This is a continuation of a remarkable thread that has now received 10,000 comments running to well over a million words. Unfortunately its size has become a problem and this is the reason for the move.
The history of the New Statesman thread goes back to December 2007 when Dr David Whitehouse wrote a very influential article for that publication posing the question Has Global Warming Stopped? Later, Mark Lynas, the magazine’s environment correspondent, wrote a furious reply, Has Global Warming Really Stopped?
By the time the New Statesman closed the blogs associated with these articles they had received just over 3000 comments, many from people who had become regular contributors to a wide-ranging discussion of the evidence for anthropogenic climate change, its implications for public policy and the economy. At that stage I provided a new home for the discussion at Harmless Sky.
Comments are now closed on the old thread. If you want to refer to comments there then it is easy to do so by left-clicking on the comment number, selecting ‘Copy Link Location’ and then setting up a link in the normal way.
Here’s to the next 10,000 comments.
Useful links:
Dr David Whitehouse’s article can be found here with 1289 comments.
Mark Lynas’ attempted refutation can be found here with 1715 comments.
The original Continuation of the New Statesman Whitehouse/Lynas blogs thread is here with 10,000 comments.
Peter #1272
I think we may be talking at cross purposes. I read yur link to skeptical science a few days ago then you posted #1237 to the met office tabular figures. This was unreferenced and had no headings. What is it?
tonyb
PeterM
First you say that I am not citing references to provide support for my statements regarding the MWP.
Then I provide you 25 references to independent scientific studies using different methods from all over the world, all confirming a MWP, which was warmer than today.
Pretty hard evidence to refute.
So instead, now you say I am going “ape shit”, or bicker about the fact that some of them were compiled by the CO2 Science site (even though they were originally published elsewhere, as indicated).
Peter, can’t you see how utterly foolish you sound?
You are providing the very best argument against the validity of the “dangerous AGW” postulation with your silly behavior, as any neutral lurker can clearly see.
Face it. Overwhelming historical as well as paleoclimate evidence points to a MWP that was marginally warmer than the current warm period, and a “hockey stick” based on a few isolated cherry-picked tree rings and analyzed using a flawed statistical approach, which has been comprehensively discredited (McIntyre + McKitrick study, Wegman, North and Bloomfield testimonies before US Congress), plus a few “spaghetti copy hockey sticks” cannot change that.
Give up on this one and move on. Otherwise you just keep making yourself look foolish over and over again.
Max
PeterM
The scientist’s name is Craig Loehle (not Loehl).
See if you can at least get that part right, even if you cannot understand what his study on the MWP has shown.
Max
Brute
JoNova’s deconstruction of Lewandowsky’s silly ABC “Siamese twins” blurb calling for the need for “immediate action” on climate change hits the spot.
Lewandowsky comes with such absurd arguments as:
WHAT? (This is no joke – he really wrote that!).
Reverting to the “argument from authority” fallacy, Lewandowsky makes a big deal of the so-called “scientific consensus” (a favorite fallacy of PeterM, as well):
Interesting is JoNova’s analysis of the “cost of consensus”:
Her sentence below summarizes the Lewandowsky article best:
Smart lady.
Max
geoffchambers
The latest study you cited by McIntyre, McKitrick and Herman (MMH2010) sounds interesting.
Whether or not IPCC will acknowledge its existence (or validity) or whether someone (like Santer) will quickly cobble together a study refuting the conclusions (which then get the full attention of IPCC, instead) is all still open.
IPCC has stuck its head in the sand before regarding published papers that invalidated some of its claims.
Unless there is a basic change of management and emphasis in IPCC, I am afraid it is likely that it will continue doing the same regarding this study.
But we shall see.
Max
PeterM
There you go again!
In 1272 you refer TonyB to temperature curves posted in a “Kung-fu Climate” guest post by Rob Honeycutt on the “Skeptical Science” blog, rather than to original data from a serious scientific publication.
My advice to you (which I have given you several times in the past):
To really find out what is going on, go back to the original data, not to someone’s re-hash on one of the pro-AGW sites, like Skeptical Science, Real Climate, etc.
Now I will walk you through the logic and arithmetic used by Craig Loehle in his cited exhaustive study of past temperatures, where he concluded:
Here is Loehle’s original data on reconstructed annual temperatures of the past:
http://www.ncasi.org/programs/areas/climate/LoehleE&E2007.csv
Download these data for the period AD500 to the end of the series in 1980.
Then download the HadCRUT annual temperature record from 1850 to 2009.
Then compare the “warmest tridecade” of Loehle (AD 870-899) with the “most recent tridecade” from HadCRUT (1980-2009).
You will se that Loehle’s “warmest tridecade” of the MWP is roughly 0.3C warmer than the “most recent tridecade”.
But WAIT!
It appears that there is a difference in the “baseline” used in arriving at the two sets of data.
Let’s compare the 131 years from 1850 through 1980 (the time period when both records overlap).
We see that the Loehle numbers averaged over this entire period are around 0.2C higher than the HadCRUT numbers.
So, adjusting for the different “baseline” values, we see that Loehle’s “warmest tridecade” of the MWP is only roughly 0.1C warmer than the “most recent tridecade” (as was also concluded by Loehle in his study).
Voila! We have a comparison based on the original data, without having to rely on someone else’s re-hash.
And this comparison shows that the “warmest tridecade of the MWP” was, indeed, marginally warmer than “the most recent tridecade” (as Loehle had concluded).
Max
Peter
RE Your skeptical science graphs. So you are getting excited about the work of an avowed non scientist (which normally makes them less-not more- credible in your eyes) taking ONE study (which no one can look at unless they pay for it) then in his word ‘scrunching’ up the scales in order to insert a meaningless global temperarure back to 1860.
Meaningless? Yes, because they have no consistency whatsoever.
If you insist on using global records you may find this useful in putting it in context
http://noconsensus.wordpress.com/2009/11/13/little-ice-age-thermometers-history-and-reliability/
Global stations are a highly moveable feast both in terms of numbers, locations and validity. They have this habit of growing a city around them or moving to an airport which effect is not allowed for adequately.
Do you call a proper ‘global’ temp one that even by 1880 only showed Africa with 14 thermometers; Asia 26, North America 233, Australia 30 and Europe 118?
There was a big upsurge in stations in N America from around this time and numbers rose to 1446 in 1914 to around 10000 at its peak in around 1980 and 2300 now. That’s one for a country the size of France. These are periapetic records Peter-I have followed many of them and they are not measuring the same micro climate they started off with. Even anomalies must be based on comparing like for like.
I think that individual station records have some merit if we are able to trace their history. For example Central England Temperature is representative of a roughly triangular area of the United Kingdom, enclosed by Bristol, Lancashire and London. The monthly series begins in 1659, and is the longest available instrumental record of temperature in the world and the most scrutinised.
This entails some 400,000 data points to come up with a temperature reliable to around half a degree, covering a small portion of the earths surface.
The individual studies have merit and the 25 cited by Max even more so when combined with the numerous records we have of tree heights, altitude of crop planting, crop productivity, habitation evidence etc etc (beautifully written about by Lamb-you really must READ his numerous books instead of skimming them hoping to make some sort of point.)
This enables us to say no more than that before individual instrumental records temperatures were ‘a little warmer’ or ‘rather warmer’ than today, but not to attempt to scientifically parse Global temperatures or reconstructions to a tiny fraction of a degree.
What is your opinion on the accuracy of SST’s?
By the way, thought you and Max might find this interesting.
http://www.newscientist.com/article/mg20727730.101-frozen-jet-stream-leads-to-flood-fire-and-famine.html?DCMP=OTC-rss&nsref=online-news
Tonyb
TonyB
Funny.
Your “frozen jet stream” reasoning for the Moscow fires and Pakistan floods was brought on Swiss TV last night by the local weatherman!
He even showed a map of Asia with a superimposed picture of the (omega-shaped) “frozen jet stream”, showing how high and low pressure fronts were being “blocked” causing these weather anomalies.
(First time I saw such a thing on the Swiss weather report, which usually confines its remarks to Switzerland and surrounds – maybe venturing as far away as the Azores occasionally.)
Max
PS BTW, it’s been raining here the past several days, so we are also suffering from the “frozen jet stream”.
PeterM and TonyB
BTW, I fully agree with TonyB that the temperature records used to compare period A with period B are hardly accurate enough to get any real valid comparison.
First of all, we have the inherent problems associated with any temperature reconstructions using paleoclimate data; these do not necessarily introduce a “warming” or “cooling” bias, but simply introduce fairly large margins of error.
The Mann study is an exception, in that the selection of specific data (while excluding others) as well as the statistical approach used both favored a minimization of past warm and cold periods while exaggerating the recent warming, as was pointed out in the scientific (statistical) study by M+M, and confirmed before the US Congress in testimony by the Wegman committee and later by North and Bloomfield, both of NAS.
Historical accounts, sea charts and voyage records, crop records, and physical data from today are more meaningful. The physical data would include abandoned farmhouses frozen in the Greenland permafrost, signs of past vegetation and even past signs of civilization revealed under receding mountain glaciers, etc.
As the late pioneer of climate science, Reid Bryson once said, referring to the remains of a medieval silver mine, which had been uncovered by a receding Alpine glacier: this actual physical evidence tells us far more than all the climate reconstructions.
Unfortunately, the “paleo-climatologists” write this all off as “anecdotal” while they consider their data as “scientific truth”, and the IPCC falls for this (since it suits the purpose?).
Then we have the many obvious problems with the modern temperature record, as TonyB has pointed out repeatedly; most of these (UHI, station shutdowns and relocations, land use changes, poor station siting, etc.) tend to introduce a “warming bias” in the most recent numbers.
All of this makes a comparison of today’s temperature record with that obtained by temperature reconstructions of the distant past fairly meaningless.
But we’ve said all that before.
Max
TonyB,
You talk about Rob Honeycutt as an “avowed non-scientist” but he’s shown a lot more iniative than many of you guys and actually drawn a few graphs! Furthermore he’s explained where he’s got his data from and exactly what he’s done. To that end he is acting in a totally scientific manner. Even you could do that too, if you tried!
There is just one thing I didn’t totally understand – but to clarify that would need Craig Loehl to chip in with some comment or explanation which he has so far not offered. Rob Honeycutt has declined to publish any of the email exchanges between them (on the ground that emails should be considered private correspondence!) but has claimed that Craig Loehl has accepted the fairness of his approach.
Maybe Dr Loehl can’t bring himself to make the same comment publicly, but I guess he sure would say just the opposite if he had identified any unfairness.
TonyN
Just done a reply to Peter which had seven links and has disappeared. Is it in the spam filter perhaps?
Tonyb
PeterM
Fe crissake get Loehle‘s name right, if you are going to quote it.
I’ve drawn exactly the “same curve” as Rob Honeycutt, and it confirms what I stated in 1281, namely Loehle’s conclusion:
The difference is only around 0.1C, which is (as TonyB has pointed out a minimal difference between two sets of numbers that have large margins of error).
But that is what the data show.
The UHI distortion would tend to make the actual difference slightly greater, but that is another discussion.
Suffice it to say that Loehle’s study confirms that the global MWP was a bit warmer than the most recent period – but, what the hell, that has been general knowledge for years (and has been confirmed by many other cited studies from all over the world using different methods, so is nothing new).
Let’s move on to something else, Peter. This obsession with the MWP is getting repetitive and boring.
Max
Heat Wave In Russia – Is It From Global Warming?
http://pielkeclimatesci.wordpress.com/2010/08/13/heat-wave-in-russia-is-it-from-global-warming/
Peter said in his #1285
“You talk about Rob Honeycutt as an “avowed non-scientist” but he’s shown a lot more iniative than many of you guys and actually drawn a few graphs! Furthermore he’s explained where he’s got his data from and exactly what he’s done. To that end he is acting in a totally scientific manner. Even you could do that too, if you tried!”
Here is my site where dozens of historic records have been carefully put together and which is accessed regularly by institutions and Universities from all over the world.
Clicking on the relevant city will often bring you to aditional information behind the first graph. There is an increasing collection of weather diaries and other observations predating actual instrumental records.
http://climatereason.com/LittleIceAgeThermometers/
If you go to the section on UHI a little way down the page, you can see for yourself the graph which shows the hugely variable number of global weather stations over the last 150 years. This is in the hope you might come to recognise the nonsensical nature of your belief in a global temperature that can be parsed to a fraction of a degree.
Going to the various other sections in the web site will enable you to enjoy the various carefully researched articles I have written which are always fully referenced.(rather more than Mr Honeycutt has written)
Yet to be added to this section are these two
http://noconsensus.wordpress.com/2010/02/06/travels-in-europe-part-1/
http://noconsensus.wordpress.com/2010/01/06/bah-humbug/
There are other articles on climate by such as Dr Hansen
There are around five articles of mine ‘on the stocks’ ranging from ‘CET through the little Ice age’ to ‘Historic arctic ice variation parts 2 and 3’
To achieve the precise degree of accuracy that you have always believed our scientists are capable of must mean (in this instance) that we are aware of the max and min temp for every day, for every point on the planet for the last 2000 years. (CET has 400,000 data points for EACH of its three stations covering just 350 years)
Surely you can’t possibly believe that our knowledge extends to such a fine degree of parsing as you were attempting to outline in your allusions to the Honeycutt article?
The history of measuring tgemperatures is given in my article here.
http://noconsensus.wordpress.com/2009/11/13/little-ice-age-thermometers-history-and-reliability/
It manages to link together the Vikings and Romans at Constatinople which fell on 29th May 1453 to the Ottomans. Fortunately we still retain the climate references of the Byzantine empire spanning 1100 years as they survived the looting.
The main point I wish to make, having researched climate history and temperatures thoroughly, is that we can only know the generality of temperatures at any one consistent fixed point, not the absolute specfics over the whole globe.
tonyb
TonyN
#1290 is an abbreviated version of my post, please don’t worry about looking in the spam filter for the original.
tonyb
Max and Peter
Highly relevant to our debate on the Rob Honeycutt analysis is this detailed study by proper statisticians, just out.
http://climateaudit.org/2010/08/14/mcshane-and-wyner-2010/#comments
Amongst the many put downs in this exhaustive report is;
“Climate scientists have greatly underestimated the uncertainty of proxybased
reconstructions and hence have been overconfident in their models.”
Exactly. We should rely on proper physical evidence as enumerated in my previous email-something Lamb was painstaking in assembling.
Tonyb
Max and TonyB
I notice that you both seem to have had a bit of trouble with TonyN’s spam filter recently. I can’t say I’ve had any problem recently. Its been pretty well behaved for me for quite a while now.
Maybe’s its learned how to distinguish crap from reasoned argument? :-)
BREAKING: New paper makes a hockey sticky wicket of Mann et al 99
Posted on August 14, 2010 by Anthony Watts
Sticky Wicket – phrase, meaning: “A difficult situation”.
Oh, my. There is a new and important study on temperature proxy reconstructions (McShane and Wyner 2010) submitted into the Annals of Applied Statistics and is listed to be published in the next issue. According to Steve McIntyre, this is one of the “top statistical journals”. This paper is a direct and serious rebuttal to the proxy reconstructions of Mann. It seems watertight on the surface, because instead of trying to attack the proxy data quality issues, they assumed the proxy data was accurate for their purpose, then created a bayesian backcast method. Then, using the proxy data, they demonstrate it fails to reproduce the sharp 20th century uptick.
Now, there’s a new look to the familiar “hockey stick”.
Before:
Not only are the results stunning, but the paper is highly readable, written in a sensible style that most laymen can absorb, even if they don’t understand some of the finer points of bayesian and loess filters, or principal components. Not only that, this paper is a confirmation of McIntyre and McKitrick’s work, with a strong nod to Wegman. I highly recommend reading this and distributing this story widely.
Here’s the submitted paper:
A Statistical Analysis of Multiple Temperature Proxies: Are Reconstructions of Surface Temperatures Over the Last 1000 Years Reliable?
http://wattsupwiththat.com/2010/08/14/breaking-new-paper-makes-a-hockey-sticky-wicket-of-mann-et-al-99/#more-23450
It seems that this paper by McShane and Wyner is the latest #1 in the climate denial blogosphere.
But I’m not too sure that everyone will be happy with it though. It still looks a bit too much like a hockey stick to satisfy the real hardline deniers.
And what does it say about the peak of the so-called warm period compared with the present day?
I can’t see any real peak but in the year 1000 the temperature on this scale was 0.4 deg C. Would you agree?
It looks to me that the 1940 peak, which you can see in the black line, is pretty close to zero on this scale. Since then temperatures have warmed by about 0.5 deg according to GISS and 0.4 deg according to Hadcrut.
Close to call? Well we’ll see how it all plays out in the next few months.
Incidentally, as Mann’s hockey stick was supposed to be broken, discredited, debunked, dead, proven a fraud, a scam etc and consigned to the pages of history and not supposed to be mentioned much in polite circles, you all seem remarkable keen to keep on attacking it.
Maybe you feel that it isn’t quite so dead after all!
Brute #1294
It broke here first-see 1292. :)
I referenced it to Peter so he can see that the reconstructions he likes parsing to fractions are highly suspect and he should rely on the anecdotal evidence that gets so readily dismissed.
Extract;
“Climate scientists have greatly underestimated the uncertainty of proxybased
reconstructions and hence have been overconfident in their models.”
tonyb
Brute
The McShane & Wyner study you cited looks interesting. As I understand it, it shows that the Mann et al. “hockey stick” can be deconstructed, even using Mann’s “cherry-picked” raw data, by applying a proper statistical analysis to the data, rather than Mann’s statistically flawed approach.
A pretty powerful invalidation of Mann’s study.
Hubert Lamb had concluded, based on the July-August average CET temperature record, that the 150-year average over the time period 1150-1300 was around 0.5C warmer than current temperature (at the time of his study). As can be seen from the record, this difference also applies for the 150-year July-August average CET over the most recent 150-year period (1860-2009).
Loehle had concluded that the period around AD 900 was warmer than the later period 1150-1300 used by Lamb, and showed that a shorter 30-year period (870-899) was marginally warmer than the most recent tri-decade (1980-2009).
It appears that M+W now show us that Lamb’s conclusion for CET summer would also apply for global annual averages, using the raw data of Mann et al. The average temperature over the 150-year period 1000-1150 on the M+T chart (around +0.25C) appears to be a bit warmer than that recorded for the most recent 150-year period (-0.15C).
[All with the caveats TonyB has repeated here on the accuracy of the current and past temperature record as well as the reconstructed temperatures from paleo-climate studies.]
Max
TonyB and PeterM
Now that McShane and Wyner have deconstructed the Mann hockey stick using Mann’s raw data, it raises the following questions:
-will IPCC replace its many “spaghetti copy hockey sticks” with this new study, at the same time conceding that its statement below (SPM 2007, p.9) was in error:
-will one of the “hockey team” now rush to publish a new “copy hockey stick” study based on other cherry-picked data in order to refute M+W in time for inclusion in the next IPCC report?
What do you both think?
Max
PeterM
You asked of the McShane & Wyner study:
The graph starts with AD 1000, showing a gradual cooling. I would agree with you that AD 1000 looks like around 0.4C.
Loehle also shows this gradual cooling and concludes that the period around 850-900 was marginally warmer (0.1C) than the period around 1000.
If we look at average temperature over longer-term climatic periods, we see that the 150-year period 1000-1150 is around +0.25C, or around 0.4C warmer than the most recent 150-year average at around –0.15C.
The 150 year period around year 900 would show an even greater difference.
But IPCC refers to “the last half century”, i.e. a “50-year period”, rather than a “tridecade” (as used by Loehle) or a 150-year period (as used by Lamb).
HadCRUT shows us that “the last half century” (1960-2009) had an average global temperature of +0.1C.
The M+W chart shows us that “the first half century” (1000-1049) averaged around +0.3C.
So the earlier “half century” was 0.2C warmer than “the last half century”, and the IPCC claim (SPM 2007, p.9) that “warmth of the last half century is unusual in at least the previous 1,300 years” has been falsified by the M+W study.
It looks even worse for IPCC if we compare “the last half century” with “the half century” from AD 850 to 899 (0.3C warmer than present).
That is why this study is so significant, Peter, not only as a invalidation of Mann’s “hockey stick” using his own data, but also as a falsification of the IPCC claim of unusual late 20th century warmth.
[Repeat caveats per TonyB.]
Max
PeterM
The secret to avoiding spam filter problems is not to overload it with too many links.
It can handle single links easily, although this is a bit more trouble.
Another way to “fool” it is to put [brackets] around the links, so it will not recognize them as links.
But it cannot distinguish between serious scientific studies and “crap” (as you put it), though.
Otherwise all links to the various Hansen studies plus IPCC reports out there would have been thrown out, right?
Max