Saturday, March 31, 2012


cc: Kevin Trenberth <>, Phil Jones <>,,
date: Thu, 23 Jul 2009 20:04:37 -0400
from: Michael Mann <>
subject: Re: ENSO blamed over warming - paper in JGR
to: Jim Salinger <>

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:
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!
On Jul 23, 2009, at 7:57 PM, Jim Salinger wrote:

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
Quoting Kevin Trenberth <[2]>:


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


kia orana from Rarotonga

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


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



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


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Kevin Trenberth

Climate Analysis Section, NCAR

PO Box 3000

Boulder CO 80307

ph 303 497 1318


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

Michael E. Mann
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]
University Park, PA 16802-5013
website: [6]
"Dire Predictions" book site:

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