Another Powerful Email from Climategate

You have to listen carefully to some people. Oppenheimer was completely dishonest in the recent CNN interview and unless you want to give your IQ points away (and my wife will tell you, at least one of us cannot afford to), you probably shouldn’t listen to that drivel. Steve McIntyre, whom has yet to blog substantially on these emails (and he should soon), made a point to the CNN reporter that Briffa had commented it was as warm in the medieval warm period MWP as it is today. It’s an older email (1999) but it’s NOT consistent with the messages presented in the IPCC reports- ever. Kieth may have changed his mind on ALL of the points in this email, but half the SKEPTIC arguments were made by Keith Briffa over ten years ago in a private email – pre Wegman. The whole thing makes me wonder if team pressure has pushed an otherwise blunt and honest Doc into some unusual positions.

The email is shown twice below, once with a few bolds, the second time with inline comments in green.

From: Keith Briffa <k.briffa@uea.ac.uk>
To: “Folland, Chris” <ckfolland@meto.gov.uk>, ‘Phil Jones’ <p.jones@uea.ac.uk>, “Michael E. Mann” <mann@multiproxy.evsc.virginia.edu>
Subject: RE: IPCC revisions
Date: Wed Sep 22 16:19:06 1999
Cc: tkarl@ncdc.noaa.gov

Hi everyone
Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable .

First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response. Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat .Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues.

Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

cheers to all
Keith

Nearly every single SKEPTIC complaint about proxy reconstructions is included in this email and its TEN YEARS OLD! Hell it’s a wonder Wikipedia didn’ t add him to the skeptic blacklist. Wiki needs money BTW, but I ain’t givin’ them a penny, there’s too much slant in the information.

I don’t know the best way to do this but I’ll put the same email as above with my comments inline in green.

Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable .

First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response. (Lessee multiple regression is dangerous because you could calibrate proxies to ANYTHING. Especially true with a TRENDY global mean series. It’s hard to know where to begin, how about find any signal you want with CPS poor man MV regression, or every point I made in Mann Analog vs Digital. They know this crap is crap, and they have known it since they started. Think about what that means. How about the point that I’ve made repeatedly that the real reason for using the high trend dataset in reconstructions is improved correlation numbers. Wow, just absolutely wow. Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent (this was one of the primary findings of the Wegman report. PRIMARY FINDING—- think about that. Every time someone points out that you can’t do multivariate regression against a slope with noisy data, because you get whatever you want, they say — look it’s confirmed by this other study. In fact that’s how the Advocaticians at Real Climate just defended Briffa’s Yamal last month. but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat . Glacier retreat isn’t temperature. Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . Another primary issue SKEPTICS have with reconstructions is that even if tree’s respond to temperature, how do we know it’s linear. Before the science was completely corrupted people used to discuss these things. Today, it’s heresy, UNFUNDED heresy. Craig Loehle has a recent, and amazingly clear paper on the topic – it’s almost ignored in climatoknowledgy. I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter. This is admission that the politics are corrupting the science. The pressure exists for consensus even ten years ago, no pre-industrial warming can be tolerated if goals are to be achieved.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues. Now at this point, I don’ t think Dr. Briffa can do anything but say he’s changed his mind since that time. However, he can’t say it’s because of new studies of the ‘same friggin’ data’ he might tho. He can’t say it’s because of the improvements in multivariate regression – they are the same. Think RegEM, TTLS, TLS, CPS (in an odd way), EIV and whatever Mann09 is called.

Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

I don’t know about you, but from a history of skepticism, Steve’s right, this email is a beast.

Don’t worry tho, there are many more. Tom Fuller rightly stated that Climategate is settling down as the drive by’s keep going. However, the better stories are yet to come.

From: Keith Briffa <k.briffa@uea.ac.uk>
To: “Folland, Chris” <ckfolland@meto.gov.uk>, ‘Phil Jones’ <p.jones@uea.ac.uk>, “Michael E. Mann” <mann@multiproxy.evsc.virginia.edu>
Subject: RE: IPCC revisions
Date: Wed Sep 22 16:19:06 1999
Cc: tkarl@ncdc.noaa.gov

Hi everyone
Let me say that I don’t mind what you put in the policy makers summary if there is a general concensus. However some general discussion would be valuable . First , like Phil , I think that the supposed separation of the tree-ring reconstruction from the others on the grounds that it is not a true “multi-proxy” series is hard to justify. What is true is that these particular tree-ring data best represent SUMMER temperatures mostly at the northern boreal forest regions. By virtue of this , they also definately share significant variance with Northern Hemisphere land and land and marine ANNUAL temperatures – but at decadal and multidecadal timescales – simply by virtue of the fact that these series correlated with the former at these timescales. The multi proxy series (Mann et al . Jones et al) supposedly represent annual and summer seasons respectively, and both contain large proportions of tree-ring input. The latest tree-ring density curve ( i.e. our data that have been processed to retain low frequency information) shows more similarity to the other two series- as do a number of other lower resolution data ( Bradley et al, Peck et al ., and new Crowley series – see our recent Science piece) whether this represents ‘TRUTH’ however is a difficult problem. I know Mike thinks his series is the ‘best’ and he might be right – but he may also be too dismissive of other data and possibly over confident in his (or should I say his use of other’s). After all, the early ( pre-instrumental) data are much less reliable as indicators of global temperature than is apparent in modern calibrations that include them and when we don’t know the precise role of particular proxies in the earlier portions of reconstruction it remains problematic to assign genuine confidence limits at multidecadal and longer timescales. I still contend that multiple regression against the recent very trendy global mean series is potentially dangerous. You could calibrate the proxies to any number of seasons , regardless of their true optimum response . Not for a moment am I saying that the tree-ring , or any other proxy data, are better than Mike’s series – indeed I am saying that the various reconstructions are not independent but that they likely contribute more information about reality together than they do alone. I do believe , that it should not be taken as read that Mike’s series (or Jone’s et al. for that matter) is THE CORRECT ONE. I prefer a Figure that shows a multitude of reconstructions (e.g similar to that in my Science piece). Incidently, arguing that any particular series is probably better on the basis of what we now about glaciers or solar output is flaky indeed. Glacier mass balance is driven by the difference mainly in winter accumulation and summer ablation , filtered in a complex non-linear way to give variously lagged tongue advance/retreat .Simple inference on the precidence of modern day snout positions does not translate easily into absolute (or relative) temperature levels now or in the past. Similarly, I don’t see that we are able to substantiate the veracity of different temperature reconstructions through reference to Solar forcing theories without making assumptions on the effectiveness of (seasonally specific ) long-term insolation changes in different parts of the globe and the contribution of solar forcing to the observed 20th century warming .
There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . I know there is pressure to present a nice tidy story as regards ‘apparent unprecedented warming in a thousand years or more in the proxy data’ but in reality the situation is not quite so simple. We don’t have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter.
For the record, I do believe that the proxy data do show unusually warm conditions in recent decades. I am not sure that this unusual warming is so clear in the summer responsive data. I believe that the recent warmth was probably matched about 1000 years ago. I do not believe that global mean annual temperatures have simply cooled progressively over thousands of years as Mike appears to and I contend that that there is strong evidence for major changes in climate over the Holocene (not Milankovich) that require explanation and that could represent part of the current or future background variability of our climate. I think the Venice meeting will be a good place to air these isssues.
Finally I appologise for this rather self-indulgent ramble, but I thought I may as well voice these points to you . I too would be happy to go through the recent draft of the chapter when it becomes available.

cheers to all
Keith