If you do a search at this blog site for ‘hockey stick’, Google will provide you with about 70 links and the first will link to a question I posted a year ago:
“What is the evidence for the medieval warm period? My understanding is that the Vikings were able to settle Greenland and grow grapes in Canada over several hundreds of years because the climate was significantly warmer. Yet this period is not evident in the famous ‘hockey stick’ graph.”
The Graph
[from BBC News]
The graph was the creation of Dr Michael Mann, et al, and was used by the United Nation’s Intergovernmental Panel on Climate Change (IPCC) to conclude in their influential 2001 assessment report that the 1990s was the warmest decade and 1998 the warmest year of the last millenium.
Indeed the ‘hockey stick’ has emerged as something of an icon for believers in anthropogenic global warming (AGW), while global warming skeptics have dismissed it as shoddy science and another example of ‘believers’ using models to support a position at odd with the evidence in particular the existence of the medieval warm period.
Now a prominent statistician who is also a Univeristy Professor, Chair of the National Academy of Sciences Committee on Applied and Theoretical Statistics, and a member of the board of the American Statistical Association, has published a rather damning report on the hockey stick. As Paul Williams commented in the thread following my blog post last Friday, “… the hockey stick has just been hit for six”!
Following are some of the conclusions from Dr Edward Wegman as summarized by the US House Committee on Energy and Commerce:
1. Mann et al., misused certain statistical methods in their studies, which inappropriately produce hockey stick
shapes in the temperature history. Wegman’s analysis concludes that Mann’s work cannot support claim that
the1990s were the warmest decade of the millennium.
Report: “Our committee believes that the assessments that the decade of the 1990s was the hottest
decade in a millennium and that 1998 was the hottest year in a millennium cannot be supported by
the MBH98/99 analysis. As mentioned earlier in our background section, tree ring proxies are
typically calibrated to remove low frequency variations. The cycle of Medieval Warm Period and
Little Ice Age that was widely recognized in 1990 has disappeared from the MBH98/99 analyses,
thus making possible the hottest decade/hottest year claim. However, the methodology of
MBH98/99 suppresses this low frequency information. The paucity of data in the more remote past
makes the hottest-in-a-millennium claims essentially unverifiable.”
2. A social network analysis revealed that the small community of paleoclimate researchers appear to review
each other’s work, and reuse many of the same data sets, which calls into question the independence of peerreview and temperature reconstructions.
Report: “It is clear that many of the proxies are re-used in most of the papers. It is not surprising that
the papers would obtain similar results and so cannot really claim to be independent verifications.”
3. Although the researchers rely heavily on statistical methods, they do not seem to be interacting with the
statistical community.
Report: “As statisticians, we were struck by the isolation of communities such as the paleoclimate
community that rely heavily on statistical methods, yet do not seem to be interacting with the
mainstream statistical community. The public policy implications of this debate are financially
staggering and yet apparently no independent statistical expertise was sought or used.”
4. Authors of policy-related science assessments should not assess their own work.
Report: “Especially when massive amounts of public monies and human lives are at stake,
academic work should have a more intense level of scrutiny and review. It is especially the case
that authors of policy-related documents like the IPCC report, Climate Change 2001: The Scientific
Basis, should not be the same people as those that constructed the academic papers.”
5. Policy-related climate science should have a more intense level of scrutiny and review involving statisticians.
Federal research should involve interdisciplinary teams to avoid narrowly focused discipline research.
Report: “With clinical trials for drugs and devices to be approved for human use by the FDA, review
and consultation with statisticians is expected. Indeed, it is standard practice to include statisticians
in the application-for-approval process. We judge this to be a good policy when public health and
also when substantial amounts of monies are involved, for example, when there are major policy
decisions to be made based on statistical assessments. In such cases, evaluation by statisticians
should be standard practice. This evaluation phase should be a mandatory part of all grant
applications and funded accordingly.”
6. Federal research should emphasize fundamental understanding of the mechanisms of climate change, and
should focus on interdisciplinary teams to avoid narrowly focused discipline research.
Report: “While the paleoclimate reconstruction has gathered much publicity because it reinforces a
policy agenda, it does not provide insight and understanding of the physical mechanisms of climate
change… What is needed is deeper understanding of the physical mechanisms of climate change.”
Read the full report here: http://energycommerce.house.gov/108/home/07142006_Wegman_Report.pdf .
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
The Vikings called Newfoundland for ” Vinland”= Wineland, Labrador for “Markland” and Baffin Island for “Helluland”.
Notice, it was the Vikings not Columbus that discovered America!
The Australian media has now published something on the report with Alan Woods concluding: “If the IPCC process isn’t fixed, and there is no evidence the IPCC intends to do anything about it, how do we know it won’t send out another very misleading message in its upcoming Fourth Assessment report?”
http://www.theaustralian.news.com.au/story/0,20876,19835476-31478,00.html
Of course The Wegman report is the kangaroo court account – for another view and THE OTHER report
http://www.nap.edu/catalog/11676.html
http://www.realclimate.org/index.php/archives/2006/06/national-academies-synthesis-report/#more-316
And anyone can play social network analysis
http://scienceblogs.com/deltoid/2006/07/hockey_social_stick_networks.php#more
Interesting to note though Wegman says “The paucity of data in the more remote past
makes the hottest-in-a-millennium claims essentially unverifiable”. Presumably implying the global nature of the Medieval Optimum, particularly in the southern hemisphere, is unclear.
And – let’s say that the Medieval Warming was as warm as it is now for argument’s sake. Therefore one should be even more worried about the upper bounds and higher of CO2 induced warming to come. Think about it !
By being just a bunch of statisticians the Wegman report has missed the climatological importance of issues. Which is strange given Wegman’s cry for the research to be more inter-disciplinary.
I’m utterly shocked about Alan Woods opinion 🙂
Jen – sorry absolute rubbish. The hockey stick is an icon only for the contrarians. Mann was a postdoc student in the study – no-one has really aked Bradley or Hughes what they think. Finally Dr Mann has written what he thinks in this comment on Real Climate:
“The un-peer reviewed report commissioned by Rep. Barton released today adds nothing new to the scientific discourse on climate change and is a poor attempt to further personalize and politicize what should be a matter of scientific debate not politics.
The impartial and independent National Academy of Sciences convened a panel of experts in climate science and statistics and performed a far more extensive review of the science, confirming the key conclusions of our earlier work, as well as numerous more recent supporting studies. Namely that late 20th century warmth is likely anomalous in the context of the past 1000 years and cannot be explained by natural variability. The scientific evidence for human influence on current climate comes from a large body of independent lines of evidence of which paleoclimate data is but a small part.
Barton’s report, written by statisticians with no apparent background at all in the relevant areas, simply uncritically parrots claims by two Canadians (an economist and an oil industry consultant) that have already been refuted by several papers in the peer-reviewed literature inexplicably neglected by Barton’s “panel”. These claims were specifically dismissed by the National Academy in their report just weeks ago. Barton’s report also reveals that his panel collaborated closely with the two Canadians, yet made no attempt to contact me or my collaborators at any point.
The panel makes the odd claim that there is “too much reliance on peer-review” which goes against every principle of current scientific practice. Barton in his ‘factsheet’ goes further and suggests that the anonymous peer reviewers themselves are in some way biased, a claim that he cannot possibly support since peer reviewers are in fact anonymous and this was not studied in the report.
Climate science, like many multidisciplinary fields, requires broad collaboration with researchers across many areas. Any well published scientist would show a wide-ranging pattern of connection with other researchers in the field. While I am flattered that the committee seems to think that I am at the center of the field, the same analysis would have shown a very similar pattern for any researcher engaged in widespread interdisciplinary research.
My colleagues and I continue to work on reducing the uncertainties in past climate reconstructions and understanding the mechanisms of past and current climate change. Policy-makers should more constructively focus their attention on the consensus findings on climate change as presented by the Intergovernmental Panel on Climate Change (IPCC) and the National Academies of all G8 countries, rather than on pursuing politically-motivated attacks against individual scientists.”
I think the National Academy of sciences and the 6 or 7 other supporting proxy studies, one not using tree rings, is far more conclusive that one report commissioned by Smokey Joe and overseen by M&M.
Ender,
So was the IPCC right or wrong to place such emphasis on the ‘hockey stick’ in their last major report – the 2001 assessment?
In addition to statisticians, I think that graphic designers, flower arrangers, and other creative types should also be involved in the debate.
One issue that has been repeatedly overlooked in this never ending debate (at least i hope it never ends) is the choice of colours and font used in IPCC report graphs and charts.
See above for an example.
They have chosen a sans serif font, but it could be argued that since most people use a sans serif font on graphs, that this is a veiled appeal to consensus, and results in viewers of the graph being biased towards accepting the graph as robust, irrefutable research.
Further, the use of primary colours such as blue and red heightens this effect.
To avoid these biases in future work, the committee directs that
1. all future graphs in IPCC publications use the wingdings font, to avoid biasing people unneccessarily towards comprehending the graphs.
2. All axis tick marks be on the inside instead of the outside. No reason, we just like it that way.
3. all future graphs use a colour scheme derived from the following palette: cream, bone, white, off-white, ivory or beige
Steve, Ender, Luke,
Are you attempting to divert attention away frm the importance of the Wegman report?
Wegman has considerable standing, qualifications and expertise and I would have thought passed the Ender/Quiggin ‘independence’ test, so I’m truly suprised and a little outraged that your all so dismissive!
Jennifer – “So was the IPCC right or wrong to place such emphasis on the ‘hockey stick’ in their last major report – the 2001 assessment?”
They didn’t place that much emphasis on it. It shows up as one graph that places recent warming in a historical context. The other umpteen pages of the IPCC report never mention it. The IPCC report is about anthropogenic global warming, its mechanicsm and possible consequences. This does not depend in any way shape or form on MBH98.
“Are you attempting to divert attention away frm the importance of the Wegman report?”
Yes – it is not important at all. As Dr Mann explained it is not peer reviewed, was written in close collaboration with M&M, and it was commissioned by Rep Barton who has clear and published links to the coal and oil industries. It also does not have any new information.
A question for you – how do you know it is correct?
Rather than attempt to divert attention away from its importance, I think that Luke and Ender were attempting to challenge its importance. Its difficult to rate the Wegman report as more important than the NAS report that Luke linked to, and which was strangely absent from your postings over the last few weeks.
Me on the other hand: I was trying to divert attention. If I outraged you, I apologise. However, I thought that this sort of post on your blog might be ok – I have posted here for a long time now, and have never forgotten this series of comments from you:
—————-
/start quote
Steve,
…
But, there seems to be limited understanding of my sense of humour and sense of irony, by many readers of this blog.
PS While Wikipedia defines irony:
“Irony is a form of utterance that postulates a double audience, consisting of one party that hearing shall hear and shall not understand, and another party that, when more is meant than meets the ear, is aware, both of that “more” and of the outsider’s incomprehension.”
I don’t mean to exclude anyone, but I do laugh a lot. My favourite post is still my post about superimposing a fish on a graph of climate data – but I sometimes wonder how many readers were laughing with me, at this http://www.jennifermarohasy.com/blog/archives/000784.html .”
Of course sometimes I am very serious.
/end quote
—————–
I would have thought you would be amused rather than outraged by my most. Perhaps it was simply not funny enough 🙂 Or perhaps i caught you at a time where you were being ‘very serious’.
Anyhoo, back to the topic:
Don’t you think that the NAS report was the best ending point for this endless discussion, given the huge volume and conflicting claims that have been thrown about over the last few years? Why give air time to this comparatively less important report when you didn’t even mention the NAS report?
Ender, I have spent far too much of my time involved with “experts”. This contact proved the old jokes. You know, an expert is a drip under presure, or someone who knows more & more, about less & less, to ultimately know everything about nothing. Well, it aint no joke.
I spent years involved with the Great Barrier Reef Marine Park, & AIMS experts. With their experts, & the James Cook ones, I thought I had met the greatest twits on earth, but no, I then got involved with Water Resource Plans, & Vegetation Management Plans.
As one local put it, after a field day, “we all know about leading a horse to water, but with these blokes, you can lead them to the problem & they still can’t see it, even after they’ve fallen into it & broke their leg”.
One of these “experts” did tell me once, “it doesn’t matter what we find, it’ll be 15 years, & 3 more inquiries before there’s any funding, & then the polly’s will do whatever they want”
The worst thing is, that the polly’s have taken to using their findings to stop something, [to please the greenies], or to charge extra for something. So these experts are starting to destroy peoples lives, with their bullshit.
So, Ender, please excuse me for taking anything written by a publicly funded “expert”, as just another funding submussion, or proof they have been in the office in the last 6 months.
Ender,
I don’t know it is correct but i’ve always had a problem with the hockey stick because it doesn’t show the medieval warm period i.e. the Mann model doesn’t accord with the bits of evidence I know about.
I’m surprised someone as well qualified as Wegner has been as scathing as he has. Given you tend to respect ‘authorities’ I am surprised you are now suggesting he is also compromised by big oil!
Steve,
I didn’t see the humour on first read (just re-read and OK!) and I’m not aware of the NAS report. I’m not getting ‘real climate’ email alerts probably because I need to re-subscribe since I cancelled my bigpond account. What about a guest post on the NAS report from you?
Jennifer – “I don’t know it is correct but i’ve always had a problem with the hockey stick because it doesn’t show the medieval warm period”
It does show these periods however most graphs of it are not at the correct scale ie: the stick is long and does not show the blips.
There is NO evidence other that anecdotal “vineyards in England” and “vikings in Greenland” that the MWP was either global or warmer that today. It could have been confined to Northern Europe only. ALL the proxy studies show that the MWP was there however recent warming is unprecendented.
Jen – in terms of me being dismissive – I can only say I made some measured comments above which I can only ask you to reread.
I’m glad you had not previously heard of the NAS report (as opposed to ignoring) but it has been out by some time – also with a quite respectable panel. I don’t want to get too shrill about it as it’s only one piece in a very big puzzle, but the outcome of the whole debate is still far from clear IMHO. This has now become a politically muddied issue that should have been sorted out in the literature. Wegman has good qualifications and both reports need to be digested with some consideration.
I am mystified by Ender’s claim that all proxies show a MWP less warm than present. The well-known Moberg 2005 and Esper 2002 proxies both show a MWP closely similar to present. As for the NAS report, it agrees that Mann’s hockey stick is bad statistics, but says some others get more or less similar results to Mann. However, Mcintyre responds that this is because they make similar errors. And how can Ender defend Mann’s stubborn refusal to make his detailed data and procedures available, and his whining on being forced to disclose these? Does Ender think it is OK to have global-level policies drummed into us by what amounts to a mystery religion by other means?
So is the ” debate ” back on again or not?
These regal pronunciations are a lot of fun…..
What was Mann’s response to the question; Where the @#$%&* is the Medieval Warming in his graph?
Vines were grown in England. And this means an absence of frost and an extended growing season. Ditto for conventional farming in Greenland. The period lasted almost a century and those conditions would certainly produce temperature ranges that are consistent with the last decade.
Where is it on Mann’s graph? And why is it not there?
Hmmm, as a Nordic, aren’t we confusing “vines were grown in England” with “vines were grown in NewFoundland”. Our old sagas say so.
The Vikings moved from Norway to Iceland, from Iceland to Greenland and from Greenland to North America.
There was no growing of crops in Greenland, seeds were imported from Iceland, however the Vikings found wild wheat and grapes in Canada. And this warm period lasted between 800-1200 AD.
David – “The well-known Moberg 2005 and Esper 2002 proxies both show a MWP closely similar to present”
But not greater as is the claim. Also none of the proxies give any clue as to the extent of this warming – it may have been confined to Northern Europe.
“As for the NAS report, it agrees that Mann’s hockey stick is bad statistics, but says some others get more or less similar results to Mann.”
First of all it is not Mann – he was a post doc student. The correct name is Mann, Bradley and Hughes so it is incorrect to assume Micheal Mann is the sole person here. The NAS does not say that MBH98 is bad statistics. All the proxy studies do get similar results and that proves that validity of the original study.
“And how can Ender defend Mann’s stubborn refusal to make his detailed data and procedures available, and his whining on being forced to disclose these”
The data was available from day 1 as required. What was not available was a step by step cookbook that 2 amateurs would need to replicate the work. What was made available was the standards required by any sceintist. I agree that Dr Manns actions after this were not perfect however he is a human being and I guess he just got really p—–d off by two incompetant non-entities saying that he did not know how to do science. Other competant and trained teams replicated the work from the available data. Also the data was not all MBHs in the first place. They used data from Briffa et al.
“Does Ender think it is OK to have global-level policies drummed into us by what amounts to a mystery religion by other means?”
Global level policies are set by polititians not scientists. The IPCC reports are a compendium of available knowledge that most scientists in the field can agree is valid. The science in the reports is basic physics and does not depend on proxy studies. What basis do you claim that global-level policies are drummed into us by what amounts to a mystery religion? If you regard physics as a mystery religion then you need to educate yourself – I did it to a level where I can understand the basics. There are many basic primers and this is a good site for understanding the history and physics of Global Warming.
http://www.aip.org/history/climate/index.html
It is an excellent site and worth a look if you want to remove the mystery religion part.
David – “The well-known Moberg 2005 and Esper 2002 proxies both show a MWP closely similar to present”
But not greater as is the claim. Also none of the proxies give any clue as to the extent of this warming – it may have been confined to Northern Europe.
“As for the NAS report, it agrees that Mann’s hockey stick is bad statistics, but says some others get more or less similar results to Mann.”
First of all it is not Mann – he was a post doc student. The correct name is Mann, Bradley and Hughes so it is incorrect to assume Micheal Mann is the sole person here. The NAS does not say that MBH98 is bad statistics. All the proxy studies do get similar results and that proves that validity of the original study.
“And how can Ender defend Mann’s stubborn refusal to make his detailed data and procedures available, and his whining on being forced to disclose these”
The data was available from day 1 as required. What was not available was a step by step cookbook that 2 amateurs would need to replicate the work. What was made available was the standards required by any sceintist. I agree that Dr Manns actions after this were not perfect however he is a human being and I guess he just got really p—–d off by two incompetant non-entities saying that he did not know how to do science. Other competant and trained teams replicated the work from the available data. Also the data was not all MBHs in the first place. They used data from Briffa et al.
“Does Ender think it is OK to have global-level policies drummed into us by what amounts to a mystery religion by other means?”
Global level policies are set by polititians not scientists. The IPCC reports are a compendium of available knowledge that most scientists in the field can agree is valid. The science in the reports is basic physics and does not depend on proxy studies. What basis do you claim that global-level policies are drummed into us by what amounts to a mystery religion? If you regard physics as a mystery religion then you need to educate yourself – I did it to a level where I can understand the basics. There are many basic primers and this is a good site for understanding the history and physics of Global Warming.
http://www.aip.org/history/climate/index.html
It is an excellent site and worth a look if you want to remove the mystery religion part.
T’other day, John Bignall wrote of the Wegman report..”We must hope that the independent statisticians who performed the review know what they are likely to be in for – character assassination and other ad hominem attacks, plus general vilification – for they are dealing with religious zealotry of the most pernicious kind.” Seems this has already begun as we are told they work for someone who works for Big Oil.
The impression from some here is that the report is just from Wegman. In fact the report was prepared by a group of statisticians under the leadership of Wegman. The report was for the US House Committee on Energy and Commerce and as such it is not clear why it ought to be peer-reviewed. Still its rather ironic that this would be one of Mann’s main defences given that the report specifically criticises the peer review process in the paleoclimate community …”A social network analysis revealed that the small community of paleoclimate researchers appear to review each other’s work, and reuse many of the same data sets, which calls into question the independence of peerreview and temperature reconstructions.”
The claim that the NAS report somehow supports the Hockey Stick is bizarre. In the gentlest possible way it points out that any projections further back than 1600 AD are unverifiable and cannot be relied on. It agrees that it may be arguable that the 1990s wasthe hottest decade in the past 400 years but doesn’t agree that this is established – they use the word “plausible”. Now many a sceptic would accept that the earth has been warming since the LIA and claiming we are warmer now that in Shakespeare’s time is wholly unremarkable. But in one swoop the stick is broken in half.
Most compelling of all, the NAS report essentially upholds all the criticism of the Hockey stick made by McIntyre and McKitrick.
It is bizarre and revealing that the supporters of the Hockey Stick (and there seems to be a lot less of them these days) take comfort that the NAS merely chose to dimplomatically slap Mann et al across the wrist rather than dumping on them in the way most climate discussion occurs these days.
Mark – “We must hope that the independent statisticians who performed the review know what they are likely to be in for – character assassination and other ad hominem attacks, plus general vilification – for they are dealing with religious zealotry of the most pernicious kind.” Seems this has already begun as we are told they work for someone who works for Big Oil.”
On the contrary I am sure that they did their job well and I have not seen any critisism of them personally. This is not a personal issue. There is no religious zealotry at all – it is just scientists defending the scientific method and process that has underpinned our modern technological society and had given us the small view of the magnificant thing we call Nature.
“In the gentlest possible way it points out that any projections further back than 1600 AD are unverifiable and cannot be relied on”
No really???? Perhaps thats why MBH had to use PCA analysis to try and sort out some signal from the noise. It also explains why MBH99 is a reference placing recent warming in a historical context – no more no less.
“Now many a sceptic would accept that the earth has been warming since the LIA and claiming we are warmer now that in Shakespeare’s time is wholly unremarkable. But in one swoop the stick is broken in half.”
So you would accept that the globe is warming however it is UNREMARKABLE!!!!! We are talking about our only life support system here. It gives us ALL our food and supports ALL life on the planet. ANY changes are remarkable and could bear directly on the Earth’s carrying capacity. Right now it is straining to support 8 billion human beings plus all the rest of the biosphere. How do you know this warming is unremarkable. To say such a thing is taking a HUGE thing totally for granted.
“It is bizarre and revealing that the supporters of the Hockey Stick (and there seems to be a lot less of them these days) take comfort that the NAS merely chose to dimplomatically slap Mann et al across the wrist rather than dumping on them in the way most climate discussion occurs these days.”
It is not a case of supporters of the hockey stick. You make is seem like it is a game of football. Scientists accept the validity of the proxy studies and have moved on to other work. What has got scientists upset is the attack on science itself. Rep Bartons attack on science is totally unprecendented and is obviously motivated by the swiftboat tactics employed by the anti global warming lobby organised by think tanks like the Marshall Institute. MBH are climate scientists not statisticians and never claimed to be. The mistakes were quickly corrected and made only miniscule differences to the resulting graphs. M&M left out proxies, selectivly used others and made mistakes of their own. Perhaps WSS should do an audit of M&Ms work.
There is the issue as to whether the Medieval optimum is truly global or regional. We may never know for sure.
In any case – if it is global it means the basic underlying system can get warmer than we think without CO2. So add CO2 and you may have even a larger warming effect?
Ender: the ‘hockey stick’ of Mann – Mann et al if you insist, though Mann would seem to be the acknowledged heavy in this field – was no better than those mystery religions of the ancients with rites undisclosed except to initiates. Mann (et al) did not adequately disclose data and procedures sufficient for independent verification. That is not science. Contrary to your statement, Mann (et al) with their hockey stick are markedly at variance with Esper 2002 and Moberg 2005 whose proxies indicate a MWP similar to present; if the latter two are correct, the recent warming is NOT unprecedented as claimed by Mann (et al) – and as promoted by the IPCC, who clearly expected global policy to be strongly influenced by the hockey stick. If Esper and Moberg are rejected because they are insufficiently global, why isn’t the hockey stick put in the same boat? Your invocation of ‘physics’ touches none of this. Theories about greenhouse physics must be judged primarily by compatibility with empirical data; and Mann (et al) handled key empirical data badly through seriously faulty statistical procedures, as both the NAS and the Wegman reports state. As for your attempted heavily personalised hatchet job on Mcintyre and McKitrick: any fair-minded onlooker will instantly be made suspicious by such ad hominem tactics.
david elder – “Mann (et al) did not adequately disclose data and procedures sufficient for independent verification. That is not science.”
I am sorry they did. How did the other teams manage it if they did not adequately disclose data?
“Contrary to your statement, Mann (et al) with their hockey stick are markedly at variance with Esper 2002 and Moberg 2005 whose proxies indicate a MWP similar to present; if the latter two are correct, the recent warming is NOT unprecedented as claimed by Mann (et al) – and as promoted by the IPCC, who clearly expected global policy to be strongly influenced by the hockey stick.”
If you look at this page
http://www.realclimate.org/index.php?p=122
there is a discussion on this topic and it clearly shows that recent warming is unprecedented.
“If Esper and Moberg are rejected because they are insufficiently global, why isn’t the hockey stick put in the same boat? Your invocation of ‘physics’ touches none of this. Theories about greenhouse physics must be judged primarily by compatibility with empirical data; and Mann (et al) handled key empirical data badly through seriously faulty statistical procedures, as both the NAS and the Wegman reports state. As for your attempted heavily personalised hatchet job on Mcintyre and McKitrick: any fair-minded onlooker will instantly be made suspicious by such ad hominem tactics.”
Esper and moberg aren’t rejected they show just about what MBH99 showed. Also remember that Esper is 2002 and Moberg is 2005 who benefited from better data that MBH had in 1998 4 years earlier.
The reason that AGW has acheived consensus is because it explains recent warming the best so I do not know what you are going on about here.
The reason for the hatchet job is that although I am nothing in the world of climatology and not even a scientist I am ****** ****** sick of ****** ***** explaining ****** MBH99 – do you get the idea? Can you imagine what MBH think?
The real issue and what we should be concentrating on is that as far as the best experts on the planet are concerned the Earth is warming from human actions that will have unpredicatable effects on the 8 billion humans inhabiting it not to mention the rest of the biosphere. This science does not depend on any statistics, faulty or otherwise, and is a real problem that need to be dealt with or it will be dealt with for us. I would prefer to control of my, and my children’s, destiny rather that let it all wash all over me like blind rabbits.
If you want to think MBH99 is the be all and end all of the problem and it is all based on faulty stats then go ahead. We will see in the future what happens. Perhaps it will be nothing and then you can all laugh at us warmers and this would be the best possible outcome, one I hope fervently is true. However I feel that there will not be too much laughing going on.
Thank you Ann for the additional info.
Ender said, “Other competant and trained teams replicated the work from the available data”.
So where the @#$%&* was THEIR (corrected) 400 years of higher temperatures?
And don’t pull this weasle stunt of suggesting that it was limited to northern europe. It was also North America and, in the absence of records from Siberia, could hardly be assumed to have excluded North Asia.
On one hand we have this article of faith that a minor change in circulation in the North Atlantic did take place to produce the Medieval Warming but when confronted with the question of why it doesn’t show up on Mann’s graph you claim it was an isolated instance.
Clearly, some of the greenland ice sheet melted over an extended period (40 times longer than the past decade) and it was certainly not followed by an ice age.
Your arguments are regurgitating faster than a model’s breakfast, me boyo.
Ender: from David Elder – I’m dreadfully sorry to have brought on that asterisk attack. I do hope I don’t provoke a recurrence with what follows. Only: how can your ‘science’ be independent of statistics when you put so much weight on Mann (et al), whose key work is in fact based on statistical analyses? And statistical analyses which – for the third time – both the NAS and Wegman reports panned? If the IPCC and your other oracles didn’t pick up such major problems, what confidence can we have in their ‘proof’ of unprecedented warming? Especially when Esper and Moberg suggest that it wasn’t so unprecedented? Sure, the planet’s future is important – and I believe in motherhood. I also believe that global-level policy should be based on the best science available. And two panels have now said – one politely (NAS) and one bluntly (Wegman) – that Mann (et al) didn’t do a good job here.
david elder – “Only: how can your ‘science’ be independent of statistics when you put so much weight on Mann (et al), whose key work is in fact based on statistical analyses?”
The science of AGW has almost nothing to do with MBH99 so it really does not matter to the AGW case whether MBH99 is correct or not. The true case for AGW is put in the thousands and thousands of other papers and work by hundreds of OTHER climate and other scientists that are working on the problem.
Please get the point that neither MBH99 or PCA analysis are at the heart of the case for AGW. MBH99 is case study of proxies that put recent warming in a historical context.
“also believe that global-level policy should be based on the best science available. And two panels have now said – one politely (NAS) and one bluntly (Wegman) – that Mann (et al) didn’t do a good job here.”
SO?? They did not say anything about or even examine the real issue only one, now quite old study, amongst the thousands done each year. MBH99 as I said before is a swiftboat issue. People who want to slow action on global warming have done a excellent job of equating MBH99 with global warming so now the general public think that if MBH99 is dodgy then the whole AGW case is dodgy when nothing could be further from the truth. This of course was the sole purpose of the attack on MBH99 and the dogged pursuit.
http://www.realclimate.org/index.php?p=253
The Osborn & Briffa paper shows (with a different statistical approach) that the global extent of the 20th century warming is indeed anomalous.
http://www.realclimate.org/index.php?p=253
The Osborn & Briffa paper shows (with a different statistical approach) that the global extent of the 20th century warming is indeed anomalous.
Sorry Ender – surely you can’t deny that the claim ” the last decade has been the warmest for 1000 years ” has featured prominently in virtually all public information on global warming?
Even my kids repeat it faithfully ( though they can’t recite their multiplication tables with any reliability).
The reason Wegman has been seized upon is I suspect, PRECISELY because the hockey stick is everywhere.
If it doesn’t really mean anything then;
1. when did you or the AGW camp ( and I’m one of them) put that on the record and;
2.why do AGW proponents refer to it so often?
Do you personally really believe that it’s being focussed on here as a strawman by dissenters?
Jim – “surely you can’t deny that the claim ” the last decade has been the warmest for 1000 years ” has featured prominently in virtually all public information on global warming?”
I am sorry but the claim “the last decade has been the warmest for 1000 years” is true according to all the proxy studies. 5 more studies confirm this so are they all wrong also? One of them is obtained from glacier records.
“1. when did you or the AGW camp ( and I’m one of them) put that on the record and;”
Because it it true
“2.why do AGW proponents refer to it so often?”
They don’t – at least the ones I listen too. Whether or not the past 1000 years was warmer or colder than the present has no bearing on what is occuring now.
“Do you personally really believe that it’s being focussed on here as a strawman by dissenters?”
Yes
You’re full of it as usual Ender. I figure that you produce enough hot air by yourself to account for some of the warming.
You parrot http://www.realclimate.org as if it was the authority on such matters. It’s run by people with vested interests and rates right up there with Mann being a lead author of the IPCC chapter in which Mann et al’s “hockey stick” got such prominence.
Mann’s response is utter drivel – or are you too blind to see that?
1 – As someone else has said, government reports don’t get peer-reviewed unless the government wants an independent check. No reason why it should when the 3 people have very strong credentials in statistics, which is far more than Mann has.
2 – “adds nothing new to the scientific discourse on climate change”? The “hockey stick” was the poster child of the AGW movement and it features in several CSIRO climate reports. Rejecting the “hockey stick” changes the picture completely. If temperatures were this warm during the Medieval Warm period then maybe they are warm now for exactly the same reason. In this sense the recent warming is pretty unremarkable! (Don’t give me that nonsense about carbon dioxide causing warming. It is exceptionally easy to prove that increased temperatures cause an increase in atmospheric carbon dioxide and that carbon dioxide has no discernible impact on global temperatures.)
3 – THE NAS report did not confirm the “hockey stick”. It said that temperatures prior to 1600 were uncertain. In other words MBH might have been correct for the last 400 years but its doubtful lthey were correct for the other 600. To put it another way, MBH might have been right for 40% of the time.
4 – “…written by statisticians with no apparent background at all in the relevant areas…” Duh! The relevant area was statistics and gooly gosh, these 3 guys are pretty damn good at that.
5 – “…uncritically parrots claims by two Canadians (an economist and an oil industry consultant)…” I think you’ll find that Wegman and co were knowlegeable enough to consider the papers by two Mc’s and draw their own conclusions as to whether their claims were accurate. Don’t you just love the attack “AN OIL INDUSTRY CONSULTANT”? This surely must be the first attempt at denigrating someone who doesn’t agree by snidely accusing them on some unspecified nefarious activities. What? Are you sure it’s not the first time?
6 – Barton’s report does not say that his panel “collaborated” with the two Canadians. Gee, if someone wrote a critical review and there were points that one wanted clarified, wouldn’t you ask them to explain in more detail? It’s funny how Mann slings around the word “canadians” as if it was a term of abuse; he doesn’t even give Steve and Ross surnames.
7 – Mann whinges that Barton’s panel didn’t contact him! Poor lad! According to you Ender, Mann fully disclosed his methodology and his data so why would Barton’s panel have to ask for further explanations?
8 – Peer-review is a funny one. Just who do you think the journals would go to if they wanted peer-review on something like a reconstruction of paleoclimate? I figure they just might go to the people who have worked in this field. Anonymous or not – and don’t tell me that the top people in teh field wouldn’t recognise each other’s work – independent peer-review phooey! (I’d something harsher but the censor would block it.)
9 – Yes, Mr Mann, climate science can require broad collaboration with researchers in many areas so why didn’t you collaborate with statisticians. Wegman’s report states very clearly that there is a real need for statisticians to be involved.
10 – Policy-makers should concentrate on the consensus of the IPCC? Don’t make me laugh. Not when Mann was a lead author of a chapter that presented the hockey stick which was one of the fundamental blobs of glue holding the so-called consensus together.
Your comments about other proxy studies are just as facile. Those studies used MBH98 as a principal crutch and as I’ve said above, just who do you think were the likely reviewers of these papers?
You say “They the IPCC] didn’t place that much emphasis on it. It shows up as one graph that places recent warming in a historical context. The other umpteen pages of the IPCC report never mention it.”. Wrong! Again! It’s in WG 1 (“The Scientific Basis”) Chapter 2, the Synthesis Report and the Summary for Policy-makers (the latter as the start of a graph with projections to 2100). It’s about the only graph that the IPCC could wave around. I mean I don’t think they wanted anyone wanted to see the graph that shows that of 11 climate factors only 1 of them was well understood!
You go on to say that the Wegaan report was … (a few things I’ve dealt with above) …” was commissioned by Rep Barton who has clear and published links to the coal and oil industries. It’s good to see you are consistent Ender. If you can’t win an argument you start throwing wild accusations and implications around. Are you going to provide evidence this time or will it just be your typical unsupported allegation?
What do you mean that there’s only anecdotal evidence of “vikings in Greenland”? That’s a heap of nonsense even by your standards. I’ve seen the Viking settlements there. They do exist. They did farm.
The MWP may have been confined to the Northern Hemisphere? Don’t make me laugh. There’s references to a whole heap of MWP papers at http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/mwpp.jsp including a couple of studies in New Zealand and three in the Antarctic.
The Mann data was NOT available from day 1 as you state. The two Mc’s had to repeatedly request the data. From http://www.climateaudit.org/index.php?cat=2&paged=5, Steve McIntyre’s blog about MBH98, we find “As follow-up, the site arge030 was listed in the original SI as being used in MBH98, but was not actually used in MBH98 calculations evidenced at Mann’s FTP site. We complained about this and other inconsistencies to Nature in November 2003, leading to the Corrigendum by Mann et al.” So Mann had to write a corrigendum to clarify what data was used and what data was in his dataset but was ignored.
Near the bottom of http://www.climateaudit.org/index.php?cat=2&paged=6 there’s a discussion about what data Mann made available immediately and what data appeared after FOUR YEARS. A key sentence or two … “There is source code at Mann’s FTP site for the calculation of tree ring principal components only. There is no source code for the calculation of reconstructed principal components, for the calculation of NH average temperature, for the Preisendorfer-type simulations, etc. etc. We have requested source code and been refused; we have sought intervention from Nature and the U.S. National Science Foundation without success.” (Readers might like to start at this page 6 and move forward to get the details in sequence.)
“Scientists accept the validity of the proxy studies and have moved on to other work. What has got scientists upset is the attack on science itself.” I haven’t had such a good laugh for a long time. I understand your position – you’re saying that scientists should be free to make any claims they like and never have to prove their argument or provide data and methodology so that others can verify their findings. that’s like saying that engineers shouldn’t have to be able to prove that their structures will not collapse! I remember back in the 1980s that there was this little claim of something called “cold fusion”. Would like the world to believe in cold fusion despite the fact that no scientists have been able to replicate the findings of the original team?
“MBH are climate scientists not statisticians and never claimed to be.” Oh yes they did – by not including a properly qualified statistician they were regarding their own skills in this field as good enough – and let’s face it, the reconstructions from the proxies is basically a statistical exercise.
“The mistakes were quickly corrected and made only miniscule differences to the resulting graphs.” Are you a comedy writer? Mann has never admitted that maybe some parts were wrong. The two Mc’s have shown that the technique that Mann used was predisposed to creating a hockey-stick graph. The above references to climateaudit will lead you to a bunch of hockey-stick graphs all created using Mann’s method on random data. If this predisposition towards hockey stick creation is a “miniscule difference” what do you call a “major problem”?
Jim – “”1. when did you or the AGW camp ( and I’m one of them) put that on the record and;”
Sorry misread the question but I am not sure.
The problem is Mann’s model, not his data.
Already in 2003, two Canadians, Ross McKitrick and Steven McIntyre, published an article in a peer-reviewed journal showing that Mr. Mann’s methodology could produce hockey sticks from even random, trendless data.
The reason the Medieval Optimum is missing is because the model is designed to generate hockey sticks.
Schiller.
I would like to nominate Ender for the “Horatio at the Bridge” award for his sterling defence of a lost cause. You are an inspiration to us all.
Steve gets the “Chartmanship” award for his excellent suggestions on involving graphic designers. http://www.numberwatch.co.uk/chartmanship.htm
It’s interesting how dogged you guys are in pursuit of your own prejudices also – at least ensure (and that’s not CO2 science site – a “whole heap” is now “4”??) that the Medieval Optimum was indeed a global phenomenon. Osborn and Briffa find using totally different stats techniques that the 20 century warming is indeed anomalous. Little support from the southern hemisphere in terms of alignment.
Not that it really matters – may mean that the impact of any CO2 warming may now be even greater.
And in terms of hockey stick graphs being created from random data – it does matter though if those trend relationships are significant or non-significant and what other relationships could be fitted.
Also nobody ever seems to comment on the grey error bounds on “that” graph.
In terms of awards – climateaudit gets the award for most whinging and bellyaching of all time. Not a site to actually gain any information or learn anything. Good for a carp and a whinge.
Schiller – “Ross McKitrick and Steven McIntyre, published an article in a peer-reviewed journal”
Which one? Nature? Science?
“The reason the Medieval Optimum is missing is because the model is designed to generate hockey sticks”
And what about the others? If MBH’s data was OK then the others used differnet models and got the same answer. I thought the data was the problem.
And I nominate Smokey Joe, M&M, and the rest of the crew for crimes against humanity. The future may judge them very harshly for helping to prevent action on a global problem just so some obscenely rich people can get richer.
Gosh Ender,
If you can’t fudge, you have to pick nits? And demand that everyone educate *you* on *your* self-chosen bit of alarmism?
You don’t get your choices that way. You come to the debate informed, or you back off. You don’t whine about how you didn’t see a widely-reprinted and commonly-known study. (Psst… you do that, you embarrass yourself. Take a clue.)
Schiller.
Ender, from David Elder – if as you claim the hockey stick is irrelevant to the debate on AGW, you’d better tell the IPCC, which waved that hockey stick with gusto. This makes total nonsense of your claim that your AGW authorities are giving us solid well-founded science. They noisily promoted a gross piece of statistical misanalysis. And this concerning one of the most crucial empirical tests bearing on AGW theory, the long-term global temperature record.
If we are going to reject anything not published in a peer reviewed journal I suggest we start with Darwin’s Origin of Species and Einstein’s Relativity Theory. Worse yet, neither author had a PhD nor were they working at a recognised research institute.
Schiller – “You don’t whine about how you didn’t see a widely-reprinted and commonly-known study”
I know very well what the publication was – I was wondering if you do and the fact that the top peer reviewed journals would not print it.
“The reason the Medieval Optimum is missing is because the model is designed to generate hockey sticks.”
BTW I really think that you should read WSS before insulting my knowledge. I am not a scientist and my knowledge is indeed small however I managed to search through WSS for the word random. I only found 3 references and only in relation to pink and white noise. WSS did not say that that PC analysis produces hockey sticks, it disagrees with MBHs centering of the analysis. This is hauntingly familiar to MM and has been refuted time and time again by MBH and almost every other climate scientist involved in proxy studies.
Perhaps you can provide the quote from the report that supports your argument. Here is the last part of the report where Wegmann et al at least make an attempt to set the record straight.
“We note here that we are statisticians/mathematicians who were asked to
comment on the correctness of the methodology found in MBH98/99. In this report we have focused on answering this question and not on whether or not the global climate is changing. We have discussed paleoclimatology only to the extent that it was necessary to make our discussion of the statistical issues clear.
The instrumented temperature record makes it clear that global temperatures have risen since 1850 CE. How this present era compares to previous epochs is not clear because the uncertainties in the proxies. However, it is clear that average global temperature increases are not the real focus. It is the temperature increases at the poles that matter and average global or Northern Hemisphere increases do not address the issue. We note that according to experts at NASA’s JPL, the average ocean height is increasing by approximately 1 millimeter per year, half of which is due to melting of polar ice and the other half due to thermal expansion. The latter fact implies that the oceans are absorbing tremendous amounts of heat, which is much more alarming because of the coupling of ocean circulation to the atmosphere. (See Wunsch 2002, 2006).”
Careful Walter – questionning any part of AGW science can lead in some quarters ( not here I might add – Ender, Phil and co are generally pretty rational and honourable)to accusations that one is also a creationist!
Presumably , flat earther , astrology nut and bombers on the surface of the moon proponent could also be included.
As ad hominem goes “creationist” is not that stinging a slur I suppose but probably better to leave Darwin out of the discussion lest we attract the attention of the “four legs good ; two legs bad ” chanters!
Ender is now worrying about the temperature at the poles. Ender, why didn’t you mention that the Arctic was hotter circa 1940 than today, and that overall Antarctica is gaining ice? Readers may also wish to check out Ender’s latest effort on Andrew Bolt’s blog – Andrew was pronounced to be using the ‘wrong’ report on the credibility of the hockey stick. In reality, the ‘right’ report (NAS) debunked the hockey stick diplomatically and the ‘wrong’ report (Wegman)debunked it bluntly. Both agreed that the hockey stick statistics were wrong, and that the associated claim of unprecedented warming at the end of the last millennium is unsound.
David Elder – so lacking any credible information, references or indeed science you are resorting to derisory attacks on me – good one. The NAS report said no such thing and repeating such lies only adds to the thinness of your own arguments. The Smokey Joe report was critical however it is not accepted by anyone other than contrarians.
So where is the reference for your claim that the Arctic was warmer in 1940? The Antarctic is gaining ice in some small areas due to an increase in precipitation due to a lack of ozone. Overall recent studies show that other areas are losing ice at an unprecendented rate.
http://sciencemag.org/cgi/content/abstract/302/5646/856
“Larsen Ice Shelf Has Progressively Thinned
Andrew Shepherd,1* Duncan Wingham,2 Tony Payne,3 Pedro Skvarca4
The retreat and collapse of Antarctic Peninsula ice shelves in tandem with a regional atmospheric warming has fueled speculation as to how these events may be related. Satellite radar altimeter measurements show that between 1992 and 2001 the Larsen Ice Shelf lowered by up to 0.27 ± 0.11 meters per year. The lowering is explained by increased summer melt-water and the loss of basal ice through melting. Enhanced ocean-driven melting may provide a simple link between regional climate warming and the successive disintegration of sections of the Larsen Ice Shelf”
http://www.geo.utexas.edu/courses/387h/PAPERS/Oppenheimer%201998%20Nature.pdf
“Assessment of the mass balance for only grounded ice92,93 yields a very different perspective (Table 1). Uncertainties are high because the mass balance is derived from differences between large and uncertain accumulation/loss estimates34 and because direct velocity measurements for most of the inland ice of the Weddell sector do not exist. Nevertheless, the negative total ice-sheet mass balance can be reconciled with the positive grounded mass balance estimates review article
328 NATURE |VOL 393 | 28 MAY 1998
only if the ice shelves are undergoing unreasonably rapid shrinkage. These issues will not be resolved until accurate ice elevations
become available from satellite-based laser altimetry. This mass-balance analysis says little about the stability of WAIS
beyond undercutting the argument that it is stable because it is not losing mass. Nevertheless,WAIS-average net discharge of grounded ice would need to increase by more than a factor of six to change the framework of the global sea-level rise problem as posed by IPCC
(that is, to double the best estimate of ,50 cm rise over the coming century).”
Now for the Arctic:
http://www.agu.org/pubs/abs/jc/1999JC900082/tmp.html
“Satellite passive-microwave data for November 1978 through December 1996 reveal marked seasonal, regional, and interannual variabilities, with an overall decreasing trend of -34,300 3,700 km/yr (-2.8 %/decade) in Arctic sea ice extents over the 18.2-year period”
http://sciencemag.org/cgi/content/summary/286/5446/1828
“CLIMATE CHANGE:
Will the Arctic Ocean Lose All Its Ice?
Richard A. Kerr
According to reports in this issue of Science (pp. 1934 and 1937) and the 15 December issue of Geophysical Research Letters, the arctic ice pack is not only shrinking in area but rapidly thinning as well. The big question now is what’s causing the shrinkage: natural polar climate fluctuations or global warming due to increasing levels of greenhouse gases. If it’s all natural, the loss of arctic ice should eventually reverse, but if global warming is at fault, the entire ice pack will eventually disappear, with drastic climate implications for the Northern Hemisphere.
So David do you actually have any information or do you want to sling off at me a bit more.
Sorry – Antarctica is now losing ice – see my Science quotes on http://www.jennifermarohasy.com/blog/archives/001487.html#comments
Things have changed in recent years including increased instability of the Greenland systems. As I said there “you need to get updated”. Things are moving.
And in terms of moving on:
(1) What happens to AGW if the Hockey Stick is wrong? Anything ? I’m contending there is actually reason to be more worried not less.
(2) Does anyone got a graph of what “the right” statistical says. Or is everyone now chicken that McIntyre will beat up on them ? The reviews seem to be saying that we don’t really know the extent of the Medieval Warming – is that the correct slant? So maybe it is unprecedented – maybe it isn’t? We simply don’t know??
David Elder – “Ender is now worrying about the temperature at the poles”
No I did not say it – Wegman did. Wegman also only said that MBH98 was unsound and using it the claims of unprecendented warming is unsound however they did not comment or study ANY of the other 5 studies that showed practically the same thing. MBH would be the first to concede that you should not use one study to refute or claim a position. This is why the studies are replicalted. MBHs peers, not M&M who are not, replicated and checked the original study and did ones of their own that comfimed the original and extended the knowledge of paleoclimate.
There are now at least 5 other studies showing recent warming is unprecedented. Neither M&M or WSS commented on any of these in any peer reviewed journal.
I am afraid that it is you who is backing a lost cause. Science is marching on while you are trying to use a 8 year old study as a swiftboat issue.
John – “You’re full of it as usual Ender. I figure that you produce enough hot air by yourself to account for some of the warming.
You parrot http://www.realclimate.org as if it was the authority on such matters”
However you parrot climateaudit in exactly the same way. At least the people at Real Climate are qualified climate scientists – the same cannot be said of climateaudit.
“Mann’s response is utter drivel – or are you too blind to see that?”
When people use this type of language it really tags them – you would not be JohnA would you? Have the people getting a pounding here called in the ‘big’ guns?
As for your other drivel – take it to Real Climate where the big boys are – they have already dealt with all this stuff. No-one disputes that there were Vikings in Greenland however that gives no quantative clue as to the temperature at the time. So where else is MBH98? Your claim that it underpins the IPCC report is only lies intended to decieve the ignorant. Again I go back to the competance of M&M – 5 other groups managed to replicate the study with the supplied data without any problems. and so on and on. Smokey Joe recieved $500 000 from the oil and gas industry in 2004 – it that not a link? How about WSS do a social analysis of Barton, M&M, yourself and the rest of the crowd. Perhaps they can start in the pro-smoking campaign.
Try again this time try not to quote a site run by a mining engineer and an economist. And you could try being a bit more polite – I know that is not your style however we have kept this discussion pretty polite so have a go.
To Luke: ‘moving on?’
Antarctica is losing ice – yes, in places. What about the whole continent?
Increased instability in Greenland – yes, in places. What about the whole island?
In both cases, my understanding is that ice losses in some places are offset or more by gains elsewhere. And what about the fact (to repeat) that the Arctic was warmer circa 1940 than today?
The demise of the hockey stick shows that the late-millennium warming cannot soundly be claimed to be dangerously unprecedented, as Mann (et al) or the IPCC supposed.
The ‘right’ temperature is probably hard to precisely estimate a millennium back. But two proxies, Esper 2002 and Moberg 2005, to repeat, suggest a MWP about as warm as today.
You fret that everybody is now scared of McIntyre. This fear is easily allayed – do the statistics properly. Avoid bad methods like those of Mann (et al) which turn just about any data into a hockey stick – as is now clear.
In one area I have some sympathy with Luke. I have no objection to sensible precautions to cut CO2 emissions – the recent AP6 initiative including the US and Australia on emission-reduction technology for instance. I do have problems with Greens using alarmist hokum like the hockey stick to ram something like Kyoto down our throats despite the fact that the EU is finding it unworkable – unless these countries want to put lots of ordinary people out of work.
Luke,
I don’t think anything “happens” to AGW if the hockey stick is discredited. Ender has made the point previously that the expert concensus doesn’t rely on one study.
However, doesn’t it significantly damage the credibility of those who have made much of the ” warmest decade in 1000 years ” call ( Ender the NAS study definitely DOESN’T endorse that statement)?
Doesn’t it demonstrate that those who so vociferously attacked critics of MBH98 were ( and are) themselves wrong?
If the public have to be persuaded about the theory of AGW then the discrediting of key sources doesn’t help.
So what does the whole episode hold for the future?
More humility and acknowledgement of uncertainty or will ideological zeal win out?
Ender, Wegman poles apart? David Elder replies:
Sorry, Ender, I thought that you were worried about climate at the poles. I thought this because you quoted Wegman to that effect. I was assuming you did so because you agreed with him. So – you’re not worried about the climate at the poles, then? . . . Oh, by the way, a trivial side-issue – what’s your scientific answer to my central query as to why the Arctic was warmer circa 1940 than today? NB. Answers involving oil companies, swiftboats and Ender’s 5 selected studies – coupled with Ender’s ignoring or misquoting contrasting studies such as Esper 2002 or Moberg 2005, as Ender has done about four times now – will not qualify an as answer.
David – but of course AGW is just getting going. Nowhere near double CO2 yet.And what conditions did the world experience in terms of heatwaves, droughts, floods, cyclones during perhaps an equally warm Medieval warming. The recent ten years has more than its share of climate nasties.
In terms of parts of Antartica and Greenland – I’m not so sure anymore – but in any case some local warming would increase the hydrological cycle so some local increase in snow pack might be expected early on. I think AGW theorists have long made this point. Plus Antarctica has complication like circumpolar voretx etc. Anyway my point is that the recent publications in Science indicate things seem to be “speeding up”. Changes are becoming more apparent.
And all of this with no solar driver.
On the Artic being warmer in 1940 – do you have a reference he asks?
On Kyoto – a lesson in hopelessness perhaps – but what hope have we got if we can’t make it work. And AP6 hasn’t done anything yet – my opinion is technology at making oil from coal, but little on CO2. But I should be more hopeful I guess.
David – “So – you’re not worried about the climate at the poles, then?”
So we are at the hair splitting part of the discussion. This normally happens when one side runs out of ideas.
“Oh, by the way, a trivial side-issue – what’s your scientific answer to my central query as to why the Arctic was warmer circa 1940 than today?”
Where is your evidence?
“Answers involving oil companies, swiftboats and Ender’s 5 selected studies ”
I am sorry I was wrong there are 8 according to wikipedia:
http://en.wikipedia.org/wiki/Image:1000_Year_Temperature_Comparison.png
Sure and your comments involving such irrefutable and quantative sources like “vinyards in England and “vikings in Greenland” are proof that the MWP was warmer that today are equally amusing.
# (light blue 1000-1965): Crowley and Lowery (2000). “Northern Hemisphere Temperature Reconstruction”. Ambio 29: 51-54. Modified as published in Crowley (2000). “Causes of Climate Change Over the Past 1000 Years”. Science 289: 270-277.
# (lightest blue 1402-1960): K.R. Briffa, T.J. Osborn, F.H. Schweingruber, I.C. Harris, P.D. Jones, S.G. Shiyatov, S.G. and E.A. Vaganov (2001). “Low-frequency temperature variations from a northern tree-ring density network”. J. Geophys. Res. 106: 2929-2941.
# (light green 831-1992): J. Esper, E.R. Cook, and F.H. Schweingruber (2002). “Low-Frequency Signals in Long Tree-Ring Chronologies for Reconstructing Past Temperature Variability”. Science 295 (5563): 2250-2253.
# (yellow 200-1980): M.E. Mann and P.D. Jones (2003). “Global Surface Temperatures over the Past Two Millennia”. Geophysical Research Letters 30 (15): 1820. DOI:10.1029/2003GL017814 .
# (orange 200-1995): P.D. Jones and M.E. Mann (2004). “Climate Over Past Millennia”. Reviews of Geophysics 42: RG2002. DOI:10.1029/2003RG000143
# (red-orange 1500-1980): S. Huang (2004). “Merging Information from Different Resources for New Insights into Climate Change in the Past and Future”. Geophys. Res Lett. 31: L13205. DOI:10.1029/2004GL019781
# (red 1-1979): A. Moberg, D.M. Sonechkin, K. Holmgren, N.M. Datsenko and W. Karlén (2005). “Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data”. Nature 443: 613-617. DOI:10.1038/nature03265
# (dark red 1600-1990): J.H. Oerlemans (2005). “Extracting a Climate Signal from 169 Glacier Records”. Science 308: 675-677. DOI:10.1126/science.1107046
And guess what they all show much the same thing.
“ignoring or misquoting contrasting studies such as Esper 2002 or Moberg 2005”
Why are these studies contrasting? They are both on the Wikipedia graph that I posted before and they seem to pretty much agree. Perhaps you can explain while you are looking up the data for the Arctic in 1940. Perhaps you could start here:
http://www.springerlink.com/(in0wl3jdaegsn055byltojqf)/app/home/contribution.asp?referrer=parent&backto=issue,6,7;journal,72,222;linkingpublicationresults,1:100247,1
The stunner for me on the hockey stick debacle was the way that the MWP was reduced to a localisd event (so virtually non-existent) but a proxie of some trees up in the Sierra Nevadas(don’t mention the bristlecones) extrapolates to a world wide global warming
First of all I thought the human civilization started in the northern hemisphere then finally walked/worked their way down south. It seems as if we follow the temperate weather for our food to grow? Second of all I do not dismiss the global warming factor. Maybe due to there being alot of reflective substances being exposed to the sun/atmosphere such as concrete and tar for roads and not to mention roof tiles. What about bare dirt that exists without vegetation.
Whenever I have ever walked into a DRY rainforest it has always felt abit cooler in the middle of that forest. So maybe vegetation plays a big part. How do we know if all these reflective type substances do not contribute to BURNING a hole in the ozone layer therefore exposing us to more heat? Hence global warming.
I honestly still do not think we are doing enough and do not take this issue seriously.
Maybe it could be just evolution also? How would we know? We are humans and prone to mistakes.
Jen – some of my posts are not getting through – Is there a problem with your provider again?
Ender, I just checked the back-end of this blog and there were two from you (from 7 and more hours ago) and 1 from Ian Mott (from the Dam thread) caught in the system. They’ve just been cleared and will now have been automatically inserted into the above thread at the time you posted them. Sorry for not checking more diligently! Cheers,
Ok then, isn’t it time to build a more nuclear power stations just in case – all agreed!
Siltstone – “Ok then, isn’t it time to build a more nuclear power stations just in case – all agreed!”
No
I would like to draw attention to a paper in the current issue of Science. Venkataramana Sridhar et al. – Large Wind Shift on the Great Plains During the Medieval Warm Period. In conclusion it states: “The MWP was a time of warmth and aridity throughout much of the western United States (7, 8, 16); this suggests that the circulation change indicated by dune morphology is part of a larger climate anomaly (33). A switch in Pacific sea-surface temperature (SST) to a quasi-perennial “La Niña” state may be an important factor (33), because such an SST regime has been associated with drought throughout much of the western half of the United States (8). This concept may also help explain more pronounced episodes of aridity during the mid-Holocene, and it has seen recent support from climate modeling studies (34).”
MWP in the western U.S, more pronounced episodes of aridity during the mid-Holocene, major climate shifts not attributable to CO2. Worse yet, in Science and peer reviewed. This is heresy. Where is the Inquisition now that it’s really needed?
Jeepers – nobody is saying that CO2 is the only driver of climate. So why is this heresy? If you think that – it simply shows how misrepresented the AGW case is in your mind. There have been a number of paleo climate modelling studies. Welcome to the real world Walter.
So imagine the USA enjoying this climate today?? I’m sure they’d flick a techno fix and emerge totally unscathed (not!).
So what would a good helping of CO2 do on top of your Holocene shift??
Incidentally do we have an indication of what drove the alleged global MWP.
Walter – “MWP in the western U.S, more pronounced episodes of aridity during the mid-Holocene, major climate shifts not attributable to CO2. Worse yet, in Science and peer reviewed. This is heresy. Where is the Inquisition now that it’s really needed?”
Walter why is this heresy? We all recognise that climate shifts have happened in the past before humans. That does not change in any way our responsibility for this one.
Also it illustrates the winners and losers. If the MWP was indeed a global event it caused a period of plenty for Northern Europe. However the losers are very well illustrated by this study. This sort of deflates the warm is good argument. In any climate change event, other than an all out ice age, there are winners and losers. In the MWP Northern Europe were probably the winners and recorded the event however, it is not recorded who the losers were because they died out and did not leave records. In short history is written by the winners.
This climate event will also have winners and losers. The problem is who will be the losers and what will they do while they are losing. Also you or I do not know, and no-one can predict the ratio of winners to losers.
Ender: we’ll have to stop meeting like this. It’s bad for both our blood pressures. In future I will simply give you enough rope and let you hang yourself.
David Elder – “In future I will simply give you enough rope and let you hang yourself”
Sure mate. If this makes you feel better then go for it. Perhaps while you are waiting for me to swing you can educate yourself so your posts can in future contain some information rather than climate audit bullshit.
I’d be interested in some opinions on this – RC reckon everyone except Van Storch has missed the point .. ..
“So what would have happened to the MBH results if Wegman and his colleagues had been consulted on PC centering conventions at the time? Absolutely nothing. ”
Wrong stats but right answer??
http://www.realclimate.org/index.php/archives/2006/07/the-missing-piece-at-the-wegman-hearing/#more-328
As a biologist I am a bit skeptical about tree ring data as changes in ring width could also be caused by changes in aridity, it is not at all clear that proxies strongly reliant on tree rings have adequately differentiated the two signals (temperature and aridity) these two variables could act together in complex ways and make the individual signals quite vague. It may even be worse at some sites where solar radiation is limiting. Never the less, the data from the last few hundred years or so indicates a rapid change of considerable magnitude which we all need to be concerned about.
One thing which seems to have escaped all eyes is looking at the graph critically.
The dark ‘median’ line – the 40 year smoothed – shows a distinct peak or series of peaks in the period pre 1400 – about the time we are talking of the Norse in the western North Atlantic. Just because the peaks are below the line marked ‘0.0’ is not a reason to dismiss them. That line is an anomaly above or below the period 1961-1990 – already over a hundred years into the period of AGW. If you draw the line through, say, an equivalent period in the early 1700’s (pre industrial revolution) then the period in concern is warmer than the ‘average’, but not as warm as now. The ‘0.0’ value would drop by 0.3.
The main things to get from the graph are that the current period is showing a rapid increase in rate of change, as well as a rapid increase in extent. Both are important, and much more important than either independently.
Also, it was nice to see someone else mention that the extent of cleared lands, of bared soil and of ‘anthropogenic habitat change’ that may be an important causal factor too. No one can deny that we have much more land under production now than at any other time in history – certainly more than would have been needed to feed the (maybe maximum of) 1 billion inhabitants on the planet in the early years of the industrial revolution.
No one has pointed out, either, that there is one system not accounted for here (oceanic CO2 dampening). What we are seeing may be that that system is getting close to capacity, and so the first 100 years or so of released CO2 ‘filled up’ the buffer, and now the problem may get much worse.
As the Hitch Hiker’s Guide to the Galaxy says, of dealing with the hagumemnons – ‘run away, very fast…’
Greg – You are absolutely correct here. Some of the things you mention have been touched on in previous discussions however you make some good points.
As far as I am concerned the various proxy studies do show that 20th century warming is unprecendented.