Tom, with respect to the difference between the models and the data, the
fundamental issue on short time scales is the magnitude of the internal
variability. Using the full CMIP3 ensemble at least has multiple
individual realisations of that internal variability and so is much more
suited to a comparison with a short period of observations. MAGICC is
great at the longer time scale, but its neglect of unforced variability
does not make it useful for these kinds of comparison.

The kind of things we are hearing “no model showed a cooling”, the “data
is outside the range of the models” need to be addressed directly.

Gavin

On Wed, 2009-10-14 at 18:06, Michael Mann wrote:
> Hi Tom,
>
> thanks for the comments. well, ok. but this is the full CMIP3
> ensemble, so at least the plot is sampling the range of choices
> regarding if and how indirect effects are represented, what the cloud
> radiative feedback & sensitivity is, etc. across the modeling
> community. I’m not saying that these things necessarily cancel out
> (after all, there is an interesting and perhaps somewhat disturbing
> compensation between indirect aerosol forcing and sensitivity across
> the CMIP3 models that defies the assumption of independence), but if
> showing the full spread from CMIP3 is deceptive, its hard to imagine
> what sort of comparison wouldn’t be deceptive (your point re MAGICC
> notwithstanding),
>
> perhaps Gavin has some further comments on this (it is his plot after
> all),
>
> mike
>
> On Oct 14, 2009, at 5:57 PM, Tom Wigley wrote:
> > Mike,
> >
> > The Figure you sent is very deceptive. As an example, historical
> > runs with PCM look as though they match observations — but the
> > match is a fluke. PCM has no indirect aerosol forcing and a low
> > climate sensitivity — compensating errors. In my (perhaps too
> > harsh)
> > view, there have been a number of dishonest presentations of model
> > results by individual authors and by IPCC. This is why I still use
> > results from MAGICC to compare with observed temperatures. At least
> > here I can assess how sensitive matches are to sensitivity and
> > forcing assumptions/uncertainties.
> >
> > Tom.
> >
> > +++++++++++++++++++
> >
> > Michael Mann wrote:
> > > thanks Tom,
> > > I’ve taken the liberty of attaching a figure that Gavin put
> > > together the other day (its an update from a similar figure he
> > > prepared for an earlier RealClimate post. see:
> > > http://www.realclimate.org/index.php/archives/2009/05/moncktons-deliberate-manipulation/). It is indeed worth a thousand words, and drives home Tom’s point below. We’re planning on doing a post on this shortly, but would be nice to see the Sep. HadCRU numbers first,
> > > mike
> > > On Oct 14, 2009, at 3:01 AM, Tom Wigley wrote:
> > > > Dear all,
> > > > At the risk of overload, here are some notes of mine on the
> > > > recent
> > > > lack of warming. I look at this in two ways. The first is to
> > > > look at
> > > > the difference between the observed and expected anthropogenic
> > > > trend relative to the pdf for unforced variability. The second
> > > > is to remove ENSO, volcanoes and TSI variations from the
> > > > observed data.
> > > > Both methods show that what we are seeing is not unusual. The
> > > > second
> > > > method leaves a significant warming over the past decade.
> > > > These sums complement Kevin’s energy work.
> > > > Kevin says … “The fact is that we can’t account for the lack
> > > > of warming at the moment and it is a travesty that we can’t”. I
> > > > do not
> > > > agree with this.
> > > > Tom.
> > > > +++++++++++++++++++++++
> > > > Kevin Trenberth wrote:
> > > > > Hi all
> > > > > Well I have my own article on where the heck is global
> > > > > warming? We are asking that here in Boulder where we have
> > > > > broken records the past two days for the coldest days on
> > > > > record. We had 4 inches of snow. The high the last 2 days
> > > > > was below 30F and the normal is 69F, and it smashed the
> > > > > previous records for these days by 10F. The low was about 18F
> > > > > and also a record low, well below the previous record low.
> > > > > This is January weather (see the Rockies baseball playoff game
> > > > > was canceled on saturday and then played last night in below
> > > > > freezing weather).
> > > > > Trenberth, K. E., 2009: An imperative for climate change
> > > > > planning: tracking Earth’s global energy. /Current Opinion in
> > > > > Environmental Sustainability/, *1*, 19-27,
> > > > > doi:10.1016/j.cosust.2009.06.001. [PDF]
> > > > > (A PDF of the published version can be obtained from the author.)
> > > > > The fact is that we can’t account for the lack of warming at
> > > > > the moment and it is a travesty that we can’t. The CERES data
> > > > > published in the August BAMS 09 supplement on 2008 shows there
> > > > > should be even more warming: but the data are surely wrong.
> > > > > Our observing system is inadequate.
> > > > > That said there is a LOT of nonsense about the PDO. People
> > > > > like CPC are tracking PDO on a monthly basis but it is highly
> > > > > correlated with ENSO. Most of what they are seeing is the
> > > > > change in ENSO not real PDO. It surely isn’t decadal. The
> > > > > PDO is already reversing with the switch to El Nino. The PDO
> > > > > index became positive in September for first time since Sept
> > > > > 2007. see
> > > > > http://www.cpc.ncep.noaa.gov/products/GODAS/ocean_briefing_gif/global_ocean_monitoring_current.ppt
> > > > > Kevin
> > > > > Michael Mann wrote:
> > > > > > extremely disappointing to see something like this appear on
> > > > > > BBC. its particularly odd, since climate is usually Richard
> > > > > > Black’s beat at BBC (and he does a great job). from what I
> > > > > > can tell, this guy was formerly a weather person at the Met
> > > > > > Office.
> > > > > > We may do something about this on RealClimate, but meanwhile
> > > > > > it might be appropriate for the Met Office to have a say
> > > > > > about this, I might ask Richard Black what’s up here?
> > > > > > mike
> > > > > > On Oct 12, 2009, at 2:32 AM, Stephen H Schneider wrote:
> > > > > > > Hi all. Any of you want to explain decadal natural
> > > > > > > variability and signal to noise and sampling errors to
> > > > > > > this new “IPCC Lead Author” from the BBC? As we enter an
> > > > > > > El Nino year and as soon, as the sunspots get over their
> > > > > > > temporary–presumed–vacation worth a few tenths of a Watt
> > > > > > > per meter squared reduced forcing, there will likely be
> > > > > > > another dramatic upward spike like 1992-2000. I heard
> > > > > > > someone–Mike Schlesinger maybe??–was willing to bet alot
> > > > > > > of money on it happening in next 5 years?? Meanwhile the
> > > > > > > past 10 years of global mean temperature trend stasis
> > > > > > > still saw what, 9 of the warmest in reconstructed 1000
> > > > > > > year record and Greenland and the sea ice of the North in
> > > > > > > big retreat?? Some of you observational folks probably do
> > > > > > > need to straighten this out as my student suggests below.
> > > > > > > Such “fun”, Cheers, Steve
> > > > > > > Stephen H. Schneider
> > > > > > > Melvin and Joan Lane Professor for Interdisciplinary
> > > > > > > Environmental Studies,
> > > > > > > Professor, Department of Biology and
> > > > > > > Senior Fellow, Woods Institute for the Environment
> > > > > > > Mailing address:
> > > > > > > Yang & Yamazaki Environment & Energy Building - MC 4205
> > > > > > > 473 Via Ortega
> > > > > > > Ph: 650 725 9978
> > > > > > > F: 650 725 4387
> > > > > > > Websites: climatechange.net
> > > > > > > patientfromhell.org
> > > > > > > —– Forwarded Message —–
> > > > > > > From: “Narasimha D. Rao” > > > > > > > >
> > > > > > > To: “Stephen H Schneider” > > > > > > > >
> > > > > > > Sent: Sunday, October 11, 2009 10:25:53 AM GMT -08:00
> > > > > > > US/Canada Pacific
> > > > > > > Subject: BBC U-turn on climate
> > > > > > > Steve,
> > > > > > > You may be aware of this already. Paul Hudson, BBCÿs
> > > > > > > reporter on climate change, on Friday wrote that thereÿs
> > > > > > > been no warming since 1998, and that pacific oscillations
> > > > > > > will force cooling for the next 20-30 years. It is not
> > > > > > > outrageously biased in presentation as are other skepticsÿ
> > > > > > > views.
> > > > > > > http://news.bbc.co.uk/2/hi/science/nature/8299079.stm
> > > > > > > http://blogs.telegraph.co.uk/news/damianthompson/100013173/the-bbcs-amazing-u-turn-on-climate-change/
> > > > > > > BBC has significant influence on public opinion outside
> > > > > > > the US.
> > > > > > > Do you think this merits an op-ed response in the BBC from
> > > > > > > a scientist?
> > > > > > > Narasimha
> > > > > > > ——————————-
> > > > > > > PhD Candidate,
> > > > > > > Emmett Interdisciplinary Program in Environment and
> > > > > > > Resources (E-IPER)
> > > > > > > Stanford University
> > > > > > > Tel: 415-812-7560
> > > > > > —
> > > > > > 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: mann@psu.edu
> > > > > >
> > > > > > University Park, PA 16802-5013
> > > > > > website: http://www.meteo.psu.edu/~mann/Mann/index.html
> > > > > >
> > > > > > “Dire Predictions” book site:
> > > > > > http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html
> > > > > —
> > > > > ****************
> > > > > Kevin E. Trenberth e-mail: trenbert@ucar.edu
> > > > >
> > > > > Climate Analysis Section,
> > > > > www.cgd.ucar.edu/cas/trenbert.html
> > > > >
> > > > > NCAR
> > > > > P. O. Box 3000, (303) 497 1318
> > > > > Boulder, CO 80307 (303) 497 1333 (fax)
> > > > > Street address: 1850 Table Mesa Drive, Boulder, CO 80305
> > > >
> > > —
> > > 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: mann@psu.edu
> > >
> > > University Park, PA 16802-5013
> > > website: http://www.meteo.psu.edu/~mann/Mann/index.html
> > >
> > > “Dire Predictions” book site:
> > > http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html
> >
> >
> >
>
> —
> 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: mann@psu.edu
> University Park, PA 16802-5013
>
> website: http://www.meteo.psu.edu/~mann/Mann/index.html
> “Dire Predictions” book site:
> http://www.essc.psu.edu/essc_web/news/DirePredictions/index.html
>
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