cc: Kevin Trenberth <trenbert@ucar.edu>, Phil Jones <p.jones@uea.ac.uk>, j.renwick@niwa.co.nz, b.mullan@niwa.co.nz
date: Thu, 23 Jul 2009 20:04:37 -0400
from: Michael Mann <mann@meteo.psu.edu>
subject: Re: ENSO blamed over warming - paper in JGR
to: Jim Salinger <j.salinger@auckland.ac.nz>

   first email:

   ________

   hi Seth, you always seem to catch me at airports. only got a few minutes. took a cursory
   look at the paper,  and it has all the worry signs of extremely bad science and
   scholarship. JGR is a legitimate journal, but some extremely bad papers have slipped
   through the cracks in recent years, and this is another one of them.
   first of all, the authors use two deeply flawed datasets that understate the warming
   trends: the Christy and Spencer MSU data and uncorrected radiosonde temperature estimates.
   There were a series of three key papers published in Science a few years ago, by Mears et
   al, Santer et al, and Sherwood et al.
   see Gavin's excellent RealClimate article on this:
   [1]http://www.realclimate.org/index.php/archives/2005/08/et-tu-lt/
   these papers collectively showed that both datasets were deeply flawed and understate
   actual tropospheric temperature trends. I find it absolutely remarkable that this paper
   could get through a serious review w/out referencing any 3 of these critical papers--papers
   whose findings render that conclusions of the current article completely invalid!
   The Christy and Spencer MSU satellite-derived tropospheric temperature estimates contained
   two errors--a sign error and an algebraic error--that had the net effect of artificially
   removing the warming trend. Christy and Spencer continue to produce revised versions of the
   MSU dataset, but they always seem to show less warming than every other independent
   assessment, and their estimates are largely disregarded by serious assessments such as that
   done by the NAS and the IPCC.
   So these guys have taken biased estimates of tropospheric temperatures that have
   artificially too little warming trend, and then shown, quite unremarkably, that El Nino
   dominates much of what is left (the interannual variability).
   the paper has absolutely no implications that I can see at all for the role of natural
   variability on the observed warming trend of recent decades.
   other far more careful analyses (a paper by David Thompson of CSU, Phil Jones, and others
   published in Nature more than  year ago) used proper, widely-accepted surface temperature
   data to estimate the influence of natural factors (El Nino and volcanos) on the surface
   temperature record. their analysis was so careful and clever that it detected a post-world
   war II error in sea surface temperature measurements (that yields artificial cooling during
   the mid 1940s) that had never before been discovered in the global surface temperature
   record. needless to say, they removed that error too. and the correct record, removing
   influences of ENSO, volcanoes, and even this newly detected error, reveal that a robust
   warming of global mean surface temperature over the past century of a little less than 1C
   which has nothing to do w/ volcanic influences or ENSO influences. the dominant source of
   the overall warming, as concluded in every legitimate  major scientific assessment, is
   anthropogenic influences (human greenhouse gas concentrations w/ some offsetting cooling
   due to sulphate aerosols).
   this later paper provides absolutely nothing to cast that in doubt. it uses a flawed set of
   surface temperature measurements for which the trend has been artificially suppressed, to
   show that whats left over (interannual variability) is due to natural influences. duh!
   its a joke! and the aptly named Mark "Morano" has fallen for it!
   m
   On Jul 23, 2009, at 7:57 PM, Jim Salinger wrote:

   Precisely.
   Mike Mann: You better rush something up on RealClimate. Jim, Brett, myself and maybe others
   will have to deal with the local fallout this will cause...oh dear......
   Bye the way June was the warmest month on record for the oceans according tro NOAA
   Jim
   Quoting Kevin Trenberth <[2]trenbert@ucar.edu>:

     Exactly

     They use 2 datasets that are deficient in the first place and then they

     use derivatives: differentiation is a high pass filter, and so they show

     what we have long known that ENSO accounts for a lot of high frequency

     variability.  It should not have been published

     Kevin

     kia orana from Rarotonga

     How the h... did this get accepted!!

     Jim

     Dominion today {24/7/09]

     Nature blamed over warming - describing recently published paper in

     JGR by Chris de Freitas, Bob Carter and J McLean, and including

     comment by J Salinger  "little new"

     McLean J. D., C. R. de Freitas, R. M. Carter (2009), Influence of the

     Southern Oscillation on tropospheric temperature, J. Geophys. Res.,

     114, D14104, doi:10.1029/2008JD011637.

     paper at

     [3]http://www.agu.org/pubs/crossref/2009/2008JD011637.shtml

     --

     Associate Professor Jim Salinger

     School of Geography and Environmental Science

     University of Auckland

     Private Bag 92 019

     Auckland, New Zealand

     Tel: + 64 9 373 7599 ext 88473

     ----------------------------------------------------------------

     This message was sent using IMP, the Internet Messaging Program.

     ___________________

     Kevin Trenberth

     Climate Analysis Section, NCAR

     PO Box 3000

     Boulder CO 80307

     ph 303 497 1318

     [4]http://www.cgd.ucar.edu/cas/trenbert.html

   ----------------------------------------------------------------
   This message was sent using IMP, the Internet Messaging Program.

   --
   Michael E. Mann
   Professor
   Director, Earth System Science Center (ESSC)
   Department of Meteorology                 Phone: (814) 863-4075
   503 Walker Building                              FAX:   (814) 865-3663
   The Pennsylvania State University     email:  [5]mann@psu.edu
   University Park, PA 16802-5013
   website: [6]http://www.meteo.psu.edu/~mann/Mann/index.html
   "Dire Predictions" book site:
   [7]http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html

