Discussion > Non-Chemtrail discussion on Warmist Trolls
EM - thanks for that.
Yes, the climate system is big and unwieldy and not conducive to precise measurement. It's not that that makes CS not science.
It's the practices of its practitioners and what is presented to us
- talking about the output of unvalidated models as 'evidence'.
- using concepts that can only exist within computer models ('radiative forcing') as if they have physical meaning
- ignoring facts that invalidate the work if they are inconvenient (the proxy decline).
- etc
There may be bits of CS that *are* science. The problem is "give a dog a bad name and it sticks".
Martin A
Entropic Man
Can I recommend this article from Jo Nova's Blog it has an interesting collection of graphs.
http://joannenova.com.au/2014/03/what-the-csiro-state-of-the-climate-report-forgot-to-tell-you/
Ross Lea
Can I also recommend this short YouTube video. On historic climate change.
https://www.youtube.com/watch?v=OP3bRZl8Xmk
Entropic Man
Hi Entropic Man
Before I go to your link how historic is historic in this instance?
Thanks
SandyS
Entropic Man
Sorry I seem to have signed myself as you in my hast. Please forgive the error. Here is another Youtube 12 min. video with the skeptics case.
https://www.youtube.com/watch?v=0gDErDwXqhc
I hope you will study the three items I have pointed to.
Ross Lea
SandyS
My apologies to you also
Ross Lea
Sandy S, Ross Lea martin A
Sandy S
It is no accident that Archbishop Usher dated the creation of the universe to 4004BC. He missed the actual date by nearly 14 billion years, but his count of the generations since Adam hit the invention of written records more or less spot on.
That dates the beginning of recorded history to 6000 years ago. Temperatures then were 14.4C +/- 0.2C, pretty close to today and going down (Marcott et al ).
We are now in the upper quartile of that range, 14.6C +/- 0.1C (GISS) and rising.
Ross lea
Your link to joannenova contains some bullshit graphs. The long term graph fails to show the pre-Cambrian snowball Earth and her recorded temperature graph somehow makes 0..16 + 0.15 +0.16 add up to 0.8. You asked why I tend not to respond to your links. There seems little point when their signal/noise ratio is so poor. I gave up on WUWT years ago.
Martin A
That sounds perilously close to an ad hom attack.
1) How do you think models should be validated? How about this? The paper describes model runs which included real world values for ENSO and gets much closer to actual temperatures than the usual randomised natural variation.
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12534.html
2) "radiative forcing" This is the change in energy input to the climate system due to an environmental variable. You cannot put it on your bench, but that does not mean it lacks physical reality. You cannot put the rate of heat generation of a chip on your bench either, but if you don't take it into account the magic smoke escapes.
3) I presume you mean the tendency of European tree rings to under read the temperatures after 1960.
For more detailed discussion try D'arrigo's paper.
www.homogenisation.org/files/private/WG1/...E)/darringo_etal.pdf
Entropic man
EM -
That sounds perilously close to an ad hom attack.
Do you really think so? I don't see how saying that saying that the way climate science is practised disqualifies it as science is in any sense verging on 'ad hom'. Any more than saying that the RBS was badly managed could be considered an ad hom attack on Fred Goodwin. If you still think so, please help me understand why you think that way.
1) How do you think models should be validated? Is that a real question? The answer has multiple layers. It's like developing any other piece of high-quality large-scale software. You can't wait until it's finished and then run a test or two and say "It's ok, it works fine". Especially when you only have one short example of reality to compare against. And doubly especially if that same bit of reality was used in the 'parameterisation' of the model.
2) You cannot put the rate of heat generation of a chip on your bench If I understand you what you mean right, you certainly can. Some other time I'll elaborate on my objections to 'radiative forcing' although I'd have thought that the definition (below) would make clear why I said it's a concept that can only exist within a computer model.
3) try D'arrigo's paper. OK but not tonight. I suspect it was written after the event but we'll see.
à bientôt
_____________________________________________________________________________________
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.IPCC
Martin A
EM - my tendency to be mealy-mouthed resulted in my not giving a clear answer to your question 1). Sorry about that.
The answer I should have given is "In the case of GCM's, it cannot be done".
The validation of a computer model of a nontrivial physical system has to be done at a number of different stages of its construction, using knowledge and information at different levels. If the system cannot be signed off at one level, there is no point in proceeding to a more detailed level.
In the case of climate science (GCM's) the information available is inadequate to permit *any* stage to be signed off as an adequately accurate simulation to produce meaningful results.
Is there any other branch of science that uses computer models in the way CS does? (Describing their output as 'evidence' despite their not having been validated, and so on.)
Martin A
Entropic Man,
Just 6000 years would have been fine. I'll have a look over the weekend if the weather permits, lovely and sunny here and apparently the moon is good for onion planting and digging is still needed.
SandyS
Entropic Man
Before I go
The long term graph fails to show the pre-Cambrian snowball Earth
I thought that the snowball earth was only a theory, therefore that graph (which I may not have seen) could be an equally valid theory?
SandyS
Sandy S
A note on terminology. A theory is a description of reality which makes testable predictions and which has passed every experimental test yet thrown at it. A hypothesis is an untested theory
The snowball earth theory makes testable predictions about glacial landforms at low latitudes, composition of sediments etc which have been geologically obaerved.
"Only a theory" marks you out as a layman rather than a scientist. Google the philosophy of Karl Popper.
Entropic man
Martin A
GCMs rely on a physical model of climate based on the equations of energy state and change common to most of physics. You probably use them yourself when calculating the behaviour of electronic devices. If basis equations such as the wave equation, the Maxwell equations and the Stefan-Boltzmann equation were wrong your devices would not function.
That model simulates the behaviour of the climate system well enough to provide detailed weather forecasts for five days ahead.
It generates climate forecasts to an accuracy of +/-0.1C. Given sufficient information it can also hindcast conditions for any period over the last billion years, which can be matched to geological evidence.
The same model correctly predicts conditions on Venus, Mars, Titan and Saturn; plus weather forecasts for Jupiter.
How much validation do you want?
Incidentally, radiative forcing is esoteric by common standards, but it is like Hex's teddy bear. If it is not there nothing works.
Other models? Finite element analysis in engineering. Aerodynamics, which uses turbulent flow mathematics to make your hair curl. Astronomy, particulary orbital mechanics. Ecology, physiology, neurology. Analysis of protein and crystal structure. Crowd behaviour. Ray tracing. Models are becoming ubiquitous analysis tools, but mostly only those in each area are aware of them.
They are also used in economic modelling. Now that is a ludicrous undertaking!
Entropic man
Comment left by 'Entropic man'
I object to that comment, I may not be a climate scientist but you know nothing about me. A theory is only a theory as it untestable concerning past events. Someone else can come up with an alternative which it Ill behoves anyone, especially you, calling bullsh1t. Having a technical background I am sceptical about any theory being the final word on anything.
That goes from the Big Bang to String Theory, I suggest that rather than thinking that anything that supports your belief system is the truth, the whole truth and nothing but the truth and that anyone who suggests otherwise is an idiot you start the question what you religiously believe. Posting here isn't like your old habitat at the BBC where you were on home territory.
sandyS
sandyS - yes, EM does have a slightly unfortunate tendency to talk to people as if they were 13 year-olds in his science class and he does seem to have an idealised view of how things are.
EM - thanks for the lecture on modelling. Some other time perhaps I'll outline some of my accomplishments in the area, including original work on the use of spectral factorisation methods for the solution of distributions in ultra-high order discrete event models.
GCMs rely on a physical model of climate based on the equations of energy state and change common to most of physics. Yes, that's what Sligo has said repeatedly, as if were an incantation that, having been pronounced, certified that the Met Office models are a correct representation of the physical reality. Why do you think that someone who knows even a little bit about modelling physical systems would be impressed by such a banal statement?
If you wish to believe that GCM's have been validated in the sense that is normally used for the validation of models whose output is relied on in situations where, if incorrect, it would cost nontrivial amounts of money, then you are free to do so.
But, as the Duke of Wellington replied (when greeted as "Mr Jones, I believe?") If you believe that, you will believe anything.
I was surprised to come across a forthright assessment of climate models, one of its authors being affiliated to The Grantham Research Institute on Climate Change and the Environment:
The Myopia of Imperfect Climate Models: The Case of UKCP09
Just one quote is sufficient to give the flavour of the report:
Given the acknowledged systematic errors in all current climate models, treating model outputs as decision relevant probabilistic forecasts can be seriously misleading.
Its authors clearly don't accept that climate models have been validated.
Martin A
Entropic Man
You said "Your link to joannenova contains some bullshit graphs. The long term graph fails to show the pre-Cambrian snowball Earth and her recorded temperature graph somehow makes 0..16 + 0.15 +0.16 add up to 0.8. You asked why I tend not to respond to your links. There seems little point when their signal/noise ratio is so poor. I gave up on WUWT years ago."
The graphs to which you refer have been produced by the use of data accepted by both sides of the debate. I am being convinced that you have a closed mind on the subject of AGW. You refuse to accept uncontested data and explore new lines of research such as the link between Solar Cycles and Global temperatures. No we have no yet identified the mechanism that can be responsible but the corelation is much better than that between atmostpheric concentrations of CO2 and Global Temperature both now in in the distant past. It is a fact that increase in Global Temperature have always preceeded atmospheric CO2 concentrations by between 200 and 800 years. This is for the very good reason that as the oceans warm they can not hold as much CO2 so it is outgased. The human contribution to "Carbon Cycle" is only 3%. For a Science Educator I find your lack of objectivity alarming. The most important principles students should take from the science education is a knowledge of scientific method (as spelled out by Richard Feynman - https://www.youtube.com/watch?v=EYPapE-3FRw-) and a strick objectivity. On the subject of computer modelling. This is a vital tool especially in my field of engineering. However to be of any use it must be modelling well defined problems using well estabished scientific principles. It must include all the relevant information there must be NO unknowns else aircraft will fall out of sky and bridges will collapse. To believe that any computer (no matter how super) can produce any meaningful results trying to model the climate with so many variables known and unkown where "parameter" are adjusted to make the models agree with reality. It is a dangerous delusion.
Ross Lea
EM, as an aside, I am in a way impressed by your dogged determination to bend and fold acceptable scientific practices to fit the CAGW dogma you hold dear and believe in so fervently. But I have to tell you, it will not fit.
Simon Hopkinson
«"Only a theory" marks you out as a layman rather than a scientist.»
The snobbishness of the pedant. The irony of his telling somebody else that they are not a scientist is profound in view of what he himself accepts uncritically.
splitpin
sandyS and MartinA
Sorry if I have "shot your fox" regards. Ross Lea.
Ross Lea
Ross Lea
Not to worry, there'll be another one along in a minute.
SandyS
Sandy S
I know that you do not know the difference between a theory and a hypothesis, yet you presume that you know betterr than the scientists.
Ross lea
Jonova put in wrong data.
The knowns in your models started out as unknowns. It has taken 400 years of science to convert them. Once again I see this blinkered view of knowledge from an engineer.
Entropic man
Martin A
My 13 year olds knew the difference between a theory and a hypothesis. If I treat you as 13 year olds it is because you show levels of scientific ignorance which would have embarrassed them.
How can an experienced modeller talk such nonsense about models?
Gentlemen
Since this conversation is once again descending into insult I'll leave you to it.
Entropic man
Martin A
How can an experienced modeller talk such nonsense about models?
Nothing I have said about models is 'nonsense'. I rather think you recognise that.
... I'll leave you to it.
He said, having been gratuitously rude to all and sundry.
Martin A
The man who's dishing out insults bows out of the conversation because someone is dishing out insults. Yowzer.. I've not seen circular reasoning as blatant and miserable as his in quite some time. I wonder if it's the PGCE course that does it to them?
But then, this is the guy that believes he's a theological agnostic, but who's contemplating asserting to his Christian wife that god doesn't exist. I don't know any 13 year-olds who have a poorer understanding of standard definitions than EM. It would be difficult to feel rebuked by someone like this ;)
Simon Hopkinson
Martin A
Sorry about that. Various things, including a server dropout, got in the wayand it slipped by.
Suggesting that climate science is not science is total bollocks. Under ideal laboratory conditions you can measure conductivity to the limits of your instrumentation as many times as you wish. It holds still on your bench and remains constant.Easy science! Under such conditions uncertainty is indeed more a philosophical than a practical problem. I am quite happy to agree on that. General Groves need not have worried.
Now imagine measuring conductivity under the conditions encountered by climate science. Your sample is 8000 miles in diameter and you cant cut bits off. Conductivity varies across your sample in response to daily, yearly, decadal, centennial and 100,000 year cycles, plus the presence of impurities you can only approximate. In some places you can only measure conductivity at certain times of year or from 100 miles above.
Under those conditions you conductivity measurement sprouts considerable confidence limits. Your attempts to measure it are still science, but your ability to get a single unequivocal number is much reduced.
I forgot to mention the activists complaining that your conductivity value is wrong and should be increased or decreased to suit their agenda. There are also politicians demanding to know the exact value for conductivity at various times in the future, with no appreciation of your problems. :-)
Incidentally, if you think climate science is too vague, try biology. No two organisms are alike. No matter how carefully you try to control the experiment the animals do what they like!
I think that the Comet experience is valid. It illustrates an engineers' tendency to work in black and white, assuming that Kipling's "tables at the end" are complete and accurate. When tested by reality they found that an unexpected phenomenon inruduced an unexpected shade of grey.
I do like simple models. They give a first approximation of the size and behaviour of the effects you are trying to study. They also give you some idea of whether your hypothesis is bollocks. I've used them in various contexts and found thenm a useful bullshit filter, despite their relatively large confidence limits.
I also accept the data coming out of observational and modelled science at face value, including uncertainties. If they deviate far from reality it rapidly becomes obvious, so why fiddle them?
Got to go. Au revoir.