Guest Post by Steven Goddard
Global Climate Models (GCM’s) are very complex computer models containing millions of lines of code, which attempt to model cosmic, atmospheric and oceanic processes that affect the earth’s climate. This have been built over the last few decades by groups of very bright scientists, including many of the top climate scientists in the world.
During the 1980s and 1990s, the earth warmed at a faster rate than it did earlier in the century. This led some climate scientists to develop a high degree of confidence in models which predicted accelerated warming, as reflected in IPCC reports. However, during the last decade the accelerated warming trend has slowed or reversed. Many climate scientists have acknowledged this and explained it as “natural variability” or “natural variations.” Some believe that the pause in warming may last as long as 30 years, as recently reported by The Discover Channel.
But just what’s causing the cooling is a mystery. Sinking water currents in the north Atlantic Ocean could be sucking heat down into the depths. Or an overabundance of tropical clouds may be reflecting more of the sun’s energy than usual back out into space.
“It is possible that a fraction of the most recent rapid warming since the 1970’s was due to a free variation in climate,” Isaac Held of the National Oceanic and Atmospheric Administration in Princeton, New Jersey wrote in an email to Discovery News. “Suggesting that the warming might possibly slow down or even stagnate for a few years before rapid warming commences again.”
Swanson thinks the trend could continue for up to 30 years. But he warned that it’s just a hiccup, and that humans’ penchant for spewing greenhouse gases will certainly come back to haunt us.
What has become obvious is that there are strong physical processes (natural variations) which are not yet understood, and are not yet adequately accounted for in the GCMs. The models did not predict the current cooling. There has been lots of speculation about what is causing the present pattern – changes in solar activity, changes in ocean circulation, etc. But whatever it is, it is not adequately factored into any GCMs.
One of the most fundamental rules of computer modeling is that if you don’t understand something and you can’t explain it, you can’t model it. A computer model is a mathematical description of a physical process, written in a human readable programming language, which a compiler can translate to a computer readable language. If you can not describe a process in English (or your native tongue) you certainly can not describe it mathematically in Fortran. The Holy Grail of climate models would be the following function, which of course does not exist.
FUNCTION FREEVARIATION(ALLOTHERFACTORS)
C Calculate the sum of all other natural factors influencing the temperature
…..
RETURN
END
Current measured long term warming rates range from 1.2-1.6 C/century. Some climatologists claim 6+C for the remainder century, based on climate models. One might think that these estimates are suspect, due to the empirically observed limitations of the current GCMs.
As one small example, during the past winter NOAA’s Climate Prediction Center (CPC) forecast that the upper midwest would be above normal temperatures. Instead the temperatures were well below normal.
http://www.cpc.ncep.noaa.gov/products/archives/long_lead/gifs/2008/200810temp.gif
http://www.hprcc.unl.edu/products/maps/acis/mrcc/Last3mTDeptMRCC.png
Another much larger example is that the GCMs would be unable to explain the causes of ice ages. Clearly the models need more work, and more funding. The BBC printed an article last year titled “Climate prediction: No model for success .”
And Julia Slingo from Reading University (Now the UK Met Office’s Chief Scientist) admitted it would not get much better until they had supercomputers 1,000 times more powerful than at present.
“We’ve reached the end of the road of being able to improve models significantly so we can provide the sort of information that policymakers and business require,” she told BBC News.
“In terms of computing power, it’s proving totally inadequate. With climate models we know how to make them much better to provide much more information at the local level… we know how to do that, but we don’t have the computing power to deliver it.“
……
One trouble is that as some climate uncertainties are resolved, new uncertainties are uncovered.
Some modellers are now warning that feedback mechanisms in the natural environment which either accelerate or mitigate warming may be even more difficult to predict than previously assumed.
Research suggests the feedbacks may be very different on different timescales and in response to different drivers of climate change
…….
“If we ask models the questions they are capable of answering, they answer them reliably,” counters Professor Jim Kinter from the Center for Ocean-Land-Atmosphere Studies near Washington DC, who is attending the Reading meeting.
“If we ask the questions they’re not capable of answering, we get unreliable answers.“
I am not denigrating the outstanding work of the climate modelers – rather I am pointing out why GCMs may not be quite ready yet for forecasting temperatures 100 years out, and that politicians and the press should not attempt to make unsupportable claims of Armageddon based on them. I would appreciate it if readers would keep this in mind when commenting on the work of scientists, who for the most part are highly competent and ethical people, as is evident from this UK Met Office press release.
Stop misleading climate claims
11 February 2009
Dr Vicky Pope
Dr Vicky Pope, Met Office Head of Climate Change, calls on scientists and the media to ‘rein in’ some of their assertions about climate change.
She says: “News headlines vie for attention and it is easy for scientists to grab this attention by linking climate change to the latest extreme weather event or apocalyptic prediction. But in doing so, the public perception of climate change can be distorted. The reality is that extreme events arise when natural variations in the weather and climate combine with long-term climate change. This message is more difficult to get heard. Scientists and journalists need to find ways to help to make this clear without the wider audience switching off.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Why IS the US government paying one of its employees (one way or another) to act as a focal point for troublemakers in another country? Is this a new direction for foreign policy?
Maybe because he didn’t do so hot over here leading charges to shut down the Power Plant for the US Captial. i.e. – he didn’t cross the Delaware in winter.
I will agree with the above posts: He should be fired. He should have been fired a long time ago.
John Philip (12:35:05) :
“Global climate models are extraordinarily useful tools, and among other things have successfully predicted the rise in temperature as greenhouse gases increased, the cooling of the stratosphere even as the troposphere warmed, the increase in the height of the tropopause, polar amplification due the ice-albedo, and other effects, and greater increase in nighttime than in daytime temperatures, and the magnitude and duration of the cooling and the water vapour feedbacks caused by the eruption of Mount Pinatubo. ”
I am always amused to read these kinds of claims, only to find that it’s just another climate hindcast. That is, you know the answer before you run your model. Nothing wrong with that, except it is NOT a prediction! It does allow you to tune you model to get perfect agreement with the past (imagine that)…
For those who want a more sober assessment of the predictive skill of modern climate models should read this:
http://climatesci.org/2008/11/14/are-multi-decadal-climate-forecasts-skillful-2/
If you remember the post about adjusting temperatures for the ENSO and AMO, the reconstruction model continues to work very well with the February Hadcrut3 numbers being out by only 0.014C and with GISS by 0.035C
The climate modelers need to adjust out the natural variation in the climate before they run their models/hindcasts (because it is true they were taking a free ride with the rise in ENSOs and the AMO from 1976 to 2006).
Warming is only half what the models predict.
Here is the latest Hadcrut3 reconstruction.
http://img14.imageshack.us/img14/8/newhadcrut3model.png
Here is GISS Model E for comparison.
http://img355.imageshack.us/img355/9043/modelehindcastoz1.png
Here is what the residual warming left over shows (after adjusting out the impact of the ENSO, the AMO and the southern AMO which I added later) compared to the original global warming models. The modelers need to use this as their starting data and then they would be more accurate.
http://img14.imageshack.us/img14/5721/newhadcrut3warming.png
The satellite temperature trendlines are much lower than the Hadcrut3 reconstruction shows – between 0.8C to 1.2C per doubling.
Steven Goddard (13:53:32) :
John Philip,
You said that some of the models did predict the recent cooling.
What was the reason for the cooling, and what do those same correct models forecast for the remainder of the century?
You beat me to the question, Steven. The second and third questions then are, which output is correct and how do we choose?
Since 2002, RSS and UAH both show cooling at a rate of nearly 4C/century.
http://www.woodfortrees.org/plot/uah/from:2002/trend/plot/rss/from:2002/trend
Which model predicted that?
actually the models include short time spans showing sinking temperatures.
http://www.realclimate.org/images/Hansen06_fig2.jpg
but you knew that, of course?!?
John Philip (12:35).
I wanted to take a look at one of the references you gave (Lucia). Most of it is outside my area of expertise. But the author also said this.
“However, it is worth nothing that at a significance level of 90%, the best estimate of the underlying trend in GMST based on the average of 38 runs is inconsistent with the observed trend. Using the language of the IPCC, the result of this test suggests we should have very low confidence that model projections based on this sort of multi-run average are correct.”
“So, what we are finding is that if I try hard enough, I can currently hunt around for methods of averaging that fail to falsify the models.”
This sounds inconclusive. But I am willing to try other references. (or be corrected).
Squidly (14:17:49) : said
“GP (13:42:36) :
Why IS the US government paying one of its employees (one way or another) to act as a focal point for troublemakers in another country? Is this a new direction for foreign policy?
Because nobody in this country has the gonads to do the right thing and fire the bastard!”
As a Brit I really resent the fact that a govt employee of a friendly power can be sent to its major ally to cause trouble and try to tip us into the dark ages through denying us much needed energy. Can’t you control the guy?
Tonyb
With advance apologies Hope this gives a chuckle or two.
Not so long ago I began working on computer models using my old, but trusty Commodore PET with the aim of predicting exactly of what the moon is made.
As it turns out the models, LCM’s [Lunar Cheese Models] ran very well., but with some differences in output, depending on the milk type, temperature, salinity, and bacterial type used. Sometimes the output indicated the moon was made of Swiss cheese – which fit well with the observed cratering; possibly from earth sourced atmospheric bleed-over of CO2. Other times the model runs suggest a composition closer to double cream Brie, which, with minor solar irradiation would flow and form the observed maria. Other runs are consistent with a sharp crumbly English cheddar [aged at least two years] resembling the lunar mountains.
But, puzzlingly often, the LCM output indicated a new cheese with a very foul “runaway smell” index. To this runaway smell cheese I have tentatively assigned the folk taxon Moon cheese.
Now, after running these models many times, I am absolutely sure they yield the correct basic chemistry of the moon — in spite of real data returned from Tranquility Base through Taurus-Littrow.
No, before you ask, I will not make public the data input for these models or how I may have adjusted them to get the proper output. Nor will I answer questions about the model’s accuracy. Just trust me.
And now, given that my models are correct, I intend to lobby Congress and the executive branch to immediately stop all attempts to return to the moon as any large scale lunar commerce would represent a dire threat to earth based cheese makers. If successful in lobbying, I shall submit proposals for grants for further research in Moon cheese.
The LCMs also predict that Moon cheese will occur from time to time on the earth itself and probably in ever increasing amounts. We should, therefore, take immediate and strong action to prevent this from happening as the runaway smell could easily make the earth uninhabitable within the next few decades. Curbing the runaway smell output might well be enforced by requiring every citizen to buy “cut the cheese credits” [CTCC’s]. The obvious benefits of CTCC’s to all mankind are self-evident.
We have at most 5–7 years before reaching the tipping point for this phenomenon Many readers may have doubts about the seriousness of the imminent runaway smell problem, but let me suggest that if you have ever been “mooned,” you probably recognize the smell whereof I write. So keep careful watch and do your best to avoid the Moon cheese! And watch where you step too.
Steve I think you missed my point. I was making the observation that vinegar is at least 5pH units more acidic than seawater. So it was a fatuous and misleading exercise for CCMAP to the liken ocean acidfication to this degree .
Since pH = -log(10)[hydrogen ion concentration] each unit of pH represents a 10-fold change in hydrogen ion concentration.
Are you telling me that there is any equilibrium mix of CO2 and salt water will approach pH 6, let alone ph 2.5?
Don
@Mike T (12:51:52) :
I agree, it would have been great to have a well-spoken, knowledgeable expert to provide balance.
Aron (14:07:12) :
“That’s nothing. Ed Milliband said young British activists should take Direct Action to other countries to bully them against using their resources. Talk about imperialism. I am a very patriotic Brit and this kind of thing is completely out of line with post-imperial British values.”
First thing Milliband’s got right.
Let them try it in China for instance, it would keep them out of OUR hair for a year or two 😉
DaveE.
Right on, TonyB. James Hansen has been on stage way too long. His 15 minutes of fame are long past. Somebody needs to get the hook!
Let’s trade him for George Monbiot. We could send the two of them to Tuvalu to measure sea levels for the next decade.
Re: sod (14:33:18)
actually the models include short time spans showing sinking temperatures…but you knew that, of course?!?
I don’t see any period of sinking temperatures longer than 2 years after the year 2000 in that graph, and we are several years into a flat to slightly declining trend. Unless of course you are talking about Scenario C, in which case the only excuse is that you are being deliberately misleading.
Paul S,
Yes – the logic seems to go.
1. The IPCC uses a wide range of model outputs, ranging from little warming to a lot of warming.
2. Because the measured temperatures were close to some of the lower forecast models, that validates the higher forecast models.
3. Thus we can expect 6+C warming this century
I predict that the stock market will either go down, up or stay the same next week. Those are my three scenarios, and I’m sticking with them through thick and thin.
sod,
The only scenario in Hansen’s graph you linked which showed a seven year cooling trend was Scenario C, which is based on low CO2 increase. The actual CO2 increase has been higher than scenario A.
I always get a kick out of people tweaking data to show that the current cooling was predicted. It wasn’t.
The Met Office and Hansen both forecast 2007 to be the hottest year ever. Hansen already forecast 2009 or 2010 to be the hottest year ever. Deal with reality please.
TonyB said:
“As a Brit I really resent the fact that a govt employee of a friendly power can be sent to its major ally to cause trouble and try to tip us into the dark ages through denying us much needed energy. Can’t you control the guy?”
Many of us Americans certainly resent it to. Hansen is an embarrasment to science, to NASA, and to the U.S.A.
I have to say…when the cat left, the mice started to play.
As dislikable as the Bush Administration was to many in the world, notice Hansen did not really start going hog-wild, until AFTER the current president took over the White House.
Why does Hansen do it? Because he knows he can.
But we share your sympathies. Fire him….and TRY him, if necessary.
Try him for what? MALFEASANCE, INCOMPETENCE, and WANTON DISREGARD FOR PUBLIC OFFICE.
History will not look too kindly of him….or his chums Gore or Holdren.
But they are one in the same: politically driven-ideologues who squelch free thought and TRUE scientific discipline.
The shameful “American Inquisition” in action!
The fact that the climate models have failed to even extrapolate a warming trend in the past 10 years, and still, in spite of that, where they not backing down…can only mean one thing: megalomania.
Too bad there is not a model to accurately predict the behavior of politically-driven scientists as to what they might do next!
Latest Hansen Short and Long-range Forecasting Outlook:
HANSEN POLITICAL DEVIATIONS ABOVE NORMAL ARE APPROACHING RECORD MAXIMA SINCE RECORDS HAVE BEEN KEPT.
PROTEST IN THE U.K. HIGHLY LIKELY AND IMMINENT. OTHER PROTESTS ARE POSSIBLE IN THE LONG-RANGE, BUT THE EXACT TIMING AND INTENSITY OF THOSE HANSEN APPEARANCES WILL DEPEND UPON OTHER FORECASTING VARIABLES DOWNSTREAM IN THE LONG RANGE AND GENERAL MODEL AGREEMENT AFTER SUCH EVENTS HAVE MATERIALIZED.
THIS IS A HIGHLY VOLATILE AND UNSTABLE SITUATION…STAY TUNED TO YOUR LOCAL WUWT FORECAST FOR DETAILS IN THE EVENT A WARNING IS ISSUED….
Chris
Norfolk, VA
John Philip, you need to check your sources for those claims.
The midrange scenario A2 projects a temperature rise from 1990-2010 of 0.35C, equivalent to a linear increase of 0.175C per decade. How are they doing? Well the trends in the 4 main indices since 1990 are:
UAH 0.168
I checked UAH and they show a DECREASE in global temperature of -0.04C (-0.02C per decade) from 1990 to 2008 (the latest full year available).
http://climate.uah.edu/dec2008.htm
I’ll be charitable and assume you were being lazy and didn’t check comments you copied from elsewhere, rather than you being deliberately deceptive.
Correction “true scientific DISCOURSE.” Although I guess the word “discipline will work LOL
Ironically, it may actually be better overall to keep him where he is and allow him to continue his ridiculousness. By doing so, he is simply undermining his own cause as he continues to look more foolish every day. A clear case of “scientist gone mad”.
sod – am I right in thinking that scenario A is the one in which CO2 emissions continue to increase unabated (“BAU”), scenario B is for CO2 emissions stabilised at around 1990 levels, and scenario C is for CO2 emissions drastically cut?
The observed temperatures are closer to scenario C than either of the others, but where are the observed CO2 emissions?
Steve Goddard: The cooling trend which NOAA’s Isaac Held was referring to above, has been over the last decade.
Since 2002, RSS and UAH both show cooling at a rate of nearly 4C/century.
http://www.woodfortrees.org/plot/uah/from:2002/trend/plot/rss/from:2002/trend
But using the usual definition of a decade as 10 years, all the indices actually show a positive trend. And if you look at the ‘raw data’ option from your 6 year RSS and UAH plot we find…
UAH #Least squares trend line; slope = -0.0231915 per year
RSS #Least squares trend line; slope = -0.0274867 per year
So I could have accepted ‘nearly -3C/Century’ at a push but ‘nearly -4C’ ,er, no.
Besides, six years is not climate, see here for a discussion of the dangers of model/data comparisons over such short periods.
Aron @ur momisugly 10:13:21:
The Pope probably got an e-mail memo from Head Office 🙂
Bill, those are wonderful graphs. I can see that those models are able to reconstruct the past quite accurately, but that does nothing for forecasting the future. I can take a pencil and sketch a graph of the past myself, equally as accurate, and I know little to nothing about how our climate works. I can probably also predict the future like the models, with likely equal, if not better accuracy.
Am I missing the point of your post?
TonyB (14:42:44) :
I keep hoping he’ll show up on a no-fly list, preferably some day when he’s out
of our countries.
Hansen’s Scenario C was for GHG levels to stop increasing in the year 2000.
It then took only 6 years for temps to reach a peak and then stay there.
For those who keep pointing to the long timelines to reach equilibrium, Hansen estimated it only took 6 years back in 1988 when he was 100% sure he had everything figured out and even testified to Congress to that fact. He has now changed the equilibrium response time to 1500 years (but he has “nailed it” for sure this time).