Guest Post By John R. Christy of the University of Alabama at Huntsville
via Dr. Roger Pielke Sr’s blog: Climate Science
The three warm-color time series are taken from Hansen’s published testimony in June 1988 in which global surface air temperatures were projected under three scenarios by his global climate model.
The red curve follows a scenario (A) of continued emissions growth based on the previous 20 years before 1988 (which turned out to be an underestimate of actual emissions growth.) The orange represents a scenario (B) of fixed emissions at the rate achieved in the 1980s. The yellow curve portrays a scenario (C) in which “a drastic reduction” in GHG emissions is assumed for 1990-2000. The observations are global tropospheric temperatures adjusted to mimic the magnitude of surface temperature variability and trends according to published climate model simulations (i.e. a reduction in satellite anomalies by 0.83.)
After tying all time series to a 1979-83 reference mean, one can see the significant divergence in the results. (Notes: 1. observed 2010 is Jan-Jul only; 2.) tropospheric temperatures are used as the comparison metric due to many uncertainties and biases in the surface temperature record, i.e. Klotzbach et al. 2009, 2010 ; 3.) both models and observations included the 1982 eruption of El Chichon while B and C scenarios included a volcano in the mid 1990s – not too different from Mt. Pinatubo.)
The result suggests the old NASA GCM was considerably more sensitive to GHGs than is the real atmosphere since (a) the model was forced with lower GHG concentrations than actually occurred and (b) still gave a result that was significantly warmer than observations.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
What I find equally disturbing is how Hansen is continuing to adjust post 1998 numbers upwards, and now shows a strong warming trend over the last 12 years which is not seen by UAH, RSS or HadCrut.
First the hockey stick and now this……
…..what is this world coming to?
Thanks for the science John
What does this mean?
(i.e. a reduction in satellite anomalies by 0.83.)
What’s with looking at the facts? That doesn’t instill a sense of fear. Hansen is an environmental wacko and should probably seek help.
So, he was wrong even if we had followed his advice. Nice.
Thank you Dr. Christy.
For the sake of us unwashed, could you explain “The observations are global tropospheric temperatures adjusted to mimic the magnitude of surface temperature variability and trends according to published climate model simulations (i.e. a reduction in satellite anomalies by 0.83.)” in a bit more detail? I am guessing it lowered the overall height of the observation curve?
Is Hansen waiting for someone to offer him ketchup for the crow sandwich?
“After tying all time series to a 1979-83 reference mean, one can see the significant divergence in the results.” Divergence is in the eye of the beholder, just ask Lisa Jackson or Obama. Divergence what divergence indeed!
My thanks to Dr. Christy for this insight.
So, if I use the name “Monckton” will our new found friends from RC come back and take a look at this? Many of them seemed convinced of Hansen’s infallibility.
Amplification of Global Warming by Carbon-Cycle Feedback Significantly Less Than Thought, Study Suggests. See here and here.
“A little known 20 year old climate change prediction by Dr. James Hansen – that failed badly – WUWT”
Model use and abuse?
Prognostication is an art, not a science. Hansen is neither but he does seem to have a PhD in BS. If the poor guy weren’t in such demand and so busy on the Snake-Oil Salesman Chicken or Beef Circuit he’d have starved in the early 1990’s. Fortunately, it’s still true that there’s a fool born every minute; and some people like Hansen and his mentor (FatAlbert) have a gehnak for the theatric.
I perceive that we have an honored guest with us in The Village (a hero some might say!). So the village idiot promises to be on his best behaviour (as he was when Lord M. dropped by – though my appropriately servile comments were restrained in the Gatekeepers – oops Moderators – dungeon).
Just one point, JC. You’re a busy guy, slagging off Jim ’bout his take on things in June 1988 (22 YEH 22 years ago!!). With all due honor and respect that applies to this domain, I don’t seem to be able to ferret out what you had to say for youself back then. Care to enlighten us?
Hey, I’m just an idiot..but i thought science sort of…moves forward…I certainly have in the last 22 years. Why are you so hungup about Jim’s understanding of things 22 years ago? Don’t you feel fulfilled in the way your own career has panned out? Do you feel that slight envy that Hansen is in fact…..well….pretty close?
It looks to me like some others need this skills testing:
http://www.ianschumacher.com/img/TempsvsIPCCModelsWM.jpg
http://deepclimate.files.wordpress.com/2009/05/ar4-a1b-a2.gif
http://joannenova.com.au//globalwarming/graphs/akasofu/akasofu_graph_little_ice-age.gif
But aren’t these actually scenarios where scenarios are images of the future, or alternative futures? They are neither predictions nor forecasts. Rather, each scenario is one alternative image of how the future might unfold. Hence the fact that scenarios show little resemblance to actuality is in no way indicative of a problem with the underlying model. In fact, the models have proven themselves to be robust, in that they are consistent with climatological belief.
fortunately hansen has his own temperature
datasetwhich more closely corroborates his testimony.and every month, it gets closer!
By the way here is the Rasool and S. H. Schneider paper predicting an ice age in 1971.
http://www.sciencemag.org/cgi/content/abstract/173/3992/138
From Climate Audit – 2006
“Willis E on Hansen and Model Reliability”
http://climateaudit.org/2006/08/26/willis-e-on-hansen-and-model-reliability/
It’s about time somebody in the field called out Hansen on his out of whack “scenarios”.
Dr. Christy,
Please know that however much derision and approbation you may receive from “consensus scientists” your efforts to uphold the standards of impartial, empirical science are appreciated by a great number of people.
John ….
Excellent article. And I agree .. Hansen is not skillful.
ON ANOTHER NOTE … I have ONE HUGE question. I’m beginning to wonder if something has gone ary with the data sensor on the satelite.
Looking at all the previous years of data, it seems there is a relatively sharp peak of temperature in the summer. However, this year looks like a car that the power steering has gone out, and it making this wide swing.
Have you guys noticed this at UAH? Is this wide swing at the top for real?
To paraphrase Richard Feynman:
When the theory makes a prediction that does not agree with observations then the theory is wrong.
Wow, if this La Nina matches 1999, he’ll be off by 0.7C, the same amount as all the warming since 1850, based on the fact that CO2 levels will be at his scariest scenario.
Unfortunately, other than the fact that this tells us his analysis was not “skilful”, this doesn’t inform us about what would be a more realistic number for a doubling of CO2, because he only based his assumptions on that one variable, when we know there have been far more factors at work, like the PDO and AMO warm phases, the active sun now gone quiet, and the extra El Nino.
Hansen treats facts like a vampire treats sunlight.
V. Idiot
Yes, science has moved on…. But Hansen hasn’t. He has “adjusted” the GISS data to conform with his 1988 vision, which is why it diverges from the satellite data. His current projections are just like his 1988 projections, way high.
Why the reduction to 0.83 of measured?
The models typically predict more warming aloft than at the surface — typically 1.2 times as much. So if you have measurements aloft (as from the satellites), and you want to infer the comparable surface values, you multiply by 1/1.2 = 0.83.
Because if he was so wrong in the past why should we re-structure our whole global energy infrastructure based on anything he says today? People are more cautious than you perhaps as our careers earned us what we have and we’ll be damned if we rely on someone as dangerous for humanity as Jim. If his prediction was about the frequency of supernova in our galaxy no one would give a damn if he got it wrong.
A wild guess but I am venturing tthat looking at time lapse CT and the shape of DMI NH ice extent curve, that melt is about over and that we are about to get one hell of a surprise.