will have made numerous references to his work? Not so. He is mentioned precisely ZERO times in the text, and only appears among the 700 plus references as the 12th listed author of a PNAS paper on "Forced and unforced ocean temperature changes..." Not a ringing endorsement. I'd say that if my attitude to Hansen's extremism is "weak", "spurious" and merely "contrarian", then you need to be equally critical of CCSP and NOAA...

6) Note in the CCSP SAP the information that a) as expected, rising average temperatures also decrease the frequency of cold spells (i.e. makes the climate LESS extreme), and b) in the United Sates, between 1940 and 1995 over 1000 people died each year (on average) from either heat related causes or hypothermia - cold being TWICE as deadly as heat. No wonder Hansen's one-sided catastrophist stance is ignored. Every CAGW sceptic knows this; and the point is neither weak nor spurious.

7) You suggest that I have failed to answer your points. Not so. I have answered every substantive point, generally with reference to mainstream sources. You misrepresented Wunsch as a solid Milankovitch convert, and did not even comment on Richard A. Muller's even more anti-Milankovitch stance (e.g. http://muller.lbl.gov/papers/Causality.pdf). Why ask for sources just to ignore them? I'm reminded of the bullying squireen in "The Quiet Man" who ominously orders his toady to write down someone's name, continuing: "Now strike it out! That's for him!" Muller, Akasofu, Huang, Taylor... Strike them out!

8) You seem torally ignorant of - in fact you seem to deny - the fact that latent heat transport is a huge element in the Earth's energy budget; and that is important, because it is unlikely that it is not affected by warming (more evaporation, more convection, more escping energy...) Strangely, IPCC and related sources never discuss this. The Trenberth source skips over it, as I pointed out. And then there's your endorsement of Hansen's extremism, death trains, Hiroshimas and all. So I draw my own conclusion: your knowledge is based on your IPCC Bible, and you are just another True Believer. I find it ironic that you accuse me of weak and spurious argument.

We started here with my cautiously saying that I *thought* one of the warming curves at WFT (wrongly colour-coded, as it happened) didn't mean what you thought. You responded in a gleefully abusive way (blaming the confusion on me), but I was prepared to set that aside and address every point you made, and carefully read every source you cited. Everyone that knows me knows why - the Prize is the Truth.

Well, I have wasted enough time here.

Jun 7, 2012 at 1:23 AM | Unregistered Commenterlogicophilosophicus

Logico

Re your points (1 ) - (6) inclusive, you can't use the US as a proxy for the entire NH. This is false equivalence and renders the entire argument you have constructed upon it invalid. Strictly speaking I could leave it at that, but let's look at what the Hansen paper has to say about this (my emphasis):

Hansen Fig 7. Hot area percentage in summer 1900 - 2011

[p 12 ff:]

A longer time scale and regional detail. Jun-Jul-Aug data on a longer time scale, 1900-present, including results averaged over the 48 contiguous states of the United States, are shown in Fig. 7. The small area of the 48 states (less than 1.6% of the globe) causes temperature anomalies for the United States to be very "noisy". Nevertheless, it is apparent that the long-term trend toward hot summers is not as pronounced in the United States as it is in hemispheric land as a whole. Also note that the extreme summer heat of the 1930s, especially 1934 and 1936, is comparable to the most extreme recent years.

Large regional anomalies are of interest, but let us first note that the extreme anomalies of the 1930s and 1940s do not obviate the conclusion that recent global warming, with high probability, is responsible for recent extreme anomalies. In the Supporting Information we show maps of temperature anomalies for six years with the greatest "hot" area (1931, 1934, 1936, 1941, 1947, 1953). Those years were warmer (globally and in the United States) than the 1951-1980 mean, so it is not surprising that the area with 3σ anomalies was greater than in the 1951-1980 climatology. The largest area of 3σ anomalies was in 1941, when it reached 2.7% of the land area. This compares with recent values as great as 20% and an average about 10%.

Year-to-year variability, which is mainly unforced weather variability, is so large for an area the size of the United States that it is perhaps unessential to find an "explanation" for deviations from the global trend. However, the interpretation matters, because, if the lesser warming in recent years is a statistical fluke, the United States may have in store a relatively rapid trend toward more extreme anomalies. If it is not a fluke, and if the basis for a reduced effect continues, it may continue to be difficult to garner support in the U.S. for climate mitigation.

Some researchers have suggested that the high summer temperatures and drought in the United States in the 1930s can be accounted for by sea surface temperature patterns plus natural variability (16, 17) Other researchers (18-20), have presented evidence that agricultural changes (plowing of the Great Plains) and crop failure in the 1930s contributed to changed surface albedo, aerosol (dust) production, high temperatures, and drying conditions. Also empirical evidence and climate simulations (20, 21) suggest that agricultural irrigation has a significant regional cooling effect. Such regionally-varying effects could be partly responsible for differences between observed regional temperature trends and the global trend.

On the matter of baselines in general, we find this:

[p 15:]

For many decades the World Meteorological Organization has used the prior three decades to define climatology (30). This is a useful procedure when the objective is to define anomalies relative to a recent period that most people will be familiar with. However, this practice tends to hide the fact that climate variability itself is changing on decadal time scales. Thus, at least for research purposes, we recommend keeping the base period fixed.

The question then becomes, what is the most appropriate base period. We argue that the appropriate base period is close to our initial choice, 1951-1980, because that was a period of relatively stable global temperature. The period 1951-1980 is also the earliest base period with good global coverage of meteorological stations, including Antarctica.

Jun 7, 2012 at 7:10 PM | Unregistered CommenterBBD

On your point (3), *what* Michaels and Balling link? You didn't link to anything and you still haven't told me which reviewed climate journal this paper(?) appeared in. Or provided a link. If on the other hand this is some stuff in a contrarian book then you should say so clearly.

Jun 7, 2012 at 7:44 PM | Unregistered CommenterBBD

On your point (7) where you accuse me of misrepresenting Wunsch as a 'solid Milankovitch convert'. This is nonsense. Here is what I said:

Wunsch's adherence to the minority position that a hypothetical stochastic 'forcing' has some role to play in initiating deglaciation is his right, but it doesn't mean he is right :-). It is also fair comment to say that WS05 as a whole supports the standard position.

Evidence that Milankovitch forcing is the cause of glacial terminations is continuing to emerge, eg Shakun et al. The stochastic argument remains hypothetical and its actual physical mechanisms are elusive. The mysteries are far from solved, of course, but Milankovitch remains the most plausible explanation on the table.

[Jun 1, 2012 at 11:39 PM]

I will take the standard position within paleoclimatology over Muller any day. He's been wildly wrong before when he veers out of his own field and one day it will be his Nemesis :-)

Why ask for sources just to ignore them? I'm reminded of the bullying squireen in "The Quiet Man" who ominously orders his toady to write down someone's name, continuing: "Now strike it out! That's for him!" Muller, Akasofu, Huang, Taylor... Strike them out!

This is both untrue and ad hominem. Please stop it.

On your point (8):

8) You seem torally ignorant of - in fact you seem to deny - the fact that latent heat transport is a huge element in the Earth's energy budget; and that is important, because it is unlikely that it is not affected by warming (more evaporation, more convection, more escping energy...) Strangely, IPCC and related sources never discuss this. The Trenberth source skips over it, as I pointed out.

Trenberth *does* quantify the effect. It's not as important as you believe, based on two sources, both obsolete. Either produce an up-to-date quantification that disagrees with Trenberth, or accept the standard position as proposed by Trenberth. Don't just dig your heels in and repeat your beliefs. Especially as this is precisely what you accuse me of - and the opposite of what I have done during the *entire of this exchange*.

Everyone that knows me knows why - the Prize is the Truth.

I am not in the least persuaded.

Jun 7, 2012 at 8:16 PM | Unregistered CommenterBBD

BBD


"On your point (7) where you accuse me of misrepresenting Wunsch as a 'solid Milankovitch convert'. This is nonsense." It seemed to be what you meant:
"...for Wunsch's view on the relationship between obliquity... and... interglacial peak spacing, see Huybers & Wunsch (2005)... Wunsch (2004) effectively sets out the null hypothesis. Then he moved on. Hubyers, it turns out, is an obliquity man ;-)" You seem to say Wunsch is a convert. Hardly nonsense, then.

"The stochastic argument remains hypothetical and its actual physical mechanisms are elusive. The mysteries are far from solved, of course, but Milankovitch remains the most plausible explanation on the table." Plausible - great.

I wrote: "Why ask for sources just to ignore them? I'm reminded of the bullying squireen in 'The Quiet Man' who ominously orders his toady to write down someone's name, continuing: 'Now strike it out! That's for him!' Muller, Akasofu, Huang, Taylor... Strike them out!" You replied: "This is both untrue and ad hominem. Please stop it." At the time I posted, I had cited all four, and you had not even acknowledged the evidence, far less commented on it. For the record, I understand Richard A. Muller is Chair of the Berkeley Earth Surface Temperature project, Akasofu is the Founding Director of the International Arctic Research Center of the University of Alaska Fairbanks, Shaopeng Huang is an expert (*the* expert?) on the use of boreholes to reconstruct ancient temperatures, and Peter Taylor has "green" credentials and multi-government level expertise as long as your arm. So ignoring them reminded me irresistably of Squireen Danaher's approach. (Ad hom argument is dismissing a debater rather than his argument, as for example when you dismiss Michaels, Balling, Wunsch, Muller, etc as having "a track record" of this or that rather than addressing the argument in hand; in this case, what argument??? It's the deafening silence I objected to, not BBD, whoever youmight turn out to be.) Example (which Montford has raised in the past): The Huang and Pollack paper 2007 was suppressed. Sure it got published somewhere - hence the unlikeable Bob Ward slated Montford for claiming suppression - but where is it now? Go to Huang's own web page and you'll see a long list of his publications. Check 2007. Hmmmm.... seems he didn't publish anything in 2007. I think in general conspiracy theories are just pissing in the wind, but in this case you have to assume Huang was leaned on (or he decided off his own bat that discretion is the better part of valour). H&P 2007 and MBH 2008 cannot coexist. What a good example of "consensus"!!!

I had written: "You seem torally ignorant of - in fact you seem to deny - the fact that latent heat transport is a huge element in the Earth's energy budget; and that is important, because it is unlikely that it is not affected by warming (more evaporation, more convection, more escaping energy...) Strangely, IPCC and related sources never discuss this. The Trenberth source skips over it, as I pointed out." You reply: "Trenberth *does* quantify the effect. It's not as important as you believe... Either produce an up-to-date quantification that disagrees with Trenberth, or accept the standard position as proposed by Trenberth. Don't just dig your heels in and repeat your beliefs. Especially as this is precisely what you accuse me of - and the opposite of what I have done during the *entire of this exchange*."

Since we're into Latin names for logical fallacies (your misapplied "ad hominem") let's get one right: ignoratio elenchi (arguing against a point not in fact made). I never said Trenberth didn't quantify latent heat transport - quite the opposite, I accepted his ~80Wsqm figure. I simply pointed out that his diagram was misleading and his text skipped over the issue. You say, "It's not as important as you believe." I believe(d) that Latent Heat Transport accounted for a third of all the absorbed energy which susequently escapes, and that increased temperatures would increase this effect - a negative feedback not adequately recognised by Trenberth. Global Warming works by narrowing the "window" of unabsorbed LW radiation escaping from the surface. I searched the Trenberth paper (2009) for "window", "wavelength" and (just in case) "frequency" - zero occurences. ("Window" appears on the diagram but is nowhere discussed.) I read the paper carefully. The actual radiation balance measured by satellite disagreed with the models, so - guess what - models were used to correct the data. (If you do a search on "model(s)" in the paper you get 30 occurrences...) Likewise the Latent Heat figure had to be adjusted with reference to *models*. As I read the paper, I found many references to uncertainties and disagreements of 10 or even 20 W/sqm in various statistics (including the Latent Heat figure). Remember that this is in the context of an AGW effect of, what was it, 2 W/sqm - something like that? One of the three data analyses used was the Japanese Reanalysis. It disagrees by over 5% in it's estimate of Latent Heat, and even disagrees in SIGN concerning the Top of the Atmosphere energy imbalance. Trenberth rejects it, stating that it is "UNREALISTIC" in its precipitation figures, so that's all right then... But if you go to Onogi et al 2007, you'll find that the primary ADVANTAGE of JRA is it's treatment of precipitation - "the best" of the reanalyses in this respect accrding to the author... Bottom line: of the 160 W/sqm of energy escaping from the Earth's surface into space, according to Trenberth, 80 W/sqm are via Latent Heat transport and only 40 via the GHG affected "window", and he *discusses* neither. (Do you still assert that this process "isn't as important as you believe"?) His figures for the CHANGE in the Latent Heat figure due to warming are lower than any of those given from data analysis - his figure is explicitly adjusted to conform to "models". If I were feeling ironic, I might dub this the Naomi Campbell approach to data.

Everyone that knows me knows that my mantra is: "The Prize is the Truth." You were "not in the least persuaded". Well, how do you persuade a "consensus"? Huang gave up on it and buried his own paper. Singer, Lindzen, the Idsos, Ballliunas, Spencer, Christy... all are vilified, much as you casually labelled Michaels, Balling, Muller and Wunsch. But a bullying "consensus" is no way to get to the truth, and when it suppresses data you can be *certain* the outcome is false.

You asserted that my points 1-6 were all invalidated because the CCSP SAP relates to the USA (actually North America and the adjacent oceans and islands). Since the issue is not global average temperatures but extreme events affected by global average temperatures, you are mistaken. But I could easily have added other regions - Australia, for example - to show that the high temperatures in the 1930's were similarly accompanied by record breaking heatwaves and all-time high temperatures. Nor did I suggest, nor do I believe, that the 30's had as many heatwaves as the past decade; I have made it clear that I understand 2000 to be a fraction of a degree (0.4 C) warmer than 1940, so that many more events will cross the defining threshold - by a fraction of a degree. But that's only point 1. Points 2-6 are independent, and also need answers. True to form, you ignore the awkward ones. No comment yet on the acceptability of a scientist (Hansen) using his position to claim effects way beyond the IPCC consensus, and repeatedly likening anyone who disagrees to genocidal aggressors? Any opinion on the view that effects on extreme temperature events (+ and -) of warming will save thousands of lives? Or millions - the CCSP SAP I cited reckons that a megadrought (corresonding to the onset of the LIA in North America) caused the deaths of 90% of the population of Mexico - say 15 million people - in a single generation.

I think - especially re the Trenberth Energy Budget paper - the vast uncertainties and (worse) retreat from the data are well demonstrated. Like the CCSP SAP, I believe that temperature trends before the current warming were cyclical (they use the word "oscillation"). There is no earthly reason to suppose that those variations switched off in 1977, and a commonsense look at the figures suggests that there may be a 0.2/60 C per year long term trend, a superimposed +/- 0.2/60 C per year oscillation, and a 0.2/60 C per year AGW signal, where the 60-year period and the 0.2's are very rough. Look at HADCRUT Factsheet 1. That's what you see. The models do not reproduce this rollercoaster, but it is consistent with pre-20th century trends and also with expected back radiation from CO2 increases. It suggests 0.7 degrees of warming by 2100. (If you plugged the Japanese Reanalysis 25 into "the models" rather than Trenberth's figures, I guess you'd have trouble reaching even 0.7...)

(And, contrary to what some contributors think, it's also consistent with A. Montford's expressed views:

"I believe that CO2, other things being equal, will make the planet warmer."

"I don't think you can get away from the radiative physics arguments for AGW.")

Finally, note that the IPCC are CO2-obsessed. "Sensitivity" to the IPCC means the warming effect of doubling CO2, which they perforce assume must trigger major positive feedback. But it is perfectly conceivable that there is little or even negative feedback to CO2 (i.e. to warming itself), and yet that there are processes which do involve major positive H2O feedbacks - e.g. changing DISTRIBUTION of heat/evaporation around the globe (or between land and sea) might greatly affect evapotranspiration, the 80W/sqm elephant in the room.

Jun 8, 2012 at 2:52 AM | Unregistered Commenterlogicophilosophicus

Whoops! 0.7 C by 2100? Should be 0.5 (since the multidecadal variation should be near a minimum, shaving off that 0.2 C).

Jun 8, 2012 at 2:07 PM | Unregistered Commenterlogicophilosophicus

I'm not in favour of this modern trend for allowing non statisticians (who cannot use proper stats packages) to access powerful programs they fail to understand the assumptions of. How many times do we see linear slopes compared between two autoregressive time series data?

Jun 8, 2012 at 2:45 PM | Unregistered CommenterCamp David

RE: Huang Pollack (and Shen?) (2007)

I cannot find this paper either. I am aware of the much-misrepresented 1997 study - is that what you meant? If it is, then there are some cautionary words from the authors to be found in a later paper (Huang, Pollack & Shen 2008).

The initial purpose of the present paper is to clarify and resolve this apparent change of perspective in our work between HPS97 and HPS00. Although science certainly allows for abandoning earlier results in favor of later results, in our case there is a different explanation. The fundamental difference between HPS97 and HPS00 is that they do not analyze the same data. Below we describe their respective datasets, and show why the results of HPS97 cannot be used for comparing MWP warmth to the 20th century.

On HPS97:

The consequence of excluding the upper 100 meters is that the 20,000 year reconstructions in HPS97 contain virtually no information about the 20th century. As the authors of HPS97 we can be criticized for not stating explicitly in the abstract and figure caption that the ‘present’ (the zero on the time axis) really represents something like the end of the 19th century, rather than the end of the 20th century. At the time we published that paper our focus was on trying to extract a broad-brush representation of Late Quaternary surface temperature variability that might be overprinted on the ensemble of world-wide continental heat flux measurements. We did not anticipate that a comparison of late 20th century and Medieval Warm Period temperatures would later become a contentious issue.

A couple of points remain.

- What evidence do you have that there *was* a 2007 paper?

- What evidence do you have that *any* HPS study was 'suppressed'?

- I am puzzled why someone who argues for a low climate sensitivity should be waving HPS borehole studies at me in the first place... more on this later.

***

Finally, I'm still waiting for you to provide the Michaels and Balling link. You still haven't told me which reviewed climate journal this paper(?) appeared in. Or provided a link. If on the other hand this is some stuff in a contrarian book then you should say so clearly.

Jun 8, 2012 at 7:45 PM | Unregistered CommenterBBD
Jun 8, 2012 at 7:46 PM | Unregistered CommenterBBD

For the record, I understand Richard A. Muller is Chair of the Berkeley Earth Surface Temperature project, Akasofu is the Founding Director of the International Arctic Research Center of the University of Alaska Fairbanks, Shaopeng Huang is an expert (*the* expert?) on the use of boreholes to reconstruct ancient temperatures, and Peter Taylor has "green" credentials and multi-government level expertise as long as your arm. So ignoring them reminded me irresistably of Squireen Danaher's approach.

Muller did good work with BEST and demonstrated scientific integrity when he admitted that his previous scepticism about the reliability of surface temperature reconstructions was misplaced. Nor did I 'ignore' him as such - I just pointed out that he was wrong about Nemesis. I assumed you knew that he had admitted error about his previous scepticism about surface temp reconstructions. I reiterate: I will stick with the standard paleoclimate position on Milankovitch. It is the most plausible explanation on the table. Fair play to you though - I can't be bothered to read Muller's contrarian take on this.

Akasofu is wrong about climate change and has retreated to a world of unphysical mechanisms, flaky claims and fringe journals. See for yourself. This is especially relevant to your oscillation argument, so I recommend an objective read.

Huang we have already discussed.

Peter Taylor is a lovely bloke and has been very helpful in private communications I've had with him in the past. I've read Chill, and thought it one of the most persuasive sceptical books out there - but it's *not* a body of peer-reviewed work in mainstream journals. It doesn't contain hard evidence that challenges the standard position.

Jun 8, 2012 at 7:49 PM | Unregistered CommenterBBD

Logico

I'm not going bicker over your use of ad hominem. If you prefer, we can call your personal reflections about me 'unnecessary editorialising'. Just keep it to the science.

This is getting too boggy. Let's focus on the core issue:

Finally, note that the IPCC are CO2-obsessed. "Sensitivity" to the IPCC means the warming effect of doubling CO2, which they perforce assume must trigger major positive feedback. But it is perfectly conceivable that there is little or even negative feedback to CO2 (i.e. to warming itself), and yet that there are processes which do involve major positive H2O feedbacks - e.g. changing DISTRIBUTION of heat/evaporation around the globe (or between land and sea) might greatly affect evapotranspiration, the 80W/sqm elephant in the room.

You believe in a low climate sensitivity because you believe that feedbacks to radiative forcing change net negative and offset that forcing change. (So why do you keep waving Huang at me? Those studies demonstrate climate variability).

We've been through this already. Known climate variability is *not* compatible with an insensitive climate system. Some repetition is now unavoidable, with added emphasis.

Here's Kyle Swanson, co-author of a somewhat misunderstood study (Swanson & Tsionis 2009) discussing the conundrum at RC:

It first needs to be emphasized that natural variability and radiatively forced warming are not competing in some no-holds barred scientific smack down as explanations for the behavior of the global mean temperature over the past century. Both certainly played a role in the evolution of the temperature trajectory over the 20th century, and significant issues remain to be resolved about their relative importance. However, the salient point, one that is oftentimes not clear in arguments about variability in the climate system, is that all else being equal, climate variability and climate sensitivity are flip sides of the same coin. (see also the post Natural Variability and Climate Sensitivity)

A climate that is highly sensitive to radiative forcing (i.e., responds very strongly to increasing greenhouse gas forcing) by definition will be unable to quickly dissipate global mean temperature anomalies arising from either purely natural dynamical processes or stochastic radiative forcing, and hence will have significant internal variability. The opposite also holds. It’s painfully easy to paint oneself logically into a corner by arguing that either (i) vigorous natural variability caused 20th century climate change, but the climate is insensitive to radiative forcing by greenhouse gases; or (ii) the climate is very sensitive to greenhouse gases, but we still are able to attribute details of inter-decadal wiggles in the global mean temperature to a specific forcing cause. Of course, both could be wrong if the climate is not behaving as a linear forced (stochastic + GHG) system.

Do you accept this?

Jun 8, 2012 at 9:08 PM | Unregistered CommenterBBD

Thank you Camp David

Jun 8, 2012 at 10:35 PM | Registered Commentershub

Look Mum! A polynomial! Over there!

Jun 8, 2012 at 11:53 PM | Unregistered CommenterBBD

Logico

The problem with arguing for a low climate sensitivity is illustrated by looking at the relationship between CO2 and temperature over geological time scales. You waved this away upthread, but it is incompatible with low sensitivity. More repetition is unavoidable:

Hansen & Sato (2012) Paleoclimate implications for human-made climate change (in press) demonstrates a clear relationship between changed RF from CO2 and T across the Cenozoic. The study emphasises that no other forcing changed to such an extent across the period (emphasis added):

Have another look at HS12 Fig 1.

Then consider the analysis:

Solar luminosity is increasing on long time scales, as our sun is at an early stage of solar evolution, "burning" hydrogen, forming helium by nuclear fusion, slowly getting brighter. The sun's brightness increased steadily through the Cenozoic, by about 0.4 percent according to solar physics models (Sackmann et al., 1993). Because Earth absorbs about 240 W/m2 of solar energy, the 0.4 percent increase is a forcing of about 1 W/m2. This small linear increase of forcing, by itself, would have caused a modest global warming through the Cenozoic Era.

Continent locations affect Earth's energy balance, as ocean and continent albedos differ. However, most continents were near their present latitudes by the early Cenozoic (Blakey, 2008; Fig. S9 of Hansen et al., 2008). Cloud and atmosphere shielding limit the effect of surface albedo change (Hansen et al., 2005), so this surface climate forcing did not exceed about 1 W/m2.

In contrast, atmospheric CO2 during the Cenozoic changed from about 1000 ppm in the early Cenozoic (Beerling and Royer, 2011) to as small as 170 ppm during recent ice ages (Luthi et al., 2008). The resulting climate forcing, which can be computed accurately for this CO2 range using formulae in Table 1 of Hansen et al. (2000), exceeds 10 W/m2. CO2 was clearly the dominant climate forcing in the Cenozoic.

What is the alternative explanation for the overall shape of the Zachos curve (Fig 1)?

If you differ with HS12, please detail why this analysis is incorrect.

Jun 9, 2012 at 12:15 AM | Unregistered CommenterBBD

BBD:

I have just returned from an internet free weekend in th hills. Very nice it was too.

You have gone into levels of detail concerning Hansen and Sato 2012 which are beyond my competence, not to mention my bedtime, so my comments are no doubt very basic. ("If you differ with HS12, please detail why this analysis is incorrect." Sounds a bit like: "Unless you can definitively rebut his paper, you must accept it." Well, read on.) I haven't looked to see whether Climate Audit or WUWT have discussed this yet - no doubt McIntire, Watts, McKitrick or Eschenbach etc could comment on the mathematics as well as the reconstruction and conclusions.

Peter Taylor wrote: "The general systems models of the earth assume an [ongoing] equilibrium state such that any increase in greenhouse gases will perturb this equilibrium, trapping more heat and raising the [average] global temperature. However, this assumed equilibrium state is never found in the natural state of the planet because there are cycles of varying output of the sun's energy, as well as delayed responses of the world's oceans which retain and recycle the heat and in particular determine a fluctuating cloud cover." (Taylor, "Chill", p 70.) That's very much my position - though you'll have noticed I also have a bee in my bonnet about the rarely considered variation in latent heat transport... Did you comment on that?

Hansen certainly assumes an almost perfect equilibrium without cyclic changes. "[This] Quasi-equilibrium means Earth is in radiation balance with space within a small fraction of 1W/m2." (HS12)

"The altered boundary conditions that maintained the climate change between [the LGM and the Holocene] had to be changes on the Earth's surface and changes of long-lived atmospheric constituents, because the incoming solar energy does not change much in 20,000 years." (HS12)

The purpose of HS12 is effectively to create a "Pleistocene Hockeystick". Variation cannot be denied, so it is essential - from Hansen's entrenched position - to drum up some evidence that

a) it never reached 2C higher than 1950, since that has been deemed an apocalyptic tipping point for warming, and

b) it had to be caused (barring details) by CO2.

I notice that water vapour is explicitly assumed to be a powerful positive feedback in the HS12 paper, which apparently claims this as a physical fact as opposed to a modelled effect. Note that I am still surprised at the lack of interest in the 80W/sqm of energy - or aybe 90+ (you didn't comment on JRA vis-a-vis Trenberth) - that disappears "up the chimney". Then there's the whole cloud thing.

Taylor notes that models have to have ad hoc constraints built in to prevent them from runnng amok. That's the flip side of the tune I have been playing: only a well-buffered system could have preserved itself for so long. The cyclic changes have all he look of a comlex system which oscillates around an equilibrium state it can never achieve. It is subject to a continual barrage of various forcings, but never wanders too far. (Of course, if you are an overspecialised species on he brink of extinction, not very far may be too far. But, like the lurid pictures of injuries presented by a murder prosecutor, that proves nthing about attribution.)

I think the paper claims (in order to keep the interglacial maxima below 2C) that deep sea temperature changes have a simple linear relationship to surface temperature changes and to sea level changes. That causes a minor problem since recent temperature changes (~1C over ~1 century - my crude figures not Hansen's) have not led to major changes in sea level. So HS12 models in an appropriate time lag.

The paper on which Hansen's depends for its temperature reconstruction is Bintanja et al 2005: "Modelled atmospheric temperatures and global sea levels over the past million years." The word "modelled" is a source of trepidation for some of us. The sea level estimates are very indirect, based on rather exact assumptions about the net fraction of the change in deep sea O18 attributable to ice melting. Are there no more direct methods? Yes, and they disagree; see a selection in -

http://pages-142.unibe.ch/products/newsletters/2009-2/Special%20section/science%20highlights/Dutton_2009-2(66-68).pdf

So I would say Hansen has done what all of us are tempted to do, and picked the one source (modelled) that supports his prior belief (modelled). That's called "confirmation bias".

[You seem to think I'm hiding some dirty little secret about Michaels and Balling (2009 wasn't it) which, as I'm sure you know, is the book "Climate of Extremes" on which I relied not at all, except that it included a pointer to some work by Kunkel. Being totally honest, I did not claim to have read Kunkel, so I included the Michaels and Balling reference. Author and date is usual. I never claimed, nor needed to claim, nor implied even remotely, that this was in a peer reviewed journal. I did point out that "you can see Kunkel's points... are uncontroversial, and can be seen in the CCSP SAP (page 3, and in detail pages 129-30)." For me, the Prize is the Truth. For you, something more tortuous is going on; if Kunkel is quoted by a non-peer reviewed source, especially one whose authors you have dismissed as erroneous and dishonest without evidence, then you have scored some kind of debating point. The issue was Kunkel, not M and B. I am certain you will find examples of confirmation bias in "Climate of Extremes" (I did); but I'll see your Michaels and raise you a couple of Hansens any day.]

[As you correctly inferred, my Huang et al 2007 was the same 1997 paper I had already mentioned, and my subsequent remark about Huang's publication record was, herefore, a mistake. My apologies - you seem to have wasted some time and effort because of my error of memory. Any suggestion that Huang was leant on is just an impression. It would be presumptuous of me to note that in 1997 Huang it looks as if found a MWP based on a standard worldwide set of boreholes, but in 2000 it had disappeared - based on a smaller selection of "qualifying boreholes".]

Jun 11, 2012 at 1:59 AM | Unregistered Commenterlogicophilosophicus

Oh yes, you asked me to look at your link re Akasofu. Skeptical about Skepticism or some such - seen it before. Sounds a lot like - well, you. However, in a spirit of egalitarianism, I suppose I should ask you if it is a peer reviwed source from a reputable climate science journal? But then, there is a repeated theme in climate science. Anyone writing a paper which is not strictly Consensus has trouble getting published. In the end they go to a Hydrology journal, or Geology, or whatever to get into print. Then the Consensus Police start demonising th journals, editors, etc... The argument shoud be about the science, but it's really about Loyalty Oaths. [In Catch-22 decides to undermine another: "From now on I’m going to make every son of a bitch who comes to my intelligence tent sign a loyalty oath. And I’m not going to let that bastard Major Major sign one even if he wants to.” The Consensus on Global Warming has a lot in common with the Great Loyalty Oath Crusade.]

If Akasofu's predictions are unscientific because he does not commit to a physical mechanism, then how come Copernicus ever managed to locate a planet? What were Mendel and Mendeleev playing at? Avogadro? Conversely, how is an ensemble of models that badly hindcast the years they were fudged to fit and fail to describe the current trend supposed to be so wonderfully scientific? "We've got a mechanism!"

Jun 11, 2012 at 2:39 AM | Unregistered Commenterlogicophilosophicus

...Re Swanson, note the "all things being equal" caveat. They rarely are.

I like the paper Swanson and Tsionis 2009, since it acknowledges "internal shifts... poorly understood", but the simplistic analogy of coupled climate systems to a team of cyclists roped together didn't convince me that the coupling must stay strictly synchronised or else collapse. Also I noted that long term trends are "presumably" due to "anthropogenic forcing" - you can't infer what you already presume.

The main argument about sensitivity and variability isn't even in Swanson, which cites Roe 2009 (paywalled).

Most sceptics have heard of Swanson's paper, which admits internal variation only in order to alibi the 21st century stasis (or slight cooling) in temperature. It's a 30-year alibi - don't expect temps to match IPCC projections anytime soon, but they are in the pipeline... You know I don't go with that.

Anyway, all things being equal... no.

Jun 11, 2012 at 8:41 AM | Unregistered Commenterlogicophilosophicus

Oh, I give up. Can't say I didn't try though.

Jun 11, 2012 at 8:47 PM | Unregistered CommenterBBD