Is Jim Hansen's Global Temperature Skillful?

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.

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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.

latitude

First the hockey stick and now this……
…..what is this world coming to?
Thanks for the science John

Robert

What does this mean?
(i.e. a reduction in satellite anomalies by 0.83.)

JinOH

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.

Jim

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?

oMan

Is Hansen waiting for someone to offer him ketchup for the crow sandwich?

terrybixler

“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!

James Sexton

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.

Jimbo

“The result suggests the old NASA GCM was considerably more sensitive to GHGs than is the real atmosphere…..”

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?

U.S. Scientist Sees New Ice Age Coming,” blares the headline of the July 9, 1971, article, which cautions readers that the world “could be as little as 50 or 60 years away from a disastrous new ice age, a leading atmospheric scientist predicts.”
The scientist was S.I.Rasool, a colleague of Mr. Hansen’s at the National Aeronautics and Space Administration. The article goes on to say that Mr. Rasool came to his chilling conclusions by resorting in part to a new computer program developed by Mr. Hansen that studied clouds above Venus. ”
Source: Washington Times

Pascvaks

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.

Village Idiot

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?

ZT

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 dataset which more closely corroborates his testimony.
and every month, it gets closer!

Jimbo

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/

Lance

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.

Deanster

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?

John F. Hultquist

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.

Rick Bradford

Hansen treats facts like a vampire treats sunlight.

Ed Caryl

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.

Curt

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.

Jimbo

Village Idiot
“Why are you so hungup about Jim’s understanding of things 22 years ago?”

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.

Stephan

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.

JamesS

@Village Idiot
The point in question is not what anyone else said about the climate 22 years ago, but what someone DID say about it, and how those predictions have turned out.
Also: “pretty close”? I may be misreading the chart, but it looks like Hanson’s predictions were for a 0.8 C to 1.2 C rise by 2010, whereas the observed is around 0.5 C.
I don’t think most scientists would consider an error of 60-140% “close.”

ZT says:
August 13, 2010 at 5:08 pm
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.
—…—…—…
??? The models have proven themselves dead wrong, since they model/predict climate behavior that does NOT occur, even when actual CO2 levels – the models’ most important input (CO2 levels) – are far greater now than the levels used in the models. Reid/Obama/Pelosi are DEMANDING new taxes of 1.3 trillion dollars as a penalty/requirement for using energy based on Hansen’s predictions for the next 90 years.
Well, here we have Hansen’s predictions for the past 20 years. And, we find Hansen is dead wrong. And, further, we find that the entire CAGW community of supposed scientists completely unable to either explain their problem, recognize their problem even exists, nor correct their problem with their precious CO2-induced CAGW theory.
Is there a problem using 20 year old theories? Well, Hansen relies on his (unverified and unsubstantiated) 1987 paper to justify extrapolating temperatures 1200 km away from measurement sites. What “new” and “corrected” temperatures has Hansen predicted the past few years? Or has he been too busy talking to friendly reporters, supporting riots and testifying (falsely) in British courts to stop badly-needed new energy sources to actually do “research”?

So, NASA was completely wrong, as usual. What’s new? 😉

Benjamin

Guys, i got a question about HadCRUT temperature record.
http://www.cru.uea.ac.uk/cru/info/warming/gtc.gif
Anyone knows what happened in 1879 ?
I mean that has to bo the strongest warming and cooling rate ever.
+0.4°C for 1879-1880 (so 0.2°C per year)
-0.3°C for 1880-1881 (so -0.3°C per year)
And that’s a warming event lost in a cold background, so it’s kind of an anti-volcano event.

James Sexton

Village Idiot says:
August 13, 2010 at 4:57 pm
“……Why are you so hungup about Jim’s understanding of things 22 years ago? …..”
4 years ago recent enough for you? See below.
oMan says:
August 13, 2010 at 4:36 pm
“Is Hansen waiting for someone to offer him ketchup for the crow sandwich?”
Naw, he simply did a study himself stating that he was essentially correct. lol, somethings a man has to do himself. And if you don’t know who to believe about Hansen’s study, well, just ask him! He’ll tell you he was right!
Stay tuned! He’ll be right back with yet another self-validating study real soon!(Some results may vary. Invented temps used.)
http://pubs.giss.nasa.gov/docs/2006/2006_Hansen_etal_1.pdf

John Whitman

This post adds more weight to my idea that we might see some career moves in NASA during their next human resource evaluation cycle.
Good luck to NASA.
John

Wayne Delbeke

Does the recent satellite sensor issues affect UAH temperature data? Just curious.

Jimbo

Here is the global warming signal at the Arctic.
http://ocean.dmi.dk/arctic/plots/meanTarchive/meanT_2010.png

James Sexton

Deanster says:
August 13, 2010 at 5:24 pm
“Have you guys noticed this at UAH? ”
I have, it seems a bit off to me, too.

Wayne Delbeke

Oops – Do the recent ….

Jeff L

This is elegance in simplicity.
The true d[snip] are the warmers.
Wait & see the divergence increase over the next decade as 1st the PDO goes cold (already starting), followed by the AMO next. Then everyone will come to the same conclusion most skeptics have already come to – natural cycles dominate the signal & GHG’s are bit players at best.

latitude

Village Idiot says:
August 13, 2010 at 4:57 pm
Why are you so hungup about Jim’s understanding of things 22 years ago?
==================================================
Simple answer, because their predictions do not pan out. Not even in 20 years.
No one’s understanding of things has changed that much in 20 years.
What we don’t know still far surpasses what very little we do know, and that has not changed.
Jim?? I hope you meant that as some sort of idol worship thing.

carrot eater

Robert,
The 0.83 is a cheeky ploy. Christy is assuming there is tropical tropospheric “hot spot”.
Christy is taking a model result that tropospheric warming should be amplified by 1.2 over the surface. Then he’s taking the satellite record, and using that ratio to work backwards to what the surface trend would be. This, because he says the actual measurements at the surface can’t be used at all.
So basically, Christy assumes the models are correct, (and also that UAH/RSS are correct), and ends up deciding the models are incorrect.
This is nothing new; it’s just the same old argument over the existence or non-existence of the predicted tropospheric hotspot, inverted. But it lets you make a more impressive looking chart.

Village Idiot says:
August 13, 2010 at 4:57 pm
“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?”
Because if Hansen’s mythic powers of prognostication are going to be used as an excuse to shatter the remnants of our economy then we should know just how accurate he really is. Since we are unable to know for certain what the future will look like in 20 years, much less the 50-100+ year scarenarios propagated by Hansen and his ilk, then we must look at their older prophecies rather than checking their constantly updated ones which can’t diverge as much from observed reality (and how Hansen observes it) for simple temporal reasons.

James Sexton

Jim says:
August 13, 2010 at 4:35 pm
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?”
Yeh, I hate it when they start going all “satellite climate science” wordspeak. Makes for a hard read, fortunately this was a short article. I’ll try to give an explanation.
The “observed” temps are temps from satellites, apparently both RSS and UAH data sets are used. However, these are not the same data sets used in Hansen’s models. Hansen used surface temps, (I presume his own, GISS) A surface temp reading does not equal a satellite read. The satellite is measuring the heat in the troposphere. So, an adjustment must be made to attempt to equate the temps. In this case, apparently -0.83. I hope that helps you and some of the others.
I don’t favor this kind of comparison, but given the corruption of surface temps data, this is probably the best set of tools, and obviously, Dr. Christy used accepted scientific methods for the comparison.

MikeC

… shouldn’t the comparrison be used with GISS rather than UAH and RSS?

Dr. Dave

I think folks like James Hansen and Tom Karl realize they have a rapidly approaching expiration date. In a couple of years a new administration will likely scour the pseudo-sciences out of NOAA and NASA/GISS. Then what will they do?
Gentlemen like Drs. Christy and Spencer (and Lindzen, Soon and many others) are at the top of their game right now. What was Dr. Christy doing 22 years ago? Probably trying to figure out if any of this made any sense in the real world. I see folks like Briffa and Mann slipping into irrelevance and…alas…James Hansen slipping into something akin to pre-senile dementia.

Kforestcat

Thanks John
Your fine example of integrity, honesty, and adherence to sound scientific principles are primary reasons why I send my daughter and money to UAH (budding electrical engineer). I find these commendable values throughout UAH and the Huntsville area.
I intend to encourage my son to attend UAH when he graduates from high school and will continue to support UAH in any way I can.
Kforestcat

Benjamin says: “Anyone knows what happened in 1879 ?”
Looks like an exaggerated and lagged response to the 1877/78 El Nino. Keep in mind that the global coverage was very poor back then, so the data is more volatile.

James Sexton

ZT says:
August 13, 2010 at 5:08 pm
“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.”
Three things ZT, first, of course they are predictions. If they weren’t predictions then why didn’t he list 10 alternate future paths? He only listed 3 because that is the way he thought things would most likely turn out.(many of us call that “prediction”) The reason why this matters, is because HE TESTIFIED IN CONGRESS ABOUT THIS LUNACY. LAWS HAVE BEEN PASSED BECAUSE OF HIS UNFAMILIARITY WITH THE WORDS, “I DON’T KNOW.” Industries have died, careers and livelihoods ruined, resources have been diverted from real problems. In many ways the EPA’s new found authority to regulate CO2 as a harmful gas stems from this wildly irresponsible man’s actions.
Secondly, “….in that they are consistent with climatological belief.” Yep, belief is about the way I’d put it too. Perhaps theology, but belief is good.
Thirdly, “..In fact, the models have proven themselves to be robust,…” If by robust you mean consistently wrong, then yes. See the 3 alternate paths of the future, none of them happen to be correct. Oddly, they undershot the CO2 ppm but still overshot the temps in every case, (I feel the need to reiterate the Dr. Christy’s conclusion) meaning they have no idea how much CO2 effects the earth’s temperatures. But what we can conclude from Dr. Christy’s submission, is that they greatly exaggerate its importance. But, I digress. What, pray tell, does robust mean in the sentence you used?

James Sexton

MikeC says:
August 13, 2010 at 6:47 pm
“… shouldn’t the comparrison be used with GISS rather than UAH and RSS?”
No, it probably should be if there were any reasonable belief in the validity of the data set. Hansen arbitrarily alters historical temps on a fairly consistent basis. There is no reason to believe (and ample examples to the contrary) that the more recent data is valid. Even HadCrut is diverging from GISS in a significant manner, and they use essentially the same temps. http://www.woodfortrees.org/plot/hadcrut3gl/from:1998/trend/plot/gistemp/from:1998/trend
Also, Dr. Christy is more familiar with the sat. temps, it’s what he works with, so naturally, he’d use them.

bubbagyro

Village Idiot says:
August 13, 2010 at 4:57 pm
Why are you so hungup about Jim’s understanding of things 22 years ago?

Dawson died before his Piltdown Man skull was exposed as a fraud. It took 40 years to expose the fraud.
How many years, V.I., should we give Hansen and Karl before they are exposed to the world? I expect they are conjuring up their next “skull” as we speak.
Hansen disqualified himself as an expert after his first model. He lied and Karl swore to it. Allegedly. We are charitable to concede that this was an honest mistake or an unintentional prevarication. Their “models” should have the same position of honor in history that the Piltdown Skull has today.

Joel Shore

There’s a number of questionable assumptions and statements in this post.
First, as carrot eater notes, the actual empirical temperature trend has been made as small as possible by first using the satellite data and then further reducing on the basis of the model prediction that the temperature trends should be larger at the surface than in the LT satellite product. So, you have a bizarre mishmash of data and model put together in such a way as to minimize the temperature trend.
The justification for this…and not using the actual surface temperature record (which would show about a 1.5X trend) is the surface record being unreliable; however, the satellite trend is not gospel either (and I believe that there are in fact two groups besides RSS and UAH who have done the analysis and reported higher trends than either RSS or UAH).
Secondly, statements are made concerning the actual emissions in relation to the scenarios that contradict not only Gavin Schmidt’s analysis but even Steve McIntyre’s ( http://climateaudit.org/2008/01/24/hansen-1988-details-of-forcing-projections/), as both concluded that the actual forcings turned out to be closest to Scenario B (if not a tad below in Gavin’s analysis).
Thirdly, the relative alignment of the three scenarios is different than in Hansen’s original graph (the most complete version of which is available in Fig. 3 of this publication http://pubs.giss.nasa.gov/docs/1988/1988_Hansen_etal.pdf ). In Hansen’s graph, Scenarios A and B were clearly further apart in the later years than they have become under the current alignment. I assume this has to do with the tying of all graphs to a 1979-1983 mean, but it seems to me that performing such ana alignment actually changes Hansen’s projections from those that he presented…and seems to do so in a way that exaggerates the trend under Scenario B, at least relative to Scenario B.

TerryS

Re: Village Idiot

You’re a busy guy, slagging off Jim ’bout his take on things in June 1988 (22 YEH 22 years ago!!).

I guess thats why its good to be a climate modeler. In the short term you just claim “thats weather not climate” and in the long term you just say “22 YEH 22 years ago” and claim the latest batch of models are so much better.

Bill Hunter

Just to think we could have tanked the economy in 1988 ended up with the blue temperature curve and been singing Shèhuì zhǔyì hǎo, shèhuì zhǔyì hǎo! around the sun warmed stone.