Reader Jimbo advises in WUWT Tips and Notes about something Dr. [Kevin Trenberth] wrote that makes you wonder what he’s talking about when there are so many uses of the word “prediction” in the IPCC AR4. It also makes me wonder what the Economist author Oliver Morton was doing running a blog by Nature. Is there no separation between science journalists and science journals?
Trenberth suggests that after the last report “…the science is settled or done and now is the time for action.”. Here we are six years later, and another IPCC report is coming out on that “settled science” and there is no successor to Kyoto. I wonder how many times the word “prediction” will be used in the upcoming AR5?
Jimbo writes: I stumbled on a quote from [Kevin Trenberth] over at the Nature Blog dated 04 Jun 2007.
Source: http://blogs.nature.com/climatefeedback/2007/06/predictions_of_climate.html
I thought I’d take a look because I was sure I had seen the IPCC use the word ‘predict’.
[My bolding throughout]
This subsection focuses on the few results of initial value predictions made using models that are identical, or very close to, the models used in other chapters of this report for understanding and predicting climate change.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-4-11.html
—————–
…Some qualitative inconsistencies remain, including the fact that models predict a faster rate of warming in the mid- to upper troposphere which is not observed in either satellite or radiosonde tropospheric temperature records….
…The first IPCC Scientific Assessment in 1990 (IPCC, 1990) concluded that the global mean surface temperature had increased by 0.3 to 0.6°C over the previous 100 years and that the magnitude of this warming was broadly consistent with the predictions of climate models forced by increasing concentra- tions of greenhouse gases. However, it remained to be established that the observed warming (or part of it) could be attributed to the enhanced greenhouse effect. Some of the reasons for this were that there was only limited agreement between model predictions and observations,…
…However, models generally predict an enhanced rate of warming in the mid- to upper troposphere over that at the surface (i.e., a negative lapse-rate feedback on the surface temperature change) whereas observations show mid-tropospheric temperatures warming no faster than surface temperatures….
…..“historical” indicates the signal is taken from a historical hindcast simulation, “future” indicates that the pattern is taken from a prediction……
…Changes in the annual mean surface temperature were found to be highly significant (in agreement with previous results from Hegerl et al., 1996, 1997). The predicted change in the annual cycle of temperature as well as winter means of diurnal temperature range can also be detected in most recent observations….
…Estimation of uncertainty in predictions
The scaling factors derived from optimal detection can also be used to constrain predictions of future climate change resulting from anthropogenic emissions (Allen et al., 2000b). The best guess scaling and uncertainty limits for each component can be applied to the model predictions,……
… An example based on the IS92a (IPCC, 1992) GS scenario (whose exact forcing varies between models, see Chapter 9, Table 9.1 for details) is shown in Figure 12.13 based on a limited number of model simulations. Note that in each case, the original warming predicted by the model lies in the range consistent with the observations….
…The range is significantly less than one (consistent with results from other models), meaning that models forced with greenhouse gases alone significantly overpredict the observed warming signal….
…All but one (CGCM1) of these ranges is consistent with unity. Hence there is little evidence that models are systematically over- or under- predicting the amplitude of the observed response/ under the assumption that model-simulated GS signals and internal variability are an adequate representation (i.e. that natural forcing has had little net impact on this diagnostic)….
…Original model prediction under IS92a greenhouse+sulphate forcing…
…The SAR predicted an increase in the anthropogenic contri-bution to global mean temperature of slightly over 0.1°C in the five years following the SAR, which is consistent with the observed change since the SAR (Chapter 2). The predicted increase in the anthropogenic signal (and the observed change) are small compared to natural variability, so it is not possible to distinguish an anthropogenic signal from natural variability on five year time-scales….
http://www.ipcc.ch/ipccreports/tar/wg1/pdf/TAR-12.PDF
——————-
…During the early summer season, October to December, both models predict drying over the tropical western side of the continent, responding to the increase in high-pressure systems entering from the west, with MM5 indicating that the drying extends further south and PRECIS further east….
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch11s11-2-3-2.html
——————-
…The IPCC commissioned a Special Report on Emissions Scenarios (SRES). Four “marker scenarios” representing different world storylines are used to estimate emissions and climate change to 2100 (IPCC, 2000). Table 16-1 summarizes these climate projections for the polar regions. In almost all cases, predicted climates are well beyond the range of variability of current climate. …
http://www.ipcc.ch/ipccreports/tar/wg2/index.php?idp=599
——————-
…The chemical and physical properties of aerosols are needed to estimate and predict direct and indirect climate forcing….
…Modelled dust concentrations are systematically too high in the Southern Hemisphere, indicating that source strengths developed for the Sahara do not accurately predict dust uplift in other arid areas….
…For summertime tropopause conditions the range of model predictions is a factor of five for sulphate. The range of predicted concentrations is even larger for some of the other aerosol species. However, there are insufficient data to evaluate this aspect of the models….
Nick Stokes says:
August 25, 2013 at 4:45 pm
“You haven’t responded to my challenge”
========
What was it again ?
Do you agree that the IPCC has in the past made a prediction? The IPCC says so as I have pointed out repeatedly.
DAV I have to wonder whether you have comprehension issues. Can you read and understand? The IPCC have said that they have made a prediction in the past. Trenberth is making stuff up. DAV are you in fact Trenberth the Magnificent? 🙂
TRENBERTH LOSES HIS STRAWBERRIES
(see the courtroom scene in The Caine Mutiny)
As greenhouse gases still accrete
This captain of the climate wars
Is searching for the missing heat
That he believes the ocean stores
He’ll prove to all humanity
That danger in the deep resides!
The Kraken that he knows to be
That Davy Jones’ Locker hides
(The soul’s more heavy than we think
A truth that everyone must face
And to what depths a soul my sink —
Oh! To what dark and dismal place!
Does Captain Trenberth understand
That data offers no appeal?
He tumbles in his restless hand
Three clacking balls of stainless steel
MY GEOMETRIC LOGIC PROVES
HEAT TELEPORTS FROM PLACE TO PLACE!
FROM SKIES INTO THE DEPTHS IT MOVES
AND IN BETWEEN IT LEAVES NO TRACE!
When silent faces stare at you
Its always best to shut your jaw
But Trenberth is without a clue
As he believes they stare in awe!
Whether the IPCC CURRENTLY makes predictions or projections is neither here nor there. I was addressing Trenberth’s 2007 false assertion that:
I showed that this statement was false HERE.
The IPCC said:
How many more time do I have to point this out to DAV and Nick Stokes? Can they in fact read and understand?
In my book, and I’m sure this is true for much of the lay public, if the ‘projection’ is strong enough to demand political action, it is a ‘prediction.’ It’s bad enough they are wasting our tax money on this hoax, but now they are trying to weasel word their way to salvaging their credibility.
I can’t type though. 🙂 I meant:
“How many more times do I have….”
Pamela Gray says: August 25, 2013 at 2:43 pm
“Come on! “Might” versus “will” makes all the difference? Not in my book. I can predict it might rain and I can predict it will rain. I can project it might rain and I can project it will rain. Either set of sentences is an appropriate use of the word “predict” or “project” and are equivalent in meaning in this case”
_____
Absolutely correct.
If making fine distinctions between the use of the word ‘projection’ and the word ‘prediction’ underpins the claim that the IPCC does not make predictions, then the IPCC might just as well set to the task of counting the number of angels that can dance on the head of a pin.
Jimbo says:
August 25, 2013 at 5:27 pm
=======
Don’t you hate it, when you have the perfect comment in your head, then somehow the keyboard lets you down.
Jimbo,
Well, that’s an impressive guppy you have
stumbled acrosshauled in. You’re quite the fisher.Do you take all of the IPCC claims as true or do you pick and choose? Just because they said it doesn’t make it true. It’s not even remotely possible whoever wrote that doesn’t really know the difference between the two terms?
Anyway, I thought you said were going to ignore me. Pulling an IPCC saying one thing when you mean another?
Jimbo says: August 25, 2013 at 4:58 pm
“Nick, I see you are trying to divert me. You have failed. Address my point HERE. I will not answer any of your question because I asked you first so deal with it.”
I just did exactly that. You have persistently truncated Trenberth’s quote:
“In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers “what if” projections of future climate that correspond to certain emissions scenarios.”
And that’s what they did in making a 5-year “what-if” projection in the SAR. By the TAR, six years later, there was no longer any “what if”.
u.k.(us) says:August 25, 2013 at 5:00 pm
“What was it again ?”
To find where the IPCC is actually saying “We predict…”
DAV says:
August 25, 2013 at 4:55 pm
“To predict, one must use one or more universal generalizations in making an inference to the observation predicted.
Not at all. I can predict that the Lakers will win at least 3 out of their next 5 games without any universal generalizations or references to any observation. It may not be a good prediction but it’s still a prediction.”
Sir, must you insist on speaking with the vulgar? Physics is a highly ramified context. In that context, the word ‘prediction’ does not have the same meaning as it has for the man in the street. Kepler’s Three Laws of Planetary Motion allowed him to predict the motions of the planets. Galileo used those laws and his telescope to predict the phases of Venus. Newton could predict. Einstein could predict. But the claim that you will become transgender tomorrow is not a prediction and cannot be for the obvious reason that it is based on no laws of human nature.
If the IPCC or Trenberth say that they can predict then they must be using Arrhenius’ work which is highly confirmed in the laboratory though not in the atmosphere. By contrast, the IPCC has not found one new physical hypothesis (universal generalization) that is highly confirmed and Trenberth has never produced one.
For someone to present himself as a scientist and then, as a scientist, to offer a forecast is nothing less than cheating. Scientists do not forecast. A forecast is a WAG. Scientists predict or not. If a scientist wishes to announce that he is speaking with the vulgar then he may predict that you will be transgender tomorrow.
To DAV and Nick Stokes, yaaaaaan. I am going to bed. Continue to deny that Trenberth was wrong in 2007. The IPCC made a prediction. Trenberth said they never did. You decide on how honest you want to be. Sleep tight.
Just as there is an index for the stock market and a separate index for all the investment classes within the stock market, and just like there is an index for just about everything else we want to measure these days, what about a ‘prediction’ index for the IPCC reports. We could make it simple like how many times the word was used in the document or a little bit more complicated like how many times it is used per thousand of the total words. We could start with a baseline established by the first report and work our way through the subsequent reports to track the rise and fall in the use of the word. We could then analyse the next report (September this year), including in the headings and the captions and text in graphs, charts and diagrams. I won’t predict but I will not be surprised if such an ‘IPCC Prediction Index’ will show a slump in the next report that will be similar to the fall of indices in all the famous stock market crashes.
Nick Stokes says:
August 25, 2013 at 5:50 pm
“Jimbo says: August 25, 2013 at 4:58 pm
“Nick, I see you are trying to divert me. You have failed. Address my point HERE. I will not answer any of your question because I asked you first so deal with it.”
I just did exactly that. You have persistently truncated Trenberth’s quote:
“In fact there are no predictions by IPCC at all. And there never have been. The IPCC instead proffers “what if” projections of future climate that correspond to certain emissions scenarios.”
Can we get serious please? Can we stop speaking with the vulgar? Computer modelers create scenarios. To say that they are projecting into the future is simply to say that they wonder if the scenario might actually play out in the future. The fact that a scenario has been created in a computer run is no reason to call it a projection. No prediction has taken place – unless you want to say that any wild idea that anyone might have is a projection.
If you believe that a scenario generated by a computer model is about the future then I challenge you to show me the logical connection between that scenario and the future. What is that connection?
A Projection used to justify a Policy
is in fact a Prediction.
“The Intent travels with the bullet.”
http://www.legallyarmedindetroit.com/2009/11/detroit-cpl-class-transfer-of-intent.html
It is kind of like the difference between “Uncertainty” and “Risk”
http://mindyourdecisions.com/blog/wp-content/uploads/2008/04/ludic_fallacy.png
Uncertainty is only an academic study of possible outcomes.
Risk is when you have something to lose under a condition of uncertainty.
Top post still says “Kenneth” in a couple places. We’re talking about the same guy, right? If we’re going to insist that words have meanings, getting the man’s name right might be a good start…
Good grief, you could light a small city if you could capture the wasted energy resulting from all the keyboard tapping above.
“IPCC makes no predictions” is true. The models make the predictions. Pachauri, et al., are deceptively trying to have it both ways. They want to be viewed as leading the charge against what they promote as a threat to the world, but they want to be able to say they weren’t responsible for the falsehoods when the whole thing falls apart. That is, they want to be able to claim they were equally duped.
Except, they have systematically trumpeted only one note, and silenced others. And that makes them responsible. By selecting what to report, and suppressing the rest, they are co-conspirators and at least equally responsible. They are actually far more responsible than the modelers. That is because the models would have no standing, and no world stage to enable policy making. The models alone are not sufficient to wreck economies, take control over people’s lives, and reverse the gains of civilization.
No, the IPCC bear full responsibility for the USE of the model predictions. They have made them their own.
DAV says:
August 25, 2013 at 1:32 pm
“Technically, Kevin is correct. They are projections and not predictions.”
As I explained above, they are WAGs. For scientists to use the word ‘projection’ where one might expect the word ‘prediction’ is to cheat. If Kevin is willing to say that the IPCC makes WAGs and only WAGs then he will have reached the level of serious discussion.
Stephen Rasey says:
August 25, 2013 at 6:00 pm
Are you addressing the highly ramified context of physics or the man on the street? Trenberth presents himself as a physical scientist and the IPCC says that it reports on physical science.
Error in post: the last word in the paragraph should be ‘prediction’.
Theo Goodwin says:
August 25, 2013 at 6:00 pm
Can we get serious please? Can we stop speaking with the vulgar? Computer modelers create scenarios. To say that they are projecting into the future is simply to say that they wonder if the scenario might actually play out in the future. The fact that a scenario has been created in a computer run is no reason to call it a projection. No prediction has taken place – unless you want to say that any wild idea that anyone might have is a projection.
Rhoda R says:
August 25, 2013 at 5:25 pm
“In my book, and I’m sure this is true for much of the lay public, if the ‘projection’ is strong enough to demand political action, it is a ‘prediction.’ It’s bad enough they are wasting our tax money on this hoax, but now they are trying to weasel word their way to salvaging their credibility.”
I understand what you have written and I agree with it but I would like to suggest that you phrase it differently for clarity. The clarification is this: The IPCC offers projections as reasons for political action and, therefore, are treating them as predictions.
“When I use a word,” Humpty Dumpty said, in a rather scornful tone, “it means just what I choose it to mean—neither more nor less.” “The question is,” said Alice, “whether you can make words mean so many different things.” “The question is,” said Humpty Dumpty, “which is to be master—that’s all.”
Read more at http://quotes.dictionary.com/when_i_use_a_word_humpty_dumpty_said#L8lMLjT1HsHfPKYm.99
DAV says:
August 25, 2013 at 5:49 pm
This comment is so sheepishly evasive that you have lost rank among those who post to distract.
Theo Goodwin says: August 25, 2013 at 6:00 pm
“If you believe that a scenario generated by a computer model is about the future then I challenge you to show me the logical connection between that scenario and the future. What is that connection?”
Scenarios are not generated by computer models. Scientists are not expert at predicting future human decisions, so they invite discussion ( see the SRES process) and make projections based on a range of scenarios. The idea is that if you want to know what will happen, look at the scenario range and find the one that you find most likely. The AR4 says, in its glossary:
“Emission scenario: A plausible representation of the future development of emissions of substances that are potentially radiatively active (e.g., greenhouse gases, aerosols), based on a coherent and internally consistent set of assumptions about driving forces (such as demographic and socioeconomic development, technological change) and their key relationships. Concentration scenarios, derived from emission scenarios, are used as input to a climate model to compute climate projections. In IPCC (1992) a set of emission scenarios was presented which were used as a basis for the climate projections in IPCC (1996). These emission scenarios are referred to as the IS92 scenarios. In the IPCC Special Report on Emission Scenarios (Nakicenovic and Swart, 2000) new emission scenarios, the so-called SRES scenarios, were published, some of which were used, among others, as a basis for the climate projections presented in Chapters 9 to 11 of IPCC (2001) and Chapters 10 and 11 of this report. For the meaning of some terms related to these scenarios, see SRES scenarios.”
Trenberth is right. The IPCC makes projections for various scenarios, and describes in detail the scenarios that are used.
“For someone to present himself as a scientist and then, as a scientist, to offer a forecast is nothing less than cheating. Scientists do not forecast. A forecast is a WAG. Scientists predict or not. “
So what do all the Met offices do?
But of course scientists makes predictions subject to scenario. Newton says that if you apply a force to an object, you’ll get an acceleration proportional to the force. He doesn’t predict that you’ll actually do it – that’s the scenario.
Whether or not it is a computer model or a thought model, the “projection” of that model into the future provides predictions at any given point along the projection. End of story folks. As in: “The model projection at 10 years out predicts that…”