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
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…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
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…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
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…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….
I am still waiting for a Warmist to address the statement from the IPCC which commented on its own report:
The IPCC has said that its Second Assessment Report made a prediction, therefore the IPCC in the past made a prediction, contradicting Trenberth who said:
I have shown that Trenberth’s statement is as false as they get.
This is how he gets out of it…
That is a fairy tale. See my comment HERE. Would like to repeat your statement that:
Can you read?
Just because a report echoes something without showing the source, particularly in a summary, that doesn’t mean the organization owns it.. People conflate the two all the time so their use of words like will and prediction is just plain sloppiness or maybe a case of making the report sound more “scientific” (IOW: puffery).
Jimbo says: August 25, 2013 at 2:57 pm
” What’s your take on this, you may have missed it earlier. The IPCC said:”
So the TAR spoke of a prediction in the SAR about the next five years. Well, if you want to be technical (and this is a very nit-picking post) they are correct. IPCC projections are predictions subject to future changes (fossil fuel burnt etc) that they do not claim to predict, but they can calculate for scenarios. The TAR did know what happened to forcings in the five years since SAR, so (if it matched the scenario) it is then correct to refer to it as a prediction.
DAV says:
August 25, 2013 at 1:45 pm
Contexts will matter. We have allowed TV weather people to say that they forecast because we all knew that they make WAGs. Scientists who say they forecast are trying to have it both ways. Prediction is a very well concept within scientific method. To predict, one must use one or more universal generalizations in making an inference to the observation predicted.
Nick Stokes says:
August 25, 2013 at 2:48 pm
“I see quoted many uses of the word “prediction”, perhaps not always carefully distinguishing from projections. But no quotes where the IPCC actually says “We predict …”.
The distinction Trenberth is referring to is just common sense. Scientists can hope to say how the Earth will respond to human actions. But they can’t, as a matter of science, predict what those actions will be. So they calculate conditional responses based on suppositions of what we might choose to do. It’s our choice.”
The Stokesian sophistry between predictions of which there are none and projections of which there are as many as GCM model runs, always ends with saying that while a chaotic system cannot be predicted, climate is said to be a boundary condition problematic; which leads us to the conclusion that they may not predict a definitive STATE but they DO predict future boundary conditions. Otherwise why would they demand to do anything in the first place. They predict a range.
Only when their GCM’s fail as abysmally as now come the Stokes’ out of the woodwork with their attempts at sophistry.
DAV, I am going to ignore you because you ignored my challenge. You have lost the argument now it’s time to go to bed. WUWT is for adults and not for children.
———–
Moving along…………
Maybe Trenberth believes that the IPCC has never made made predictions but he is aware of predictions.
Nick Stokes says:
August 25, 2013 at 4:14 pm
“So the TAR spoke of a prediction in the SAR about the next five years. Well, if you want to be technical (and this is a very nit-picking post) they are correct.”
It’s too nitpicky for the sophist; maybe he wants it more hand-wavy? Hey let’s throw some trillions away, there’s a fuzzy mirage at the horizon!
Theo Goodwin says:
August 25, 2013 at 12:54 pm
One reason is that they are terrified of falsification.
=========
Too true. Einstein publicly made 3 predictions to test general relativity. None of these predictions were obvious at the time. All have been verified to a high degree of accuracy.
Here is what he had to say at the time:
The chief attraction of the theory lies in its logical completeness. If a single one of the conclusions drawn from it proves wrong, it must be given up; to modify it without destroying the whole structure seems to be impossible
What a contrast with climate science, where every failed prediction builds on a long history of failed predictions, and yet another adjustment is made to rationalize the failure.
The straight line 0.5C/century warming observed since the LIA outperforms the billion dollar predictions of the IPCC ensemble models.
http://scienceandpublicpolicy.org/images/stories/papers/reprint/present_halting.pdf
Oooops!
Pamela Gray says:
August 25, 2013 at 12:39 pm
Hey Trenberth! It looks like someone has found the missing predictions you say are not there! Too bad you can’t find your hotspot.
Trenberth and the rest of the Gorebull Warmers have had their hands in their hotspot past their elbows for years!!!
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
Whether there are real predictions based on real data or simply predictions/projections dependent on a set of scenarios is not relevant. Common people do not make this distinction when forming their opinions about climate. Governments and politicians know this and exploit it to their own benefit. The lack of emphasis that these predictions/projections are based on many different “what if” situations that most likely will never happen is a lie by omission. The damage is done. I place the main fault at the feet of a supposedly free press that should be the guardians of truth. But alas, sales numbers today are based on dramatic headlines and stories not the truth.
If “they are correct” then is Trenberth wrong when he said?:
Trenberth was clear and so was the IPCC. Their two statements are in direct conflict. You really do need to take a break Nick, have a Kit Kat.
Nick Stokes says:
August 25, 2013 at 2:48 pm
“I see quoted many uses of the word “prediction”, perhaps not always carefully distinguishing from projections. But no quotes where the IPCC actually says “We predict …”.
============
Shame. You know better. The IPCC mandate is to report, not create the science.
Nick Stokes says:
Nick, what forum are you responding to? Yes they did say, “WE”–or do you not know what SAR is?
Jimbo says:
Let me put the two statements together for better understanding:
I can’t understand anyone trying to defend this. Come on now!
This has to be the best prediction yet:
Dr. Virginie Guemas et. al. – Nature Climate Change – 2013
The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models,
Didn’t the reviewers gently point out that you don’t predict the past?
Why does anyone take them seriously? Money and stupidity. I think we can no longer be charitable and blame ignorance.
Another illustration of Confucius’ concern for the rectification of names. He said that if words did not have a clear and agreed upon meaning, that would lead to moral decay. He got that right.
I have no hope this will end any time soon. The corn- ethanol program is alive and well, after all.
Jimbo says: August 25, 2013 at 4:24 pm
‘If “they are correct” then is Trenberth wrong when he said?:
In fact there are no predictions by IPCC at all. And there never have been.
Trenberth was clear and so was the IPCC.’
What Trenberth actually said was:
“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 he’s right. The IPCC says that is what they are doing, and they spell out the scenarios in great detail.
You haven’t responded to my challenge – instead of a whole lot of quotes of people talking about predictions, find an instance of the IPCC actually making one. Using words like “we predict…”. That’s what you need to refute Trenberth.
Questioner (Q) – Do you predict a rise in global temperatures due to humankind use of fossil fuels ?
Answerer (A) – No. On the basis of our models we project that it is possible that global temperatures will rise due to increased CO2 concentration in our atmosphere.
Q – In light of the latest observations that there has been no statistcally significant global warming in the past seventeen years despite increasing CO2 concentration do you maintain that your projections are of concern?
A- Yes we do. We believe that the underlying trend is masked by natural trends and by the absorbtion of heat by the oceans.
Q – On the basis that water hotter than its surroundings ( above 4 degrees Celsius) will rise can you expalin why surface sea temperatures have not risen commensuralty?
A- The warmer water is mixed at deep oceanic depths and so is being absorbed.
Q- Hmm..If there is no definite warming and you are unwilling to make a prediction what measures in your opinion should be undertaken?
A- Use of fossil fuels should be constrained if not elimated. We believe that the most effective constraint will require the use of fossil fuels to be uneconomic.
Q- This will stop your projections becoming predictions?
A- Possibly. We do not make predictions.
Q – So you wish to impose taxes on the general populace to offset an unsubstanitated projection?
To quote the “Kaiser Chiefs” song, ” I Predict a Riot”
Jimbo says: August 25, 2013 at 4:38 pm
“I can’t understand anyone trying to defend this. Come on now!”
You haven’t answered my defence. As Trenberth says, the IPCC makes conditional (“what if”) predictions. When the conditions are known to be satisfied, they become unqualified predictions, and can be referred to as such. That was the case here, six years after the SAR..
Nick Stokes you have huffed and puffed but you have not addressed my point HERE. Is the IPCC wrong or Trenberth? This really is a simple question and requires a simple answer. Are you up to it? I await your response. Thanks.
Theo Goodwin,
Scientists who say they forecast are trying to have it both ways.
I agree that would be bad but give Kev his due: he said the IPCC doesn’t make predictions and that is true. He never said HE doesn’t make predictions. Not that the little insert from Jimbo quoting Kevin show even he can conflate the projection with prediction. The way the GCM’s are built amounts to a curve fit (that’s what all that “tuning” does) but, past the end points, the result is a projection.
The IPCC is not in a position to make predictions even if they claim they do.
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.
All this flapdoodle about semantics is indicative of not only how shaky the ground under the alarmists is, but how well aware they are that they have no credibility outside of their own little circle.
Sociopaths are not put off by inconsistencies in their stories, however. They simply ignore them when they are pointed out to them. They obviously firmly believe simultaneously both that the IPCC made predictions and that it did not. Typical Ingsoc doublethink, right out of Orwell.
And of course it will always be “projected” or “predicted,” never “demonstrated by empirical data.”
Empirical data? We don’t got no empirical data! We don’t need no stinkin’ empirical data!
Sigh . . .
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. Can you do it? Can you reconcile the two contradictory statements?