Dear All,
I was away over the weekend at Bowdoin College in Maine, giving a
talk about the
last 1000 years. There were three others as well on other paleo aspects,
Richard Alley,
Gary Clow and Wally Broecker !  The latter briefly mentioned to me that
he had had
something in last Friday's Science, which was getting at the Mann et al.
series. He
didn't have a copy so we've not seen it here yet.  I tried to get a copy
of Science on
the bookstand at Logan airport last night - I guess it's not sold that way !
Wally was going on about this 1500 yr cycle of Bond's, which seemed
pretty flimsy.
I was showing all the various series in a general talk - and I used some
of the overheads
from the upcoming Science paper. This is due to appear in the issue for
the last week
of April. It is all accepted now.  I will forward if you'll all abide by
the Science rules. Both
Wally and Alley seem convinced that the climate of Greenland changed by
10 C in
the space of 2-3 years at times in the past (Y Dryas etc).  I had long
talks with both
and they don't seem to have got their heads around spatial scales (local
changes
and hemispheric). Also they don't seem to realise where we are coming
from.  He
has a downer on trees (believes all the multiproxy series depend
exclusively on
trees) but he thinks Ed Cook is a great scientist. The latter is true,
but he might
just think that because he's at Lamont. I did tell him that Keith's paper
on the age
banding is out in JGR. I should send him a reprint and maybe ask that great
scientist to go and explain it to him ! Ed's in NZ at the moment. Also
Wally believes
much more in glacier advances/retreats. I'll get Keith to send him
Sarah's paper
where the long Tornetrask reconstruction is shown to agree with Storglaciaren
advance/retreat dates from moraine evidence. Also Sarah's been working on
similar
glaciers in the Swiss Alps with long tree-ring reconstructions.  One
interesting
thing was he didn't seem to realise that a lot of the tree-ring
reconstructions use
density. Seemed to think they were all ring widths and there had to be
moisture
changes we were not accounting for.
It is easy to respond to a Perspectives piece. Some of you did it
with respect to
one of mine. I'm not sure it will achieve much - it won't come out before
the paper
in the last week of April.  I need to wait to se what he says. Our paper
(me, Tim and
Keith) clearly says that the MWP couldn't have been warmer (for the NH
average)
than the late 20th century.
Another possible reason for not doing anything is that the IPCC
report will be out
soon. The summary is written in pretty clear language.
The above is my first thoughts, not having read the piece and just
got off the
flight back.
Best to ignore Woijcek. All he seems to want to do is deflect us into
responding.
Cheers
Phil
At 11:47 25/02/01 -0700, mhughes@ltrr.arizona.edu wrote:
>Dear all,
>WHat mechanism does "Science" have for repsonding to Perspective pieces? Most
>of the answer to Wally is contained within his own piece - he comments on the
>ambiguity of the record, which, in various ways, we have all done. What he
>doesn't offer, however, is anything other than an anecdotal alternative. As
>always, he seeks to damn ( in this case with faint praise) the records or
>work
>that don't serve his purpose , and to elevate any scrap of evidence that does
>serve it. I think it will be important for us to stick closely to what we
>have
>written in published papers. CHeers, MAlcolm
>
>Quoting "Michael E. Mann"
:
>
> > Dear Phil, Ray,
> >
> > What do you guys think. If we're all on board, than an appropriately
> > toned,
> > "high road" response here might be appropriate. We don't want to engage
> > Wally in a personal battle, but simply should correct the record where
> > Wally has muddied it. Again, Phil et al do have a Science article in
> > press
> > that serves this purpose to some extent, so I'm especially interested in
> > what
> > Phil thinks (Phil?)...
> >
> > mike
> >
> > At 02:52 PM 2/24/01 -0700, mhughes@ltrr.arizona.edu wrote:
> > >Dear Mike et al., I think we should definitely let Wojick stew in his
> > own
> > >juice - as Mike pointed out to me the other day he, and his like, have
> > a
> > >specific agenda, and anything we write will be pressed into the service
> > of
> > that
> > >agenda. I'm not so sure about Wally. I share Tom's disinclination to
> > get
> > into a
> > >street fight with Wally - generally I take the view that life's too
> > short and
> > >uncertain for such activities. On the other hand, would we let such a
> > shoddy
> > >piece of work(and editing) go by if it were from another author? There
> > are so
> > >many holes in Wally's argument, and such a selective choice of evidence
> > that it
> > >should beggar belief. One of the more obvious holes is that he writes
> > of the
> > >Great Basin droughts of the 10th through 14th centuries as proof of
> > warmer
> > >conditions then, but doesn't explain why we don't have such conditions
> > now.
> > >Interestingly, Larry Benson, Dave Meko and others have good evidence
> > that
> > these
> > >same multidecadal periods were marked by a great excess of
> > precipitation
> > just a
> > >few hundred miles north in northern Nevada and California and southern
> > Oregon.
> > >He just hasn't grasped that the methods that are appropriate for
> > tracking the
> > >consequences of major changes in boundary conditions don't work in the
> > late
> > >Holocene. I've been trying to figure out the issue of "Was there a
> > Medieval
> > >Warm Period, and if so where and when" for a decade or so, and still
> > have the
> > >impression that the records for the 9th through 14th centuries are
> > extremely
> > >mixed. But then, I didn't come to the investigation with a certain
> > knowledge of
> > >the absolute truth, and have had to 'misfortune' to work with people
> > who let
> > >careful analysis get in the way - Henry Diaz, Ray and Mike, and others.
> >
> > >Anyway, the point of this rant is that I think we should give careful
> > >consideration to making a measured response to Wally. Cheers, Malcolm
> > >
> > >
> > >
> > >
> > >Quoting "Michael E. Mann"
:
> > >
> > >> Hi Tom,
> > >>
> > >> Thanks for your quick reply. I agree with you entirely. I think its
> > very
> > >> unfortunate he's chosen to disinform the community rather than engage
> > in
> > >> a
> > >> constructive dialogue (we tried the latter w/ him in a series of
> > emails
> > >> last
> > >> year, but clearly to no avail).
> > >>
> > >> On the other hand, think that a war of words w/ Broecker would be
> > >> exploited
> > >> by the skeptics, and perhaps we should just try to let this thing
> > die...
> > >>
> > >> I'm not sure. I'd appreciate knowing what others think?
> > >>
> > >> mike
> > >>
> > >> At 10:25 AM 2/24/01 -0600, tom crowley wrote:
> > >> >Mike,
> > >> >
> > >> >I was not aware of the Broecker piece - I am dismayed but not
> > >> surprised.  I
> > >> >do not know what to do - I personally cannot stand the combative
> > >> personal
> > >> >approach Broecker relishes but it does seem as if some rebuttal is
> > >> called
> > >> >for.  Maybe you Ray Phil I and Malcolm could pen a response - we are
> > >> >heading to Germany in a week, for a month, so I am not sure how much
> > I
> > >> can
> > >> >keep up on this but it seems as if some response is called for.
> > >> >
> > >> >What think ye?
> > >> >
> > >> >Tom
> > >> >
> > >> >
> > >> >>Dear Mike,
> > >> >>
> > >> >>Thanks for passing this along.
> > >> >>
> > >> >>Wojick of course completely misrepresents Broecker, and puts his
> > >> >>conventional intellectually dishonest spin on this.
> > >> >>
> > >> >>That having been said, it is a bit disappointing that Wally
> > continues
> > >> to
> > >> >>cling to some of his flawed beliefs which aren't supported from
> > either
> > >> our
> > >> >>best current understanding of the observations or of the results of
> > >> careful
> > >> >>modeling experiments. My own perception is that the climate
> > community,
> > >> >>modelers as well as observationalists, simply don't take seriously
> > >> anymore
> > >> >>the idea that the history of climate change over the past 1000
> > years
> > >> is
> > >> >>part of an internal oscillation. The sediment core evidence oft
> > cited
> > >> by
> > >> >>Broecker (e.g. Bond et al) for this is tremendously weak, and I, as
> > >> well as
> > >> >>the vast majority of my colleagues, simply don't buy it for even a
> > >> second.
> > >> >>But people don't like to challenge Broecker publically. He can and
> > >> will
> > >> >>play hardball.
> > >> >>
> > >> >>There is an odd irony. Broecker refused to accept the modeling
> > >> evidence
> > >> >>that the 100 kyr ice age Pleistocene variations were part of an
> > >> internal
> > >> >>oscillation paced by insolation variations, favoring instead the
> > >> >>discredited notion that they were a direct response to (too weak)
> > >> >>eccentricity forcing, until the evidence became insurmountable
> > (from
> > >> my
> > >> >>adviser, Barry Saltzman, may he rest in piece, and people like Dick
> > >> >>Peltier). Ironically, Broecker then took credit for the very
> > >> proposition he
> > >> >>had fought w/ tooth and nail.
> > >> >>
> > >> >>Broecker is even more wrong, and unfortunately equally stubborn, in
> > >> this case.
> > >> >>And, again, the reason: because his pet theory, that climate
> > >> variability is
> > >> >>a simple millennial oscillation, is finally being challenged w/
> > hard
> > >> data
> > >> >>and hard facts.
> > >> >>
> > >> >>Broecker misrepresents the nature of that data that we and others
> > have
> > >> >>used, and misunderstands the source of the muted hemispheric trends
> > >> (there
> > >> >>*is* a hemispheric "medieval warm period" and "little ice age",
> > just
> > >> not of
> > >> >>the magnitude or the distinctiveness that Broecker imagines).
> > >> Individual
> > >> >>regions in our reconstructions, and Phils, and others, vary by
> > several
> > >> >>degrees C, ie, the proxies we use have no problem whatsoever in
> > >> resolving
> > >> >>high-amplitude temperature variations in the past. The problem is
> > that
> > >> when
> > >> >>we look at  the different regions we find that periods of cold and
> > >> warm
> > >> >>often occur at very different times in different regions, and so in
> > a
> > >> >>hemispheric or global average, a lot of purely regional variability
> > >> cancels
> > >> >>out. The resulting trends are somewhat smaller. I remained
> > befuddled
> > >> as to
> > >> >>why Wally doesn't understand this point. Its been explained to him
> > >> time and
> > >> >>time again. Maybe he's just not listening, or doesn't want to
> > >> listen...
> > >> >>
> > >> >>In fact, Tom Crowley has clearly shown that the observed millennial
> > >> >>temperature reconstruction is precisely consistent w/ our
> > >> understanding of
> > >> >>*forced* climate change over the past 1000 years (solar changes,
> > >> volcancic
> > >> >>output, and recent greenhouse gas concentrations). There is, simply
> > >> put, no
> > >> >>room for a global millennial internal oscillation. Regionally, such
> > >> types
> > >> >>of climate phenomena, associated for example with changes in the
> > North
> > >> >>Atlantic ocean circulation, are supported by the observations. This
> > >> >>explains why, for example, European temperature variations are
> > >> somewhat
> > >> >>larger than those in other regions not effected so strongly by such
> > >> climate
> > >> >>processes.
> > >> >>
> > >> >>Other recent perspectives, by Ray Bradley and myself provide a far
> > >> more
> > >> >>balanced and nuanced (and less dogmatic or defensive) viewpoint.
> > I'm
> > >> not
> > >> >>sure a written response to Broecker is worthwhile (this is,
> > afterall,
> > >> a
> > >> >>"perspective" and everyone understands that a scientist may have a
> > >> flawed
> > >> >>perspective). If Wally wants this to be his legacy, so be it...
> > >> >>
> > >> >>Phil and others have a review article coming out in the near future
> > >> which
> > >> >>also provides a much more balanced perspective on the climate
> > changes
> > >> of
> > >> >>the past millennium, and will set the record straight once again
> > (good
> > >> >>timing Phil!). Science's embargo policy prevents me from saying
> > much
> > >> more
> > >> >>at this time, but if Phil or anyone else wishes to comment further,
> > >> I'd
> > >> >>encourage it.
> > >> >>
> > >> >>Well, I've still got some snow to shovel here in Charlottesville!
> > >> Happy
> > >> >>weekend to all,
> > >> >>
> > >> >>mike
> > >> >>
> > >> >>p.s. For those with electronic subscriptions, Broecker's latest
> > piece
> > >> can
> > >> >>be found here:
> > >> >>
> > >> >> PALEOCLIMATE:
> > >> >>        Was the Medieval Warm Period Global?
> > >> >>        Wallace S. Broecker
> > >> >>        Science Feb 23 2001: 1497-1499. [Summary] [Full Text]
> > >> >>
> > >> >>
> > >> >>
> > >> >>While my previous perspective piece is here:
> > >> >>   CLIMATE CHANGE:
> > >> >>   Lessons for a New Millennium
> > >> >>   Michael E. Mann
> > >> >>   Science 2000 July 14; 289: 253-254. (in Perspectives) [Summary]
> > >> [Full
> > >> >>Text]
> > >> >>URL:
> > >>
> > >>
> S=10&h
> > >>
> > >>its=10&RESULTFORMAT=&author1=Mann&searchid=QID_NOT_SET&stored_search=&
> FIRSTI
> > >> >>NDEX=&fdate=10/1/1995&tdate=2/28/2001
> > >> >>
> > >> >>and Bradley's is here:
> > >> >>
> > >> >>   PALEOCLIMATE: Enhanced: 1000 Years of Climate Change
> > >> >>   Ray Bradley
> > >> >>   Science 2000 May 26; 288: 1353-1355. (in Perspectives) [Summary]
> > >> [Full
> > >> >>Text]
> > >> >>
> > >> >>URL:
> > >>
> > >>
> TS=10&
> > >>
> > >>hits=10&RESULTFORMAT=&author1=Bradley&searchid=QID_NOT_SET&stored_sear
> ch=&FI
> > >> >>RSTINDEX=&fdate=10/1/1995&tdate=2/28/2001
> > >> >>
> > >> >>>Dear Michael--The third point below has comments on the
> > controversy
> > >> >>>betweenyou and Broecker--I'd be interested in your response (did
> > >> Wally not
> > >> >>>just understand what your data show?).
> > >> >>>
> > >> >>>Mike
> > >> >>>
> > >> >>>Three Wojick Pieces on Climate Change.
> > >> >>>I've been busy busy.
> > >> >>>
> > >> >>>David
> > >> >>>
> > >> >>>FIRST, the latest issue of Insight Magazine includes a
> > >> point-counterpoint
> > >> >>>between measly old me and the great Robert Watson. Boy has he got
> > >> >>>credentials! Too bad he's wrong.
> > >> >>>
> > >> >>>
> > >> >>>
> > >> >>>Symposium: Do scientists have compelling evidence of global
> > warming?
> > >> >>>
> > >> >>>Yes: Rising sea levels worldwide and retreating Arctic glaciers
> > are
> > >> ominous
> > >> >>>signs.
> > >> >>>
> > >> >>>By Robert T. Watson -- chairman of the UN Intergovernmental Panel
> > on
> > >> >>>Climate Change, chief scientist at the World Bank and former chief
> > >> science
> > >> >>>advisor to the Clinton White House.
> > >> >>>
> > >> >>>No: Despite the overheated rhetoric, there is no new evidence of
> > >> warming
> > >> >>>
> > >> >>>By David E. Wojick -- covers climate policy for Electricity Daily
> > and
> > >> is a
> > >> >>>science adviser to the Greening Earth Society
> > >> >>>
, as well as Undereditor of
> > the
> > >> >>>Washington Pest
> > >> >>>
> > >> >>>SECOND, the February 15 Eco-logic on-line has published "The Black
> > >> Hole of
> > >> >>>Global Climate Government" by David Wojick, my detailed attack on
> > the
> > >> >>>Framework Convention on Climate Change. It includes a lot of the
> > >> actual
> > >> >>>treaty language.
> > >> >>>
> > >> >>>
> > >> >>>
> > >> >>>THIRD, here is a draft Electricity Daily article of mine. Seems
> > I'm
> > >> not the
> > >> >>>only one who thinks the IPCC is nuts.
> > >> >>>
> > >> >>>Climate Guru Kicks The Hockey Stick
> > >> >>>by David Wojick (dwojick@shentel.net)
> > >> >>>
> > >> >>>Global warming is natural and the recent warming is probably no
> > >> exception.
> > >> >>>This is the controversial argument made by prominent climatologist
> > >> Wallace
> > >> >>>S. Broecker in today's issue of Science.
> > >> >>>
> > >> >>>Broecker's bombshell bears the seemingly innocent title "Was the
> > >> Medieval
> > >> >>>Warm Period Global?" It may seem esoteric, but whether the
> > apparent
> > >> warmth
> > >> >>>reported in Europe about 1000 years ago was global or simply local
> > is
> > >> >>>becoming a central issue in climate science. What makes it
> > >> contentious is
> > >> >>>the recent claims by the United Nations Intergovernmental Panel on
> > >> Climate
> > >> >>>Change that the earth is warmer now than it has been for
> > millennia,
> > >> and
> > >> >>>that therefore human carbon dioxide emissions are to blame.
> > Broecker,
> > >> a
> > >> >>>leading figure at Lamont-Doherty Earth Observatory, Columbia
> > >> University,
> > >> >>>questions both IPCC claims.
> > >> >>>
> > >> >>>The focus of the debate is a 1000-year temperature reconstruction
> > >> known in
> > >> >>>climate circles as the "hockey stick". Produced in 1999 by M. E.
> > >> Mann, R.
> > >> >>>S. Bradley, M. K. Hughes, the long handle of the hockey stick
> > shows
> > >> global
> > >> >>>temperatures for the first 8 centuries as basically unchanging,
> > >> followed by
> > >> >>>the sharply up-tilting blade of the last 150 years or so. The Mann
> > et
> > >> al
> > >> >>>hockey stick is the central feature of the recently released IPCC
> > >> working
> > >> >>>group one Summary for Policy makers, which claims to embody the
> > best
> > >> of
> > >> >>>climate science.
> > >> >>>
> > >> >>>Broecker does not like the hockey stick, nor the conclusions the
> > IPCC
> > >> draws
> > >> >>>from it. He says " A recent, widely cited reconstruction (Mann's)
> > >> leaves
> > >> >>>the impression that the 20th century warming was unique during the
> > >> last
> > >> >>>millennium. It shows no hint of the Medieval Warm Period (from
> > around
> > >> 800
> > >> >>>to 1200 A.D.) during which the Vikings colonized Greenland,
> > >> suggesting that
> > >> >>>this warm event was regional rather than global. It also remains
> > >> unclear
> > >> >>>why just at the dawn of the Industrial Revolution and before the
> > >> emission
> > >> >>>of substantial amounts of anthropogenic greenhouse gases, Earth's
> > >> >>>temperature began to rise steeply. Was it a coincidence? I do not
> > >> think so.
> > >> >>>Rather, I suspect that the post-1860 natural warming was the most
> > >> recent in
> > >> >>>a series of similar warmings spaced at roughly 1500-year intervals
> > >> >>>throughout the present inter-glacial, the Holocene."
> > >> >>>
> > >> >>>Broecker presents the evidence for a global Medieval Warm Period,
> > as
> > >> well
> > >> >>>as for a Little Ice Age from around 1300 to 1860, when the present
> > >> >>>temperature rise begins. He also argues that the "proxy" evidence
> > >> used by
> > >> >>>Mann et al, such as tree ring data, is ill suited to the time
> > period
> > >> and
> > >> >>>temperature variation -- less than one degree C -- in question.
> > >> >>>
> > >> >>>As he puts it, "In my estimation, at least for time scales greater
> > >> than a
> > >> >>>century or two, only two proxies can yield temperatures that are
> > >> accurate
> > >> >>>to 0.5 C: the reconstruction of temperatures from the elevation of
> > >> mountain
> > >> >>>snowlines and borehole thermometry. Tree ring records are useful
> > for
> > >> >>>measuring temperature fluctuations over short time periods but
> > cannot
> > >> pick
> > >> >>>up long-term trends because there is no way to establish the
> > >> long-term
> > >> >>>evolution in ring thickness were temperatures to have remained
> > >> constant."
> > >> >>>
> > >> >>>Broecker acknowledges that the proxy evidence is necessarily
> > somewhat
> > >> >>>"murky", but his conclusion is that "climatic conditions have
> > >> oscillated
> > >> >>>steadily over the past 100,000 years, with an average period close
> > to
> > >> 1500
> > >> >>>years... The swing from the Medieval Warm Period to the Little Ice
> > >> Age was
> > >> >>>the penultimate of these oscillations." The implication being that
> > >> some, if
> > >> >>>not all, of the present warming is the natural swing out of the
> > >> Little Ice
> > >> >>>Age, and that Mann et al, as well as the IPCC, are mistaken.
> > >> >>>
> > >> >>>
> > >> >>>--
> > >> >>>
> > >> >>>
> > >> >>>Dr. David E. Wojick
> > >> >>>President
> > >> >>>Climatechangedebate.org
> > >> >>>Subscribe to the free debate listserv at
> > >>
> > >> >>>Non subscribers can follow the debate at
> > >> >>>
> > >> >>>
> > >> >>>
> > >> >>>
> > >> >>>
> > >>
> > >>_______________________________________________________________________
> > >> >>                     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
> > >> >>
> > >> >
> > >> >
> > >> >
> > >> >
> > >> >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)
> > >> >
> > >> >
> > >> >
> > >> >
> > >>
> > _______________________________________________________________________
> > >>                     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
> > >>
> >
> > >>
> > >>
> > >>
> > >
> > >
> > >
> > >
> > >
> > >
> > _______________________________________________________________________
> >                     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
> >
> >
> >
> >
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
----------------------------------------------------------------------------


Dear TGCIAers:
A proposed date/place for the next TGCIA meeting is: 9.00 on Wednesday 30th
May to 14.00 on Friday 1st June at Shell International Bldg, Amsterdam. Rob
Swart and colleagues at WGIII TSU have kindly agreed to be local hosts.
I suggest this date after  consulting with 9 TGCIA members present at WGII
plenary at Geneva last week. The window is narrow between IPCC and SUBSTA
meetings (the latter is now almost certainly delayed until mid June).
Please put this date in your diary, but also let me know of any major
conflict with IPCC/UNFCC-type schedules.
Unless I hear to the contrary( *let us say by Monday 5th March*), the
proposal is that this dates stands .
This meeting is particularly because top of the agenda from our last meeting
is consideration of developing a 'one-stop-shop' for data and guidance for
scenario-based climate impacts assessment, which would lay the foundations
for compatible research for the next IPCC assessment (whatever form it may
take).  We might well also consider what recommendations to make concerning
the form of the next assessment (a subject probably on the agenda of the IPCC
London Plenary in September).
More follows next week, assuming these dates hold, about agenda and
arrangements.
Kind regards,
Martin parry
Prof. Martin L. Parry
Jackson Environment Institute
University of East Anglia
Norwich
NR4 7TJ
Tel:  +44 (0) 1603 592 318
Fax: +44 (0) 1603 593 896
E-mail: parryml@aol.com
Web:


Mike et al,
Sorry about the multiple sendings. I've forgotten my glasses and
couldn't see I'd
missed a comma.
Another thing to point to is the special issue of Climatic Change by
Astrid Ogilbie
and Trausti Jonsson.  They point to the LIA not being very appropriate in
Iceland.
Cheers
Phil
Mike,
So Julia handled it. Even she thought it was handwaving, but it
passed the usual
Science review process.  Obviously this isn't great as none of us got to
review it. Odd
that she didn't send it to one of us here as she knew we were writing the
article she
asked us to !  Anyway that is water under the bridge.
As for authorship we have this article coming out so this rules us
out.  Tom isn't
keen and he's away.  Wally told me he didn't reckon Tom, so Tom has got
the right
vibes. Julia is asking us to go ahead and hinting at a joint response.
One possibility is
either you or Macolm taking the lead.  Malcom and Henry wrote the MWP
piece in
Climate Change in 94. Keith and I think something pointed about the MWP
is the way
to go. Could add in that even the two warming periods in the 20th century
don't show
warming everywhere - especially the early 20th century.
Remember that we are all basically averaging long series together and
if one site
shows a big warming/cooling then the average will to a lesser extent.
Also bring in
a few of the papers where people have compared tree based reconstructions
with
glacial advances/retreats (eg Raper et al in J. Glaciology and Luckman et
al in the
Holocene. Also there are more in that Interhemispheric Linkages Book of
Vera amd
work by Ricardo Villalba and others).
Basically need to point to a load of literature that we would expect
someone writing
an article of this type to be aware of. Also the North Atlantic isn't the
last word in NH
and global averages. Clearly said in Hughes and Diaz and papers therein.
Also the latest IPCC report will use and reference the latest curves,
but from
1400 they are not that different from Bradley and Jones (1993), so why
the fuss now.
Clearly the MWP is the issue that has got a few worked up, but we have
concluded
nothing that couldn't have been gleaned in 1994. Maybe we're stating it
more clearly
now, but the recent warmth of the 1990s is a factor as well.
Cheers
Phil
>From: "Julia Uppenbrink"
>To: "Phil Jones"
>Subject: RE: Science issue Feb 22/23
>Date: Mon, 26 Feb 2001 17:05:45 -0000
>X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)
>Importance: Normal
>
>Dear Phil
>
>Thanks for your message regarding Wally Broecker's Perspective. I am of
>course aware of this Perspective coming out - I did handle it - I realized
>that it was perhaps a bit handwaving in parts but I thought the message was
>interesting and the article passed the usual screening. But we are always
>open to criticism! So please do send a letter to us; you can send it
>directly to me, and you may cowrite it with Tom Crowley and Mike Mann or you
>can send separate letters (if the concerns overlap a lot then one letter is
>perhaps better than several). The letter will be handled through our letters
>department, and we will get a response from Wally plus possibly outside
>review before we make a decision to publish.
>
>I look forward to receiving your letter.
>
>Best wishes
>
>      Julia
>
>-----Original Message-----
>From: Phil Jones
>Sent: 26 February 2001 14:40
>To: Julia Uppenbrink
>Subject: Science issue Feb 22/23
>
>
>
> >
> >  Dear Julia,
>          I don't know if you have seen the Perspectives piece in last
>week's issue of
>   Science by Wally Broecker.  I guess it was nothing to do with you and it
>contains
>   several inaccuracies and sweeping statements. I accept it is a personal
>view
>   and I've not seen the issue yet , only a copy that I was ironically given
>by Wally
>   Broecker as we were both guest speakers at a meeting at Bowdoin College,
>ME
>   on Saturday. I got back this morning to Norwich.
>         I talked to Wally about it over the weekend and will send him a few
>reprints
>   pointing out a few of the things he should have read. Some things he
>states are just
>   wrong.
>         I don't want to change the article already accepted, but what are
>the possibilities
>   of writing a response to Wally's piece in a later issue. I've been
>contacted by a couple
>   of people in the US about Broecker's piece (Mike Mann and Tom Crowley),
>who are
>   quite unhappy about it and would like to respond. They both know about
>the invited
>   piece and wanted me to comment, hence my email to you. The invited piece
>does
>   address some of the issues, but not the link between high and low
>frequency
>   proxy series.
>
>   Best Regards
>   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
>----------------------------------------------------------------------------
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
----------------------------------------------------------------------------


Dear Mike  et al,
I offer the following comments on your letter
for your consideration.
It seems to me there are 2 primary issues to
address:
(A) what does proxy evidence say about whether
the Medieval Warm period was global
(B) what do we know about potential mechanisms
for the Medieval Warm period
(i) evidence for a forced phenomenon
(ii) evidence for internal variability
Issue (A) is currently dealt with in your sections (1) and
(2). One point that could be perhaps conveyed more
clearly is the necessity of using the spatial information
conveyed in (multi) proxy reconstructions, rather than
overly interpreting sets of local proxy evidence. I
felt this point could have been stressed more, and is one
which the casual reader may not appreciate.
Issue (B, Bi) is in your section (3). I suggest a more
explicit mention of conclusions with regard to the
Medieval Warm period in recent work on this topic.
The first statement in this section doesn't provide
(I don't think) explicit evidence to back itself up. The
sentence starting "These results ..." could be more
explicit about what those studies show with respect to
the Medieval Warm period, in addition to the more general
statement about the partitionng between forced and internal
variability. A reader could ask "Ok, if 50% of the variability
is explained by volcanic and solar forcing, that doesn't
exclude the other 50% playing a strong role for events such as
the Medieval Warming." Such a question could be dealt with
in advance by stating what role these studies suggest for
radiative forcing in the Medieval Warm period.
For issue (Bii), I would suggest being explicit that
it is incumbent upon authors to provide some evidence to
support their speculation. What evidence can the author
provide to support his speculation concerning the role of
the THC in the Medieval Warm period? Rather than explicitly
stating this is not a likely mechanism, I would contrast the
speculation he has offered on this topic to the stronger
(in my opinion) evidence provided by modeling studies to
support the idea of the importance of radiative forcing.
... a few more minor comments
(1) I agree with the overall message you are conveying, but
might choose somewhat differing wording in a place or
two. The statement is made "(1) It cannot reasonably be
argued that the Middle Ages were as warm as the
20th century at global or hemispheric scales." This
might be a bit strong ... I would think one can have
a reasoned discussion on this topic. Perhaps something
like "We strongly disagree with the assertion that the
Middle Ages were as warm as the 20th century at global
or hemispheric scales."
(2) In the second to last sentence, I would add the
qualifying phrase "on planetary scales" after the
text "... responsible for centennial-millenial changes ...".
Regards,
Tom Delworth
ps The central issue is one that I have not been heavily
involved in, and thus don't think it's appropriate for
me to sign on as an author. Good luck, and please
send me a copy of your final submission.
pps I previously provided to Tom correlations between the
THC and global/hemispheric temperature based on a 900 year
run of our R30 coupled model. These correlations were
relatively low (0.27), but probably significant. The
applicability of those correlations to the issue of the
Medieval Warming may not be strong. If the Medieval Warming
is a multi-century event, then I should really be looking at
the correlations of low frequency (>50 years) filtered model
output from a run of several millenia duration. Thus, the
900 year run may not be applicable. I will revisit this
topic using a multi-millenial R15 coupled run, but probably
won't have any results today. I don't think that would
change the essential conclusions, however. I recall that
experiments with the R15 model in which the THC was substantially
weakened through the addition of fresh water to the North
Atlantic provided strong regional temperature anomalies, but
their global expression was small. These experiments are
being repeated with the higher resolution model.
In light of these issues, I suggest that the focus be
not so much on saying the THC cannot be responsible for the
Medieval Warming, but rather on saying (1) there is strong
evidence for a substantial role of radiative forcing, and (2) the
burden is on the author to provide evidence for the role of
the THC.
?
"Michael E. Mann" wrote:
>  Dear Colleagues,
>
> Below is a draft of a short letter to Science that Tom Crowley and I
> have put together, after discussing  w/ Phil, Ray, and Malcolm. We
> feel that a reply to Broecker's recent "Perspectives" piece is
> warranted to correct several misconceptions that Wally unfortunately
> chose to perpetuate (attached as an html file FYI). We have been given
> encouragement to submit this by Julia Uppenbrink at Science.
>
> We are working under a very tight timeline owing to Tom's travel
> schedule (leaves on an extended travel on friday) so we would greatly
> appreciate it if you could respond ASAP w/ comments, suggestions, etc.
> Please note that we are currently near the length limitations (and
> probably shouldn't include more than 15 references) so we're looking
> to sharpen and hone, but not lengthen the piece at this point.
>
> Thanks in advance for your feedback,
>
> mike
>
> _________________________________________
>
> Medieval Warming Redux
> In a recent "Perspectives" opinion piece, W. Broecker suggests that
> the
> "hockey stick" reconstruction of climate change over the past 1000
> years -
> with extreme warming only in the late 20th century - is incorrect, and
> that
> the so-called "Medieval Warm Period" was at least as warm as the 20th
> century and due to oscillations in the thermohaline circulation. To
> reach
> this conclusion, Dr. Broecker rejects traditional empirical "proxy"
> climate
> indicators of past climate (e.g. tree ring, ice core, coral, and long
> historical documentary records) that are the foundation of a number of
>
> hemispheric reconstructions, as well as our current best physical
> understanding of the factors controlling climate at
> century-to-millennial
> timescales. We disagree with Broecker on several major points:
> (1) It cannot reasonably be argued that the Middle Ages were as warm
> as the
> 20th century at global or hemispheric scales. Although regional warmth
>
> during the Middle Ages may have sometimes been significantly greater
> than
> present, four different hemispheric-scale reconstructions (Jones,
> Mann,
> Briffa, Crowley) have been completed for the last 1000 years -- all of
> them
> showing warmth in the Middle Ages that is either no warmer or
> significantly
> less than mid-20th century warmth. This is because it has been known
> for a
> quarter of a century that the timing of warmth during the Middle Ages
> was
> significantly different in different regions (Lamb, Dansgaard,
> Hughes).
> Failure to take this observation into account can lead to serious
> errors in
> the inference of hemispheric temperature trends. Although one analysis
> of
> heat flow measurements suggests warmer temperatures than the surface
> proxies during the Middle Ages (Huang and Pollack, GRL. 1997), the
> considerable sensitivity of the resulting trends to a priori
> statistical
> assumptions has lead borehole researchers to restrict their attention
> to
> the more reliably interpretable temperature fluctuations during the
> past
> five centuries (Huang and Pollack, Nature). Our conclusion is also
> supported by measurements from tropical glaciers indicating an
> unprecedented level of recent warming with respect to the last
> 1,000-2,000
> years (Thompson).
> (2) High-resolution proxy climate records which form the foundation of
>
> recent hemispheric temperature reconstructions are far more reliable
> indicators of century-to-millennial scale climate variability than is
> implied by Broecker. The potential limitations in interpreting
> long-term
> climate change from proxy indicators such as tree rings, have been
> long
> recognized by dendroclimatologists (e.g., Cook "segment curse" paper)
> and
> are almost always taken into account in framing interpretations of
> long-term trends. For example, Mann et al (1999) verified that a
> significant subset of multiple-millennial length tree ring and ice
> core
> proxy climate indicators used to reconstruct the trend over the past
> millennium passed rigorous statistical tests for fidelity at the
> millennial
> timescale, and that the basic attributes of the hemispheric
> reconstruction
> using more recent non-tree ring proxies available over the past few
> centuries yielded essentially the same result as that based on both
> tree
> ring and non-tree ring based information (Mann et al, Earth
> Interactions,
> 2000). Several independent reconstructions (Jones et al and Crowley
> and
> Lowery ), using a wide variety of proxy climate indicators and
> different
> statistical approaches, yield similar hemispheric temperature trends.
> Even
> the centennial-scale changes within the so-called "Little Ice Age" of
> the
> 15th-19th centuries are largely in agreement. Furthermore these
> centennial
> changes have been shown to be in "agreement" , rather than "in
> opposition"
> (as argued by Broecker) with evidence from alpine glacial advances
> (Raper
> reference).
> (3) Physical considerations show that external forcing, not internal
> variability, played the dominant role in the transition from the
> "Medieval
> Warm Period" to "Little Ice Age" (these terms are used loosely and
> are, in
> fact, ill advised in the context of hemispheric or global temperature
> changes -see e.g. Bradley and Jones, 1993; Hughes and Diaz, 1994). One
> of
> the major points of Broecker's argument is that changes in the
> thermohaline circulation are a primary driver of climate change on
> this
> time scale. These results do not consider recent modeling studies
> (Free,
> Crowley) that demonstrate at a high significance level (>99%) that
> about
> 50% of the pre-anthropogenic (pre-1850) variance can be explained by
> changes in volcanism and low frequency solar irradiance. Although the
> latter term is still not well constrained from observational studies,
> there
> are a number of independent lines of evidence suggesting such changes
> (Hoyt, Lean, Lockwood).
> (4) It is not justifiable to argue that changes in the thermohaline
> circulation cause significant hemispheric or global changes in
> temperature.
> Although changes in the conveyor play a major role in the Atlantic
> Basin,
> to a first approximation changes in ocean circulation simply
> redistribute
> heat on the planet without significantly raising global temperature,
> or
> even hemispheric temperature. This conclusion is born out by very low
> correlations between warmth in the Greenland sector and the
> hemispheric
> indices over the last 1000 years (Crowley footnote ref.), a low
> correlation
> that is shared by coupled model experiments (Delworth citation)? In
> fact,
> sediment core data from the subtropical North Atlantic often cited as
> indicative of a distinct "Medieval Warm Period" and "Little Ice Age"
> (Keigwin Sargasso Sea), has recently been shown to be more consistent
> with
> changes in the North Atlantic Oscillation (Keigwin and Pickart),
> implying a
> zero sum pattern of regionally alternating warm and cold superimposed
> on
> far more modest hemispheric variations over the past 1000 years. This
> pattern itself may be forced, rather than internal in nature, and
> would
> explain the limited evidence for more dramatic cold and warm periods
> in
> regions such as Europe (see Mann, Sci Perspective, 2000).
> The above arguments lead us to conclude that, although the conveyor
> may be
> changing, radiative forcing perturbations were primarily responsible
> for
> centennial-millennial changes in the last 1000 years, with attendant
> implications for interpretation of earlier Holocene oscillations (e.g,
>
> Denton and Karlen). Furthermore, the weight of evidence indicates that
> the
> late 20th century hemispheric warming is significantly greater than
> the
> Middle Ages.
>
> Michael E. Mann
> Thomas J. Crowley
> WHO ELSE???
>
> ___________
> ___________________________________________________________
>                     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
>
--
Thomas L. Delworth
GFDL/NOAA                      e-mail: td@gfdl.gov
P.O. Box 308                    Phone: 609-452-6565
Princeton, NJ 08542 USA           FAX: 609-987-5063


Thanks for clarifying Tom,
Yes, these are my sentiments as well, and I would conditionally sign-on to
this effort. In the meantime, I think there is a lot of good science to be
done!
mike
At 10:53 AM 3/2/01 -0600, tom crowley wrote:
>Dear All,
>
>A few more comments re Mikes note - Mike and I thought that if we cannot
>make a case to our colleagues, why muddy the waters further (as either
>Keith, Malcolm, or Ray said)?
>
>That said, I don't think this has been wasted time.  I still think a
>thoughtful short paper on the subject of Holocene climate change wold be
>useful, this time stating it from OUR perspective (i.e., not focusing
>exculsively on Broeckers message).  By broadening this it may be more
>interesting; we could also include a couple of figures and maybe add some
>input from Tom Delworth and Henry Pollack.  I would be willing to take a
>crack at this, and if anyone wants to CONDITIONALLY sign on, I would be
>more than happy to include you.
>
>I probably would not begin this until late April, after our trip to Germany
>and the meeting in Virginia.
>
>Tom
>
>ps  fyi I  counted the average spacing between the warm and cold
>oscillations in the iron oscillations illustrated by Broecker.  Regardless
>of whether warm or cold are used, the mean spacing is indeed 1.5 k,
>although the s.d. is 0.4k  HOWEVER, the mean spacing between the four main
>warm phases illustrated by Broecker on the same figure is, believe it or
>not, 2.15!  much closer to the solar peak.  This calls to mind the
>interesting (and clever) Wigley and Raper paper  in Proc. Roy. Soc. (1990)
>indicating that, given the uncertainties in chronology, solar forcing plays
>a role i n Holocenn climate change.  It therefore seems that the conveyor
>is indeed oscillating but the time scale of the larger scale CLIMATE shifts
>may be more regulated by solar, with volcanism adding some stochastic
>contribution.  Something like this is worth adding to the proposed Eos
>piece.
>
>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)
_______________________________________________________________________
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


Folks,
Two points here:
1. I read with some consternation Wally Broecker's latest piece in
Science (23Feb. 2001).  First you can all take up some other topic
since Wally says only Boreholes and treeline changes are accurate
enough to do low frequency trends.  What does he mean by "only two
proxies can yield temperatures that are accurate to 0.5°C"? and do you
agree that tree rings and sediments, etc are not sufficiently accurate
to exhibit correct low frequency trends?
2. Here are some references to recent Holocene time-frame records you
probably have seen, but just in case...  I found them interesting
without knowing how good or representative they are.
Surprisingly they were given me by one who cited them as examples of
evidence for a MWP and LIA.  I read them differently but they caused me
to consider one question I hadn't heard discussed (see below).
Based just on these four, one comes to the following tentative
conclusions and observations:
Conclusions:
*MWP was a generally warm time interspersed with coolings and not well
synchronized hemispherically or globally.
*LIA was global and capable of better (but not completely) synchronized
large amplitude variations
*20th Cent. was the only time when all records agree (tree ring
problems with CO2?)
MIGHT THIS RELATIVE UNIFORMITY BE USED AS A CHARACTERISTIC OF 20TH
CENTU WARMING THAT SETS IT APART FROM PREVIOUS CLIMATE CHANGES?
*Borehole inversion is too smoothed to be of much use but it does
indicate a larger temp amplitude if it weren't smoothed. ~1.5°C
And this brings up my question.  How one averages these records.
One way would be to note that the temperature amplitude (1000 - 1950)
for each is ~1.5°C.  Thus you could conclude that hemispheric/global
climate varied ay over a degree Celcius (although with regional
differences)
Another way would be to average the records.  The resulting temperature
amplitude  would be smaller because extremes would cancel since
variability is large and each region's extremes occur at different
times.
Thus, if people simply looked at several records they would get the
impression that temperature variations were large, ~1.5°C. Imagine
their surprise when they see that the ensemble averages you publish
have much smaller amplitude.
Comparison of amplitudes is given below (although difficult to do since
amplitude depends on averaging so these are very approximate).
Approximate Temperature Amplitudes for period 1000-1950
Mann et al 1999		~0.5
Jones et al 1998	~0.8
Crowley and Lowery	 ???
Briffa 2000		 ???
Dahl, Jensen	    	~1.5
Huang, et al            ~0.8 (500 yrs only)
Overpeck et al          ~1.3 (400 yrs, polar only)
Bradley & Jones(93)	~0.7 (600 yrs only)
(Not surprising that the contrarians take great exception to Michael's
small amplitude.)
This is important in the current debate even, it would
appear, with people like Wally.
I have been looking
for what the real issue is between researchers like yourselves and
skeptical scientists.  Politics and agendas aside, I think it is close
to this.
Anyone looking at the records gets the impression that the temperature
amplitude for many individual records/sites over the past 1000 years or
so is often larger than 1°C.  They thus recognize that natural
variability is unlikely to generate such large changes unless the sun
is having more effect than direct forcing, or there is some fortuitous
but detectable combination of forcings.  And they see this as evidence
that the 0.8°C or so temperature rise in the 20th century is not all
that special.
The community, however, in making ensemble averages gets a much smaller
amplitude ~0.5°C. which they say shows that reasonable combinations of
solar direct plus volcanos and internal variability with the help of
THC can indeed explain this AND the 20th century warming is unique.
Thus, the impass--one side pointing to large temperature variations in
many records around the globe and the other saying "yes, but not
synchronous and so averaged hemispherically no big deal.
But, just replying that lack of synchronous events (sometimes by a few
decades) is the reason might not be enough.  It seems to me that we
must go one step further.  We must address the question:  what forcings
can generate large amplitude temperature variations over hundreds of
years, regional though they may be (and, could these occur at different
times in different regions due to shifting heat inertia patterns)?  If
we can't do this, then there might be something wrong with our
rationale that the average is low amplitude even though many regions
see high amplitude.  This may be the nubbin of the disagreement, and
until we answer it, many careful scientists will decide the issue is
still unsettled and that indeed climate in the past may well have
varied as much or more than in the last hundred years.
(Also, I note that most proxy temperature records claim timing errors
of +-50 years or so.  What is the possibility that records are
cancelling each other out on variations in the hundred year frame due
simply to timing errors? as in hitting or missing C&L's triple warming
peak 1000-1200 AD)
Regards,
Referendes to proxy temp records
(1) Bodri, L. and V.Cermak Climate change of the last
millennium inferred from borehole temperatures: Regional patterns of
climatic changes in the Czech Republic - Part III, Global and Planetary
Change, 21, 225-235. 1999
As with other borehole data the record is incredibly smoothed.  It has
essentially three warming features.
from 1000 to after 1500 there is a broad warming pulse;
1550-1750  cooling
1750-1850 warming
1850-1900 cooling
1900-1950?  rapid warming
Total amplitude ~1°C (1.5°C if not
smoothed?)
I don't know what to make of the more than 500 year warming pulse.
Most records show warming either in the 1100's or 1200's but usually
not both.
The rest of the record looks reasonable given the smoothing.
(2) Filippi , M.L., Lambert, P., et al, Climatic and
anthropogenic influence on the stable isotope record from bulk
carbonates and ostracodes in Lake Neuchatel, Switzerland during the
last two millenia, Jour. of Paleolimnology, 21, 19-34, 1999
Graph actually begins at 805 AD (all dates are advertised as
+-50 yrs)
Starts out warm but already cooling which it does till about 1150.
warms till 1242, second peak 1298 then cools to minimum at 1500
warms significantly to 1600 then cools to about half of 1500 max and
essentially stays that way till 1850 when cools to 1500 level again and
immediately rebounds
into 1950s and still warming.
Total amplitude
~2.5°C
(3)  Naurzbaev, M.M. and  E.A.Vaganov,Variation of early
summer and annual temperature in east Taymir and Putoran (Siberia) over
the last two millennia inferred from tree rings, JGR 105, 7317-7326,
2000
Interesting record.
moderately cool 800-950,
rapid warming to max 1000 dip ~1050, recovers till ~1180
cools fast to minimum  ~1250,
warms to max		~1400
cools to 1450 slight cooling till 1700
warms to 		~1780
rapid cooling to	~1830
rapid warming till 	~1930
Total Amplitude
~1.5°C
(4)  Wilson, A.T., Hendy, C.H. and Reynolds, C.P., Short-term
climate change
and New Zealand temperatures during the last millennium, Nature 1979,
315-317,
Used stalagmites (delta 18 O proxy)
This is a strange record, but the authors compare it
favorably with the
central England record.
1100 starts  and warms in two pulses one at 1250, min at 1300, big max
at 1400, followed by dive to minimum 1450
rises to max 1500
drops to min 1600
rises a bit 1700 and into 1850
drops to minor min1880  rises after that
Total Amplitude
~1.5°C
STRANGE RECORD
Charles. "Chick" F. Keller,
IGPP.SIO.UCSD - Attn: Chick Keller
9500 Gilman Drive
La Jolla, CA 92093-0225
(858) 822-1510  office
(858) 456-9002  home
Is the noticeable increase in surfers off Scripps Beach a possible
indication of global warming?


HIi Tim,
That all sounds great, and indeed, the 19th century will be a *hot* topic
(pun intended) as we try to rectify Tom's model response w/ the
instrumental record and proxy reconstructions. Ironically, the 19th century
is one in most dispute over the past millennium, it seems!
You accurately summarize what my understanding is of the breakdown of lead
roles. I don't see any reason for changing that. I think Scott and I will
have our hands full w/ the other items, so if you can take the lead role on
the MXD paper (comparing the two methods, etc.) that would be great.
My intention is to give you and Scott full credit for anything I show at
meetings that is a result of mutual collaboration. Of course, both of your
are co-authors of my EGS talk.
So all sounds great! Scott: when Tim sends revised plots, can you prepare
some revised ppt files and let me know when they are available to download?
Hope to get all this straightened away next week after I return from the
frozen north (Michigan)...
mike
That soundsAt 07:05 PM 3/14/01 +0000, Tim Osborn wrote:
> >Thanks alot, these look good. I think we're really making some good
> >progress now.
> >
> >Just to confirm, my understanding is that you're next working on a similar
> >plot showing the
> >comparison of the REG-EM results w/ the straight gridbox age-banded
> >estimates you and Keith have produced over the longer period (ie, back to
> >1600 or so?). It would be great to be able to show those at EGS.
>
>Mike, you're welcome to show these results at EGS.  I had to leave early
>today (Wednesday) as my wife was ill, but I'll be back at work tomorrow.
>What I'll do first is just to modify the figures I've already sent to you,
>comparing the verification REG-EM run with instrumental data over the
>1856-1900 period.  What I want to do is to modify the final map so that the
>grid boxes that actually have tree-ring sites in them are highlighted in
>some way.  Then we can visualise more clearly whether the 'local'
>information is much better than the 'non-local' information.  I was in a bit
>of a hurry with my e-mail earlier, I didn't mention that the map is based on
>all those grid boxes with at least 20 years of instrumental data during the
>1856-1900 period.  I found the year-by-year pattern correlations quite
>informative too, and was particularly impressed by the fact that there were
>no really poor years! (at least that's my recollection, not having the plots
>in front of me at home).
>
>Having modified the map as described, I'll repeat the analysis but comparing
>the 1404-1855 period of the full reconstruction from REG-EM with our
>existing year-by-year maps and quasi-hemispheric averages.  I shall compare
>them against our "traditionally-standardised" version, since it would be
>unfair to compare them with the age-banded version.  The year-by-year maps
>we have already got are calibrated on a grid-box by grid-box basis
>(individually) using simple linear regression between the density series and
>the instrumental temperature.  This gives us coverage for those grid boxes
>with density data in them.  We throw away those that do not correlate
>significantly with their local grid box temperature.  That leaves around 100
>boxes, with fewer further back in time.  We then try to reconstruct all
>remaining northern hemisphere grid boxes, using principal component
>regression (PCs of the calibrated density used as predictors on a grid box
>by grid box basis), but only actually retain those that have significant
>correlations during an independent verification period.  So we gain quite a
>few more grid boxes, again time-varying.  So we have this (perhaps rather
>odd!) combination of local regression plus principal component regression
>producing our maps.  I shall use this set of year-by-year maps for the
>comparison with REG-EM, though as with the instrumental temperatures, I'll
>sometimes highlight or subsample just those with trees in (i.e. those
>locally-calibrated).
>
>Our original plan for carving up the analysis/papers was for me to take the
>lead on the comparison of methods with the same data set, Scott on the
>comparison of data sets with the same method, and Mike to concentrate on the
>19th century stuff including verification against the instrumental data etc.
>  I saw Tom Crowley last week and he showed some results indicating how
>critical the 19th century is for getting a good match between his forced
>model results and the various proxy reconstructions - so the 19th century
>could certainly be a hot topic.  Phil Jones would be useful here as he may
>know of more early instrumental data from Europe that might help (depending
>upon homogeneity!).  Anyway, I'm refreshing our minds about the 3-way split
>of work because: (i) this might be an appropriate point to confirm that such
>a split is still the best way to go (I'm still happy with it); and (ii) to
>point out that the REG-EM comparisons with our existing density-based maps
>falls into the bit that I'm to take the lead on - so while I'm completely
>happy for you to show these at EGS or other meetings, I'd still like to
>write the comparisons up for a journal paper.
>
> >p.s. Tim: are you going to be at EGS? I know Phil will...Also, I'm hoping
> >that one of the 3 of you can make it to the Charlottesville workshop in
> >April. You and Phil have both indicated you can't go, I think? At present,
> >Keith hasn't yet confirmed. It would be a shame not to have him, you, or
> >Phil present. Can you suggest some sort of "alternate" (Schweingruber?) the
> >Europeans might invite if Keith can't make it. Thanks...
>
>I can't make it to EGS, as I have work to prepare for my 3 talks I'm giving
>at NCAR in the first week in April!  For the Charlottesville workshop, I
>spoke to Keith yesterday and I think he has now booked his flights - so I'd
>take that as confirmation.  He's in touch with Julie Jones at GKSS about it.
>  I put in a good word about how pleasant Charlottesville was!
>
>Best regards to you both,
>
>Tim
>
>
>Dr. Timothy J. Osborn
>Climatic Research Unit
>University of East Anglia
>Norwich  NR4 7TJ, UK.
>Telephone: 01603 592089
>Fax:       01603 507784
>e-mail:    t.osborn@uea.ac.uk
>homepage:  ~timo
_______________________________________________________________________
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


Mike & Scott,
I've redone the verification against instrumental temperatures for 1856-1899.  Previously I'd used 1856-1900, but I've now realised that 1900 is not part of the verification period (the pattern correlation = 1 gave it away!).  So I've now stopped in 1899.  It makes virtually no difference to the quasi-hemispheric series and their correlations.  What it does affect is the grid-box by grid-box temporal correlations, since I was previously using one perfect value at the end of each series.  So the correlations are mostly a bit lower now, though still fairly good I think.  There's a reasonable area with r > 0.3.  Signal to noise should increase fairly dramatically if some kind of regional averaging were done.  I've outlined the boxes that actually have chronologies in them.  There's not enough instrumental data to verify the more northern ones, but the European and USA ones do well (r in range 0.5 to 0.9).  The more distant oceanic regions are a bit poorer, excep the northern Indian Ocean.  So that's it for the verification, for the moment.
I've compared the 1404-1855 (i.e., pre-instrumental) reconstruction with the Briffa et al. and Osborn et al. reconstructions.  Correlations are all quite high (0.7 to 0.85) for the quasi-hemispheric series, while the pattern correlations average around 0.6.  The box-by-box temporal correlations show many boxes with r in the range 0.6 to 1.0, indicating little sensitivity to the method used.  One notable feature of the latter results is that there's less agreement in the boxes that actually have trees than those don't!  There's two different interpretations of this that I'm working on, which seem equally possible.  More later.  I was going to send the time series and maps from this comparison, but I've just realised that I'm using anomalies from two different baselines (1961-90 for ours, 1901-60 for REG-EM) so the % variance explained and the time series aren't right - that'll have to wait till Friday now.
Tim


Dear Tim, Scott
On the road w/ tenous email connection so have to be brief. This sounds
good. Hoping we can have age-banded connections by the end of tnext week
so I can show in Nice! Scott: can you rectify the comparisons that Scott
is
producing w/ your own comparisons that show more of a discpreapancy ?
Thanks,
mike
Fri, 16 Mar 2001, Tim Osborn wrote:
> Dear Mike & Scott,
>
> Attached is "traditional.ps", comparing the 1404-1855 (i.e.
> pre-instrumental) REG-EM reconstruction with our existing Osborn et al.
> maps and Briffa et al. quasi-hemispheric series (see refs below).  Neither
> the REG-EM nor the existing reconstructions use the age-banded trees, so
> low frequencies are suppressed.  [Scott - thanks for the new age-banded
> results, but I probably won't get to them till next week due to other
> commitments.]
>
> The time series comparisons are, as you see, quite good - thought you'd
> expect this as we're comparing two methods but identical data!  Red is
> REG-EM, black is from the Osborn et al. existing reconstructions (then
> averaged into quasi-hemispheric means), while blue is from Briffa et al.
> (where we average the tree-density into regions/hemisphere *before*
> calibrating against regional/hemispheric temperature).  Blue & black agree
> quite closely, so all correlations and % var explained are between red and
> black.
>
> Timeseries are:
>
> '0-90' = full spatial average over each of our existing maps.
> '0-70' = full spatial average over each of the REG-EM maps.
> 'masked' indicates REG-EM maps are masked by the time-dependent coverage of
> our existing maps.
> 'land20-90' or 'land20-70' indicates only land grid boxes north of 20N are
> averaged.
> 'treeboxes' indicates only those grid boxes that contain tree-ring sites
> are averaged together.
>
> The pattern correlations range from 0.2 to 0.8, with a mean of 0.6
> (approx).  Fairly consistent then.  The pattern of temporal correlations is
> reasonable, ranging from 0.0 to 0.9, with a mean of 0.6 (approx).
>
> Comments:
> (1) Time series generally have less variance in REG-EM, especially early
> on, though masking of data brings them closer to our time series.
> (2) Getting the mean level correct (I've converted REG-EM to behave like
> anomalies from 1961-90 mean) helps with the %variance explained considerably.
> (3) The temporal correlations are poorer for boxes containing trees than
> those that do not!
>
> The decreased variance early in the REG-EM [comment (1)] is, I guess,
> because the fewer the records with data, the earlier the
> truncation/weighting function kicks in etc. and therefore the less the
> variance that is reconstructed.  As the 'skill' of REG-EM decreases, the
> more the values are filled in with something near to their mean, I seem to
> recall.  This raises the question that the early values might be biased
> towards the observational mean?  If so, it might be better to replace box
> values by missing values when their expected 'skill' becomes fairly low.
>
> Comment (3) can be explained two ways.  In the non-tree boxes our two
> methods (REG-EM and principal component regression) have similarities, and
> given the common input data, one would expect similar reconstructions -
> which the high correlations indicate.  In the tree boxes, however, the
> difference is our approach uses only local information, while REG-EM still
> uses non-local information too.  So, either (i) our reconstructions are
> poorer *because* we're ignoring non-local information, or (ii) REG-EM
> reconstructions are poorer *because* real local variations are partly
> masked by regional-scale variations.  It might be possible to choose either
> (i) or (ii) as a preferred explanation, using verification or other
> consideration, but I'd prefer to stick with (i) and (ii) as being equally
> possible and therefore justifying both approaches.  This is politically
> better too!  What I get out of the comparison is that the REG-EM is
> producing variability that is highly correlated with our method, given the
> same input data.  The main concern is the difference in variance and hence
> absolute anomalies.  We should look at this again when I've compared the
> age-banded stuff too.
>
> Another long e-mail, but I hope that this is useful (especially for EGS)
> and will form the basis of a comparion of methods paper.
>
> Have a good weekend!
>
> Tim
>
>
>
>
>
>
>
> Briffa KR, Osborn TJ, Schweingruber FH, Harris IC, Jones PD, Shiyatov SG
> and Vaganov EA (2001) Low-frequency temperature variations from a northern
> tree-ring-density network. Journal of Geophysical Research 106, 2929-2941.
>
> Osborn TJ, Briffa KR, Schweingruber FH and Jones PD (2001)
> Annually-resolved patterns of summer temperatures over the Northern
> Hemisphere since AD 1400 from a tree-ring-density network. In preparation.
>
_______________________________________________________________________
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


X-MIME-Autoconverted: from 8bit to quoted-printable by spdmraac.compuserve.com id QAA21095
Dear everybody,
I am still busy compiling the report from the kickoff meeting (and I
also still await some input pieces from some of you...).
For those of you who could not be there, let me just say that I
enjoyed very much to see the group here, and to witness the really
lively and productive discussions. Let's keep it that way.
While U wait for the report - I would like to get you thinking about
the project again by circulating the second draft of a small piece
which is edging towards a working definition of vulnerability, mostly
written by Richard and with input from Pete, Miguel and myself. All
comments are welcome. This is not intended for publication of course,
but it could be a start of something more substantial in due course.
So please send me the elements still missing for the overall report,
and comment to the four authors about the vulnerability piece.
Best regards,
Wolfgang
--
Wolfgang Cramer
Department of Global Change and Natural Systems
Potsdam Institute for Climate Impact Research
PO Box 60 12 03, D-14412 Potsdam, Germany
Tel.: +49-331-288-2521, Fax: +49-331-288-2600
mailto:Wolfgang.Cramer@pik-potsdam.de
~cramer
----------------------------------------------------------------------
NOTE: IF YOU NEED TO SEND ATTACHMENTS TO ME, PLEASE:
1) avoid sending MS-Word *.doc files (send rtf instead)
2) if the attachments exceed 500kB, contact me before sending anything
----------------------------------------------------------------------
PS: Sticking to my promise to avoid attachments, I send the plain
ascii text here. Some time Monday you should find the pdf of it on the
web site.
Internal ATEAM document \u201cTowards a definition of
vulnerability\u2026\u201d \u2013 do not cite
Draft version 2.0 (16/3/01)
TOWARDS A DEFINITION OF VULNERABILITY
OF ECOSYSTEM FUNCTIONING TO GLOBAL CHANGE
Richard J.T. Klein, Pete Smith, Miguel B. Araújo and Wolfgang
Cramer
This   document   aims   to  stimulate   the   discussion   of
vulnerability to global change, which is a key feature of  the
EU   project  Advanced  Terrestrial  Ecosystem  Analysis   and
Modelling  (ATEAM).  The  goal  of  ATEAM  is  to  develop  an
operational  quantitative assessment of  vulnerability  across
European ecosystems. The rationale for this assessment and its
initial elements are also found in this document.
Common features in present definitions of vulnerability
Vulnerability is a multi-dimensional concept that has  been  a
topic  of  study  in  many  different scientific  disciplines,
ranging  from  anthropology and psychology  to  economics  and
ecology.  As  such, it has been defined and assessed  in  many
different  ways  for many different purposes.  The  scientific
literature    provides   many   examples   of    vulnerability
assessments,  each  with their own explicit  or  (more  often)
implicit  interpretations of what vulnerability means  to  the
object of study.
In  spite  of  this  diversity the various interpretations  of
vulnerability have a number of things in common:
1.    Vulnerability is always an attribute of a system, in the
broadest  meaning of the term. Systems that may be vulnerable
include  individual people, communities, countries,  economic
sectors,  landscapes,  resources,  ecosystems  and   so   on.
Importantly, in ATEAM the system of interest is not ecosystems
per  se  but the set of functions that ecosystems perform  in
providing goods and services to human society.
2.    Vulnerability  always refers to  some  potential  of  or
exposure  to  harm or damage. It is therefore  meaningful  to
specify  exactly to which forcing a system is thought  to  be
vulnerable.  In  ATEAM multiple forcings are considered,  all
related  in some way to global change. In response  to  needs
expressed by the European Commission these forcings  are  the
increasing  atmospheric concentration  of  CO2,  the  climate
change that is the result of this increasing concentration, as
well  as  the  effects  of changing  land  use  and  land-use
policies.
3.    Definitions of vulnerability tend to capture some notion
of  the  extent to which the system would be unable to avoid,
defend  itself  against, cope with, adjust  to  or  otherwise
prevent  or minimise potential harm or damage. This mechanism
of damage prevention or minimisation (termed adaptation in the
context of climate change) is important because it defines the
difference between the potential harm or damage and the actual
or residual impacts that will occur. It can be argued that if
a   stress-exposed  system  has  the  ability  to  avert  the
potentially severe impacts that could ensue from this stress,
then it is not vulnerable (footnote 1).
The first assessments of vulnerability to climate change (such
as  the  First and Second Assessment Reports of the  IPCC  and
many  national vulnerability studies) were carried out without
considering   adaptation   as   an   important    aspect    of
vulnerability.  These assessments implicitly assumed  present-
day  behaviour  and activities to continue  unchanged  in  the
future,  irrespective of how they would be affected by climate
change.   By  ignoring  adaptation  these  studies   did   not
distinguish  between potential and residual impacts  and  thus
their   results  represented  serious  overestimates  of   the
system\u2019s vulnerability. On the other hand, the studies  served
to  generate awareness of the potential magnitude  of  impacts
and of the need for adaptation.
A  recent discussion of vulnerability: the IPCC Working  Group
II
Each  of  the  aforementioned features  of  vulnerability  was
incorporated  in  the proposed definition of vulnerability  in
the  IPCC Working Group II Third Assessment Report, which  was
as follows:
The  degree to which a system is sensitive to and unable  to
cope    with   adverse   impacts   of   climatic    stimuli.
Vulnerability is a function of a system\u2019s exposure  and  its
adaptive capacity.
However,  the IPCC Working Group II Plenary meeting in  Geneva
(13\u201316 February 2001) adopted a somewhat modified and expanded
definition  in the final, government-approved version  of  the
Summary  for  Policymakers. The adopted definition  no  longer
captures  the important notion that vulnerability  depends  on
both  potential impacts and the inability to cope  with  these
impacts,  as  was  indicated by the word \u201cand\u201d  in  the  first
sentence of the above definition:
The  degree to which a system is susceptible to,  or  unable
to  cope with, adverse effects of climatic change, including
climate  variability  and  extremes.  Vulnerability   is   a
function  of  the character, magnitude and rate  of  climate
variation  to  which a system is exposed,  its  sensitivity,
and its adaptive capacity.
Building blocks for a definition to be used in ATEAM
The  former  definition of vulnerability captures the  various
aspects  of vulnerability discussed above but it is likely  to
be  too broad to be made operational in ATEAM. ATEAM addresses
the   interaction  between  ecosystems  and  society  and   in
particular  the provision of goods and services by  ecosystems
for  human use. Of relevance to ATEAM are therefore  not  only
the  exposure and adaptive capacity of ecosystems  to  climate
change  but  also  the adaptive capacity of human  systems  in
relation  to a change in the provision of ecosystem goods  and
services.  To develop a meaningful definition of vulnerability
for  ATEAM  it could be useful to explore a number of  related
concepts: risk, sustainability and resilience.
A relatively widely accepted interpretation of risk is that it
is  a  function of the probability of occurrence of  an  event
combined with an estimate of the magnitude of its impact.  For
example,  in the context of species conservation risk  can  be
seen  as  a  measure of the probability that a negative  event
(i.e.,   a  threat)  combined  with  the  individual  species\u2019
response  to  these  events (i.e., an  indicator  of  species\u2019
vulnerability) would lead a species to extinction (Araújo  and
Williams, 2000).
Amongst  the many definitions of sustainability, a useful  one
is based on the conservation and substitutability of different
types  of capital: human-made capital, natural capital,  human
capital  and  social  capital (Serageldin  and  Steer,  1994).
Sustainable  development,  of  which  the  most  widely   used
definition is \u201cdevelopment that meets the needs of the present
without compromising the ability of future generations to meet
their own needs\u201d (WCED, 1987), prescribes that the total stock
of  capital  does  not  decrease over  time.  Whether  or  not
substitution  and compensation of different types  of  capital
are  allowed  depends on the preferred level of sustainability
(cf. weak versus strong sustainability).
The   relationship   between  sustainability   and   ecosystem
vulnerability  is  based  on  the  extent  to  which  external
forcings lead to a decrease in natural capital and thus in the
potential  of  ecosystems to provide goods  and  services  for
human   use.   A  possible  (anthropocentric)  definition   of
sustainability in the context of ATEAM could therefore be:
The  ability  of an ecosystem to provide humans  with  goods
and  services  in  the  present,  without  compromising  the
ability   of  future  human  generations  to  obtain   these
ecosystem goods and services in the future.
The  concept of resilience is well known in ecology,  although
two distinct interpretations of the term exist. As defined  by
Holling  (1973),  resilience  determines  the  persistence  of
relationships within a system and is a measure of the  ability
of   these  systems  to  absorb  changes  and  still  persist.
According  to  Pimm (1984), however, resilience describes  the
speed  with  which  a  system returns to  its  original  state
following  a perturbation. Holling (1973), on the other  hand,
considered  this to be the stability of a system, whilst  Pimm
(1984) referred to stability as the combination of resilience,
resistance, persistence and variability.
In  an  attempt to define the resilience of the  Dutch  coast,
Klein et al. (1998) distinguished between a morphological,  an
ecological   and   a  socio-economic  component   of   coastal
resilience,  each of which represents another  aspect  of  the
coastal  system\u2019s  capacity to cope with  perturbations.  They
described  coastal resilience as a measure of  the  extent  to
which a coast is able to respond to external pressures without
losing actual or potential functions:
The  resilience of the coast is its self-organising capacity
to  preserve  actual  and  potential  functions  of  coastal
systems  under  the  influence  of  changing  hydraulic  and
morphological  conditions. This capacity  is  based  on  the
(potential) dynamics of morphological, ecological and socio-
economic processes in relation to the demands that are  made
by the functions to be preserved.
Given the focus of ATEAM on ecosystem services, we might  want
to work towards a similar type of definition of vulnerability,
whereby  vulnerability  could be described  in  terms  of  the
likelihood that an ecosystem loses a significant amount of its
capacity  to provide goods and services that are important  to
society. A definition that includes the temporal dimension  of
global  change and sustainability could describe vulnerability
in  terms  of  the  risk  of  ecosystem  sustainability  being
compromised. Before suggesting a \u201cfinal\u201d definition,  however,
we  would like to invite views and suggestions from the entire
ATEAM consortium.
References
Araújo,  M.B.  and Williams, P.H., 2000: Selecting  areas  for
species   persistence  using  occurrence  data.  Biological
Conservation, 96(3), 331\u2013345.
Holling,  C.S.,  1973: Resilience and stability of  ecological
systems. Annual Review of Ecology and Systematics, 4, 1\u201324.
Klein, R.J.T., M.J. Smit, H. Goosen and C.H. Hulsbergen, 1998:
Resilience  and  vulnerability: coastal dynamics  or  Dutch
dikes? The Geographical Journal, 164(3), 259\u2013268.
Pimm,  S.L., 1984: The complexity and stability of ecosystems.
Nature, 307, 321\u2013326.
Serageldin,  I.  and A. Steer (eds.), 1994: Making Development
Sustainable:   From  Concepts  to  Action.  Environmentally
Sustainable  Development Occasional  Paper  Series  No.  2,
World Bank, Washington DC, iii+40 pp.
(WCED)  World Commission on Environment and Development, 1987:
Our  Common  Future, Oxford University Press,  Oxford,  UK,
xv+383 pp.
_______________________________
1  In  this  document  we  do not elaborate  on  the  possible
different  interpretations of adaptation. Adaptation  will  be
the  subject  of  more detailed discussion at a  later  stage,
aimed     at     an     appropriate    (semi-)    quantitative
operationalisation.
Attachment Converted: "c:\eudora\attach\vCard.vcf"


Phil et al,
There is a problem w/ figure 4 (and discussion thereof) in your paper to
appear in Science. Unfortunately, I didn't catch this until I re-read the
paper just now. You haven't shown the right Mann et al NINO3
reconstruction. Are you sure you have used the *cold-season* NINO3
reconstruction, as discussed (and available) in the Mann et al Earth
Interactions paper, and not the annual mean reconstruction!!

I don't believe that has the trend that the series you show does. That
NINO3 series  agrees closely (r=0.63) w/ the Stahle et al series (once
the sign has been flipped on that series, and the off-by-one-year date
convention is taken into account), far closer than
what you have shown. I'm pretty sure you've used the wrong series.
Moreover, it is inappropriate to refer (as you do) the Nino3 reconstruction
as an SOI reconstruction, no matter whether it has been
renormalized, sign-switched, etc. There are fundamennal differences between
the low-frequency behavior of NINO3 and SOI, (consider
for example the 20th century!) and they aren't dynamically equivalent! To
say there is a "long-term trend" in our "SOI reconstruction"
is extremely misleading. There is a long-term trend in our *NINO3*
reconstruciton. Only Stahle produced an SOI reconstruction, and it is only
meaningful to correlate the two at annual timescales where they should
similarly reflect largely interannual ENSO variability.
Moreover, I don't think this is true (or as true) of our colld-season NINO3
series, which is the right one to use. Hopefully, you still
have a chance to change this in the galleys, etc.
Thanks in advance for your attention to this,
mike
_______________________________________________________________________
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


Simon,
Could you - or Vanessa - buy a THES today from the paper shop and check this out.  I would
quite like to draft a short letter to THES as suggested by Steve.  But I need to see how
the issue was presented in this week's issue.
Thanks,
Mike
From: "Farrar, Steve"
To: 'Mike Hulme'
Subject: RE: kyoto survey - press inquiry from the THES
Date: Thu, 5 Apr 2001 09:45:33 +0100
X-Mailer: Internet Mail Service (5.5.2653.19)
Dear Mike,
thanks for that. I feel terrible but despite the pain it cost to reply to the survey,
the deadline has now passed. We had such a high response rate that we decided to run the
piece in this week's paper while the issue of the US withdrawl from the protocol was
still high in everyone's mind. So I cannot include your responses. However, you make a
number of very significant points, not least your reply to question 2 on the strength of
the evidence and the political framework outlined in your final sentences. I wonder -
and I know this is pushing it - whether you might consider rearranging some of these
sentences to form a brief letter to the editor for the following week's paper? I would
like this issue to stay alive in the THES and allow the paper to play a small role in
persuading as many scientists as possible to take part in a scientific/political debate
that may contribute to influencing those people who *can* change things. Not an original
objective, I know, but the THES does have a fairly unique position within the academic
community and hence a responsibility. Anyhow, sorry for the bad news
best wishes
Steve
***********************
Steve Farrar
Science Reporter
Times Higher Education Supplement
66-68 East Smithfield
London E1W 1BX
United Kingdom
[1]www.thes.co.uk
Tel: (44) 020 7782 3299
Fax: (44) 020 7782 3300
-----Original Message-----
From: Mike Hulme [[2]mailto:m.hulme@uea.ac.uk]
Sent: 04 April 2001 19:57
To: Farrar, Steve
Subject: Re: kyoto survey - press inquiry from the THES
Steve,
I hate these sort of questionnaires since Y or N answers are barely
adequate.  However, I've given it a go with some other comments .............
(by the way, Prof. Trevor Davies is Head of my School here at UEA - I am
only Director of a Centre within the School, albeit a highly relevant one!).
You can quote me if appropriate, but let me know before hand.
Mike
At 12:30 02/04/01 +0100, you wrote:
>Dear Mike,
>
>hope you're well. I am conducting a survey of heads of UK university
>departments of environmental science for the Times Higher Education
>Supplement. I am keen to explore views concerning the United States and
>the Kyoto agreement. I wonder if you could answer the following Yes/No
>questions when you get a moment. Note, I will not identify you unless you
>specifically state that you do not mind being quoted.
>
>I do hope you can help
>
>all the bets
>
>Steve
>
>1: Do you believe human activities are at least in part responsible for
>driving global climate change?
YES
>2: Do you feel the evidence for this is sufficiently strong to start
>reducing emissions?
NO - to reduce emissions requires more evidence than that humans are
altering climate.  We need to know something about the potential risks
associated with future climate change, whether these risks can be minimised
through adaptive action and then have some socially negotiated basis for
deciding about the necessity and extent of desirable emissions
reductions.  On none of these issues do we have a good basis to work
from.  The precautionary principle, if chosen, would imply start reducing
emissions now - but I am not convinced a blind application of the
precautionary principle in this case is the most appropriate instrument.
>3: Do you think the measures proposed at Kyoto were too weak, correct, or
>too strong?
The 5.2% emissions reduction by 2010 by Annex I countries were not driven
by science but by real-politik.  By definition they were the best
achievable.  The real issue however is not about target setting - it's
about the dynamics of change worldwide in energy technologies, investment
strategies, consumer and community behaviour and aspirations, etc.  It is
*these* things that in the end will deliver a safer climate - not the
Protocol per se.  More attention should be directed at the diverse and
myriad set of actions needed to decarbonise our societies.
>4: Are you disappointed that George Bush has abandoned the Kyoto agreement?
YES - but it is too early to say that Kyoto is dead.  The USA does not have
the power of veto - and Bush will have to propose some climate management
strategy of his own.  We wait and see.
>5: Should the rest of the world press on with the agreement without the
>United States?
Probably YES.  This can be achieved and should provide valuable lessons in
global climate management which we can learn from in the long-term.
>6: Do you feel the US should be allowed to count carbon sequestration
>measures such as planting new forests towards any carbon emissions
>reduction target?
YES.  The UK are doing it in their national climate change programme so why
not the USA?
>7: Are you optimistic that there will be a new emissions control agreement
>within the next 12 months?
A 'new' one?  We haven't got one yet.  I would think maybe not in the next
12 months, but the critical issues about global climate management will be
clearer.
>8: Should the Kyoto preliminary targets be watered down to gain the
>Americans' support?
NO.  If the USA don't like them, let them not ratify or propose a strategy
of their own.
>If you would like to add any comments to this survey as to the
>implications of the US's rejection of Kyoto for the planet, what UK can do
>about it or what role scientists can play in this debacle, please do so.
In a literal sense the implications for global climate are trivial - what
will affect the course of global climate (and only then climate beyond
about 2030 - up until then climate is pretty much pre-determined by inertia
in the system) in the long-run are the effects of cumulative decisions
taken by many, many people/governments/businesses over the next 10-20
years.  Let's not kid ourselves that the USA President is more powerful
than he would like to think.  The planetary system is much bigger than one
4-year term of a US president.
The UK is playing a key role both within the negotiating machinery of the
FCCC, in pioneering new scientific analyses, and in working out new forms
of adapting to climate change.  This momentum in the UK is not going to be
halted by Bush.
Scientists need to be there to point out the long-term nature of the
problem - it is not a classic political issue where a one-term government
can solve or worsen the problem.  Scientists need to point out that for
long-term planetary management we need new analytical tools, new criteria
for investment decisions, a new appreciation of the concept of global
citizenship.  What climate change forces us to do is to think about the
influence we are having on the quality of life for the next generation but
one - not our own generation or even our children's
generation.  Conventional politics is not a system geared up for this
challenge.
>***********************
>Steve Farrar
>Science Reporter
>Times Higher Education Supplement
>66-68 East Smithfield
>London E1W 1BX
>United Kingdom
>[3]www.thes.co.uk
>Tel: (44) 020 7782 3299
>Fax: (44) 020 7782 3300
>
>
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Dr Mike Hulme
Executive Director
Tyndall Centre for Climate Change Research
School of Environmental Sciences
University of East Anglia
Norwich  NR4  7TJ
UK
tel:            +44 (0)1603 593162 (or 593900)
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References
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4.


HI Tim,
THanks for looking into this so quickly. I agree w/ your assessment. It is
probably just the fact that the signal of interest in SOI and NINO3 is
really the interannual signal, and this is not evident in the low-frequency
component shown, which emphasizes discrepancies that are actually small
compared to amplitude of the interannual signal present in both Stahle et al
and Mann et al. So I would urge showing the annual reconstructions in this
case, rather than smoothed for this reason...
In IPCC we only chose to show 1700 to present, which is a better
calibrated/verified interval than back to 1650, so I'd encourage you guys to
restrict it to 1700-present if you can. Other than that,
I think it is important to acknowledge that SOI and NINO3 have different
low-frequency trends over the 20th century, and might well have different
trends in the past. It is true that many of the proxies used are sensitive
to the SOI (e.g. mexican tree rings), but others are sensitive to Pacific
SST (e.g. corals from GBR, New Caledonia, Galapagos) and our claim is that
the calibration process will select out the best estimate of the temperature
patterns, rather than SLP patterns, associated w/ ENSO, from the multiproxy
network. In the future, we'll be going after SLP reconstruction too, and
it'll be interesting to see what the difference is.
I hope that clarifies. Please let me know if I can be of any further help,
provide further clarification, etc. Thanks again,
mike
>From: Tim Osborn
>To: "k.briffa"
, Michael Mann
,
>      "p.jones"
, "T.Osborn"
,
>  mann
>CC: rbradley
>Subject: RE: problem
>Date: Wed, 4 Apr 2001 23:02:35 +0100
>
> >Thanks for getting back to me so quickly. I could be wrong, but i just
> >want to make sure. The cold-season NINO3 is far more consistent w/ DJF
>SOI
> >and Stahle's recon, so I just want to be sure that is the one that
> >is shown.
>
> >> >Are you sure you have used the *cold-season* NINO3
> >> >reconstruction, as discussed (and available) in the Mann et al Earth
> >> >Interactions paper, and not the annual mean reconstruction!!
> >> >
> >> >
> >> >
> >> >I don't believe that has the trend that the series you show does. That
> >> >NINO3 series  agrees closely (r=0.63) w/ the Stahle et al series (once
> >> >the sign has been flipped on that series, and the off-by-one-year date
> >> >convention is taken into account
>
>Dear all,
>
>I've found a machine with telnet and have been able to check my files &
>programs.  The file I'm using matches the ninocold-recon.dat file
>downloadable
>from the ei_reconsb.html.  It also correlates at r=0.63 with Stahle.  I
>don't
>have access to plotting here, so I cannot investigate further the reason
>for
>the apparent mismatch, though I wonder whether it is due to the heavy
>(30-yr)
>smoothing used in the Science paper - much more smoothing than is typically
>used when looking at ENSO!  These 30-yr differences are in fact quite small
>in
>comparison with some of the interannual variations, and perhaps the series
>would look very much more alike if unfiltered?  Anyway, as far as I can
>tell,
>the figure is ok.
>
> >> >Moreover, it is inappropriate to refer (as you do) the Nino3
> >>reconstruction
> >> >as an SOI reconstruction, no matter whether it has been
> >> >renormalized, sign-switched, etc. There are fundamennal differences
> >>between
> >> >the low-frequency behavior of NINO3 and SOI, (consider
> >> >for example the 20th century!) and they aren't dynamically equivalent!
>To
> >> >say there is a "long-term trend" in our "SOI reconstruction"
> >> >is extremely misleading. There is a long-term trend in our *NINO3*
> >> >reconstruciton. Only Stahle produced an SOI reconstruction, and it is
> >>only
> >> >meaningful to correlate the two at annual timescales where they should
> >> >similarly reflect largely interannual ENSO variability.
>
>Phil/Keith - I've got a copy of our paper with me and I agree with what
>Mike
>says above, but on the other hand the lack of space constrains us.  I
>wonder
>whether we can squeeze anything in at the proofs stage (have you had them
>yet
>Phil?).  With a quick read I couldn't actually spot the phrase "long-term
>trend", but we could still add something about SOI and SST being coupled on
>interannual time scales and possibly doing somewhat different things on
>longer
>timescales.  Mike - would you not agree, however, that your predictors
>(excluding corals) are mainly remote from the Nino 3 SST region and that
>they
>are likely responding via atmospheric teleconnection patterns and therefore
>perhaps should pick up the SOI even if calibrated against Nino 3 SST?  Feel
>free to disagree - just wanted to get your reaction!
>
>Best regards
>
>Tim
>
>
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