First here is Dr. Keith Briffa’s response in entirety direct from his CRU web page:
My attention has been drawn to a comment by Steve McIntyre on the Climate Audit website relating to the pattern of radial tree growth displayed in the ring-width chronology “Yamal” that I first published in Briffa (2000). The substantive implication of McIntyre’s comment (made explicitly in subsequent postings by others) is that the recent data that make up this chronology (i.e. the ring-width measurements from living trees) were purposely selected by me from among a larger available data set, specifically because they exhibited recent growth increases.
This is not the case. The Yamal tree-ring chronology (see also Briffa and Osborn 2002, Briffa et al. 2008) was based on the application of a tree-ring processing method applied to the same set of composite sub-fossil and living-tree ring-width measurements provided to me by Rashit Hantemirov and Stepan Shiyatov which forms the basis of a chronology they published (Hantemirov and Shiyatov 2002). In their work they traditionally applied a data processing method (corridor standardisation) that does not preserve evidence of long timescale growth changes. My application of the Regional Curve Standardisation method to these same data was intended to better represent the multi-decadal to centennial growth variations necessary to infer the longer-term variability in average summer temperatures in the Yamal region: to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.
These authors state that their data (derived mainly from measurements of relic wood dating back over more than 2,000 years) included 17 ring-width series derived from living trees that were between 200-400 years old. These recent data included measurements from at least 3 different locations in the Yamal region. In his piece, McIntyre replaces a number (12) of these original measurement series with more data (34 series) from a single location (not one of the above) within the Yamal region, at which the trees apparently do not show the same overall growth increase registered in our data.
The basis for McIntyre’s selection of which of our (i.e. Hantemirov and Shiyatov’s) data to exclude and which to use in replacement is not clear but his version of the chronology shows lower relative growth in recent decades than is displayed in my original chronology. He offers no justification for excluding the original data; and in one version of the chronology where he retains them, he appears to give them inappropriate low weights. I note that McIntyre qualifies the presentation of his version(s) of the chronology by reference to a number of valid points that require further investigation. Subsequent postings appear to pay no heed to these caveats. Whether the McIntyre version is any more robust a representation of regional tree growth in Yamal than my original, remains to be established.
My colleagues and I are working to develop methods that are capable of expressing robust evidence of climate changes using tree-ring data. We do not select tree-core samples based on comparison with climate data. Chronologies are constructed independently and are subsequently compared with climate data to measure the association and quantify the reliability of using the tree-ring data as a proxy for temperature variations.
We have not yet had a chance to explore the details of McIntyre’s analysis or its implication for temperature reconstruction at Yamal but we have done considerably more analyses exploring chronology production and temperature calibration that have relevance to this issue but they are not yet published. I do not believe that McIntyre’s preliminary post provides sufficient evidence to doubt the reality of unusually high summer temperatures in the last decades of the 20th century.
We will expand on this initial comment on the McIntyre posting when we have had a chance to review the details of his work.
K.R. Briffa
30 Sept 2009
- Briffa, K. R. 2000. Annual climate variability in the Holocene: interpreting the message of ancient trees. Quaternary Science Reviews 19:87-105.
- Briffa, K. R., and T. J. Osborn. 2002. Paleoclimate – Blowing hot and cold. Science 295:2227-2228.
- Briffa, K. R., V. V. Shishov, T. M. Melvin, E. A. Vaganov, H. Grudd, R. M. Hantemirov, M. Eronen, and M. M. Naurzbaev. 2008. Trends in recent temperature and radial tree growth spanning 2000 years across northwest Eurasia. Philosophical Transactions of the Royal Society B-Biological Sciences 363:2271-2284.
- Hantemirov, R. M., and S. G. Shiyatov. 2002. A continuous multimillennial ring-width chronology in Yamal, northwestern Siberia. Holocene 12:717-726.
Now a few points of my own:
1. Plotting the entire Hantemirov and Shiyatov data set, as I’ve done here, shows it to be almost flat not only in the late 20th century, but through much of its period.
How do you explain why your small set of 10 trees shows a late 20th century spike while the majority of Hantemirov and Shiyatov data does not? You write in your rebuttal:
“He offers no justification for excluding the original data; and in one version of the chronology where he retains them, he appears to give them inappropriate low weights.”
Justify your own method of selecting 10 trees out of a much larger data set. You’ve failed to do that. That’s the million dollar question.
Briffa Writes: “My application of the Regional Curve Standardisation method to these same data was intended to better represent the multi-decadal to centennial growth variations necessary to infer the longer-term variability in average summer temperatures in the Yamal region: to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.”
OK Fair enough, but why not do it for the entire data set, why only a small subset?
2. It appears that your results are heavily influenced by a single tree, as Steve McIntyre has just demonstrated here.
As McIntyre points out: “YAD061 reaches 8 sigma and is the most influential tree in the world.”
Seems like an outlier to me when you have one tree that can skew the entire climate record. Explain yourself on why you failed to catch this.
3. Why the hell did you wait 10 years to release the data? You did yourself no favors by deferring reasonable requests to archive data to enable replication. It was only when you became backed into a corner by The Royal Society that you made the data available. Your delays and roadblocks (such as providing an antique data format of the punched card era), plus refusing to provide metadata says more about your integrity than the data itself. Your actions make it appear that you did not want to release the data at all. Your actions are not consistent with the actions of the vast majority of scientists worldwide when asked for data for replication purposes. Making data available on paper publication for replication is the basis of proper science, which is why The Royal Society called you to task.
Read about it here
Yet while it takes years to produce your data despite repeated requests, you can mount a response to Steve McIntyre’s findings on that data in a couple of days, through illness even.
Do I believe Dr. Keith Briffa? No.
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@ur momisugly richcar (08:52:49) :
Yes, I have seen that and Mike from the RC Group had this to say:
Its a nice paper. The conclusion that certain regions were similarly warm (i.e. comparable to late 20th century) during medieval times is uncontroversial (for example, this is true w/ the Obsorn and Briffa, 2006 study mentioned in the main article). Other evidence indicates that the eastern and central tropical Pacific, by contrast, was quite cold at that time. Such an enhanced east-west temperature gradient across the tropical Pacific during medieval times is suggestive of a La Nina type pattern, something that too has been discussed in the recent past (http://www.ncdc.noaa.gov/paleo/pubs/trouet2009/trouet2009.html). Stay tuned for more on that theme in the near future. – mike
I would never claim that EVERY reconstruction will show a cooler MWP. And it doesn’t matter anyway because what is happening today is being measured.
@Scott A. Mandia (18:12:27) :
—>”I have to admit I love your passion but not your statements. If you were a scientist you would understand how we think and that it goes against our nature to have “group think.” There may be exceptions but it certainly is not the rule.”
This is instrospective fail. If you are really making this claim, then frankly I fear for your future as a scientist. You are elevating scientists above human nature, which is dangerously naive and egotistical considering you claim to be one.
—> “The Nobel Prize goes to the first person that can show why we are all wrong about AGW. That is quite an incentive. Ah, but to have one’s name said along with Galileo, Darwin, and Einstein…..”
You are displaying more naivete. Any scientist worth their salt will tell you that the nobel prize is as much political as it is about results. There are literally hundreds of papers in each subject that are worthy every year, and only one gets it. Again, the Nobel Prize in any subject, much like winning an oscar, is awarded by means of politics as much as hard work. This is fact.
—> “I never said we should stop questioning data. I think when the data keeps looking the same perhaps we should start thinking that maybe it is accurate. The NASA example you give is comparing apples to oranges (or should I say Tang?)”
Yes you did. You implied that because a particular shape continues to show up from a small group of researchers, it should be accepted as a real signal. If you accept something as a real signal, then you are witholding your questioning of the data. And no, that is not an apples-oranges comparison.
—> “A person at RC posted an interesting observation. CA, and subsequently WUWT, got into a tizzy because it appeared that only a subset of tree data was being used to reconstruct past climate. Posters at these two sites asked why not use ALL of the tree data instead of a subset? Shouldn’t all of the data be better than a small subset?
Now let us think about surfacestations.org. The claim there (and often here) is that the full NOAA station record is contaminated by UHI and we should only use a SUBSET of validated rural stations. I think it was 70 out of 1221?”
This is a failure in comprehension. A small subset of cores with a particular shape when graphed was used bare (with other data removed for the time-period-in-question) in a dataset that was used over-and-over again in multiple studies that were claimed to be independent. When the data ane methods used to make these shapes were called for, 10 years of obfuscation and stonewalling resulted. Surfacestations.org has revealed inconsistencies with data collection (using the very standards of those who take the data) across a broad spectrum of sites by actually visiting the sites and documenting what the stewards of this network failed to document. They then called for the questioning of sites that are out of compliance with the very same open standards the data collectors are supposed to be going by. If you can’t spot the difference in the two methods, I’m sure someone else around here can explain it better for you.
Jim ….
“Without Steve’s question, there would be no need of an answer. Steve laid out what he did already. It was pretty simple. What other information is there to be had?”
****************
I think there is a real discussion about this issue to be had. As Steve noted, why did Briffa exclude those trees? Only Briffa within a real scientific discussion can state that answer. For all you and I know, there is a valid reason, er .. or maybe not! But, I don’t think we need to all dog pile Briffa before a discussion has taken place. THE IMPORTANT PART .. and what has frustrated me wihtin the debate on Climate, is that there is no real scientific discussion! I will be suprised if the “team” comes to the table without their political bias to discuss this issue. If they hold to form, they will just dismiss the issue. I haven’t been over to RealClimate [and rarely do I go their anymore because of their practice of sweeping objection under the rug], but I’m sure there is a comment burried somewhere that dismisses Steve as a nobody, and as such, shouldn’t even have a right to speak.
As for Crap and Trade … you’ll get no objection from me on that one. But then, we are talking poltics there. Politicians are liscensed to lie …. I’m sure you already know that.
Scott A. Mandia
I’m responding to you here because it’s almost impossible to get logical polite but opposing points of view through at realclimate due to their ideological filtering of posts.
Your doctor analogy is better expressed like this.
All the PhD’s in Phlogistic theory, supported by the United Nations Panel on Phlogistry tell you that Phlogistonics theory is sound, and the evidence supports it. One PhD in Phlogiston Theory tells you you are not being told the truth. Who are you going to believe ?
Well, you’d probably examine the evidence yourself. Let’s say you find an error in one of the pieces of evidence. Lets say for the sake of argument that in this particular piece of evidence (which the Phlogiston Theory PhD’s had been denying you access to for 9 years while they used it as a case reference) you find that they only have a sample size of 10, combined with one of the 10 samples having an extremely disproportional “signal” which dominates the overal signal of the group. You look around and find other samples taken from the same experiment, a couple of hundred of them, which were inexplicably not included in the results, but when included show there was no detectable signal.
Would you have doubts. You’d perhaps bring this topic up. Suddenly you are accused of absolutely disgraceful behaviour, and told that it doesn’t matter because there’s all the other pieces of evidence which prove it. Looking at them more closely you notice severl of them use an algorithm that gives a positive result with random data instead of the study data; and another one where they have cut out the results which they found but which contradicted their summary, and yet another where the input data was so noisey that the error bars (had they been shown) would render the result meaningless.
After all that would you trust the consensus ? You’d perhaps try to log on to RealPhlogiston.org and discuss these issues, but your posts are constantly filtered despite being polite and dealing strictly with the topic. Other of your posts are so butchered prior to the response (which appears inline immediately with your post after being in moderation for some hours), that your points are effectively misrepresented.
So it is with climate science and RealClimate.
Do you really think McIntyre has done a DISSERVICE to climate science by pointing out that this proxy signal is basically determined by only 10 tree cores, one of which has a huge and clearly spurious signal, which do not even match local temperature trends and yet has been included in loads of proxy studies where the algorithm of the study latches onto this proxy in particular and effectively amplifies it over the remaining proxies ?
Scott A. Mandia (14:14:21) :
Tanks kindly for the reply.
No I haven’t reviewed the link but read both the papers in original form. I don’t think its a conspiracy at all. The second paper specifically merges instrumental data with borehole proxies, yet the original paper uses boreholes alone to infer a quite different result. This original was sometimes invoked in the contentious issue of whether the Medieval Warm Period was warmer than the 20th C. Now most research from different places suggest it was. They are aggregated at C02 science.
The authors specifically mention in the later paper that they didn’t have they were not aware that their paper would have caused such contention. This, of course, was before Mann et al. Post Mann came the contention, and so Huang and Pollack merged their borehole proxies with the temperature record of the 20th century. Now these are different data sources. The former showed a warmr MWP whereas the latter showed a warmer present. Whether the authors feared losing status or feared being blackwalled by their peers and so saw merging as a compromise, I do not know. However, I don’t see it as a conspiracy. Aas far as we know, if thermometers existed in the MWP it may well have been recorded as being warmer than today. Fossil evidence, Greenland cores, nay as far as Japan across to America when all aggregatedsuggest it was a fair bit warmer than the last 40 years…
Anyhow, the climate debate has been unfairly treated as being a battle between sceptics and advocates, so I hope you’ll understand that impartiality is a more rational perspective than an adversorial one – which is why its challenging – in the nicest possible way – to respond to your queries and propositions. As for Professor Briffa – his status as a fellow member of the race supercedes that of his academic credentials, so peace and good health to him.
NB. I’m giving greater weight to the 20,000 year figure 1 in both papers. If the MWp, just to give the benefit of the doubt, was marginally cooler globally than the last 40 years, then why was the Holocene optimum warmer?
Tom Jones (20:15:48) :
1. Global temperatures have been rising in parallel with industrial development.
2. The rise in temperatures correlates well with CO2 in the atmosphere.
Global temperatures have been rising in parallel with the price of a stamp.
The rise in temperature correlates well with the price of stamps.
FedEx and UPS are doing good. It’s the Post Office where the trouble is coming from. 😉
bill (02:48:47) :
Gene Nemetz (23:05:54) :
The Hockey Stick crowd
I didn’t specify Briffa.
Welcome to the Mandia School of Logical Fallacy and Hyperbole:
“What bothers me the most about this story and appears to be a running theme here at WUWT is that somehow there is this massive conspiracy among scientists to delude the public for no other reason than we do not wish to look wrong.”
~ Hasty Generalization http://en.wikipedia.org/wiki/Hasty_generalization
“To suggest that it isn’t [that the hockey stick isn’t real] implies that scientists are colluding or that every proxy analysis technique always results in the same shape.”
~ Straw Man http://en.wikipedia.org/wiki/Straw_man
“Suppose you are feeling very sick. You visit ten doctors and here are the replies…etc.”
~ False Analogy http://en.wikipedia.org/wiki/False_analogy
“Now I ask for fair play. To Anthony W, Steve M, and everybody else who has been directly or implicitly calling Dr. Briffa a cheat or a fraud while he was too sick to respond to these false allegations, you owe him a public apology. Step up to the plate, folks.”
~ Red Herring http://en.wikipedia.org/wiki/Red_herring_(logical_fallacy)#Red_herring
Furthermore…if a logical fallacy is not used, then a simple avoidance of the question takes place…or even the post.
Chris
Norfolk, VA, USA
“bill (21:33:00) :
Patrick Davis (20:45:26) :
http://www.cru.uea.ac.uk/cru/about/history/
Today, CRU is still dependent upon research grant income to maintain the size and breadth of our research and student communities. The European Commission of the European Union (EU) provides the largest fraction of our research income under the Environment and Climate Change Programme. …. Although EU funding is very important, we also endeavour to maintain the diverse pattern of funding reflected by the research described in this “history of CRU” and in the list of Acknowledgements below.
Since 1994, the situation has improved and now three of the senior staff are fully funded by ENV/UEA and two others have part of their salaries paid. The fact that CRU has and has had a number of long-standing research staff is testimony to the quality and relevance of our work. Such longevity in a research centre, dependent principally on soft money, in the UK university system is probably unprecedented. The number of CRU research staff as of the end of July 2007 is 15 (including those fully funded by ENV/UEA).
£226,981 is for the period:
01-Jul-03 30-Jun-08
£45,400/year.
The recipients are:
Prof K.R. Briffa
Prof P.D. Jones
Dr T. Osborn
Dr S. Tett
Thats about £11k each. assuming that no money is spent on research.
Keep real.”
Yeah I do keep real, I wish Mann, Hansen, Briffa et al would do the same. But then I don’t have to protect Govn’t funding (Income). So what you’re saying, in short, you’re govn’t, in full or not, funded, right? So how are all the OTHER grants allocated to Dr Briffa, errm, allocated? Clearly you have “indside” info. As far as I am concerned, a “research” grant is exactly that, a research grant to do research. Seems Dr Briffa, and others, see it as climate welfare.
It wouldn’t surprise me if Keith Briffa is more unnerved by the insinuations of scientific misconduct than he is by Scott Mandia’s (snipped) analogy. Chances are that he actually agrees with Scott’s analogy, though I have no way of knowing.
May I offer another analogy?
If a plane technician tells you that the plane you are about to board is not in a good enough condition to fly, and that he deems it extremely unsafe, would you board the plane? Would your action (presumably of not boarding) change if an economist points you to some screws in the wing of the plane that are perfectly in place, telling you that he therefore concludes that he regards it as totally save to board the plane? What if 99 engineers tell you it is unsafe and one tells you it is safe?
Sorry Dr. Briffa,
But the questions posed for you here by Anthony and others are the real ones.
Do you have answers for them? As far as I can tell, no.
You seem to fail to comprehend — perhaps because the implications are so enormous not only for you, personally, but also for the entire AGW house of cards — that it is YOUR OWN data selection process that requires justification.
This problem is magnified by your ten year track record of refusing to be forthcoming with the data which now reveal such enormous and apparently devastating anomolies. Nothing in your post changes that — in fact, nothing in your post even *addresses it.* You are here now in the real world of online readers who may not be experts in “climage science,” but are able to smell a red herring that has been rotting for ten years.
Real science is replicable. Your results, now that the data are no longer being hidden from independent scrutiny, fail that basic test. Not only are they not replicable, they are based on a manifestly disengenous process of selecting data to fit preconcieved conclusions.
As an long time environmentalist, I am shocked and dismayed that the AGW scare — which is distracting us from the REAL environmental issues that require human attention and engenuity — is based on “science” like that represented in your post. It may be too late to save your reputation from what you have already done, but it is NOT too late to come clean and admit that your methods were flawed and your results appear to be entirely wrong.
Bart Verheggen (06:15:11) : “May I offer another analogy?If a plane technician tells you that the plane you are about to board is not in a good enough condition to fly, and that he deems it extremely unsafe, would you board the plane? Would your action (presumably of not boarding) change if an economist points you to some screws in the wing of the plane that are perfectly in place, telling you that he therefore concludes that he regards it as totally save to board the plane? What if 99 engineers tell you it is unsafe and one tells you it is safe?”
~ False Analogy (again!) http://en.wikipedia.org/wiki/False_analogy
i) You are referring to structural safety above…a far cry from some erroneous GCM extrapolations. Not even apples to oranges. Apples to baseballs.
ii) There are FAR more than just economists, namely engineers, scientists, physicists, and others who strongly object to the current IPCC “orthodoxy”.
ii) Your 1 in 99 ratio is way off. And even if it were not, the 1 scientific objector to the 99 group-think “consensus” is one thing when calculating structural and life safety….quite another when fretting about something that may happen based upon a few GCMs, is not shown in real world observations to be occurring!!
Chris
Norfolk, VA, USA
psi (07:05:53) : “As a long time environmentalist, I am shocked and dismayed that the AGW scare — which is distracting us from the REAL environmental issues that require human attention and engenuity — is based on “science” like that represented in your post.”
I could not agree more on your point above…as my screen name on here might suggest.
And you rarely hear this argument…but it should be shouted from the housetops.
Chris
Norfolk, VA, USA
psi (07:05:53) :
“Sorry Dr. Briffa […]”
Reply:-
I agree with your conclusions – harsh but fair. Unless the reasoning behind the decissions is made clear and all data made available when a paper is published, it is clearly propagana, not science.
Hi Chris —
You write:
“I could not agree more on your point above…as my screen name on here might suggest.
And you rarely hear this argument…but it should be shouted from the housetops.”
Let’s start shouting. See my email to NPR in the most recent thread on Tree Ring data.
Bart Verheggen (06:15:11) :
May I offer another analogy?
If a plane technician tells you that the plane you are about to board is not in a good enough condition to fly, and that he deems it extremely unsafe, would you board the plane? Would your action (presumably of not boarding) change if an economist points you to some screws in the wing of the plane that are perfectly in place, telling you that he therefore concludes that he regards it as totally save to board the plane? What if 99 engineers tell you it is unsafe and one tells you it is safe?
I just finished rereading Agathe Christie’s detective story ” they do it with mirrors”.
Unfortunately climate presentations and climate projections are done with mirrors, i.e. the semblance of scientific method not the method.
If the methods of the IPCC and GCM projections were used to build a plane, of course you should never enter it. No engineer would design and extrapolate something without error propagation and limits of application. You cannot compare video games ( GCMs) with engineering diagrams, and therefore neither the outputs of such endeavors can be given probabilities of failure that are comparable.
I will say it once more on this board”
officially there is no error propagation in the GCM models, it is all done with mirrors and sleight of hand of the modellers, so there is no meaning to probability of output.( check AR4 chapter 8 for “likelihood”).
How are you all so sure that Briffa’s science was flawed? There has been no evidence that proves this, just circumstantial evidence that suggests that
as a possibility.
Most posters at WUWT and CA have had Briffa’s name in the public blog court,
have found him guilty, and have sentenced him along with the implicit suggestion that many scientists are just as incompetent or fraudulent. Of course, all of this was done while Dr. Briffa was seriously ill and unable to mount a defense.
Much of this debate is about “hiding data”. It is also sad that the best reconstruction to date by Mann et al. (2008) is not being discussed. Mann et al.’s paper, supplemental information that describes their methodology, and
all of the data used were released FREE to the general public.
To see it all:
http://www.pnas.org/content/early/2008/09/02/0805721105.abstract
http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html
BTW, Mann eta al.’s plot was essentially the same with or without tree rings. Shocker!
savethesharks (08:53:24) : said
“psi (07:05:53) : “As a long time environmentalist, I am shocked and dismayed that the AGW scare — which is distracting us from the REAL environmental issues that require human attention and engenuity — is based on “science” like that represented in your post.”
Could not agree more on your point above…as my screen name on here might suggest.
And you rarely hear this argument…but it should be shouted from the housetops.
***
I heartiiy agree-the real issues are being obscured in the shouting. Can I suggest you read Peter Taylors book ‘Chill,’ he is an outstanding ecologist/environmentalist and puts the arguements very clearly for placing greater emphasis on sustainibility-whilst attacking the science that surrounds the AGW scare that is submerging the debate .
This leads to a review of his book and ensuing discussion.
http://www.harmlesssky.org
The review includes a biog of Peter. I think you would get on with him very well.
tonyb
Scott Mandia – you are saying that it is anything but terrible scientific practice to withhold data for almost a decade when it is critical to confirming the conclusion?
You then say that, UPON FORCED PUBLICATION, when that data shows very favorable selection of data, and that selection isn’t justified in the author’s rebuttal that this isn’t scientific misconduct?
It seems that you only accept an e-mail from Briffa saying, “Hey, let’s remove this data because it doesn’t fit the conclusion we want!!!”
Stop confusing the issue of scientific misconduct with the conclusions of other studies. Those studies cannot justify the conduct, regardless of whether they confirm or deny Briffa’s work.
Briffa’s work may be right or wrong, that is immaterial. What is material is that he hid his data and then, upon exposure was shown to have selected data which was very favorable to his desired conclusion, and then did NOT justify it by releasing his method for selection.
Chris,
As with any analogy, there is a point where it breaks down. However, I think the basic premise is valid: Climate scientists by and large agree that in the long run it is not safe to continue with business as usual emissions. ‘safe’ is admittedly a subjective term, so therefore debatable.
The 99% should have read 97.4%, which according to this survey (http://tigger.uic.edu/~pdoran/012009_Doran_final.pdf) is the percentage of climatologists who are actve publishers on climate change who think that human activity is a significant contributing factor in changing mean global temperatures.
The people who vehemently disagree with this view are mostly not climate scientists (with a handful of exceptions of course), but come from a wide variety of other fields, as you say.
Bill1234,
I do not KNOW the whole story behind the Briffa data and neither do you. This whole thing looks to me like many people are telling the world how bad a book is before even reading it because they do not like the cover. Let us find out before we convict Briffa.
My second point is that this whole “controversy” is being used to somehow claim that ALL hockey-stick-shaped reconstructions are invalid. Of course, that is absurd.
Scott A Mandia:
You are being extremely disingenuous when you write:
“
This is a warming of approx 0.17/decade in the past 30 years
Take a look at this IPCC 2007 image:
http://www2.sunysuffolk.edu/mandias/global_warming/images/global_mean_temperature.gif
Do you see that the RATES of warming are on the rise? The rate for the past 100 years is 0.07/decade.
The rate of warming has more than DOUBLED.
”
But the rate of warming has NOT “doubled”. The appearance of accelerated warming is provided by your having used different time periods.
The IPCC used the same trick in AR4 (2007). Figure 1 from FAQ 3.1, is on page 253 of the WG1 section (i.e. the section by the IPCC’s purportedly scientific working group, and it was not submitted for peer review.
The published graph shows the slope over the last 25 years is significantly greater than that of the last 50 years, which in turn is greater than the slope over 100 years. This is said to show that global warming is accelerating. It is important to note that this grossly misleading calculation is in chapter 3 of WG1 and also in the SPM that states, “The linear warming trend over the last 50 years is nearly twice that for the last 100 years”. Thus, policymakers who only look at the numbers (and don’t think about the different timescales) will be misled into thinking that global warming is accelerating.
Of course, you and the IPCC could have started near the left hand end of the graph and thus obtained the opposite conclusion!
Using the HADCRUT3 data for mean global temperature, the 40-year trend from 1905, has a slope of 1.46 degrees per century . The 100-year trend has a slope of 0.72.
So, applying your method, but comparing the early period to the total period, the rate of warming has REDUCED BY MORE THAN HALF.
Richard
Scott Mandia. I don’t know what faith this hockey stick brings. Its as though you’re more interested in it being reproduced than the means by which it is contrived. Galileo had a similar battle when he maintained that the earth revoloved around the sun. For all intents and purposed from the human perspective, it seemed to, in a man made universe.
As such, propositions of this nature are not amenable to rational argument.