Mike’s AGU Trick
By Steve McIntyre
There has been considerable recent discussion of the fact that observations have been running cooler than models – see, for example, Lucia’s discussion of IPCC AR5 SOD Figure 9.8 (see here). However, Michael Mann at AGU took an entirely different line. Mann asserted that observations were running as hot or hotter than models. Mann’s assertion was taken even further by Naomi Oreskes, who asserted that climate models were under-estimating relative to observations. Oreskes squarely placed the blame for the supposed underestimates on climate skeptics.
In today’s post, I’ll look closely at the illustration in Mann’s AGU presentation, an illustration that gave an entirely different impression than the figure in the IPCC draft report. The reason for the difference can be traced to what I’ve termed here as “Mike’s AGU Trick”.
The IPCC AR5 SOD Graphic
An excerpt from IPCC AR5 SOD Figure 9.8 is shown below, clearly showing that the multimodel ensemble (red) is running noticeably hotter than observations (black). In my opinion, the difference is not merely “noticeable” but “statistically significant”, but that’s a story for a different day.
Figure 1. Excerpt from IPCC AR5 SOD Figure 9.8, comparing model ensemble to observations.
Mann’s AGU Presentation
However, Mann at AGU asserted that observations were running as hot or hotter than models. Mann’s model comparandum was Hansen’s Scenario B, which is widely regarded as the most reasonable scenario to use to interpret Hansen’s “forecast” – see past CA points on this issue.
Figure 2. Mann’s AGU slide comparing observations to Hansen’s 1988 Scenario B projection.
I took the photo with a new phone, with which I was then unfamiliar and unfortunately can only provide a muddy zoom on the graphic. Despite the muddiness, you can see that observations (red) appear to cohere with Hansen’s 1988 forecast (blue). In the loop below, I’ve overplotted data for models and observations to show more clearly what was shown to the AGU audience. (There was a bit of detective work in figuring this out – see below.) Click on the figure below for a loop illustrating the components of the zoomed figure). (Note: see below for Mann’s use of his AGU Trick to hide the divergence in a presentation a few months earlier at Rutgers).
Figure 3. Blowup of Mann’s slide comparing Hansen’s Scenario B to observations. Blue – Hansen’s Scenario B; red – “observations”.
Mann’s AGU slide obviously has a completely different rhetorical impression than the IPCC graphic. Whereas the discrepancy between observations and models was immediately noticeable in the IPCC graphic, Mann’s AGU graphic showed no such discrepancy. There were two reasons for the difference, the combination of which I’ll call “Mike’s AGU Trick” and will analyse below.
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Read the full post here: http://climateaudit.org/2013/03/02/mikes-agu-trick/
Reading the comments is also entertaining, particularly in watching Nick Stokes trying to defend the Mann, while McIntyre wipes the floor with his argument.
Comical. Just change the data….
I’m glad Mann does not work in pharmaceuticals. With the way he blatantly changes data, he could wind up killing more people than smallpox…
What is it with these guys – why are they determined to undermine anyone who says the world is NOT heading for global catastrophe?
Surely any sensible thinking person would be relieved that the doomsday projections of the past are not going to be realised yet these people persist in their pathetic excuse for notoriety.
Mann, Gleick, Oreskes, Lewandowsky…… the AGU has been reduced to a parade of clowns.
What a disgrace!
Steve at his best!
But he seems surprised that the likes of Mann et al would plummet to such depths of chicanery and deceptions when it has been their operating mode since the get go.
We should actually expect much more such behaviour from The Team. As their 15 minutes of fame fades away, as the global attention they invented and so desperately crave wanes, as their careers, once so shiny and precious, accelerate down the slippery slope of academic malfeasance and invented hysteria, their desperation will know no bounds.
History will be very cruel to these pretenders to academic excellence, very, very cruel. They will leave a tainted, putrid personal and institutional record for future studies of how and why they could be so wrong, for so long.
Hmm, again creative accountancy and the miracle of figures who lie.
Charlatan.
I believe it is important to note that the “actual” anomalies, plotted here against the model outputs, are based on “adjusted” numbers, rather than actual DATA; and, thus, are likely to be closer to the model outputs than the underlying data would have been. If Anthony’s recent draft paper (Watts et al 2012) is correct, the difference could be as much as a factor of two.
I object to the use of the term “observations” to refer to “adjusted” numbers, rather than to the DATA. The term “obscurations” might be more appropriate for the “adjusted” numbers.
I looked at the meta data of your picture Steve and I see it is a iphone 4s. Setting the pixels setting to the maximum will get you the best image that you can then crop later, as the digital zoom does not improve image quality.
one thing i have always found fascinating about these “prediction” plots is why to they jog around so much?? is it to give the illusion that they have accounted for natural variability? for example, in the IPCC figure, what is it that causes the jumping up and down in say, the light green line? are they predictng a volcano for that year? an el nino event? iguess if their prediction was a straight line it wouldnt be that impressive.
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[full article posted at Canada Free Press archive]
Fred from Canuckistan says:
March 3, 2013 at 7:19 am
History will be very cruel to these pretenders to academic excellence, very, very cruel. They will leave a tainted, putrid personal and institutional record for future studies of how and why they could be so wrong, for so long.
_____________________
You are counting your chickens… what difference has the truth made, so far?
Now what does Flim-Flam rhyme with?
Ed Reid says:
March 3, 2013 at 7:32 am
I object to the use of the term “observations” to refer to “adjusted” numbers, rather than to the DATA.
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agree 100%
“Figures don’t lie, but liars figure”
We have to bear in mind that, as much as we can see the fallacy and chicanery at work here (and in most of the Team’s work), opinion formers in education and the media cannot. Politicians cannot – and will not. There is too much money and reputation invested in their preferred outcome.
We can talk to one another on WUWT day in day out – but convincing those who form policy to to take the science seriously is still an uphill task which has hardly begun. The people who need to listen will still not read WUWT nor the other sceptical blogs; they believe the Team’s propaganda.
Hansen updates his 1988 prediction track semi-regularly on his own website. 2012 is included now.
http://www.columbia.edu/~mhs119/Temperature/T_moreFigs/PNAS_GTCh_Fig2.gif
Something else we need to bear in mind is that schools nowadays don’t teach kids how to read a graph, and probably haven’t for many years. I went to Grammar School in the 1960s and have no problems in this respect, nor in following the basic science since I studied maths, biology, physics and chemistry to ‘O’ level standard. Much of the ability to follow climate science rests on the ability to read graphs.
Children in much of the world are no longer given the tools to follow complex arguments of this kind – and then become environmental activists or journalists spouting all the rubbish they were taught [or indoctrinated with] in their turn.
Happy to see this cross posted here. These are intentional efforts to mislead by the climate science community. They need lots of exposure. Somehow a good portion of the public finds Michael Mann and his cronies to be credible. Amazing.
Janama says
‘
Life as a debunked doomsday prophet isn’t likely to be a bed of roses. And if you have an ego the size of a small galaxy (or Zaphod Beeblebrox) you need to keep your ever-dwindling band of faithful acolytes still needing your pronouncements.
‘Come and hear Jim Hansen and Mike Mann – discredited one-time soothsayers’ will not generate the adulation they crave.
I have always suspected that Mr. Mann was more than a one-trick pony. Perhaps his next field could be Magic.
Ed Reid says:
March 3, 2013 at 7:32 am
I believe it is important to note that the “actual” anomalies, plotted here against the model outputs, are based on “adjusted” numbers, rather than actual DATA
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True. And Mann’s graph showed GISS Land Temp only. Ignoring the facts that land only makes up 30% of the surface, and is mostly in the Northern Hemisphere. While the models are projecting land and sea temps combined.
Isn’t science supposed to present both sides of the argument in an objective fashion? At what point does cherry picking become scientific fraud?
Mann is speaking at the University of Victoria on Monday. This will likely be the same presentation.
University of Victoria, British Columbia, Canada.
I’ll repeat a comment I made at ClimateAudit:
Steve writes: “Mann and Kump used Land-Only data (which runs hotter)…”
They definitely would not have wanted to present a sea surface temperature model-data comparison. During the satellite era, the simulated warming rate of CMIP5-modeled sea surface temperatures are almost twice the observed warming rate:
http://bobtisdale.files.wordpress.com/2013/02/05-global.png
The graph is from my most recent model-data sea surface temperature comparison:
http://bobtisdale.wordpress.com/2013/02/28/cmip5-model-data-comparison-satellite-era-sea-surface-temperature-anomalies/
Regards
“Mike’s AGU Trick”. – I love it! But there are 3 elements, not 2.
Kudos to the indefatigable Steve McIntyre for pointing out yet again how deceptive Mann can be.
Any casual observer can see that actual temps most closely match Hansen’s Scenario C, while emissions have been higher than Scenario A (1.9% annual Anthropogenic CO2 increase vs. 1.5%). From Hansen et al 1988, “Scenario B has decreasing trace gas growth rates, such that the annual increase of the greenhouse climate forcing remains constant at the [1988] level.” Instead, siince 1988, human GHG emissions have grown > 50%! Clearly, Scenario B didn’t happen.
Scenario C corresponds to a CESSATION of additional CO2 forcing post 2000 (which Hansen himself said was highly unlikely).
So comparing “actual temperatures” with B instead of A is a third element of the trick. Likely, the ever-flexible aerosols will be hand-waved into arguing why forcing due to CO2 was different than envisaged. But he shouldn’t be allowed to get away with this, as Hansen accounted for aerosols (using 1958-1985 measurements as a baseline for the future). One has to show measurements of increased aerosols beyond that baseline.
I wonder what Hansen, Pierrehumbert and Muller will say about Mann’s presentation. Remember Muller lambasted Mann for pasting actual temperatures onto proxy reconstructions. Orestes is a cheerleader for the cause and thus provides essentially only comic relief.
The wall of consensus is crumbling – Mann’s presentation is a desperate effort to paste in new mortar while nobody is looking.
At best, Equilibrium Climate Sensitivity is 1/2 of Hansen’s model (which called for 4.2ndeg C warming per doubling of CO2), but it’s quite probably lower — even much lower.
Kurt in Switzerland