Spectator Magazine front page spread: 'Relax: Global Warming is a myth'

[lomiller]

And an observed value of T = 15 +/- 0.1 C invalidates models A and B, right?

No an observed value of T = 15 +/- 0.1 C would fall within the error of both models.

What the deniers tend to do with climate models is conflate them with weather models. Weather is chaotic, but it’s randomly distributes (approximately normal distribution) around an underlying trend. The models (including separate runs from the same model) do the same, but since the underlying attractor is defined by the physical characteristics of the system it will remain the same despite random variation in the realization. Weather models on the other hand seek to predict a single realization rather then the attractor.

By way of analogy lets say you have a perfectly fair 6 sided die. Any single role can be any integer from 1 – 6 but as you role more often their average should converge on 3.5. “Weather” in this analogy is the single role; “climate” is the average of lots of rolls.

Now let’s say you wanted to model the die. The “weather” model would try to predict the exact outcome of each roll. The “climate” model wouldn’t try to predict the individual roles, but merely get close enough to the basic physics of a fair die to get the correct average of 3.5 +/- over the course of lots of rolls.

[Wangler]

No an observed value of T = 15 +/- 0.1 C would fall within the error of both models.

What the deniers tend to do with climate models is conflate them with weather models. Weather is chaotic, but it’s randomly distributes (approximately normal distribution) around an underlying trend. The models (including separate runs from the same model) do the same, but since the underlying attractor is defined by the physical characteristics of the system it will remain the same despite random variation in the realization. Weather models on the other hand seek to predict a single realization rather then the attractor.

By way of analogy lets say you have a perfectly fair 6 sided die. Any single role can be any integer from 1 – 6 but as you role more often their average should converge on 3.5. “Weather” in this analogy is the single role; “climate” is the average of lots of rolls.

Now let’s say you wanted to model the die. The “weather” model would try to predict the exact outcome of each roll. The “climate” model wouldn’t try to predict the individual roles, but merely get close enough to the basic physics of a fair die to get the correct average of 3.5 +/- over the course of lots of rolls.

Soo, you are saying that climate modeling is like rolling the dice? ;)

[aleCcowaN]

No an observed value of T = 15 +/- 0.1 C would fall within the error of both models.

What the deniers tend to do with climate models is conflate them with weather models. Weather is chaotic, but it’s randomly distributes (approximately normal distribution) around an underlying trend. The models (including separate runs from the same model) do the same, but since the underlying attractor is defined by the physical characteristics of the system it will remain the same despite random variation in the realization. Weather models on the other hand seek to predict a single realization rather then the attractor.

By way of analogy lets say you have a perfectly fair 6 sided die. Any single role can be any integer from 1 – 6 but as you role more often their average should converge on 3.5. “Weather” in this analogy is the single role; “climate” is the average of lots of rolls.

Now let’s say you wanted to model the die. The “weather” model would try to predict the exact outcome of each roll. The “climate” model wouldn’t try to predict the individual roles, but merely get close enough to the basic physics of a fair die to get the correct average of 3.5 +/- over the course of lots of rolls.Thank you for the explanation. I must confess it surprises me a bit that a climate model could be considered valid just without checking if it can first predict normal weather -I mean predict a weather that looks normal, not predicting the weather-. Why is it not predicting weather a normal check for throughly climate prediction? Mustn't it be so?

My "experience" -haha! too big word!- with such models is pretty funny, as in times they develop VB capabilities in M. Excel I started to play with "models" about regional development and enterprise. I even "modeled" some businesses I was thinking to start with detailed interactions, delays and cash flows installed everywhere, just to finally understand that putting a big client who refused to pay his bill filled all columns with the red colour of bankruptcy. I learned a lot from those models. I learnt that there's a minimal capital you need to protects you from a random failure, that there is a rate between capital and each bill that moves the center of the business from one point to other. Even I made one "á la Montecarlo"simulation in a PERT, to learn myself and show the students how non-critical branches can randomly result in very critical with dyer consequences.

Computer modeling is powerful indeed, but I think that the whole business, not the sole physics and basic premises, is what make them valuable. I want to ask now everyone, are there Internet links where I can found more info about the climate models that support conclusions about GW? I mean, serious, organizational links -not the usual gruesome-adjectivated loosely-founded crap some people like to flood with-

[TellyKNeasuss]

You actually fantasize that your question answers my question?

I think that the point of my reply was obvious.

[TellyKNeasuss]

It is my understanding that the IPCC presented forecasting based upon various models created by assorted researchers.

The purpose of this forecasting was to lay a foundation for consideration of potential policy direction.

This type of process was what that paper was directed at, if I understand correctly.

The real question is: did the IPCC tell the climate modelers how to develop their models or did the IPCC use the results of climate models that had been developed independently? If the answer is the latter, then writing an article about the IPCC's forecasting methodology is a strawman.

[lomiller]

Thank you for the explanation. I must confess it surprises me a bit that a climate model could be considered valid just without checking if it can first predict normal weather -I mean predict a weather that looks normal, not predicting the weather-. Why is it not predicting weather a normal check for throughly climate prediction? Mustn't it be so?

I’m not really sure what you are trying to say. Getting realistic distribution of temperatures around the trend is an important test for climate models. Even though it’s not their primary purpose climate models actually do a decent job of predicting the weather over the short term.


Computer modeling is powerful indeed, but I think that the whole business, not the sole physics and basic premises, is what make them valuable.

Keep in mind there is a distinct difference between physical and statistical models. Climate models are of the physical variety.


I want to ask now everyone, are there Internet links where I can found more info about the climate models that support conclusions about GW? I mean, serious, organizational links -not the usual gruesome-adjectivated loosely-founded crap some people like to flood with-

I’d suggest reading realclimate. While not an organization per say, on of their primary contributors Gavin Schmidt is on of the chief climate modelers for NASA and has published about as many papers on the subject as anyone.

http://www.realclimate.org/

[aleCcowaN]

I’m not really sure what you are trying to say. Getting realistic distribution of temperatures around the trend is an important test for climate models. Even though it’s not their primary purpose climate models actually do a decent job of predicting the weather over the short term. The last is what I wanted to check. Fair enough. I gonna read about those models a bit.

I’d suggest reading realclimate. While not an organization per say, on of their primary contributors Gavin Schmidt is on of the chief climate modelers for NASA and has published about as many papers on the subject as anyone.

http://www.realclimate.org/Thank you a lot! I will visit it.

[shadron]

I am referring to the given fact that no climate model makes any credible long-term prediction whatsoever, in contrast to what you happen to claim.

See for instance at Climate Science:

http://climatesci.org/2008/07/31/on-the-credibility-of-climate-predictions-by-koutsoyiannis-et-al/

Abstract:

“Geographically distributed predictions of future climate, obtained through climate models, are widely used in hydrology and many other disciplines, typically without assessing their reliability. Here we compare the output of various models to temperature and precipitation observations from eight stations with long (over 100 years) records from around the globe. The results show that models perform poorly, even at a climatic (30-year) scale. Thus local model projections cannot be credible, whereas a common argument that models can perform better at larger spatial scales is unsupported.”

Extract from the conclusions:

...

A fundamental and societally relevant conclusion from this study is that the use of the IPCC model predictions as a basis for policy making is invalid and seriously misleading.

Let me know if anything is still unclear to you in the given statements.

See your quote and raise you one:


So what did Koutsoyiannis et al do? They took a small number of long station records and compared them to co-located grid points in single realisations of a few models and correlate their annual and longer term means. Returning to the question we asked at the top, what hypothesis is being tested here? They are using single realisations of model runs, and so they are not testing the forced component of the response (which can only be determined using ensembles or very long simulations). By correlating at the annual and other short term periods they are effectively comparing the weather in the real world with that in a model. Even without looking at their results, it is obvious that this is not going to match (since weather is uncorrelated in one realisation to another, let alone in the real world). Furthermore, by using only one to four grid boxes for their comparisons, even the longer term (30 year) forced trends are not going to come out of the noise.


http://www.realclimate.org/index.php/archives/2008/08/hypothesis-testing-and-long-term-memory/

[shadron]

- that the climate is somehow inherently indescribable in mathematical terms, and so a computer program cannot be adequately specified?
- or is it that you mistrust the analysis to be able to define the problem well enough that a suitable mathematical expression can be chosen to encompass the physics?
- or that the up front analysis is wrong, and so the chosen algorithm is inadequate?
- or that the method is incorrectly coded and yields bad answers?
- or that the coder deliberately can cheat and pull a value out of a random number generator to deliver? A
Did you read what I stated? It is all of them you listed.

Oh, too bad. I guess that means we cannot pare it down to a matter of fact because your shotgun approach, your thrusting around trying to find a weakness (as I put it in my previous posting) is pointing at everything from observations of climate in action to dividing by zero in the code. But wait, this changes...

Yes the problem is the modeling cannot be done and the "cheating" can easily be done through "unconscious" bias. What goes into a computer climate model is based on the subjective opinions of the scientists creating them.So now it's the science. (BTW, my questions about conspiracies were triggered by your use of the word "cheating". I'm glad you cleared that up.) You think there is no science in climatology. It is all randomness, no objective cause/effect relationship that can be exploited to determine how things might go in the future, or even to explain the past. Seems odd to me, as there are damned few, perhaps zero, physical processes which aren't amenable to the scientific method. Ah, but wait yet again...

Every model produces distinctively different results. You are confusing "close-enough" with the same. But they average within the same linear trend. Because they all include similar CO2 climate forcing equations.Wow - so you really do gripe because they are not identical, as pointed out by SezMe. But they are identical enough to predict global warming. But they're wrong because they all use the same "CO2 forcing equations". So maybe now we are focusing on the culprit, and, as opposed to what you say above, you believe that the forcing equations are either wrong or are incorrectly modeled. I thought that might be the case, based on:

Scientists who rely on computer climate models simply do not understand the limitations of the simulations. It is simply a matter of ignorance.So you, as a computer programmer, see fit to call climatologists ignorant in their specialty (not yours, since this is not a matter of analysis, design, coding, following a spec, or incorrect algorithm use). That's some weak stance. But, to get back to those CO2 forcing equations, by which I presume you mean the radiative forcing equations as applied to the gas CO2. They are defined by:

The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values.(http://www.agu.org/pubs/crossref/2003/2003GL018141.shtml)

Now let's get specific: what in this theory of radiative forcing do you object to? Is it the way of measuring incoming irradience, or the way in which the balance is computed, or what? These forcing equations and values are derived in a lab, but are certainly valid, as valid as the temperature at which water turns to ice at STP. What, precisely, are you objecting to? What would you replace the forcing equations with? Get specific, PopTech. We all want to hear about it.

[CapelDodger]

The real question is: did the IPCC tell the climate modelers how to develop their models or did the IPCC use the results of climate models that had been developed independently? If the answer is the latter, then writing an article about the IPCC's forecasting methodology is a strawman.

Indeed it is. One often hears of "the IPCC models" but the IPCC has no models. It exists to collate the published science from institutions around the world and present a synopsis for the benefit of politicians - most of whom are not scientists, nor expert in anything except politics and governing (if that).

However, for the IPCC to be presented as the Central Committee of the Global Climate Hoax it has to be presented as doing the modelling. This provides a story simple enough for the target audience to comprehend.

[CapelDodger]

I think that the point of my reply was obvious.

True, but that doesn't matter to Herzblut. Like mhaze, when he has nothing to say (which is usually) he says anything.

[Wangler]

The real question is: did the IPCC tell the climate modelers how to develop their models or did the IPCC use the results of climate models that had been developed independently? If the answer is the latter, then writing an article about the IPCC's forecasting methodology is a strawman.

My understanding is that the IPCC used the results of these independent climate models to forecast future trends, primarily to assist policy decisions. I think that that makes the article's slant appropriate.

[CapelDodger]

My understanding is that the IPCC used the results of these independent climate models to forecast future trends, primarily to assist policy decisions. I think that that makes the article's slant appropriate.

The predicted trends are in the published science. The IPCC makes no forecasts of its own, it summarises the forecasts available in a manner accessible to non-experts. That's its remit.

It's an interesting read.

[macdoc]

Link to the IPCC reportts
http://www.ipcc.ch/

and this is the update to that...

http://www.realclimate.org/images/cover_copenhagen_synthesis.jpg
even more current reading

http://www.pik-potsdam.de/news/press-releases/files/synthesis-report-web.pdf

[Wangler]

Link to the IPCC reportts
http://www.ipcc.ch/

and this is the update to that...

http://www.realclimate.org/images/cover_copenhagen_synthesis.jpg
even more current reading

http://www.pik-potsdam.de/news/press-releases/files/synthesis-report-web.pdf

I have perused a large part of the reports, but I admit not reading from cover to cover.

[macdoc]

The Synthesis report is not a hard read as it's only 20 pages with lots of charts - it's really an executive summary

....the IPCC is a bit of a trudge but also has summaries.

[Herzblut]

Since were into opinions of people my impression of you is as someone who has no scientific background whatsoever.
You're talking about your opinion, while I am referring to people's self assessments.