You have just lifted this straight out of Roger Pielke's site. Did you read these papers?

Prof Pielke's main point is that the climate system may exhibit chaotic behaviour (initial condition dependent) and that current models may not include these switches, thus missing abrupt climate transitions. He also makes points about the scale at which predictions are made and the relevance of general climatic predictions based on global warming for smaller scale chaotic climatic situations.

It seems to me that the key issue is whether greenhouse forcing is sufficient to overcome variability in initial conditions of other parameters and give meaningful results when simulated in climate ensembles. Many climatologists think so, and given the relative stability of the climate during the holocene, and the lack of any specific mechanisms posed that could cause some initial condition -dependent chaotic climate switch, this is the current working hypothesis.

In any event, these arguments are somewhat more detailed and sophisticated than the usual "we can't predict the weather so why can we predict the climate" argumnent (which is a fallacy) as you can see on various blogs on Realclimate. Reading these is quite informative, I myself have learned much from these discussions.

Another good source which lays out many of the fallacious arguments that float around the climate change debate is here: http://www.iop.org/activity/policy/Publications/file_4147.pdf
The author also discusses major areas of uncertainty in climate modelling.

Obviously, many aspects of long-term climate modelling are yet to be understood and refined, but we should at least move beyond cutting and pasting from various websites, selectively choosing quotes to support our own viewpoints, and endlessly raising debunked arguments as though they shed light on the subject.

You know - if push came to shove, and there was a vote of how much of 'global warming' directly due to anthropogenic effects - my vote probably would not be that much different from RWood...

The only difference would probably be that I would put more weight on something other than CO2 (deforestation other environmental changes etc).

But why am I a skeptic? With all due respect, but it's because of "consensus" groupthink such as appears in Dr O's post above:

So, we no longer have a Younger Dryas, a Climactic Cptimum, the Roman and Medieval Warm period etc etc etc - we have relative stability (sigh... as Gavin at RC would say) - the history / geology books show that this is not the case.)

I am really sorry that the hockey stick still lives...

http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html

And until it disapears from climate models - I will remain unconvinced of the models' future skill.

cheers

Arnost

At least get your facts straight before you criticise. The beginning of the Holocene is pragmatically placed ~11,400 calendar years BP, while the Younger Dryas occurred at the end of the Pleistocene around ~12,900 - ~11,500 calendar years BP. In other words the Holocene begins at the end of the Younger Dryas, although the beginning of the Holocene is somewhat arbitrary. The Younger Dryas was indeed severe, with massive temperature drops recorded in many regions. The beginning of the Holocene is somewhat arbitrary.

This is why I said "Holocene", not "Holocene+end of Pleistocene". That said, at the very beginning of the Holocene some large global changes occurred as the Younger Dryas ended. So, I am referring to the period following the warming at the end of the Younger Dryas. Now as far as the rest of your comment goes, none of the other climatic periods that you mention even come close to the Younger Dryas in terms of deviation from the Holocene average. This is why I said RELATIVE stability. Fro example the climatic optimum was 0.5-2 deg C warmer than today. The medieval warm period was probably similar to today. Relative to the Pleistocene, the great majority of the Holocene has been stable. Anyway, the premise I discussed above had to do with the perormance of climatic models and possible chaotic climate change based on initial conditions, and their performance under Holocene conditions.

Your misinformed attack also notes that my position was reminiscent of "consensus groupthink". Nice buzzwards, but I actually pointed out blogs on the subject that cover both sides of the chaos/modelling debate.

Instead of unfounded criticism, maybe you should expand on your argument concerning "something other than C02":

Well all you quoted in your post was an article from a web-site, and all I quoted was a reply on that same website from a renowned scientist. What did I do different to you! We both posted something from the same website, I can't see any difference there. I have been told to add some scientific argument to my own words & viewpoint, on a previous post, so I decided to quote from a renowned scientist.......and I still get into trouble from you. I can't win whatever I do it seems from your side!

"This is because
climate is constrained by factors such as the
incoming solar radiation, the atmospheric composition and the reflective and other properties
of the atmosphere and the underlying surface."
"Also a climate model requires the interactions between the atmosphere, the oceans and the land/ice surface to be included. The atmospheric part is a global weather model, extended to be able to include the temporal evolution of key atmospheric constituents, whilst the ocean component consists of a similarly structured fluiddynamical model of ocean properties such as currents, heat and composition. The land/ice surface properties are included particularly as they determine the reflectivity and other key aspects of the climate system. Putting these components together to make a climate model is a complex task."
"It is wildly over-simplistic to suppose that
a few parameter values can be adjusted to reproduce the many diverse attributes that constitute the complex behaviour of the climate system. If it were possible to do this we would indeed have emerged with a climate “theory of everything”!"
The above quoted from your link Dr Odious is what I am talking about. he then goes on to say the ensemble models and new super computers will solve all the problems.......But the problems are too complex for a start. It is no use building a super dooper ensemble whammy computer, if we don't really understand how CO2 mixes and moves in and out and through the oceans and depths and atmosphere, and we don't know enough about this one factor for a start, and I could bring up albedo and clouds, etc, etc...And we understand even less about how the sun operates and how it changes and has run the climate in the past, we do not undertand how all the radiation of various complex rays and bands affect the earth and how cosmic rays of a certain type affect cloud growth and decay, and the earth's magnetism and the sun's affects on it are still not well understood. We do not know the cyles of volcanism. We are making new discoveries of different things affecting global temperatures daily, ie twilight zone effect. But the worst thing is we do not know what the sun will do in the future it has gone up and down erratically like a crazed yo-yo with active and quiet periods in the past, and will obviously do so again.......if we cannot put a prediction of solar activity in the future into the global models, and we can't, then sorry they have not got my vote of confidence at all, ensemble or whammy wonderful super computer, or what ever, they are doomed to failure!

Talking about the evolution of this thread, by the looks of it there's been some reference to evolutionary theory accompanying it. I'm guessing another thread will have to start for that, bringing with it another climate of change as well, with more bombardments of facts (and figures).

Actually I was thinking the same thoughts as you on those
posts HH.
The sad thing now about this "debate" thread is that any newcomer, particularly if he / she is like myself, an older and poorly educated person, who would like to make some comments, do some debating and suggest a few ideas of their own will have every likelihood of copping a, at times somewhat vitriolic spray, if their comments and outlook don't agree with those of a tiny coterie of supporters of a specific"consensus" global warming scenario.
It seems that even the supporters of the global warming scenario are apparently not immune if they deviate from this "consensus" line.
To participate now in this thread you have to have a hide as thick as an elephants.
To the other participants, thank you! It could have been a lot of fun!
If things change I might even be back!

Perhaps Nazdeck you should restart the 'what do you believe' thread...

"... tiny coterie of supporters of a specific"consensus" global warming scenario." ????

ROM, it may look that way inside this forum, but out in the world, the word "tiny" is hardly appropriate!!

Out of context AGAIN!

Dr O. – I apologise for the “buzz words” and stand corrected on the Younger Dryas.

Expanding as invited – three heretical ideas:

Relatively understudied anthropogenic effects on the ocean which may have a significant bearing on global warming are surfactant (i.e. detergent) and oil pollution. By reducing wave action (and especially reducing salt spray by way of the “oil film effect”) surfactants and oil spills reduce the ability of the oceans to produce cloud forming hygroscopic nuclei which leads to less low level clouds and therefore reduces albedo -> Global Warming.

http://www.floodsclimbers.co.uk/globalwarming.html

The pollution in itself may reduce phytoplankton which leads to less atmospheric CO2 being absorbed by the ocean -> Global Warming.

http://earthobservatory.nasa.gov/Newsroom/NasaNews/2003/2003091615946.html

Another “anthropogenic” cause of global warming may be a bias that has crept into the instrumental temperature records as a consequence of repainting of thousands of Stevenson screens worldwide with paints of uncertain infrared characteristics following the commercial unavailability of infra-red radiation reflecting whitewash.

http://www.norcalblogs.com/watts/2007/05/rising_surface_temperatures_ba.html

cheers

Arnost

Not quote "from", you just took his sentence and quoted it verbatim. I read his papers and then associated discussion on another site, and provided a separate link to another paper on the subject. I think there is a difference.

The truth of this statement notwithstanding, I've acknowledged that there are many aspects of the climate that are not well understood and that possible chaotic behaviour not captured in models cannot 100% be ruled out. This point was made on Realclimate. However, they certainly aren't doomed to failure, because the ideas you cite haven't been demonstrated to cause the models to go haywire. Indeed the models reconstruct the climate of the past century quite well.

This is not about winning anything, and you are taking this very personally for some reason. I consider this just healthy debate and if you take offense then my apologies. I have attempted not to get personal and when it did happen with another forum contributor I ended dialogue with that person. I was critical of your direct plagiarism without appropriate attribution of Pielke's sentence. In the scientific field, you have to be much more thick skinned than this to get by, as debate can be very heated.

Anyway, since your are taking offense at being tackled on your scientific views, perhaps we may as well call it quits too

Can you please elaborate? I'm missing the point here.

Ah still going round a round in circles. Back to the fallacy of climate change being unpredictable because it is an initial value problem.

Just an interesting tid-bits. The IPCC Working Group 3 report - http://www.ipcc.ch/SPM040507.pdf has just come out. Its pretty clear that greenhouse emissions are out of control, so no need to bother about modeling AGW because we probably can't avoid it. Best to just buckle up for the ride because its going to get mighty bumpy.

I think you're right David, think of the earth as the great global warming experiment.

On the plus side, it will be pretty interesting to see what happens. Hey, maybe we can get filthy rich documenting the changes and publishing papers on global warming effects on vegetation, ecosystems, etc etc.

Ka-ching

lol Keith; lets not go there again.

What I mean is referring to geological time, and the Eons, Epochs or Eras in geological time which form part of what is supposed to be our understanding of how (climate) evolution of the planet has occurred over many hundreds, thousands or millions of years. The use of the geological time implies evolutionary ideas. I’m not saying that this is a good or a bad thing, just that it assumes quite a concrete understanding of the history of this planet, like assuming we have a concrete understanding of climate.

hhhmm, well then let me see. If it can only be proven wrong, then someone must be right to have proven this wrong, which can't be 'cause its impossible to be absolutely right. Oh maybe then they could be proven wrong that they were right in their original proving of someone else being proven wrong. But er then that could make the original person right and not wrong, which is not possible??? HANG ON A MINUTE!
Round and round we go..... ROFL

Sorry to be rather off topic folks, just thought that this thread needed an injection of humour rather than so many opposing "absolute truths".
Keep up the good discussion, but try to keep the supercillious arrogance and personal attacks from posts otherwise the mods will close this thread for good, which I for one don't want. This simple old bald fella is learning a lot here

"I was critical of your direct plagiarism without appropriate attribution of Pielke's sentence"

Lets get this straight DO I have never plagiarised anyones work ever and never would. I put Quotation marks around the quote,, unfortunately, I missed the last quotation mark at the end...You had just quoted from that paper, Pielkes remarks were at the end of it, I assummed that you had read it so I quoted back from the same paper you had done, assummming that you had already read the quotation, and put it is "" marks so you would know. Maybe, in hindsight I should have said it was from the paper you quoted from, however, there was never any intention to plagarise anyone...that is a bit severe a statement imo from you!
And I have read his work on several occasions and am familiar with a lot of it, and find that he is good on all subjects in general terms.

I suggest you read up on scientific method. David's statement has the backing of odd folk like Einstein.