Sunday, May 6, 2012


cc: Jerry Meehl <>, Jonathan Overpeck <>, Phil Jones <>
date: Thu, 25 Jan 2007 09:51:05 -0700
from: Caspar Ammann <>
subject: [Fwd: Re: [Fwd: Recommended reading?]]
to: Tom Wigley <>, Kevin Trenberth <>

Tom and Kevin,
below the summary I just sent to a few realclimate folks for further
comment. I will keep you posted on any additional information that is

Well, if I recall right the most recent 'venting' on climateaudit did go
towards the hurricanes and sea level. Currently their site is not
responding, and it might just be strategic... I would assume that
they are going to launch a multi-pronged approach trying to undermine a
string of arguments that are currently either in the chain to link to
GHG forcing and/or that have one of the biggest impacts in the popular
perception. Its going to be in their usual fashion: Stir up a lot of dust
and move to the next thing before anybody can answer. In the end there is
little left...

Trying to interpret a priority list from my personal feeling of this
guy. I do this based on a google-cash because his site is down or
something. So here is my hunch/speculation. I'll see if I can get the
document somewhere but I'm not very optimistic about this. By the way,
I'm also going to forward this to Susan an few others that might have
heard the rumor. Before I do send it to Susan, you might chip in on
this list for "internal and IPCC use":

- keeps bugging away about the HadCRUT3 data, looking at some individual
grid cells.

- stationarity in the climate system (see below; but my hunch is that
they go for much larger real world variability than in most models, and
thus there is a chance that its all noise; so their argument. Of course
the space-time-geophysical process framework is much stronger, but at
least this is a direction they might go; key is that models are only one
way to do detection-attribution).

- declining temperatures in Antarctica: inconsistent with polar
amplification ... not sure if he knows that central Antarctica has no
sea ice feedback, but more importantly what circulation changes can do
(difference vortex inside and outside)

- "Statistics of Rekordbreaking Temperatures": human landuse/heat island
effect; also check this paper that McIntyre has been looking at (single
point: Philadelphia and record breaking temperatures):

- hurricanes are a poisson process not driven by a systematic underlying
forcing increase.

- Arctic ice shelves: break off individual parts not unusual. Arguments
might come that initial breakup started 1930s not now and "everybody"
knows that it has been warm then when CO2 was low... etc.

- Satellite record (Mears-Wentz and also Christy): Not uniform warming
at all... he points out that S-Hem is flat.

- solar: well one could only hope that he follows the
so-idiotic-that-its-already-funny versions that Haemeranta is sending
around. Sun is as active as never before, and then the predictions are
for cooling... I think MM will try to simply say that solar
contributions have been not well included and are actually much more
important. By the way: Ammann et al. has now been accepted by PNAS,
should have a say in the solar influence...

- climate reconstructions 1 (the obvious and usual): key issues are
bring proxies up to date, contamination of all reconstruction with bad
data that is shared and thus all are wrong, secrecy in proxy data

- climate reconstructions 2: Maybe the "bomb" is their claim of
non-stationarity. Maybe they want to show that calibration on present
day is tainted with problems, jumping on the bandwagon of VS that
degrees of freedom are limiting stats. My answer of course is think
physically and use time history... (some paper by Sonechkin, which
really doesn't understand how field reconstructions work, but the
stationarity issue is more difficult to blow off the table with
arguments... maybe we should be prepared for that one).

- climate reconstructions 3: Tree line and glaciers as indicators: It
was "warmer" before so why bother now. My answer generally is that we
have a GW signal of 30 years. If in medieval times there would have been
current temperatures for the durations as it had in these times
(different actual timing in different locations) then the so called
signal of Medieval Warm Period would be much stronger. Currently almost
nothing is in equilibrium. Glaciers are collapsing (mass!) not simply
melting and the trees take many decades to change the tree line.

- sneaking in papers into AR4 that were past deadline

Caspar M. Ammann
National Center for Atmospheric Research
Climate and Global Dynamics Division - Paleoclimatology
1850 Table Mesa Drive
Boulder, CO 80307-3000
email: tel: 303-497-1705 fax: 303-497-1348

Caspar M. Ammann
National Center for Atmospheric Research
Climate and Global Dynamics Division - Paleoclimatology
1850 Table Mesa Drive
Boulder, CO 80307-3000
email: tel: 303-497-1705 fax: 303-497-1348


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