Climategate emails

The following are some of the controversial ClimateGate emails, grouped by category:

Dendrochronology

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Because how can we be critical of Crowley for throwing out 40-years in the middle of his calibration, when we’re throwing out all post-1960 data ‘cos the MXD has a non-temperature signal in it, and also all pre-1881 or pre-1871 data ‘cos the temperature data may have a non-temperature signal in it! If we write the Holocene forum article then we’ll have to be critical or our paper as well as Crowley’s! ... Also we have applied a completely artificial adjustment to the data after 1960, so they look closer to observed temperatures than the tree-ring data actually were Also, we set all post-1960 values to missing in the MXD data set (due to decline), and the method will infill these, estimating them from the real temperatures – another way of “correcting” for the decline, though may be not defensible![Tim Osborne][1]

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We actually eliminate records with negative correlations (this is mentioned breifly in the GRL article,), and we investigated a variety of weighting schemes to assure the basic robustness of the composite--but I certainly endorse your broader point here. Many of these records have some significant uncertainties or possible sources of bias, and this isn't the place to get into that. [Michael Mann] ... It was a majority decision to leave the Mann and Jones 2000-year series in the Figure 1 (as it was to remove the Briffa and Osborn tree-ring based one) , and the details of the logic used to derive the Mann and Jones series is to be found in the (cited) text of their paper. Signing on to this letter , in my mind. implies agreement with the text and not individual endorsement of all curves by each author. I too have expressed my concern to Phil (and Ray) over the logic that you leave all series you want in but just weight them according to some (sometimes low) correlation (in this case based on decadal values). I also believe some of the series that make up the Chinese record are dubious or obscure , but the same is true of other records Mann and Jones have used (e.g. how do you handle a series in New Zealand that has a -0.25 correlation?) . Further serious problems are still (see my and Tim's Science comment on the Mann 1999 paper) lurking with the correction applied to the Western US tree-ring PC amplitude series used (and shown in Figure 2). There are problems (and limitations ) with ALL series used. At this stage , singling out individual records for added (and unavoidably cursory added description) is not practical. [Keith Briffa][2]

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1. There are few tree-core series that extend beyond the early 1980s. This is because many of the sites we're using were cored before the early 1980s. So most tree-ring records just don't exist post 1980. [Phil Jones] ... If you look at the figure in the attached article in Science by Briffa and Osborn, you will note that tree-ring temperature reconstructions are flat from 1950 onward. I asked Mike Mann about this discrepancy at a meeting recently, and he said he didn't have an explanation. It sounded like it is an embarrassment to the tree ring community that their indicator does not seem to be responding to the pronounced warming of the past 50 years. Ed Cook of the Lamont Tree-Ring Lab tells me that there is some speculation that stratospheric ozone depletion may have affected the trees, in which case the pre-1950 record is OK. But alternatively, he says it is possible that the trees have exceeded the linear part of their temperature-sensitive range, and they no longer are stimulated by temperature. In this case there is trouble for the paleo record. Kieth Briffa first documented this late 20th century loss of response. Personally, I think that the tree ring records should be able to reproduce the instrumental record, as a first test of the validity of this proxy. To me it casts doubt on the integrity of this proxy that it fails this test. Sincerely, Jeff [Severinghaus][3]

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If you examine my Fig 1 closely you will see that the Campito record and Keith's reconstruction from wood density are extraordinarily similar until 1850. After that they differ not only in the lack of long-term trend in Keith's record, but in every other respect - the decadal-scale correlation breaks down. I tried to imply in my e-mail, but will now say it directly, that although a direct carbon dioxide effect is still the best candidate to explain this effect, it is far from proven. In any case, the relevant point is that there is no meaningful correlation with local temperature. Not all high-elevation tree-ring records from the West that might reflect temperature show this upward trend. It is only clear in the driest parts (western) of the region (the Great Basin), above about 3150 meters elevation, in trees old enough (>~800 years) to have lost most of their bark - 'stripbark' trees. As luck would have it, these are precisely the trees that give the chance to build temperature records for most of the Holocene. I am confident that, before AD1850, they do contain a record of decadal-scale growth season temperature variability. I am equally confident that, after that date, they are recording something else. [Malcolm Hughes][4]

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date: Mon Nov 13 09:29:49 2006 from: Keith Briffa subject: Re: Mitrie to: "Nanne Weber" Between you and I , I believe there may be problems with the analysis of the Bristlecone data. We can talk by phone about this Keith[5]

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Global Warming Methodology

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the results of this study will show that we can probably say a fair bit about <100 year extra-tropical NH temperature variability (at least as far as we believe the proxy estimates), but honestly know f***-all about what the >100 year variability was like with any certainty (i.e. we know with certainty that we know f***-all).[Ed Cook][6]

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“

Sorry for sounding a bit testy here. I've been fielding a whole raft of questions, comments, and criticisms from Mike Mann, Tom Crowley, and Malcolm Hughes. Some of them useful, many of them tiresome or besides the point. I never wanted to get involved in this quixotic game of producing the next great NH temperature reconstruction because of the professional politics and sensitivities involved...I should also say that the amount of ignorance about tree rings in the global change/paleo/modeling community is staggering given what has been published. Like it or not, they simply don't read our papers.). ... This all reinforces my determination to leave this NH/global temperature reconstruction junk behind me once I get this paper submitted. It's not worth the aggravation. [Ed Cook][7]

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I am increasingly unconvinced by the majority of climate impact studies - including some of those I am involved in - and feel we are not really giving the right message to our audiences.[Mike Hulme][8]

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All methods strongly underestimates the amplitude of low-frequency variability and trends. This means that it is almost impossible to conclude from reconstruction studies that the present period is warmer than any period in the reconstructed period.[Bo Christiansen][9]

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From: GIORGI FILIPPO To: Chapter 10 LAs -- Congbin Fu , GIORGI FILIPPO , Bruce Hewitson , Mike Hulme , Jens Christensen , Linda Mearns , Richard Jones , Hans von Storch , Peter Whetton Subject: On "what to do?" Date: Mon, 11 Sep 2000 16:58:02 +0200 ???(MET DST) ...First let me say that in general, as my own opinion, I feel rather unconfortable about using not only unpublished but also un reviewed material as the backbone of our conclusions (or any conclusions). I realize that chapter 9 is including SRES stuff, and thus we can and need to do that too, but the fact is that in doing so the rules of IPCC have been softened to the point that in this way the IPCC is not any more an assessment of published science (which is its proclaimed goal) but production of results. The softened condition that the models themself have to be published does not even apply because the Japanese model for example is very different from the published one which gave results not even close to the actual outlier version (in the old dataset the CCC model was the outlier). Essentially, I feel that at this point there are very little rules and almost anything goes. I think this will set a dangerous precedent which might mine the IPCC credibility, and I am a bit unconfortable that now nearly everybody seems to think that it is just ok to do this. Anyways, this is only my opinion for what it is worth.[10]

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Phil, Here are some speculations on correcting SSTs to partly explain the 1940s warming blip. If you look at the attached plot you will see that the land also shows the 1940s blip (as I'm sure you know). So, if we could reduce the ocean blip by, say, 0.15 degC, then this would be significant for the global mean -- but we'd still have to explain the land blip. I've chosen 0.15 here deliberately. This still leaves an ocean blip, and i think one needs to have some form of ocean blip to explain the land blip (via either some common forcing, or ocean forcing land, or vice versa, or all of these). When you look at other blips, the land blips are 1.5 to 2 times (roughly) the ocean blips -- higher sensitivity plus thermal inertia effects. My 0.15 adjustment leaves things consistent with this, so you can see where I am coming from. Removing ENSO does not affect this. It would be good to remove at least part of the 1940s blip, but we are still left with "why the blip". [Tom Wigley, to Phil Jones and Ben Santer][11]

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Date: Thu Mar 27 16:46:23 2008 from: Phil Jones subject: Re: Truncating tem series before filtering to: Mike Salmon Mike, Good. I doubt if any of them will notice. Cheers Phil At 16:44 27/03/2008, you wrote: Hi Phil, [1]http://www.cru.uea.ac.uk/cru/data/temperature/ now has the final year removed if incomplete. Batten hatches and prepare for Skeptix! Mike Prof. Phil Jones Climatic Research Unit Telephone +44 ??? School of Environmental Sciences Fax +44 ??? University of East Anglia Norwich Email ???@uea.ac.uk NR4 7TJ UK[12]

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Freedom of Information Act Sidestepping

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FOI is causing us a lot of problems in CRU and even more for Dave, as he has to respond to them all. It would be good if UEA went along with any other Universities who might be lobbying to remove academic research activities from FOI. FOI is having an impact on my research productivity. I also write references for people leaving CRU, students and others. If I have to write a poor one, I make sure I get the truth to the recipient in a phone call. I'm also much less helpful responding to members of the public who email CRU regularly than I was 2-3 years ago. I've seen some of what I considered private and frank emails appear on websites. Issue here is blogsites have allowed these climate change deniers to find one another around the world. Cheers Phil[13]

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From: Phil Jones To: "Tas van Ommen" Subject: Re: FW: Law Dome O18 Date: Mon Feb 9 09:23:43 2004 Cc: ???@virginia.edu Dear Tas, Thanks for the email. Steve McIntyre hasn't contacted me directly about Law Dome (yet), nor about any of the series used in the 1998 Holocene paper or the 2003 GRL one with Mike. I suspect (hope) that he won't. I had some emails with him a few years ago when he wanted to get all the station temperature data we use here in CRU. At that time, I hid behind the fact that some of the data had been received from individuals and not directly from Met Services through the Global Telecommunications Service (GTS) or through GCOS.[14]

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Ethics Breaches

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[2009 email, Mike Mann to Phil Jones] On a completely unrelated note, I was wondering if you, perhaps in tandem w/ some of the other usual suspects, might be interested in returning the favor this year ;) I've looked over the current list of AGU fellows, and it seems to me that there are quite a few who have gotten in (e.g. Kurt Cuffey, Amy Clement, and many others) who aren't as far along as me in their careers, so I think I ought to be a strong candidate. anyway, I don't want to pressure you in any way, but if you think you'd be willing to help organize,I would naturally be much obliged. Perhaps you could convince Ray or Malcolm to take the lead? The deadline looks as if it is again July 1 this year. looking forward to catching up w/ you sometime soon, probably at some exotic location of Henry's choosing ;) mike[15]

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Censorship

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Thanks Mike It seems to me that this "Kinne" character's words are disingenuous, and he probably supports what De Freitas is trying to do. It seems clear we have to go above him. I think that the community should, as Mike H has previously suggested in this eventuality, terminate its involvement with this journal at all levels--reviewing, editing, and submitting, and leave it to wither way into oblivion and disrepute, Thanks, mike[16]

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Solar Warming

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Simon Tett and I went to conference that the press releases relates to. This was in Tenerife last week. The conference was entitled solar variability and climate, but climatologists were very thin on the ground...Many in the solar terrestrial physics community seem totally convinced that solar output changes can explain most of the observed changes we are seeing. The far-sighted ones are begining to doubt with the rapid rate of recent warming, however. ... There was nothing new at the conference, but the solar terrestrial group are not going to go away. The next IPCC report may keep them quiet for a while, but trying to downplay solar influences in thier mind will probably be impossible. As with the greenhouse skeptics they are so set in their ways and have little comprehension of our literature beyond what they read in Science and Nature.[Phil Jones][17]

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Medieval Warming Period and Little Ice Age

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date: Wed, 30 Aug 2000 14:07:38 -0400 from: Ed Cook subject: Oroko Swamp to: Keith Briffa Hi Keith, Here is the Oroko Swamp RCS chronology plot in an attached Word 98 file and actual data values below. It certainly looks pretty spooky to me with strong "Medieval Warm Period" and "Little Ice Age" signals in it. It's based on substantially more replication than the series in the paper you have to review (hint, hint!)...[Ed Cook][18]

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It is important to learn about past climate change, especially over the past 1000 years, but it is even important to use new and improved evidence from proxy sources (i.e. not to cling to outdated concepts of the past such as the MWP and LIA). How can we ever hope to progress if we have conform to incorrect concepts? On the early mid-20th century warming - look at the figures in Ch 9. The decrease from 1940-75 didn't happen if you look at global records. MBH was published in 1998 and wasn't just a tree-ring study. [Phil Jones][19]

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Hi Phil, Kevin, Mike, Susan and Ben - I'm looking for some IPCC-related advice, so thanks in advance. The email below recently came in and I googled "We have to get rid of the warm medieval period" and "Overpeck" and indeed, there is a person David Deeming that attributes the quote to an email from me. He apparently did mention the quote (but I don't think me) in a Senate hearing. His "news" (often with attribution to me) appears to be getting widespread coverage on the internet. It is upsetting. I have no memory of emailing w/ him, nor any record of doing so (I need to do an exhaustive search I guess), nor any memory of him period. I assume it is possible that I emailed w/ him long ago, and that he's taking the quote out of context, since know I would never have said what he's saying I would have, at least in the context he is implying. Any idea what my reaction should be? I usually ignore this kind of misinformation, but I can imagine that it could take on a life of it's own and that I might want to deal with it now, rather than later. I could - as the person below suggests - make a quick statement on a web site that the attribution to me is false, but I suspect that this Deeming guy could then produce a fake email. I would then say it's fake. Or just ignore? Or something else?[20]

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