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….
Class dismissed.
The IPCC proposed multiple emissions scenarios and what the consequences of each scenario would be, complete with error ranges.
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-10-26.html
Now, you can call them predictions, projections, forecasts, prognostications, or WAGs, but not in any of them did temps flatten out for 17 years.
Whatever you wish to call them, they are wrong.
Nick Stokes says:
“Trenberth is right.”
Well, so much for Nick’s credibility. Because Trenberth is wrong.
“Thus climate projections and climate predictions are the same thing. This means that the climate projections need to be compared with real world data in the same manner as a prediction. Kevin [Trenberth] is not correct when he writes that the ”IPCC does not do forecasts“. They most certainly do.” ~Roy Spencer [from “Climate Misconceptions” post on his blog, ca 5-11-11]
Furthermore, Trenberth unprofessionally tried to upend the Scientific Method when he wrote:
Trenberth is trying to place skeptics in the impossible position of proving a negative, because the Null Hypothesis falsifies his belief system.
“Say anything” to keep that grant gravy train rolling, eh, Kevin?
No, I see many making this mistake. That is not the kind of projection the IPCC is doing. It sets various hypothetical start conditions, and uses the models as substitutes for its postulated mechanisms, and then takes the outputs as logical consequences of those starting conditions. So it says, “If it’s cloudy, it will rain.”
In this case, the start conditions (CO2 emissions and atmospheric content continuing to rise), it said it would get warmer. The projection is now falsified even as a projection! The start conditions did not, in fact, lead to the models’ logical output.
So it no longer matters if the temperature rise was a projection or prediction; the models are invalidated completely. “Unfit for purpose.”
Nick Stokes says:
August 25, 2013 at 6:43 pm
“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.”
===========
Very good, I like it.
Edit: “In this case, given the start conditions:
Let us not forget that the IPCC also predicted/projected/forecasted/prognosticated/WAG’ed about ice extent too. Keep your eye on the SH:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-10-13.html
And the reality:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.antarctic.png
It matters little what they call it. They put down numbers with error ranges and they reality keeps falling outside of their error ranges. That’s called being wrong.
The fact is that we can’t account for the lack of predictions at the moment and it is a travesty that we can’t.
Perhaps the words relating to predictions have had their meanings altered by McQuarie dictionary.
For non-Australians, it is an in-house joke.
False.
One of the may crucial fictions and falsehoods the IPCC depends on is that the WG1 does the real science, and everything flows from that. In reality, WG2 & 3 are preparing their “reports” simultaneously with WG1’s work, and simply edit and snip (and sometimes demand rewrites) to make sure the “reported” WG1 output supports the precooked conclusions.
Dear Anthony / Moderators,
Second paragraph, last line: I wonder how may times the word “prediction” will be used in the upcoming AR5?
Should be “many”.
REPLY: Fixed thanks, Anthony
An issue that plagues the place where science and politics meet is that Kevin Trenberth knows the IPCC can’t credibly predict anything but the language used to convince politicians says otherwise.
Cleverly slanted redefinitions of existing words is a common trick in the more political arts subjects. To see a scientists resorting to this kind of thing is sad. Has he no better argument than semantic jiggery pokery.
From IPCC AR4 WG1 8.1.1
A specific prediction based on a model can often be demonstrated to be right or wrong, but the model itself should always be viewed critically. This is true for both weather prediction and climate prediction. Weather forecasts are produced on a regular basis, and can be quickly tested against what actually happened. Over time, statistics can be accumulated that give information on the performance of a particular model or forecast system. In climate change simulations, on the other hand, models are used to make projections of possible future changes over time scales of many decades and for which there are no precise past analogues. Confidence in a model can be gained through simulations of the historical record, or of palaeoclimate, but such opportunities are much more limited than are those available through weather prediction.
So, by their own words, the only difference between a prediction and a projection is that the former can be verified by actual events, while the latter cannot. OK fine. But the fact of the matter is that since the IPCC started making “projections”, decades have passed. By their own definition, since we now have actual emissions and actual temperatures to compare to, the “projections” are no longer projections, they are in fact predictions that can be verified.
And they are wrong.
Dear Thomas Traill,
A is A.
If it comes true it was predicted, if it doesnt it was just a projection based on assumptions, and the science has moved on, and the models have been updated etc etc. It’s a wonderful thing climate science, it can never be wrong.
old44 says:
August 25, 2013 at 7:04 pm There is a whole new greenfield opening for Macquarie Dictionary here.
Lets quantify the paramaters.
When does the concept of ‘forecast’ or ‘Projection’ become a ‘prediction’?
a)at 10% confidence
b)at 50% confidence
c)at 95% confidence
d)at 97% confidence
e)some of the above
f)all of the above
Hint The IPCC had a 97% confidence they are right about most things.
Pamela Gray says:
August 25, 2013 at 1:38 pm
Seems to me they are splitting hairs of the length and width found on the anal end of a gnat.
All of my life I have respected the institution of scientific methodology, among many things, as being the most precise in the use of language. I thought that scientist used Latin for the very specific reason that it was, for the most part, dead and therefore more resistant to misinterpretation.
But in my life I have watched the protestors of the sixties morph into the administrators of the same ‘higher’ institutions from where they spawned. Now with the added power of crony capitalism via the incestuous student loan-tuition relationship and the totalitarian power of determining who may teach and what they may teach at their madras’s, err, schools. (Kate’s expression ‘The opposite of diversity is university’ applies well in this day. Imagine a campus protest now). Instead of environment being an offshoot of hard science it’s a funding food fest for the most emotive press release that can push the attack on realist that day. Careers, reputations, tons of financial resources and the well being of our progeny are wasted for ‘feel-good’ exploited for political ends.
I do understand that civilization is something very new to our very recent species. And I believe that humans and their brains with the resultant civilization are still evolving. Religions and superstitions die hard, but they do die and we have a better standard of living and life expectancy than ever. But the power du jour is determined to reverse all of that with yet another religion( Faith before FOI ).
So in today’s episode we have the Trenberths and the Stokes asking us to invest trillions we don’t have on the distinction between ‘prediction’ and ‘probability’ with the ‘promise’ that the ‘Anthropocene’ will look like one of the bands in the Grand Canyon. Now that was CLIMATE CHANGE you could believe in and fast.
What Nick is trying to say is that the IPCC never makes any predictions, they make projections based on emission scenarios. However, according to Nick, it is acceptable to refer to these projections as predictions if at a later date the known emissions actually fall within the emission scenario range. If Nick is willing to call these predictions, then it is seems to me the IPCC does make predictions even though they are conditional predictions. I wonder if Trenberth would balk at the term “conditional prediction”?
Is the ‘Statement for Policymakers’ based on predictions or probabilities?
roncram says: August 25, 2013 at 8:08 pm
“I wonder if Trenberth would balk at the term “conditional prediction”?”
Probably not. Here’s how the AR4 glossary defines projection:
“Projection: A projection is a potential future evolution of a quantity or set of quantities, often computed with the aid of a model. Projections are distinguished from predictions in order to emphasize that projections involve assumptions concerning, for example, future socioeconomic and technological developments that may or may not be realised, and are therefore subject to substantial uncertainty.”
Sounds like conditional prediction. Science is all about these. I gave the example of Newton – if you apply a force to a body and it will accelerate proportional to the force. It doesn’t say you will do that, or how much force – that’s the scenario. Then when you check the prediction, when you know how much force and how much mass, you can test it as a prediction. And of course, it generally won’t be right – friction etc. The scenario didn’t exactly apply. Doesn’t mean Newton’s laws are useless.
Trenberth:
the science is settled or done and now is the time for action
================================
great. if the science is settled, then what possible need is there for climate scientists? there is nothing left for them to discover. they should all be made redundant and engineers hired in their place to make things happen.
take the 100 billion dollars or so spent on climate science and redirect this to climate engineering. you want it hotter, we will make it hotter. you want it colder, we will make it colder. and for a lot less $$ than currently being quoted. and we will turn a profit at the same time, so that taxpayers and energy consumers aren’t stuck with the bill.
right now farmers and loggers are getting billions of dollars in free CO2 fertilizer, which is being passed along to the consumers in the form of lower prices. Its time we started kicking some of this back to the power companies, so they can cut energy prices even further, increasing the amount of airborne fertilizer and further increasing food supplies, further lowering food prices and energy prices.
That will create a true peace dividend. Low energy prices and low food prices. Not the phoney peace we have today, propped up by billions of $$ in handouts. Take this dividends and kick start the space program. Add reflectors in space to light the night and open up the Arctic to exploration. Use the reflectors to shade the deserts and restore the rains where needed. Sure there will be winners and losers, but overall there will be winners. Bring back the spirit of exploration that created the world we know, before we became afraid of own shadows.
Rigidly speaking (out of kindness granting Trenberth a premise) the models make “projections” not “predictions”.
But the IPCC uses those projections to make predictions. From the projections of the models the IPCC leaps to making predictions.
Trenberth relies on his definition of “model” to claim that models do not make predictions but projections — but the IPCC does not function like — is not a “model”. His error in critical thinking is to make the assumption that “climate models” and the IPCC are equivalent in nature — that the conclusive process at the IPCC is equivalent to “modeling”.
The conclusive process at the IPCC is, as we all know, emotional (and the emotions are quite base).
The IPCC does not just run the numbers like a computer model. We can say of a computer model — garbage in, garbage out.
But of the IPCC, which does not function like a computer, we can say — garbage in plus garbage people equals self-aggrandizing, self-benefiting incompetence spewing forth as “science”.
Adolf Hitler said something like — Trust only your heart, your heart will never lead you astray.
The warmists completely trust their hearts. They JUST KNOW they are doing the right and necessary thing. Their emotions tell them so.
Eugene WR Gallun
.
Nonsense. The projection is the entire thing from now into the future. A single point along that projection is a prediction. And when that given point in time (pick one, it doesn’t matter) occurs in real time and is now, the prediction can be wrong, shades of wrong, shades of right, or right. That condition of the point (wrong-kinda wrong-kinda right-right) along the projection does not change the thing from a “projection” to a “prediction” just because it is right, or wrong for that matter. It simply says that the prediction for that projection is what it is. The model got it right or did not at that point. So far, there have been lots and lots of failed predictions along the projection of these models. Every day that passes is another failed predicted point of that projection. And it is mighty entertaining to watch!
Pamela Gray says:
August 25, 2013 at 6:46 pm
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.
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agreed. for those scenarios where reality matches the assumptions. So for example if the IPCC makes projections based on CO2 growth of 5,10,15%, and the observed increase is 10%, then the 10% projection is indeed a prediction.
So a prediction is a realized projection. Once the projection is realized, the accuracy of the prediction can be compared with reality for accuracy. Thus, the realized IPCC projections of the past can now be analyzed as predictions to see if they are falsified.
And they are. In spectacular fashion the IPCC models are running hot for those scenarios where forcings match observations, which should be next to impossible if it is due to chance, given the number of models and the number of simulations. which leads us to conclude that the error is not due to chance. rather, the models are biased hot, or in some other fashion fundamentally flawed.