Dear Chapter 10,
Sorry I missed out on the meeting.
In general I like the proposed Figure and suggested Box contents (and I
particularly agree that the diversity of downscaling methods and results
precludes using them as a basis of consolidated regional conclusions).  I
also agree with others that it looks better with the +- signs
included.  However, there are 2-3 points that concern me, mostly from the
perspective of climate scenarios (Chapter 13 - and also Chapter 9).
- it needs to be made very clear if any numbers are cited in the Box (e.g.
2-6degC for continental warming) that these refer to only *one* forcing
scenario, namely 1% p.a.
- rather than talk about GHG and SUL I would suggest the more conventional
nomenclature of GG and GS (the SUL runs are not just SUL forcing of course,
which might give that impression).
- another very important caveat concerns the GS (SUL) results - these all
stem from IS92a type aerosol forcing a la IPCC SAR.  Most of the new SRES
forcings used in TAR and Chapter 9 for example have much smaller or even
positive SO4 forcing relative to 1990.  In principle this could actually
switch the sign of the precip. changes in some regions.  There is the
danger of inconsistency here between Chapter 9 (TAR aerosol effects) and
Chapter 10 Box (SAR aerosol effects) if this is not carefully
explained.  For example, in CAM and JJA it appears that aerosols switch the
P change from 'strongly negative' to being 'uncertain' - but this is only
for IS92a aerosol forcing: it is not a conclusion that would be valid for
SRES aerosol forcing!
- as Filippo says, another key uncertainty not represented in the Box is
forcing uncertainty - again, Chapter 9 present a wide range of Tglobal
results, part of which relates to prior assumptions about which SRES
forcing materialises.  We do a disservice if we give the impression in
Chapter 10 Box that these regional responses are independent of what future
forcing materialises.  For example, under the lowest SRES forcing (B1) the
precip. response in some regions would revert back to being very small and
therefore indistinguishable from noise.
- with regard to temperature and Filippo's comment, Chapter 9 has global
maps of T change, averaged across the standard set of AOGCM experiments
(ranges are also shown).  This is in effect the information being
sought-for by readers of Chapter 10 is it not.  I would have thought that
back-references in the Box to Figure 9.9 would be sensible.
See you all in Victoria,
Mike
At 14:35 27/06/00 +0100, Noguer, Maria wrote:
>Dear all,
>
>Here are two examples that Paul has put together regarding the map of
>changes in precipitation drawn from Figure 10.5
>Do you think it works? Please send me any suggestions that you may.
>
>
>
>
>
>Regards,
>
>Maria
>
>**********************************************************************
>Dr. Maria Noguer
>IPCC WGI Technical Support Unit
>Hadley Centre for Climate Prediction and Research
>The Met Office
>London Road
>Bracknell
>Berkshire, RG12 2SY
>UK
>
>Tel: +44 (0) 1344 854938
>Fax: +44 (0) 1344 856912
>e-mail: mnoguer@meto.gov.uk
>www.met-office.gov.uk
>www.ipcc.ch
>**********************************************************************
>
>
>


Dear Keith and Tim,
Thank you for the papers which I have received some days ago. They
produced an impression on me. It is really a big job. I do not have
time now to evaluate in details the results obtained. I want to make
two remarks only.
First, I think, that the method of standardisation is very
interesting, but it is disputable for the regions and sites where
trees grow under extreme climatic conditions, for example at the polar
timberline in Siberia. In such conditions the shape of age curve and
the age of maximum growth are very changeable in different trees
growing at the same site. It will be very interesting if you can
present the age curve obtained for one such site, for example for the
North Taymir Peninsula.
Second, I do not agree that in the northern Siberia the 15th century
summers were warmer than those observed in the 20th century, at least
in the Western and Middle Siberia. May be it is a result of
stundartisation?
We suggest to inscibe in list of references the next papers:
1. Vaganov E.A., Shiyatov S.G., Mazepa V.S. Dendroclimatic study in
Ural-Siberian Subarctic. - Novosibirsk "Nauka", Siberian
Publishing Firm RAS, 1996. - 246 p. (in Russian).
2. Mazepa V.S. Influence of Precipitations on Tree-Ring Growth of
Coniferous in Subarctic Regions of Eurasia //Lesovedenie, No. 6,
1999. - P.14-21. (in Russian).
Abstract. Influence of precipitation on tree-ring variability of coniferous
trees in Subarctic regions of Eurasia has been shown. Depending
on the region, significant ecological factor for tree growth are
precipitation of autumn-winter, winter-spring and summer periods.
Ecological explanation of such influence has been given. On the
base of relationships between tree-rings and rainfall the
reconstructions of precipitation in different regions of
Subarctic for last 200 years have been developed.
3. Mazepa V.S. Spatial Reconstruction of Summer Air Temperature in the North of
the West Siberia since 1690 on the base of Tree-Ring Data.
//Siberian ecological journal, No. 2, 1999. - P.175-183. (in Russian).
Abstract. Opportunity of annual reconstruction of  summer thermal
conditions from Polar Urals (64-68°N, 64-68°E) up to Yenisei
River (66-70°N, 86-89°E) is caused by high and sufficiently
stable relationship between coniferous tree growth (Larix
sibirica, Picea obovata) and corresponding climatic factors.
Percent variance in tree-ring chronologies explained by climate
(June-July temperature) in this extreme for growth of trees area
reaches 50%.  Spatial reconstruction of air summer temperature on
the base of point reconstruction for 11 corresponding
meteostations has been developed. Analysis of reconstructed
temperatures has shown their significant changes for last 300
years. The most strong fall of temperatures was observed in XIX
century, but rise in temperature was observed in XVIII and XX
centuries.
4. Mazepa V.S. Dendroclimatic reconstructing air summer temperatures since  1690
in subarctic regions of siberia.  //Problems of ecological
monitoring and ecosystem modelling, Volume XVII. - St.Petersburg
Gidrometeoizdat, 2000. - P.170-187. (in Russian).
Abstract.  The further development of many-year dendroclimatic
study carried out in subarctic regions of Siberia and on the
polar timberline, is given in this paper. Climatic factors
determining the year-to-year and many-yeared tree-ring width
variability were revealed, using multiple regression models. The
spatial year-to-year reconstruction of air summer temperatures
was made on the base of available dendroclimatic network. The
reliability of spatial summer temperatures reconstruction in the
boreal zone of the Urals and Siberia was evaluated. The temporal
dendroclimatic zoning of the area investigated was carried out
according to the chronology similarity. The regional border
changes, depending on warm and cold periods, were shown. Five
regional chronologies showing the nature of summer months thermic
regime variability were developed. Extremely cold and warm
periods were revealed. The coldest periods are: the first half of
XVII and XIX centuries. The warmest periods are: the second half
of XVII, XVIII and middle of XX centuries.
To-day R. Hantemirov and A. Surkov will go to the Yamal Peninsula for
subfossil wood collecting. I and V. Mazepa will go to the Polar Ural
Mountains in some days.
Best regards,
Stepan                          mailto:stepan@ipae.uran.ru


Mike
Had a very good meeting with Shell yesterday. Only a minor part of the
agenda, but I expect they will accept an invitation to act as a strategic
partner and will contribute to a studentship fund though under certain
conditions. I now have to wait for the top-level soundings at their end
after the meeting to result in a response. We, however, have to discuss
asap what a strategic partnership means, what a studentship fund is, etc,
etc. By email? In person?
I hear that Shell's name came up at the TC meeting. I'm ccing this to Tim
who I think was involved in that discussion so all concerned know not to
make an independent approach at this stage without consulting me!
I'm talking to Shell International's climate change team but this approach
will do equally for the new foundation as it's only one step or so off
Shell's equivalent of a board level. I do know a little about the Fdn and
what kind of projects they are looking for. It could be relevant for the
new building, incidentally, though opinions are mixed as to whether it's
within the remit.
Regards
Mick
______________________________________________
Mick Kelly                       Climatic Research Unit
University of East Anglia     Norwich NR4 7TJ
United Kingdom
Tel: 44-1603-592091          Fax: 44-1603-507784
Email: m.kelly@uea.ac.uk
Web:
______________________________________________


Sorry this kept you awake...but I have also found it a rather alarming
graph.  First, a disclaimer/explanation.
The graph patches together 3 things: Mann et al  NH mean annual temps + 2
sigma standard error for AD1000-1980, + instrumental data for 1981-1998 +
IPCC ("do not quote, do not cite" projections for GLOBAL temperature for
the next 100 years, relative to 1998.  The range of shading represents
several models of projected emissions scenarios as input to GCMs, but the
GCM mean global temperature output (as I understand it) was then reproduced
by Sarah Raper's energy balance model, and it is those values that are
plotted.  Keith pointed this out to me; I need to go back & read the IPCC
TAR to understand why they did that, but it makes no difference to the
first order result....neither does it matter that the projection is global
rather than NH....the important point is that the range of estimates far
exceeds the range estimated by Mann et al in their reconstruction.  Keith
also said that the Hadley Center GCM runs are being archived at CRU, so it
ought to be possible to get that data and simply compute the NH variability
for the projected period & add that to the figure, but it will not add much
real information.  However, getting such data would allow us to extract
(say) a summer regional series for the Arctic and to then plot it versus
the Holocene melt record from Agassiz ice cap....or....well, you can see
other possiblities.
[......At this point Keith Alverson throws up his hands in despair at the
ignorance of non-model amateurs...]
But there are real questions to be asked of the paleo
reconstruction.  First, I should point out that we calibrated versus
1902-1980, then "verified" the approach using an independent data set for
1854-1901.  The results were good, giving me confidence that if we had a
comparable proxy data set for post-1980 (we don't!) our proxy-based
reconstruction would capture that period well.  Unfortunately, the proxy
network we used has not been updated, and furthermore there are many/some/
tree ring sites where there has been a "decoupling" between the long-term
relationship between climate and tree growth, so that things fall apart in
recent decades....this makes it very difficult to demonstrate what I just
claimed.  We can only call on evidence from many other proxies for
"unprecedented" states in recent years (e.g. glaciers, isotopes in tropical
ice etc..).  But there are (at least) two other problems -- Keith Briffa
points out that the very strong trend in the 20th century calibration
period accounts for much of the success of our calibration and makes it
unlikely that we would be able be able to reconstruct such an extraordinary
period as the 1990s with much success (I may be mis-quoting him somewhat,
but that is the general thrust of his criticism).  Indeed, in the
verification period, the biggest "miss" was an apparently very warm year in
the late 19th century that we did not get right at all.  This makes
criticisms of the "antis" difficult to respond to (they have not yet risen
to this level of sophistication, but they are "on the
scent").  Furthermore, it may be that Mann et al simply don't have the
long-term trend right, due to underestimation of low frequency info. in the
(very few) proxies that we used.  We tried to demonstrate that this was not
a problem of the tree ring data we used by re-running the reconstruction
with & without tree rings, and indeed the two efforts were very similar --
but we could only do this back to about 1700.  Whether we have the 1000
year trend right is far less certain (& one reason why I hedge my bets on
whether there were any periods in Medieval times that might have been
"warm", to the irritation of my co-authors!).  So, possibly if you crank up
the trend over 1000 years, you find that the envelope of uncertainty is
comparable with at least some of the future scenarios, which of course begs
the question as to what the likely forcing was 1000 years ago. (My money is
firmly on an increase in solar irradiance, based on the 10-Be data..).
Another issue is whether we have estimated the totality of uncertainty in
the long-term data set used -- maybe the envelope is really much larger,
due to inherent characteristics of the proxy data themselves....again this
would cause the past and future envelopes to overlap.
In Ch 7 we will try to discuss some of these issues, in the limited space
available.  Perhaps the best thing at this stage is to simply point out the
inherent uncertainties and point the way towards how these uncertainties
can be reduced.  Malcolm & I are working with Mike Mann to do just that.
I would welcome other thoughts and comments on any of this!
Ray
At 01:34 PM 7/10/00 +0200, you wrote:
>Salut mes amis,
>
>I've lost sleep fussing about the figure coupling Mann et al. (or any
>alternative climate-history time series) to the IPCC scenarios. It seems to
>me to encapsulate the whole past-future philosophical dilemma that bugs me
>on and off (Ray - don't stop reading just yet!), to provide potentially the
>most powerful peg to hang much of PAGES future on, at least in the eyes of
>funding agents, and, by the same token, to offer more hostages to fortune
>for the politically motivated and malicious. It also links closely to the
>concept of being inside or outside 'the envelope' - which begs all kinds of
>notions of definition. Given what I see as its its prime importance, I
>therefore feel the need to understand the whole thing better. I don't know
>how to help move things forward and my ideas, if they have any effect at
>all,  will probably do the reverse. At least I might get more sleep having
>unloaded them, so here goes......
>
>The questions in my mind centre round the following issues. If I've got any
>one of them wrong, what follows in each section can be disregarded or (more
>kindly) set straight for my benefit.
>
>1. How can we justify bridging proxy-based reconstruction via the last bit
>of instrumental time series to future model-based scenarios.
>
>2. How can the incompatibilities and logical inconsistencies inherent in
>the past-future comparisons be reduced?
>
>3. More specifically,  what forms of translation between what we know about
>the past and the scenarios developed for the future deal adequately with
>uncertainty and variability on either side of the 'contemporary hinge' in a
>way that improves comparability across the hinge.
>
>4.  Which, if any, scenarios place our future in or out of 'the envelope'
>in terms of experienced climate as distinct from calculated forcing? This
>idea of an envelope is an engaging concept, easy to state in a quick and
>sexy way (therefore both attractive and dangerous); the future could leave
>us hoisted by our own petard unless it is given a lot more thought.
>
>1. I am more or less assuming that this can already be addressed  from data
>available and calculations completed, by pointing to robust calibration
>over the chosen time interval and perhaps looking separately at variability
>pre 1970, if the last 3 decades really do seem to have distorted the
>response signatures for whatever reasons. I imagine developing this line of
>argument could feed into the 'detection' theme in significant ways.
>
>2 & 3. This is where life gets complicated. For the past we have biases,
>error bars that combine sources of uncertainty, and temporal variability.
>For the future we have no variability, simply a smooth, mean, monotonic
>trend to a target 'equilibrium' date. Bandwidths of uncertainty reflect
>model construction and behaviour.  So we are comparing apples and oranges
>when we make any statement about the significance of the past record for
>the future on the basis of the graph. Are there ways of partially
>overcoming this by developing different interactions between past data and
>future models?
>
>My own thinking runs as follows:  Take variability.  Do we need to wait for
>models to capture this before building it into future scenarios? This seems
>unnecessary to me, especially since past variability will be the validation
>target for the models.  Is there really no way of building past variability
>into the future projections?  One approach would be to first smooth the
>past record on the same time-span as the future scenarios.  This would get
>us to first base in terms of comparability, but a very dull and pretty
>useless first base in and of itself.  It would, however, allow all kinds of
>calculations of inter-annual variability relative to a mean time line of
>the 'right' length.  This in turn could be used in several ways, for
>example:
>         - build the total range of past variability into the uncertainty
>bands of each future scenario.
>         - take the 30,50 or 100 year period (depending on the scenario for
>comparison) during which
>            there was the greatest net variability, or the greatest net fall
>in Temperature, or the
>            greatest net increase in T. and superimpose/add this data-based
>variability on the mean
>            trends.
>         - take the n-greatest positive anomalies relative to the trend and
>use them to define an upper
>            limit of natural variability to compare with the (to my mind)
>more realistic future scenarios.
>
>These and cleverer variants I cannot begin to think up seem to me to hold
>out the possibility of linking future projections of GHG forcing with what
>we know about natrual variability in reasonably realistic ways and perhaps
>even of redefining the 'past data-future scenario' relationship in ways
>that  benefit both the paleo-community and the quality of future
>projections.
>
>4. I also think the above kinds of exercise might eventually lead us
>towards a better definition of 'the envelope' and more confidence in
>deciding what is outside and what is not. The same sort of approach can be
>taken towards projections of P/E I imagine and, more particularly, at
>regional rather than global or hemispheric level.
>
>Sorry if all this sounds stupid or obvious. I got afflicted with the 'need
>to share' bug.
>
>Frank
>
>
>____________________________________________
>Frank Oldfield
>
>Executive Director
>PAGES IPO
>Barenplatz 2
>CH-3011 Bern, Switzerland
>
>e-mail: frank.oldfield@pages.unibe.ch
>
>Phone: +41 31 312 3133; Fax: +41 31 312 3168
>
>
Raymond S. Bradley
Professor and Head of Department
Department of Geosciences
University of Massachusetts
Amherst, MA 01003-5820
Tel: 413-545-2120
Fax: 413-545-1200
Climate System Research Center: 413-545-0659
Climate System Research Center Web Site:

mate/climate.html
Paleoclimatology Book Web Site (1999):

e/paleo/html


Thanks Frank,
My apologies...
Sorry, no, I hadn't looked in detail at your original email to Ray,
only his response, and simply wanted to note that others have already
jumped on this bandwagon, so Ray deserves neither all the blame,
nor all the glory, depending on your perspective :)
And, as I stated, IPCC clearly considers such a plot not appropriate
for prime time--so you won't see anything like this in the TAR.
WHat I find most useful, howevever, along the lines of what you discuss, is
using empirical reconstructions as a baseline for comparison against model
simulations of both free and forced variability. A number of studies have
attempted this recently, and the results are encouraging from the point of
view that (a) the coupled models appear to be getting the internal
variability of mean global/hemispheric temperatures about right [this leads
us in the
direction of having greater faith in future scenarios from such models]
and (b) the models,forced with paleoestimates of past volcanic, solar, and
GHG radiative forcings, appear to be able to explain more than 50% of the
variance in the paleo temperature reconstructions. A paper to appear in
this Friday's "Science" by Tom Crowley describes some impressive results
along these lines.
It is agreed that hydrological change and regional temperature anomalies
superimposed on any large-scale temperature changes are of key
importance from any practical point of view. And I think this
is what we're all working towards, more regionally detailed
reconstructions of climate fields (temperature, drought, slp, etc.)
in past centuries. Clearly more high-resolution proxy evidence is
necessary,  in both time and space. I make many of these very points in a
"Perspectives"
article also to appear in Science on Friday, accompanying Tom Crowley's
article.
Will appreciate any comments on it. Hope the above provides some
clarification.
cheers,
mike
At 06:59 PM 7/10/00 +0200, you wrote:
>Hi Mike,
>
>Not sure if your reply implied you were taking my points seriously or not -
>I'm not even sure if Ray sent them on to you or you just received his
>reply!  My reactions to the graphs on the website are that the temperature
>one does not address my points (but it does not aim to and I fully agree
>that if the projections are sufficiently reliable it hardly needs to!),
>that P/E is likely to be much more important than temperature per se and
>that the historical sea-level curve is not really acceptable - very much
>more high resolution work needs to be done on that before we have any real
>sense of past variability on decadal to century timescales.
>
>Cheers,
>
>Frank
>
>____________________________________________
>Frank Oldfield
>
>Executive Director
>PAGES IPO
>Barenplatz 2
>CH-3011 Bern, Switzerland
>
>e-mail: frank.oldfield@pages.unibe.ch
>
>Phone: +41 31 312 3133; Fax: +41 31 312 3168
>
>
>
>
>At 06:59 PM 7/10/00 +0200, Frank Oldfield wrote:
>Hi Mike,
>
>Not sure if your reply implied you were taking my points seriously or not -
>I'm not even sure if Ray sent them on to you or you just received his
>reply!  My reactions to the graphs on the website are that the temperature
>one does not address my points (but it does not aim to and I fully agree
>that if the projections are sufficiently reliable it hardly needs to!),
>that P/E is likely to be much more important than temperature per se and
>that the historical sea-level curve is not really acceptable - very much
>more high resolution work needs to be done on that before we have any real
>sense of past variability on decadal to century timescales.
>
>Cheers,
>
>Frank
>
>____________________________________________
>Frank Oldfield
>
>Executive Director
>PAGES IPO
>Barenplatz 2
>CH-3011 Bern, Switzerland
>
>e-mail: frank.oldfield@pages.unibe.ch
>
>Phone: +41 31 312 3133; Fax: +41 31 312 3168
>
>
>
>
>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137


Keith
I've sent you a few slides taken by Hakan Grudd as promised . I think these should be supplemented by a bit of a colourful timeseries - part of a chronology. It could be a piece of the Tornetrask series (northern Sweden) from where the pictures are taken - but I think a section of the 3-region average (Tornetrask,Yamal, Taimyr) possibly showing the 563 A.D. would be better. So I am sending a couple post script files and a suggested colour scheme. What do you think?  I suggest a one hundred year section of the average series , showing annual values. Note that in these Figures , A.D. 536 is marked by a filled triange. Just showing the initiation of a dramatic cooling in A.D. 536 and the widespread cold summers of the 540's (a major vocano? if perhaps not as David Keys makes out in his recent book), or a comet ( as Mike Baille says in his?) , is quite appealing.
Keith


Dear Fortunat
I am pleased to hear from you. I have still not been in touch about the data I showed you
in Vienna! As for your question - of course I will send the series you mention - but it is
only an average of three regional tree-ring chronologies ( Northern Sweden, Yamal,Taimyr)
and not calibrated in terms of temperature. Nevertheless, it is representative of summer
warmth over a large Russian region, We have recently submitted a paper describing a
different standardization approach ( for preserving low frequency variance) applied to a
big high-latitude network of tree-density data. This yields regional (up to 600-year)
calibrated reconstructions and a hemispheric curve - all representing april-sept season. I
have asked my colleague Tim Osborn here to send the data and a copy of the papers to you, I
am on the verge of leaving for 2 weeks so if you need more information contact him.
As for other areas of the world - Phil Jones has an alternative Hemisphere curve and there
are some southern hemisphere chronologies ( temp. sensitive). There are short precip
reconstructions for several spots - but systematic Palmer Drought Indices for the U.S. from
about 1700. I will be happy to talk on the phone about all these in two weeks.
best wishes
Keith
At 11:01 AM 7/19/00 +0200, you wrote:
Dear Keith,
How are you? Hope everything is going well.
I am writing because I am interested in your climate reconstruction for
the last millennium.
The Etheridge ice core data of CO2 indicate that CO2 was below average
in the 17th and 18th centuries by a few ppm. Very few (1-2 points) of
ice core C13 data (Francey tellus, 99) suggest that this drawdown was
caused by additional terrestrial carbon storage (Joos et al, GRL, 99;
Trudinger, Tellus, 99). We try to investigate this suggestion using the
Lund-Potsdam-Jena dynamical global vegetation model (LPJ-DGVM).
A diploma student of mine, Philippe Bruegger, has used the Mann et al
annual mean temperature patterns (2 EOFs only) in combination with the
Etheridge CO2 record to drive the LPJ model. Instead of absorbing
carbon, the model is releasing carbon due to a reduced CO2 fertilization
effect in the model that outweights any climatic effects. Thus, the
model results is clearly not compatible with the ice core results.
Obviously, the study is hampered by the limitation of the climate
reconstruction (as well as by the few C13 ice core data). Instead of
changes in monthly values of Temp and precip (and cloud cover)  changes
in ANNUAL mean temperature were used to force LPJ.
Could you or Phil Jones provide alternative forcing fields that focus
e.g. more on summer temperature? Any info about precipitation?
I would also appreciate very much to obtain reprints of your most recent
articles, namely the article in Quaternary Science Rev. 2000.
Thanks for any help you can provide.
Regards, Fortunat
--
NEW FAX NUMBER; NEW FAX NUMBER; NEW FAX NUMBER; NEW FAX NUMBER;
Fortunat Joos, Climate and Environmental Physics
Sidlerstr. 5, CH-3012 Bern
Phone:    ++41(0)31 631 44 61      Fax:      ++41(0)31 631 87 42
e-mail:   joos@climate.unibe.ch;   Internet:
[1]~joos/
References
1. ~joos/


Tom and Mike,
What Tom said is essentially correct. Tim Osborn here recalibrated
each series, as a composite, against the same NH series for the April-
Sept average north of 20N (using land only data). All this does is
rescale the series as it is simple regression (y=ax+b). Because y is
based on temps wrt 61-90 this means that the axis is then wrt 61-90.
Doing this we can then add the same instrumental temp series. It also
brings the series together and the web page was just for illustrative
purposes. For Mike's series you get pretty much the same result by
subtracting 0.12 from Mike's numbers as this is the difference between
Mike's base period and 1961-90.
There is nothing sinister going on !  I'll summarise this to Rob.
Cheers
Phil
PS I seem to be stirring up loads of emails about historical data. You
are both on those emails so you can see what crap is being written and my
(time wasting for me) replies. Apologies for replying. I should know better
and keep quiet.  We can all expect more of this if IPCC stays in roughly
the same form pre-Victoria. It's relatively easy to knock historical
records, so as long as it gets no worse than this we'll be fine.


Dear Ray
You sent me this op-ed (?) (Letter to editor?) about the need to convert
the US from a carbon-based economy to a hydrogen-based economy.  I can't
guess why you wanted me to know your views, but it does help me to better
understand what motivates your scientific work and judgment.  It also
throws some doubt about your impartiality in promoting the "hockey stick'
temperature curve that a number of us have been critical of.
In any case, I doubt if espousal of this energy policy will help BP and
ARCO discover a source of hydrogen somewhere.
You quote the "progressive" Business Council approvingly: "We accept the
views of most scientists that enough is known about the science and
environmental impacts of climate change for us to take actions to address
its consequences."  And from BP chairman : "the time to consider the policy
dimensions of policy change is not when the link between greenhouse gases
and climate change is conclusively proven, but when the possibility cannot
be discounted and is taken seriously by the society of which we are part."
I note that BP and ARCO are still out there exploring for oil; they don't
seem to be quite ready yet to put real money where their mouth is.
You call  for the US to take leadership in stabilizing the
climate.  Perhaps the government will turn to you to learn how to do
this.  A far less ambitious goal would be to stabilize the atmospheric
concentration of CO2.  According to the IPCC this would require an emission
reduction  of 60 to 80 percent (with respect to 1990) --- WORLDWIDE.
Have you ever considered the consequences of such a policy -- assuming it
could really be adopted?
Best wishes ,
Fred
**********************************
At 10:34 AM 8/1/00 -0400, you wrote:
>   WASHINGTON, DC -- In August 1997, a few months before the Kyoto
>   Conference on Climate Change, the Global Climate Coalition (GCC)
>   helped launch a massive advertising campaign designed to prevent the
>   United States from endorsing any meaningful agreement to reduce global
>   carbon emissions. This group included in its ranks some of the world's most
>   powerful corporations and trade associations involved with fossil
> fuels. The
>   campaign effectively undermined public support of U.S. efforts to lead the
>   international effort to stabilize climate.
>   While the public image of the GCC was that of a unified group, there was
>   dissent. John Browne, Chairman of British Petroleum, on May 19, 1997,
>   announced that "the time to consider the policy dimensions of policy change
>   is not when the link between greenhouse gases and climate change is
>   conclusively proven, but when the possibility cannot be discounted and is
>   taken seriously by the society of which we are part. We in BP have
>   reached that point."
>   BP withdrew from the Global Climate Coalition. Dupont had already left.
>   The following year, Royal Dutch Shell left.
>   In 1999, Ford withdrew from the GCC. A company spokesman noted,
>   "Over the course of time, membership in the Global Climate Coalition has
>   become something of an impediment for Ford Motor Company to
>   achieving our environmental objectives."
>   In rapid succession in the early months of 2000, Daimler Chrysler, Texaco,
>   and General Motors announced that they too were leaving the Coalition.
>   This accelerating exodus reflected the conflict emerging within GCC ranks
>   between firms that were clinging to the past and those that were planning
>   for the future.
>   Some of the exiting companies, such as BP Amoco, Shell, and Dupont,
>   joined a progressive new group, the Business Environmental Leadership
>   Council, which says, "We accept the views of most scientists that enough is
>   known about the science and environmental impacts of climate change for
>   us to take actions to address its consequences."
>   Membership requires companies to have programs for reducing carbon
>   emissions. BP Amoco, for example, plans to bring its carbon emissions to
>   10 percent below its 1990 level by 2010, exceeding the Kyoto goal of
>   roughly 5 percent for industrial countries.
>   Dupont has already cut its 1990 greenhouse gas emissions by 45 percent
>   and plans to reduce them by 65 percent by 2010.
>   There is a growing acceptance among the key energy players that the
>   world is in the early stages of the transition from a carbon-based to a
>   hydrogen-based energy economy. In February 1999, ARCO CEO
>   Michael Bowlin said, "We've embarked on the beginning of the Last Days
>   of the Age of Oil." He then discussed the need to convert our
>   carbon-based energy economy into a hydrogen-based energy economy.
>   With the organization that so effectively undermined U.S. leadership in
>   Kyoto no longer a dominant player in the global climate debate, the
> stage is
>   set for the United States to resume leadership of the global climate
>   stabilization effort.
>Raymond S. Bradley
>Professor and Head of Department
>Department of Geosciences
>University of Massachusetts
>Amherst, MA 01003-5820
>
>Tel: 413-545-2120
>Fax: 413-545-1200
>Climate System Research Center: 413-545-0659
>Climate System Research Center Web Page:
>
>Paleoclimatology Book Web Site (1999):
>
S. Fred Singer, President
Science & Environmental Policy Project
9812 Doulton Court
Fairfax, VA 22032

Tel:  703-503-5064
e-fax  815-461-7448 (your fax will be sent as email to my
computer)
**********
"The improver of natural knowledge absolutely refuses
to acknowledge authority, as such. For him, scepticism
is the highest of duties; blind faith the one unpardonable sin."
Thomas H. Huxley
**********
"That theory is worthless.  It isn't even wrong!" - W. Pauli
**********


Chris and John (and Mike for info),
I'm basically reiterating Mike's email. There seem to be two lots of
suggestions doing the rounds. Both are basically groundless.
1. Recent paleo doesn't show warming.
This basically stems back to Keith Briffa's paper in Nature in 1998
(Vol 391, pp678-682). In this it was shown that northern boreal forest
conifers don't pick up all the observed warming since about the late
1950s. It was suggested that some other factor or a combination of
factors related to human-induced pollution (e.g. nitrogen deposition,
higher levels of CO2, ozone depletion etc). Hence in a new paper
submitted to JGR recently we develop a new standardization approach
(called age banding) and produce a large-scale reconstruction
(calibrated over the period 1881-1960 against NH land north of 20N)
back to 1402. If you want a copy of this can you email Keith and he'll
send copies once he's back from holiday.
This background is to illustrate how Singer et al distort things. The
new reconstruction only runs to 1960 as did earlier ones based solely
on tree-ring density. All the other long series (Mike's, Tom Crowley's
and mine) include other proxy information (ice cores, corals,
historical records, sediments and early instrumental records as well as
tree-ring width data, which are only marginally affected). All these
series end around 1980 or in the early 1980s. We don't have paleo data
for much of the last 20 years. It would require tremendous effort and
resources to update a lot of the paleo series because they were collected
during the 1970s/early 1980s.
It is possible to add the instrumental series on from about 1980 (Mike
sought of did this in his Nature article to say 1998 was the warmest of
the millennium - and I did something similar in Rev. Geophys.) but there
is no way Singer can say the proxy data doesn't record the last 20 years
of warming, as we don't have enough of the proxy series after about 1980.
 takes the argument further
saying that as trees don't see all the warming since about 1960 the
instrumental records recently must be in error (i.e. this group believes
the trees and not the instrumental records). This piece by Idso and
Idso seems to want to have the argument whichever suits them.
2. Everyone knows it was cooler during the Little Ice Age and warmer in
the Medieval Warm Period.
All of the millennial-long reconstructions show these features, but they
are just less pronounced than people believed in the 1960s and 1970s,
when there was much less paleo data and its spatial extent was limited
to the eastern US/N.Atlantic/European and Far East areas. The issue
seems to revolve around the average temperatures we have for earlier
centuries in the millennium. I use the argument that for the instrumental
period we need sites located over much of the NH (land and marine)
regions in order to claim we have a reasonable record for the whole
hemisphere. We wouldn't dream of extending the NH series based on longer
European records and in the extreme just CET, so with the paleo data we
need records from as many regions as possible. The coverage still could
be better, but it is far better than it was 25 years ago, when the ideas
embodied in the MWP and LIA became sort of mainstream.
The typical comments I've heard, generally relate to the MWP, and say
that crops and vines were grown further north than they are now (the
vines grown in York in Viking times etc). Similarly, statements about
frost fairs and freezing of the Baltic so armies could cross etc. Frost
fairs on the Thames in London occurred more readily because the tidal
limit was at the old London Bridge (the 5ft weir under it). The bridge
was rebuilt around the 1840s and the frost fairs stopped. If statements
continue to be based on historical accounts they will be easy to knock
down with all the usual phrases such as the need for contemporary
sources, reliable chroniclers and annalists, who witnessed the events
rather than through hearsay. As you all know various people in CRU
(maybe less so now) have considerable experience in dealing with this
type of data. Christian Pfister also has a lifetime of experience of
this. There is a paper coming out from the CRU conference with a
reconstruction of summer and winter temps for Holland back to about
AD 800, which shows the 20th century warmer than all others. Evidence is
sparser before 1400 but the workers at KNMI (Aryan van Engelen et al.)
take all this into account.
I hope this is of use and hasn't been a total waste of time.
In Victoria last month, did you discuss how the policymaker's summary will
report the millennial temperature series ? Are there any tentative
phrases you're working on a la Balance of evidence etc ? Is Chapter 12
thinking of a new sentence to supercede the above ? Any sentence on the
millennium record should be in Ch. 2.
Cheers
Phil
Prof. Phil Jones
Climatic Research Unit        Telephone +44 (0) 1603 592090
School of Environmental Sciences    Fax +44 (0) 1603 507784
University of East Anglia
Norwich                          Email    p.jones@uea.ac.uk
NR4 7TJ
UK
----------------------------------------------------------------------------


Ben,
Here a few main points about the paper. I've ignored minor English/wording
things I spotted.
p4 It seems better to put the other anthro forcings before the natural
get discussed. (top of page). ie Other heteorogeneous.. sentence should be
before Stratospheric aerosols.
p4 Bottom. Could reference Delworth et al to illustrate the 'perfect'
model argument. They reproduced reality 1 out of 5 attempts.
p5 Don't like phenomenology of ENSO, change to ENSO sequences ?
p6 middle. Emphasise that withe models you can look at a lot longer series.
p6 bottom. Whether the model was really 'perfect' Michaels would find
some problem.
p7 2/3rd way down. Say something about Santer et al (2000a).
p9 Don't think you need to say you got the SOI from CRU.
p10 ECHAM4 has solar, but how much does it change by. Or is it constant ?
p11 end of 2. Presumably in combining the SAT and SST you used anomalies.
Worthwhile saying.
p12-15 Section 3 gets to read like a recipe. It is important, but it
might be better as an Appendix. Also I guess the amount of detail depends
on success of other submissions.  I think the section needs reworking a
bit as the style changes somewhat.
Have you considered whether alpha and tau and t(ramp) can differ by a
month between the surface and 2LT.
The lag you use is 7 months. The science paper of Tom's uses 6 months.
In the later tables I wasn't clear how raw and nofilt relate to each
other. I guess all the Tables need longer captions with more
explanation. I couldn't figure out what the () numbers referred to in
the Tables.
p17 I wonder if it's possible to show in a diagram that the iterative
scheme works and you're getting to a global rather local minimum.
p19 The higher 'ratios' get nearer to my 2, but only at the high end.
p20  The last 4 numbers in Table 3 have been multiplied by 0.1 .
p23 An interesting aside would be to show in one of the Tables how
much change in the observations is due to volcanoes (ie show how
much cooling due to this there has been). People will quote this
value. It shows that 'natural' factors (solar/volcanoes) have led
to cooling as solar effects will be very small over this time.
p24 Emphasise later that models and obs all show 2LT level
changes more than surface.
p24 Say something about how good ECHAM4 is for ENSO, or refer to a paper.
p25-33 All good stuff, but it does take a time to read. Not a very
helpful comment, I know, but I'm being a referee.
p33 Does Fig 7 use the same data as in Fig 5 ? One shwing things
through time, the other as a distribution.
p35 PCM crept into the Hamburg section, so it should be said here when
the GISS section starts.
p38 Quantify the volcanic cooling. I mentioned this earlier.
p39 Not clear what independent components are wrt Smith et al (2000).
p42  Surface data has errors too.
p43  The last sentence of the acknowledgements is like a red rag to a bull
for Michaels. Even the perceptive adjective will not placate him.
Have to go home now. I think I've covered most things I noticed.
Have a good weekend !
Cheers
Phil


Great Tom, I think we are converging to much clearer meanings across
various cultures here. Please get the inconclusive out! By the way,
"possible" still has some logical issues as it is true for very large or
very small probabilities in principle, but if you define it clearly it is
probably OK--but "quite possible" conveys medium confidence better--but
then why not use medium confidence, as the 3 rounds of review over the
guidance paper concluded after going through exactly the kinds of
disucssions were having now. Thanks, Steve
On Wed, 23 Aug 2000 tkarl@ncdc.noaa.gov wrote:
>
>
> Steve, I agree with your assesement of inconclusive --- quite possible is
> much better and we use 'possible' in the US National Assessment.  Surveys
> has shown that the term 'possible' is interpreted in this range by the
> public.
>
> Tom
>
>
>
>
> Stephen H Schneider
on 08/23/2000 03:02:33 AM
>
>
>
>  To:      Thomas Stocker
>
>  cc:      Jerry Meehl
, Timothy Carter
>
, maureen.joseph@eci.ox.ac.uk,
>           lindam@ucar.edu, m.hulme@uea.ac.uk,
>           peter.whetton@dar.csiro.au, giorgi@ictp.trieste.it,
>           Tom Karl/NCDC, cubasch@dkrz.de,
>           ckfolland@meto.gov.uk, hewitson@egs.uct.ac.za,
>           "Stouffer, Ron"
>
>
>
>  Subject: Re: THC collapse
>
>
>
>
>
>
>
>
>
> Hello all. I appreciate the improvement in the table from WG 1,
> particularly the inclusion of symmetrical confidence levels--but please
> get rid of the ridiculous "inconclusive" for the .34 to .66 subjective
> probability range. It will convey a completely differnt meaning to lay
> persons--read decisionmakers--since that probability range represents
> medium levels of confidence, not rare events. A phrase like "quite
> possible" is closer to popular lexicon, but inconclusive applies as well
> to very likely or very unlikely events and is undoubtedly going to be
> misinterpreted on the outside. I also appreciate the addition of
> increasing huricane intensities with warming moving out of the catch all
> less than .66 category it was in the SOD.
>   I do have some concerns with the THC issue as dealt with here--echoing
> the comments of Tim Carter and Thomas Stocker.  I fully agree that the
> likelihood of a complete collapse in the THC by 2100 is very remote, but
> to leave it at that is very misleading to policymakers given than there is
> both empirical and modeling evidence that such events can be triggered by
> phenomena in one century, but the occurrence of the event may be delayed
> a century or two more. Given also that the likelihood of a collapse
> depends on several uncertain parameters--CO2 stabilization level, CO2
> buildup rate, climate sensitivity, hydrological sensitivity and initial
> THC overturning rates, it is inconceivable to me that we could be 99% sure
> of anything--implied by the "exceptionally unlikely" label--given the
> plausibility of an unhappy combo of climate sensitivity, slower than
> current A/OGCMs initial THC strength and more rapid CO2 increase
> scenarios. Also, if 21st century actions could trigger 22nd century
> irreversible consequences, it would be irresponsible of us to not mention
> this possibility in a footnote at least, and not to simply let the matter
> rest with a very low likelihood of a collapse wholly within the 21st
> century.  So my view is to add a footnote to this effect and be sure to
> convey the many paramenters that are uncertain which determine the
> likelihood of this event.
>   Thanks again for the good work on this improtant table. Cheers, Steve
>
>
> On Wed, 23 Aug 2000, Thomas Stocker wrote:
>
> > DEar Jerry, Tim and Ron et al
> >
> > I agree that an abrupt collapse - abrupt meaning within less than a
> decade, say
> > - has not been simulated by any climate model (3D and intermediate
> complexity)
> > in response to increasing CO2. Some models do show for longer
> integrations a
> > complete collapse that occurs within about 100-150 years. If you put that
> into
> > context of the apparent stability of THC during the last 10,000 years or
> so,
> > this is pretty "abrupt".
> >
> > Following up on the discussion regarding THC collapse, I think the
> statement Ron
> > apparently added to Ch9 needs to be made more specific. In order to keep
> Ch7 and
> > Ch9 consistent, I propose to Ron the following revision:
> >
> > "It seems that the likelihood of a collapse of the THC by year 2100 is
> less
> > than previously thought in the SAR based on the AOGCM results to date."
> >
> > There is really no model basis to extend this statement beyond 2100 as
> evidenced
> > by the figures that we show in TAR. There are many models that now run up
> to
> > 2060, some up to 2100, but very few longer.
> >
> > Also I should add for your information, that we add to Ch7 a sentence:
> >
> > "Models with reduced THC appear to be more susceptible for a
> > shutdown."
> >
> > Models indicate that the THC becomes more susceptible to collapse if
> previously
> > reduced (GFDL results by Tziperman, Science 97 and JPO 99). This is
> important as
> > "collapse unlikely by 2100" should not tempt people to conclude that THC
> > collapse is hence not an issue. The contrary is true: reduction means
> > destabilisation.
> >
> > Best regards
> >
> > thomas
> > --
> > ------------------------------------------------------------------
> > Thomas Stocker
> > Climate and Environmental Physics         stocker@climate.unibe.ch
> > Physics Institute, University of Bern     phone:  +41 31 631 44 64
> > Sidlerstrasse 5                      NEW    fax:  +41 31 631 87 42
> > 3012 Bern, Switzerland        ~stocker
> > ------------------------------------------------------------------
> >
>
> ------
> Stephen H. Schneider
> Dept. of Biological Sciences
> Stanford University
> Stanford, CA 94305-5020 U.S.A.
>
> Tel: (650)725-9978
> Fax: (650)725-4387
> shs@leland.stanford.edu
>
>
>
>
>
------
Stephen H. Schneider
Dept. of Biological Sciences
Stanford University
Stanford, CA 94305-5020 U.S.A.
Tel: (650)725-9978
Fax: (650)725-4387
shs@leland.stanford.edu


Hi again Malcolm
I am forwarding the data in another message (from Tim).  I am sending the whole lot for
simplicity. Please don't pass on until we hear whether the paper is accepted or not.
Remember that , although they are strongly correlated with them, these data are not
identical in the high frequency domain to the equivalent data standardised using say a
Hugershoff  function. The main purpose here was to extract long-timescale variations and I
still consider the inter annual to decadal variability to be better defined  using the
'traditional' approach. For a first look  anyway these are fine
best wishes
Keith
At 04:14 AM 8/24/00 -0700, you wrote:
Dear Keith,
It was good to talk with you this morning. This is a reminder about
sending your Western North America banded record as you
suggested. I suspect that you are right to think that it would eventually
be best to use a customized banded set, but as a start, I think it would
be good to compare the WNW record with the mean series Graybill
and Idso used in their 1993 paper, and with the single site Campito
Mountain record. I'll start with a simple graphical comparison and
then move to comparing waveforms extracted by, for example, SSA.
My hope is that we can fairly rapidly generate a note to something like
GRL or JoC's new short format, putting a believable version of these
records out there for general use.
Please reply to the mhughes@ltrr.arizona.edu address. I'm sending it
from my other address as well as a 'belt-and-braces' approach
because of recent e-mail problems. Looking forward to working on
this with you, Cheers, Malcolm
Malcolm Hughes
Professor of Dendrochronology
Laboratory of Tree-Ring Research
University of Arizona
Tucson, AZ 85721
520-621-6470
fax 520-621-8229


Dear Mike,
Regarding my last mesage,
In case you wonder about my background, I have attached a 2-page version of
my CV, in rich-text format, file bjhmcv2.rtf
My experience, ranging from laboratory work with CO2 fluxes and marine
algae, through to organising events at the UN climate negotiations, combined
with a strong mathematical and linguistic background, is a somewhat unusual
combination which perhaps makes me more a "jack of all trades" than a
specialist. On the other hand, this has given me an interdisciplinary
overview which may be valuable for bridging the gap between science and
policy, appreciating dilemmas and uncertainties, and communicating these
around the world.
However, Kyoto left me very disillusioned by the apparent lack of connection
between climate science and policy -in the protocol there was not one
sentence discussing what we need to do to stabilise the climate in the long
term, based on scientific predictions. This made me wonder, what is the use
of my intricate research on air-sea CO2 exchange, if the policymakers ignore
even the most basic knowledge? I left UEA and started working at home,
developing interactive web graphics showing the link between per-capita
emissions and global climate change. Eventually, I realised that working
alone was neither effective nor sustainable, and this has led to unfortunate
personal circumstances. Now I need the stimulus of working again in a team,
in an institute, even if this requires sacrificing of my own ideas. I am not
just looking for a "job", it is more important to me, to rejoin the research
community, and feel I am making the best use of my skills. I hope you can
help, if only to discuss the possibilites.
I have also attached a zip package containing the interactive java applets
which I developed,
it's only 90K including supporting webpages and historical data.
Once unzipped (all in one directory), you have to open the file
"starthere.html" in any java-enabled web browser.
I can send a self-extracting windows version if you prefer, on the other
hand you may find it easier just to look at the website
www.chooseclimate.org/applet/
Currently, this uses only very crude formulae loosely based on IPCC SAR and
GCI's C&C, -but the presentation is unique: you can adjust the parameters
just by dragging controls with a mouse, and all the linked plots respond
instantly. It's hard to describe in words, which is why I encourage you to
have a look.
Ben
****************
Dr Ben Matthews ben@chooseclimate.org,
----- Original Message -----
From: Mike Hulme
To: Ben Matthews
Sent: 04 September 2000 13:38
Subject: Re: interactive climate science-policy website,
> Thanks for this note Ben.
>
> I would be interested in talking about your ideas at some stage,
> particularly in relation
> to our outreach strategy.  We are appointing a Communications Manager very
> soon and you are
> welcome to attend the presentations as listed below:
>
> I would suggest that we arrange a meeting a  little further down the line,
> once the Centre
> has started operating in its new premises after 2 October.
>
> Mike
>
> ______________________________________
Attachment Converted: "c:\eudora\attach\cca21.zip"
Attachment Converted: "c:\eudora\attach\bjhmcv2.rtf"


Dear Mike
I have attached the final version of the RP2 outline proposal on the
interaction between the flexible mechanisms and the WTO trade rules.
Please jettison the previous draft.
As noted earlier, Neil and I see this project as delivering multiple
benefits to the Tyndall Centre on the basis of a limited, 'value-added'
investment, not least in terms of tying Shell International to the Centre.
We also highlight the suggestion of a workshop on common themes to
be held in a couple of years' time to link related projects across the
research programmes (though this is not covered by the current proposal).
Regards
Mick
______________________________________________
Mick Kelly                       Climatic Research Unit
University of East Anglia     Norwich NR4 7TJ
United Kingdom
Tel: 44-1603-592091          Fax: 44-1603-507784
Email: m.kelly@uea.ac.uk
Web:
______________________________________________
Attachment Converted: "c:\eudora\attach\tyndall11.doc"


Dear CLAs/LAs
As you all know, in my Victoria follow-up e-mail of 2 August I presented a
summary of the agreement we reached in Victoria on a common use of
terminology to express degree of likelihood in the TAR. At that time the
word or term to be used for the central box of 33 to 66% had not been agreed
and the word "inconclusive" was proposed for that category. Since that time
there has been a lengthy discussion, including Working Groups II and III,
regarding the best word to be used in this category. To cut a long story
short the term we would now like you to use for this middle category is
"medium likelihood". I am sorry I have not been able to canvas this around
all of you but from the discussions this term was agreed by all to be the
best compromise. In particular, it clearly maintains the scale as one of
degrees of likelihood, whereas inconclusive could be confused as to whether
a degree of likelihood was being expressed or whether there was insufficient
information to conclude a likelihood. I attach a table showing what should
now be the final scale.
During the discussions it became clear that in addition to making likelihood
statements it is sometimes more appropriate to express statements in terms
of a degree of confidence, and indeed several chapters use this terminology.
As you know the Uncertainties Guidance paper by Richard Moss and Steve
Schneider recommends a scale of confidence from Very Low to Very High
confidence. WGII in particular are using this scale and so I would ask that,
if you choose to express things in terms of a level of confidence, that you
use the terms as they are laid down in the guidance paper. This in no way
affects the use of the likelihood scale where this is more appropriate. For
example, if we are highly uncertain how well a model handles a particular
process, we may have "very low confidence" in a model result which is highly
dependent on this process. If we have no other corroborating evidence we may
therefore conclude that there is insufficient information to assign a
likelihood in this case. By following the guidance paper when expressing a
level of confidence we will hopefully improve the consistency between the
two reports. Incidentally, if there are instances in the WGII report where
they are able express degrees of likelihood they are going to try and use
our scale.
Thirdly, there has been a lot of discussion about the impression which the
likelihood scale, if taken out of context, could give for low likelihood,
high consequence events, such as a disintegration of the WAIS or a shutdown
of the THC in the next 100years. Please bear in mind that policymakers must
balance likelihood and consequence in deciding whether or not to take
action. Therefore please take extra care when considering text for these
types of issues as simply expressing them as "extremely unlikely" does not
give the full picture. For example, you could say an aircraft was "extremely
unlikely" to crash on its next flight but if there was a 1% chance I would
not fly on it. While it is a true statement the right balance is only
achieved when the consequence is also brought in to put the risk in context.
I apologise for this late change to our scale but I hope you all agree that
it is an improvement. If anything is not clear about any of the above please
do not hesitate to contact me.
Best regards
Dave
>
-----------------------------------------
Dr David Griggs
IPCC WGI Technical Support Unit
Hadley Centre
Met. Office
London Road
Bracknell
Berks, RG12 2SY
UK
Tel +44 (0)1344 856615
Fax: +44 (0)1344 856912
Email: djgriggs@meto.gov.uk
-----------------------------------------
Attachment Converted: "c:\eudora\attach\Agreed terminology2.doc"


Mike and Tim
Notes from the meeting with Shell International attached.
Sorry about the delay.
I suspect that the climate change team in Shell International is probably
the best route through to funding from elsewhere in the organisation
including the foundation as they seem to have good access to the top
levels.
Mick
______________________________________________
Mick Kelly                       Climatic Research Unit
University of East Anglia     Norwich NR4 7TJ
United Kingdom
Tel: 44-1603-592091          Fax: 44-1603-507784
Email: m.kelly@uea.ac.uk
Web:
______________________________________________
Attachment Converted: "c:\eudora\attach\shell.doc"


Dear All
we heard the opinions of most LAs, namely Jens, Richard, Linda, Peter,
and Hans as well as some interesting interpretations of my email (Linda says:
" You seem to be assuming that the most desirable result is
if the SRES results have no contrasts with the IS92a results.
I don't understand your reasoning on this." I do not have any particular desire
on the new data. We said that one thing to look at was the agreement with
the old data and thus I noticed that relaxing the criteria would yield a greater
agreement). I would say that a broad range of opinions was covered, from
one where the SRES should essentially be commented upon concerning their
agreement with the old data to one in which all the old stuff should be
replaced with SRES stuff. Some people want to make the BOX more central,
others want to get rid of it.
Given this, I would like to add my own opinion developed through the weekend.
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.
Going to the problem at hand, I have a proposal that is in between the
two extreme positions. I think the SRES runs should be included and
highlighted in the chapter, but should not be the only source of our
conclusions, partially also for the reasons I state above (I seem to
remember that in Chapter 9 the SRES results were only a small section
in the whole chapter in which it was said that they essentially confirmed
previous findings). Also let me say
that, as it currently stands, the box is essentially meaningless, because
it simply repeats what is already said in the executive summary.
With these premises here is my proposal:
1) We leave 10.3 more or less as it is, a discussion of published science
on model behavior, uncertainty, some climate change runs.
Perhaps we shorten it or something like that. I am not in favor of
presenting Giorgi and Francisco-type plots for the SRES runs for the simple
reason that they do not convey effectively what readers want. Proof is that we
had all the plots there and we were accused of not having any results in
the chapter !! I think people want something more direct, i.e. plots similar
to the +/- one we had proposed in the BOX.
2) We make the BOX only with SRES results, i.e. the BOX becomes a
summary presentation of the SRES projections. In this way we accomplish
several objectives: we highlight the SRES results in a way that is of direct
impact (after all this is what working group II people are really interested
in); we can explicitly state that the results are preliminary and sort
of differentiate them from the more IPCC-proper chapter material (of course
we are not going to say so); we
have a natural place for the BOX (end of 10.3), do not need to rewrite
the whole thing and just need to make the proper connections with the
rest of the chapter. All and all I think this is a feasible and clean
solution. The rest of the material in the old box (sections a and c) was
really just general material repetitive of what we were saying in various
other part of the chapter.
3) In the executive summary we summarize what we believe are the
confident patterns from the combination of old and new runs.
As to what should the SRES box look like. I hear people liked a lot
our +/- plot, so we do the same types of plots, both for precip and
temperature, one for the A2 and one for B2 scenarios, plus one or
two paragraphs explaining the plots. This will portray agreement not
only across models but also across what are now considered plausible
scenarios. We can easily fit 4 plots in a page
and if need be fit the 1-2 paragraphs on another page (I do not see
anything wrong with a 1.5 page box).
For precipitation I think the old criteria are fine. For temperature this
is what I propose. In the precip plots we had 4 sub-categories, (+, -
large change, small change) plus the inconclusive, or whatever we
decided to call it. Similarly, we could do 4 categories here
1) Amplification positive, 2) Amplification negative (i.e. less than
the global average), 3) strong amplification (> 50%), 4) small amplification
(between 25 and 50 %). I cannot visualize it at the moment, but I think
this will work to figures analogous to the precip ones. Correct me if I
am wrong.
To the two technical issues:
1) Do we soften our requirement, i.e. from n-1 to n-2 model agreement?
I do not feel strongly about it but am more in favor of not softening
the criterion. We are looking for confidence and model agreement
and should have stringent requirements on it.
2) Do we include the outliers in the analysis? I say yes, not having
time for more detailed analysis as to why they should not be included.
In Chapter 9 they are presented as bracketing the answers not as being wrong.
This is the problem of not having published research on this. perhaps a paper
would have excluded them on scientific grounds, but can we at this point?
I am not sure we can have solid enough foundations to legitimate it.
Besides, I have done analysis without them as well and things did not change
almost at all.
To the operational issues:
1) I agree there is no time for a paper to be delivered before the
Sept. 26 deadline. After the deadline however, and with some calm, I
think we should have a paper on it.
2) Meeting or conference call. I myself am not keen on a meeting of the
Europeans. Jens is not back until the end of the week, which means the
meeting would have to be during the last week before deadline. With all
that is still left to do on the chapter and other internal committments I have,
I certainly could do without spending 2 days to do this (which is always the
minimum it takes me to get anywhere and back)and  I cannot do it
over the weekend since I am not here.
It sounds like we would have to contact people by phone
anyways (see Peter and Linda's messages), so why not a conference call
directly?
>From the technical viewpoint Linda seems to be the best person to
organize this. As soon as Jens is back perhaps? (Jens if you can read this
can you let us know when this is possible?).
3) We just got the MPI data and the full CCC ones (I guess some was lost in
the previous run). We need to incorporate these so we have all models
available. I and Bruce will interact on this.
4) I agree we should contact the TSU about it, but I also think we should have
a proposal on it with less spread than current to present them.
Last but not least, please work on your section revisions (especially those
who have nothing to do with the BOX) so at least we get that out of the way.
Cheers,   Filippo
################################################################
# Filippo Giorgi, Senior Scientist and Head,                   #
# Physics of Weather and Climate Section                       #
# The Abdus Salam International Centre for Theoretical Physics #
# P.O. BOX 586, (Strada Costiera 11 for courier mail)          #
# 34100 Trieste, ITALY                                         #
# Phone: + 39 040 2240 425                                     #
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# email: giorgi@ictp.trieste.it                                #
################################################################


Dear All
I think I heard replies to my last proposal from most of you. I have also
had a phone conversation with Linda. So let me try to summarize the
situation
1) From the replies I got, it sounds like at least the basic idea of my
proposal is viable. In particular I read an at least semi-consensus, and
certainly some strong individual positions, that the SRES material , since
it is unpublished (and remember unreviewed until now), should not be
presented as our sole or even primary source of conclusions. Now, I share
that position and in fact quite strongly. Presenting such material breaks
the proclaimed IPCC rules. Now the rules have been softened for this case,
but remember that there are people around who are paid to find faults in
the IPCC process and the last thing I want to do is being accused of
having broken the rules.  I think the TSU people are too optimistic and
casual in the way they change the rules during the process and expect
people to accept that this "just"  happens. Remember what happened to Ben
Santer after the SAR. Besides, I myself think that material for a document
as important as the TAR cannot be drawn from last-minute barely quality
checked and un-peered reviewed material (people have barely looked at the
MPI run that was completed last friday !!). It is up the the IPCC to
better plan these things and avoid the mess. Be it as it may, unless
somebody is strongly against this position, I will assume that we can
proceed from this basis.
2) Having said the above, it is also clear the we can present the IPCC data
in some format. Chapter 9 is doing it (remember also in their case the SRES
stuff is only a minor component of the chapter) so we can and I think we
should because it is relevant and important material,
but with the proper caveats clearly up front, i.e. that whatever
we present is a preliminary analysis that has not undergone a publication
process. It would be certainly strange and confusing to have the SRES
discussed in Chapter 9 but not in our chapter in some form. Besides we went
through a significant effort to get it and process it. I myself think
that the SRES information is important to provide. It is
just unfortunate, but not surprising, that it came around too late.
3) So the question is at this point how do we present the SRES. I suggested
not to incorporate it within the text of 10.3, since 10.3 is our assessment of
published research which has undergone peer and government review. I stand
strongly by that suggestion. Obviously 10.3 might need a bit of rewriting
to make it flow better with possibly different conclusions but not more than
that. I then suggested to make the Box an SRES Box including the +/- format
figures (I thought we needed 4, i.e. two for each scenario, but Linda pointed
out we really need only 2, one for precip and one for temperature each
including the two scenariost). Now
this offers several advantages: we can say right up front that this is from
a preliminary analysis; we can separate it cleanly from the rest of the
"official " text; it gives direct info in a format that people seem to like.
Two very legitimate comments were made on this. Peter said, if we give
this more palatable format (the +/- figures)
only for SRES data would it not implicitly give it
too much attention? Linda said: why not present similar plots for the
IS92 data? The obvious action which would address both of these concerns is
to present similar plots for the IS92 data. This is certainly an option.
The only problem I see is that I think the clear separation of published and
unpublished results would be lost if we put it in the BOX. The alternative
is to do those figures and put them in 10.3, leaving the SRES for the BOX.
This could be a good option, although it might require significant effort.
All and all, I am still in favor of an SRES-only box with a clear statement
up front that gets us off the hook in case of problems (you can see it
as a sort of disclaimer I guess).
So let's come to the next point: we need to decide on this and soon. The
best way appears to be a conference call. Linda suggested thursday, which
is fine with me. It now looks like Richard cannot organize this. So Linda
I am afraid you are left with the organization of it. The call
would have to be during European-South African afternoon - US morning
and I am afraid I am not sure what time in Australia. problems is: Jens can
you make it? I think Jens is the person in the group most strongly opposed
to presenting SRES data, so it important he is in the conference call. It
is also critical that Peter participates, given he has been the main
player in all this. Now here is my proposal:
Conference call on thursday 3 p.m. Trieste-Hamburg time, which means 4 p.m. Cape
town time, 2 p.m. Bracknell time, 9 a.m. Boulder time, 8 a.m. Fairbanks time
and ??? Australia time. Linda is this feasible for you to organize?
Is this ok for all? Conbin, are you available at all?
items of discussion:
Question 1): Do we do an SRES BOX with +/- figures?
Question 2): What are the technical details (n-1 vs. n-2 model agreement,
inclusion of outliers, threshold for large vs. small vs. no
change both for precip change and temperature amplification
factor).
Question 3): Do we do similar figures for IS92 data which would either replace
the current figures on IS92 in the text (I think this would be
perfectly acceptable since it is simply a way to present
in a different way published results).
Question 4): How do we incorporate the SRES results within the current
executive summary
I hope that by thursday I will have all data to do all relevant figures.
I need to get CCC control and MPI-DMI data from Bruce and dig out the old
IS92 data. If not by thursday then hopefully by friday. Once I have the
data I can easily directly calculate all the thresholds necessary for
doing the relevant figures. I will then circulate all the material to you.
Needless to say that any data based on SRES that is circulated among us
should NOT go any further (except for the chapter of course) until we decide
what to do with it (a paper or something like that).
In the mean time, I will never tire to keep asking you to please work on
the section revisions and let's get those out of the way.
Cheers,  Filippo
################################################################
# Filippo Giorgi, Senior Scientist and Head,                   #
# Physics of Weather and Climate Section                       #
# The Abdus Salam International Centre for Theoretical Physics #
# P.O. BOX 586, (Strada Costiera 11 for courier mail)          #
# 34100 Trieste, ITALY                                         #
# Phone: + 39 040 2240 425                                     #
# Fax: + 39 040  2240 449 (or + 39 040 224 163)                #
# email: giorgi@ictp.trieste.it                                #
################################################################


Dear all,
It could be viewed that using n-1 for 9 models where we used n-1 for five
models before is an implicit change in the stringency of our criterion.
When we had five models, agreement (0/5, 1/5, 4/5 or 5/5) could be expected
37% of the time just by chance (ignoring the near zero case).  With nine
models the equivalent figure for n-1 is only 3.5%, and it is still much
lower for n-2 (18%)... (assuming that my somewhat rusty probability
calculations are correct).  It really depends on what we had understood the
purpose of the criterion to be.  I am not certain how much this was
discussed.
Also, I would prefer Friday night as well if it means that more information
will be available.
Cheers
Peter
-----Original Message-----
From: Hans von Storch
Sent: Wednesday, 13 September 2000 19:48
To: Congbin Fu; GIORGI FILIPPO; Bruce Hewitson; Mike Hulme; Jens
Christensen; Linda Mearns; Richard Jones; Hans von Storch; Peter Whetton
Subject: n-1 / n-2
Dear friends,
I have already indicated that I favour the n-1 version. Obviously, this
choice is arbitrary, but it was made BEFORE we did the analysis. By
changing the criterion AFTER we have seen the data, we may be targeted
by critics for biased rules. Using material, which is unpublished and
unreviewed is already a bit shacky (Hans Oerlemans is unwilling to
participate in the IPCC process because of a similar incident in the
1995 report!).
Hans
--
Hans von Storch
Institute of Hydrophysics
GKSS Research Center, Max-Planck-Strasse 1, PO Box,
WWW:
e-mail: storch@gkss.de and storch@dkrz.de
Phone: + 49 / 4152 87 1831, fax: + 49 / 4152 87 2832
privat fax: + 49 / 4153 582 522


Warwick,
I did not think I would get a chance today to look at the web page.
I see what boxes you are referring to. The interpolation procedure cannot
produce larger anomalies than neighbours (larger values in a single
month). If you have found any of these I will investigate. If you are
talking about larger trends then that is a different matter. Trends
say in Fig 2.9 for the 1976-99 period require 16 years to have data
and at least 10 months in each year. It is conceivable that at there are
24 years in this period that missing values in some boxes influence
trend calculation.
I would expect this to be random across the globe.
Cheers
Phil
Warwick,
Been away.  Just checked my program and the interpolation shouldn't
produce larger anomalies than the neighbouring cells. So can you send
me the cells, months and year of the two cells you've found ? If I
have this I can check to see what has happened and answer (1).
As for (2) and (3) we compared all stations with neighbours and these
two stations did not have problems when the work was done (around 1985/6).
I am not around much for the next 3 weeks but will be here most of
this week and will try to answer (1) if I get more details. If you have
the names of stations that you've compared Olenek and Verhojansk with
I would appreciate that.
Cheers
Phil
At 05:13 AM 9/14/00 +1000, you wrote:
>Dear Phillip and Chris Folland (with your IPCC hat on),
>Some days ago Chris I emailed to Tom Karl and you replied re the grid cells
>in north Siberia with no stations, yet carrying red circle grid point
>anomalies in the TAR Fig 2.9 global maps.  I even sent a gif file map
>showing the grid cells barren of stations greyed out.  You said this was
>due to interpolation and referred me to Phillip and procedures described in
>a submitted paper.  In the last couple of days I have put up a page
>detailing shortcomings in your TAR Fig 2.9 maps in the north Siberian
>region, everything is specified there with diagrams and numbered grid
>points.
>[1]   One issue is that two of the interpolated grid cells have larger
>anomalies than the parent cells  !!!!?????
>This must be explained.
>[2]  Another serious issue is that obvious non-homogenous warming in Olenek
>and Verhojansk is being interpolated  through to adjoining grid cells with
>no stations, like cancer.
>[3]  The third serious issue is that the urbanization affected trend from
>the Irkutsk grid  cell neare Lake Baikal, looks to be interpolated into its
>western neighbour.
>
>I am sure there are many other cases of this, 2 and 3
> happening.
>Best regards,
>Warwick Hughes  (I have sent this to CKF)
>


Dear Tom,
The difference between the Campito Mountain record and, for example, the one
from the Polar Urals that you mention, is that there is no meaningful
correlation between the Campito record and local temperature, whereas there is a
strong correlation in the Polar Urals case. I give  references to the work
reporting this phenomenon at the end of this message, but I'm afraid I'm missing
the references to the technical comments that are being responded to in the last
two. 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.
I'm split between Harvard Forest and UMASS these days, and my copy of your paper
is not with me today. I'd be interested to know what the name of the site for
the LaMarche central Colorado record was.
Cheers, Malcolm
Reference List
1. 	Graybill, Donald A., and Sherwood B. Idso. 1993. Detecting the
Aerial Fertilization Effects of Atmospheric CO2 Enrichment in Tree-Ring
Chronologies. Global Bioeochemical Cycles 7, no. 1: 81-95.
2. 	LaMarche , V. C., D. A. Graybill, H. C. Fritts, and M. R. Rose.
1984. Increasing Atmospheric Carbon Dioxide: Tree Ring Evidence for Growth
Enhancement in Natural Vegetation. Science 225: 1019-21.
3. 	---1986. Carbon Dioxide Enhancement of Tree Growth At High
Elevations. Science 231: 859-60.
4. 	---1986. Technical Comments: Carbon Dioxide Enhancement of Tree
Growth At High Elevations. Science 231: 860.
Quoting tom crowley
:
> Dear Malcolm and Keith,
>
> as I discuss in my Ambio paper the "anomalous" late 19th century warming
> also occurs in a LaMarche tree ring record from central Colorado, the
> Urals
> record of Briffa, and the east China phenological temperature record of
> Zhu.
>
> Alpine glaciers also started to retreat in many regions around 1850,
> with
> 1/3 to 1/2 of their full retreat occurring before the warming that
> commenced about 1920.
>
> The Overpeck et al Arctic synthesis also discusses warming before 1920 -
> that record matches very closely the Mann et al reconstruction in other
> details back to 1600.
>
> Unpublished work by us on coral trends also suggests slight warming
> between
> about 1850-1920.
>
> So, are you sure that some CO2 fertilization is responsible for this?
> May
> we not actually be seeing a warming?
>
> Tom
>
>
>
> Thomas J.  Crowley
> Dept. of Oceanography
> Texas A&M University
> College Station, TX  77843-3146
> 979-845-0795
> 979-847-8879 (fax)
> 979-845-6331 (alternate fax)
>
>
>


Dear All,
I just wanted to keep you informed about the status of our draft JGR paper.
First, thanks to all of you for your comments - they were very helpful. I am now
in the process of revising the paper, and hope to have a new draft ready by Oct.
10th. After several discussions with Tom, I have decided to repeat the
volcano/ENSO signal separation for the observed data and for the GSOP
experiment.
The reason for this is that there was a conceptual flaw in what I had done
previously. The flaw related to the determination of the "pre-eruption"
reference temperature, used as a baseline for estimating the maximum
volcanically-induced cooling. Let's call this baseline temperature "TBASE".
Previously, I was estimating TBASE for Pinatubo and El Chichon from either the
raw or Gauss-filtered temperature data at time t=0 (the eruption month).
If I was calculating TBASE from the filtered data, the estimate of TBASE was
biased by "contamination" from post-eruption cooling. In other words, since I
was using a 13-term Gaussian filter, temperature values from t=0 + 6 months were
influencing TBASE, likely leading to an underestimate of the true TBASE value.
I've now modified the program so that TBASE is not computed from the filtered
data; instead, it is an average of the temperature anomalies in the MREF months
prior to the eruption. There is some sensitivity to the choice of MREF (I've
been experiment with values ranging from 6-18 months), which again underscores
the uncertainties inherent in separating ENSO and volcanic signals.
The maximum volcanically-induced cooling is still estimated using filtered data,
but now I'm using a 5-term binomial filter rather than the 13-term Gaussian.
These changes require repeating most of the analyses in the paper. Preliminary
results indicate that the revised estimation of TBASE increases the ratio of the
Chichon/Pinatubo maximum coolings, and brings this closer to the ratio of the
Chichon/Pinatubo radiative forcings.
Tom has also made a number of useful suggestions regarding reorganization and
shortening of various sections of the manuscript. Hopefully the next iteration
will be a little shorter than the current version of the paper!
I will be out of my office next week, but should be back by October 2nd.
With best regards, and thanks again for all your help,
Ben
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-264
Livermore, CA 94550, U.S.A.
Tel:   (925) 422-7638
FAX:   (925) 422-7675
email: santer1@llnl.gov
----------------------------------------------------------------------------


***************
Ben (or, really, everybody else),
I don't know whether you have all seen the paper analyzing the observed
data that Ben and I sent to J. Climate ?? This is where the JGR paper
began, and it is useful to compare both papers. In the J. Climate paper
we  assessed the best fits using a subjective balance of raw and lowpass
filtered results. The reason for this was because of the difficulty of
setting up an automated procedure -- which is the problem that Ben is
currently having to deal with. In the next iteration of the JGR paper,
the reason for moving to a more automated procedure will be explained.
Both the subjective and automated procedures have their advantages and
disadvantages. The latter procedure, of course, is in no way
'objective'. Many subjective choices have to be made in setting up the
procedure. This is why the word 'automated' is used above, rather than
'objective'.
If you have not seen the J. Climate paper, let me know and I will send
you a copy. There is a companion paper that has been accepted by GRL
that I will send at the same time.
Cheers, Tom.
***************
Ben Santer wrote:
>
> Dear All,
>
> I just wanted to keep you informed about the status of our draft JGR paper.
> First, thanks to all of you for your comments - they were very helpful. I am now
> in the process of revising the paper, and hope to have a new draft ready by Oct.
> 10th. After several discussions with Tom, I have decided to repeat the
> volcano/ENSO signal separation for the observed data and for the GSOP
> experiment.
>
> The reason for this is that there was a conceptual flaw in what I had done
> previously. The flaw related to the determination of the "pre-eruption"
> reference temperature, used as a baseline for estimating the maximum
> volcanically-induced cooling. Let's call this baseline temperature "TBASE".
> Previously, I was estimating TBASE for Pinatubo and El Chichon from either the
> raw or Gauss-filtered temperature data at time t=0 (the eruption month).
> If I was calculating TBASE from the filtered data, the estimate of TBASE was
> biased by "contamination" from post-eruption cooling. In other words, since I
> was using a 13-term Gaussian filter, temperature values from t=0 + 6 months were
> influencing TBASE, likely leading to an underestimate of the true TBASE value.
> I've now modified the program so that TBASE is not computed from the filtered
> data; instead, it is an average of the temperature anomalies in the MREF months
> prior to the eruption. There is some sensitivity to the choice of MREF (I've
> been experiment with values ranging from 6-18 months), which again underscores
> the uncertainties inherent in separating ENSO and volcanic signals.
>
> The maximum volcanically-induced cooling is still estimated using filtered data,
> but now I'm using a 5-term binomial filter rather than the 13-term Gaussian.
>
> These changes require repeating most of the analyses in the paper. Preliminary
> results indicate that the revised estimation of TBASE increases the ratio of the
> Chichon/Pinatubo maximum coolings, and brings this closer to the ratio of the
> Chichon/Pinatubo radiative forcings.
>
> Tom has also made a number of useful suggestions regarding reorganization and
> shortening of various sections of the manuscript. Hopefully the next iteration
> will be a little shorter than the current version of the paper!
>
> I will be out of my office next week, but should be back by October 2nd.
>
> With best regards, and thanks again for all your help,
>
> Ben
> --
> ----------------------------------------------------------------------------
> Benjamin D. Santer
> Program for Climate Model Diagnosis and Intercomparison
> Lawrence Livermore National Laboratory
> P.O. Box 808, Mail Stop L-264
> Livermore, CA 94550, U.S.A.
> Tel:   (925) 422-7638
> FAX:   (925) 422-7675
> email: santer1@llnl.gov
> ----------------------------------------------------------------------------
--
**********************************************************
Tom M.L. Wigley
Senior Scientist
ACACIA Program Director
National Center for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000
USA
Phone: 303-497-2690
Fax: 303-497-2699
E-mail: wigley@ucar.edu
Web:
**********************************************************


>Date: Fri, 22 Sep 2000 15:50:05 -0400
>To: Tim Osborn
>From: "Michael E. Mann"
>Subject: Re: my visit
>Cc: srutherford@virginia.edu, k.briffa@uea, p.jones@uea
>Bcc: mhughes@ltrr.arizona.edu, rbradley@geo.umass.edu
>In-Reply-To:
>References:
>
>HI Tim,
>
>Very busy, so just a short response for the time being.
>
>Regarding our MBH98 and GRL99 datasets, I'm pretty sure that Scott put those
>on anonymous ftp for you some months ago. So you *should* already have had
access to all the data we used. In fact, it was only a few select series of
Malcolm's that weren't made available from the get-go.  So data has never
>been an issue for us. I'm happy to hear that it is not an issue for
you/keith/phil and that you are ready to make your density data available...
>
>A few points of clarification might help here:
>
>The revised method (based on ridge regression) is currently in development
as far as paleoreconstruction is concerned (we have a paper to be submitted
on application to the instrumental record only). We intend to test it on
synthetic proxy datasets (as described in my previous email) before
applying it to actual proxy data, so your visit, unfortunately, occurs at a
time that is too premature for comparison with results from this method.
Rather, we were hoping
>you shared some of the interest along the lines of
developmental/methodological
>issues.
>
>Comparison between warm-season reconstructions would be fine, but you should
>be aware of the extreme caveats with regard to our seasonal
reconstructions, as spelled out in detail in our "Earth Interactions"
article. We don't do nearly as well for warm-season or cold-season as for
annual-mean, and we believe this is consistent w/ the mix of seasonal
information contained in the multiproxy dataset. Obviously, things are
somewhat different for the more seasonally homogeneous density chronology
dataset. So to us, this comparison might not
>seem as worthwhile as it would for you all, but we can do it if all provisos
>and caveats are fully recognized and embraced from the start...
>
>The idea of testing wavelet methods of distinguish contributions on
different timescales sounds like it is of interest to all of us, and
perhaps we can
>move in that direction during your visit.
>
>In any case, we'll have more than enough to do, talk about, investigate,
and no need to necessarily hammer it all out beforehand.
>
>Comments from others (Scott, Phil, Keith?) welcome,
>
>mike
>
>At 09:24 AM 9/22/00 +0100, Tim Osborn wrote:
>>At 10:11 19/09/00 -0400, you wrote:
>>>I will put you up at the "Red Roof Inn" for the 10 nights...
>>>Will have reservations made for you for the night of the 10th through 19th,
>>>checking out morning of the 20th...
>>
>>That sounds great. Thanks.
>>
>>
>>Mike,
>>
>>I've talked over various ideas with Keith and Phil (and I'm cc'ing this to
>>them as well as to Scott), and I've now made some slightly firmer/clearer
>>suggestions, combining your ideas and ours.
>>
>>(1) We're still keen to spend part of the time on reconstruction method
>>issues, since that is one of the specifics that our current funded project
>>needs to address.  To avoid being too retrospective, we could do something
>>that combined both your Nature98 and your revised methods:
>>
>>(a) compare your summer/warm season reconstructions (old & new methods)
>>with our reconstructions of Apr-Sep temperature from tree-ring densities
>>(regional/hemispheric averages and spatial comparisons).
>>
>>(b) In (a), we would be comparing reconstructions based on different
>>palaeodata *and* different statistical reconstruction methods.  So a better
>>approach would be to use your (old & new) methods with our tree-ring
>>density data set to reconstruct Apr-Sep temperature fields, and then
>>compare with our reconstructions.  This would be a good way of comparing
>>methods.
>>
>>(c) We could exchange data/methods to continue comparisons after the end of
>>my visit.  We would be keen, for example, to obtain your Nature98 & GRL99
>>datasets and software to play around with after my return.  In exchange, we
>>can provide you with our tree-ring density data set and the reconstructions
>>that we have produced from it.  Of course, such subsequent work would
>>continue to be collaborative, keeping each other informed/involved with the
>>work.
>>
>>(d) If the tree-ring density data provided useful "added value" to your
>>reconstructions (perhaps at the higher frequencies and providing finer
>>spatial detail?), then we could use an appropriate method (perhaps your new
>>revised one) to produce a new reconstruction using all palaeodata.  Such a
>>reconstruction might prove to be an important and well-used product.
>>
>>(2) Of your two specific suggestions I quite strongly prefer the first.
>>The reason is that, again, our project specifically requires comparison of
>>palaeo and model data and the development of appropriate methods to do
>>this.  Your first suggestion would take us along those lines.  There are
>>two related strands here.  The first is to use the model outputs to assess
>>the reliability of the reconstructions (i.e., following the ideas you laid
>>out in your e-mail), which is certainly of interest.  The second is to use
>>the reconstructions to evaluate the model simulations of "natural"
>>variability.  We've done some comparisons with the HadCM2 and HadCM3
>>simulations - I shall brings papers/results along.  What we need to develop
>>further are ways of incorporating the paleo biases/errors in such
>>comparisons.  We have begun this, but when I visit we might be able to come
>>up with better methods and apply them to Hadley Centre and/or GFDL
>>comparisons.
>>
>>Your second suggestion, while interesting, is less appealing at this stage,
>>principally because we won't have time to do everything.  As it happens,
>>Keith and I have just submitted a paper (to that well-known(!) journal
>>"Dendrochronologia") about timescale-dependent calibration of tree-ring
>>data - I shall bring a copy with me.  My feeling is that the quantity of
>>data overlap available for calibration would be a strongly limiting factor
>>in most timescale-dependent approaches, whether they use wavelets or some
>>other filtering-type approach.  What interests me more would be the
>>application of wavelets to the full palaeorecords to facilitate in the
>>definition of timescale-dependent coherent patterns (PCs?), rather than
>>just to the calibration period.  Anyway, we can talk these ideas over even
>>if there's no time to begin any work yet.
>>
>>I think that a chance to exchange preprints, data, and discuss ongoing
>>developments of our work and yours will, in itself, prove to be a useful
>>outcome of my visit.
>>
>>Best regards
>>
>>Tim
>>
>>
>>
>>Dr Timothy J Osborn                 | phone:    +44 1603 592089
>>Senior Research Associate           | fax:      +44 1603 507784
>>Climatic Research Unit              | e-mail:   t.osborn@uea.ac.uk
>>School of Environmental Sciences    | web-site:
>>University of East Anglia __________|   ~timo/
>>Norwich  NR4 7TJ         | sunclock:
>>UK                       |   ~timo/sunclock.htm
>>
>>
>>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@virginia.edu   Phone: (804) 924-7770   FAX: (804) 982-2137


Dear Mike
I know Tim has communicated with you about plans for his visit to Virginia. We have discussed ideas here and I ,for one, am excited about the prospects of joint work. Thank you for agreeing to his visit and for taking the trouble to arrange things .
The purpose of this brief message is simply to reiterate what we said in our brief discussions in Venice - namely that it is our intention to work with you rather than in any sense of competition. Our motivation for wanting to do some of the detailed comparisons between the results of our work and your own is to understand the sources of uncertainty in both. We are also committed to doing some of this work by the terms of our current NERC grant.   We wish to involve you as much as possible , get your advice , and solicit criticisms of our approach -especially in relation to the Palaeo-model comparisons .
Our EC proposal was not funded , but we wish to follow it up with another to PRESCIENT (a NERC Thematic Programme of research along the same lines), and again we would be happy to collaborate with you. Better two way communication between here and there would be a major help.
It is my feeling that  the relatively short time Tim has with you , might be best spent getting to grips with the finer details of your "old" and "new"  approaches, including the details and results of your other work that is only partly described in the publications ( seasonal runs,  different data sets etc.) and , most importantly, discussing approaches and philosophies for data-model comparison work. That way he could come away with some concrete plans , and the means of fulfilling them, on his return. Any time you can spare to discuss and liaise along these lines would be much appreciated. He has discussed the specifics of your suggestions and I am happy with the approach and prioritization he has expressed.
While he is with you , we can always exchange emails if any issues need wider discussion.
very best wishes
Keith