Jump to content

Global warming computer models are very unreliable.


SkepticLance

Recommended Posts

"On top of this, some climate scientists believe that even the IPCCs global forecasts leave much to be desired."

 

That's some nice unspecific hearsay.

 

The point I am making is that even alarmists like the New Scientist writers appreciate that climate models are unreliable, whether local or global in nature.

 

The unspecific hearsay you're quoting doesn't say that the climate models are unreliable. And even if they are, at what? Reconstructions, projections, or both? The former is what matters in diagnosing present problems with the climate system.

Link to comment
Share on other sites

To Bascule

 

Further quotes from the same article :

 

Quoting Palmer agains.

 

"He warns that models often share the same biases and blind spots about features of the climate system that are critical for regional forecasts. They cannot reproduce El Ninos in the Pacific Ocean, for instance. Nor can they simulate the weather systems that bring drought to the Sahel region of Africa, or the Atlantic storm tracks and blocking high pressure zones that determine whether Western Europe is wet or dry."

 

Another quote

 

"Last year, a panel on climate modelling that was preparing the ground for next week's summit concluded that current models 'have serious limitations' and that their uncertainties 'compromise the goal of providing society with reliable predictions of regional climate change' "

 

And another

 

"The big picture remains clear. Our planet is straying into unknown climatic territory, with consequences that we probably have to accept are almost impossible to predict."

 

And another

 

"Equally worrying is the fact that climatologists are losing confidence in the ability of existing models to work out what global warming will do to atmospheric circulation - and hence to local weather patterns like rainfall."

 

While the focus of this article was local and regional predictions, and the impossibility to carry out such, it is also clear that the climate scientists interviewed for the article had less than total confidence in the ability of models to predict accurately on a global level also.

 

The article suggests that, to solve the problem, an increase in computing power of the order of 1000 fold will be needed. No doubt this will happen eventually. In ten years time, I will probably not be continuing this argument because I would then be wrong. Today, I am not wrong.

Link to comment
Share on other sites

What do predictions actually matter, versus a sound, scientific diagnosis of problems with the climate system now? Many do not yet accept that anthropogenically-induced forcings are driving the present shift in Earth's radiative imbalance. Why cast FUD on the models which show this to be the case, simply because they can only reconstruct and cannot reliably project into the future? Everyone should be aware of problems in the climate system which man is causing now...

Link to comment
Share on other sites

To Bascule

 

There is truth in what you just said. I agree with you with one proviso.

 

I do not like calls for action that include too much urgency. There are too damn many silly bugger ideas out there. For example : pumping vast amounts of sulfate aerosol into the atmosphere to cool things down. It has now been suggested that such an action would have the side effect of ozone layer damage on a massive scale.

 

We have seen the effect of ethanol biofuel production on food prices, and the exacerbation of poverty. Malnutrition increase can only follow.

 

Action must be considered, well researched, and well managed. This takes time, and we cannot afford to be rushed into silly so-called remedial action.

Link to comment
Share on other sites

If this happens in spite of the non linear relationship between CO2 and warming, it is because the rate of CO2 emission increases - non linear.

That was precisely my point. I only brought it up because I was responding this quote of yours, which seemed to imply otherwise:

 

 

I have said, several times, that my own prediction for the future is a continuation of the current situation. Warming of 0.18 Celsius per decade plus or minus a bit, and a sea level rise of 3 mm per year plus or minus a bit, until about 20 years after humans manage to control carbon emissions.

 

It's quite possible I've misinterpreted you. You and I have been known to do that with one another more than once. However, what I am missing is how you can "predict" that the increases will continue as they are now (linearly) despite the non-linearity of the CO2 attributions.

 

I posit that if the rate of increase is on the rise, then the effects of that increase will also be on the rise.

 

 

As an analogy, you have a bucket into which you are pouring water. For the past week, your average fill rate has been 1 gallon per day, so you extrapolate that in 5 days you will have added 5 gallons. However, the situation here is that the fill rate has increased exponentially, and is now 3 gallons per day, yet you continue to posit that after 5 days the bucket will still only have 5 gallons which were added.

 

Do you see now why I questioned your post and reminded you that the rate of change was nonlinear?

 

 

 

I do not like calls for action that include too much urgency. There are too damn many silly bugger ideas out there. For example : pumping vast amounts of sulfate aerosol into the atmosphere to cool things down. It has now been suggested that such an action would have the side effect of ozone layer damage on a massive scale.

But nobody here has suggested ANY such silliness, and yet you continue arguing against it. I think you'll find that we all quite agree that measures should be logical, well thought out, and appropriate. However, the moment you get into subjective measures like "too much urgency" or "silly bugger ideas," then we've already lost sight of the issue.

 

When we argue that there are stupid ideas we waste time we could otherwise be using to explore the good ones.

Link to comment
Share on other sites

Swansont. Thanks for seeing that, I was wondering how to rephrase if my point wasn't got across.:) I admit though, that I do take the logic one step further. Even if the Forcings-> Temp change equations are robust, (and they seem to be) since there is a flaw in the GHG-> Forcings relationship, then when taken as a whole, the model can only be described as flawed.

 

inow, I believe I have shown that the model used in Hansen 1988 when taken as a whole is flawed. You might notice that the part of the model concerning the GHG-> Forcing relationship is not mentioned at all in the RC piece. By only talking about the forcings themselves, Gavin strives to create the picture that the complete model is robust. This is simply not true. The politest word I would use here is "spin".

The blog (RealClimate.org) is run by multiple climate scientists

Is it? If you Whois the site it was registered by a Betsy Ensley of Environmental Media Sevices. As EMS is owned by Fenton Communications (an advertising company) and since Ms. Ensley as still listed as "Admin" on Whois, it is probably more accurate to say that "Realclimate is run by an Advertising Company".

 

Since Ad companies are not exactly known for their philanthropic leanings and since EMS are known to have orchestrated "scare" campaigns to materially benefit the clients of Fenton Communications it is not unreasonable to suspect a bias.

 

Just as I would view comments on smoking as suspect if funded by the tobacco lobby, so I treat Realclimate. (That doesn't stop me following the links on their pages to read the papers though.;)) Realclimate has an agenda, or perhaps their backers do, and we both know that those with agendas will not be unbiased. I accept that fact and work from there.

 

In the words of the Vorlon, "Understanding is a Three Edged Sword.":D

Also, your post above about scenario A in the Hansen 1988 paper implies that there were not other scenarios considered.

I don't really see how you got that impression as I mentioned both Scenarios A and B, but *shrug*. I didn't mention C as it did not pertain the the matter at hand.

 

In a way I'm glad you quoted ChrisCs comment from that thread. His dismissal of the Douglass paper based on the RC piece here has an interesting follow up. Gavin makes the comment in the above article (referring to RAOBCORE 1.4) "The authors of Douglass et al were given this last version along with the one they used, yet they only decided to show the first (the one with the smallest tropical trend) without any additional comment even though they knew their results would be less clear."

 

On William Briggs blog he goes a bit further "There are additional problems with that paper - for instance, they were given more up to date analyses of the radiosonde data which they did not even mention (probably because it did not support their thesis)."

This is a strong accusation. When challenged by Dr Douglass he replied "My criticism of your methodology was put on the RC website in December and neither you nor your co-authors have chosen to respond....."

 

The response from David Douglass is telling, "I was unaware of the RC website comments about our paper until some time later (Why did not you send them to one of us directly for our response? We would have given you one.). I am accustomed to scientific discussion at this level via published papers in refereed journals. We expected any criticism of our paper to be a comment in a refereed journal so that we could respond also in a refereed journal. Do you know of any such comment of our paper that has been written?

 

The unrefereed comments on the RC blog were unsigned To whom should we have addressed our unrefereed comments? (Did you just say that you were the author?). This is not the way good science is done.

 

Contrary to your information we were never sent the RAOBCORE ver1.4 data"

I happen to agree with with Dr. Douglass that comments on blogs "is not the way good science is done". I also note the exchange took place on 12th April 2008 and as of today the RC piece still contains the false claim re RAOBCORE 1.4. I can only conclude that RC are unwilling to change their stance even when shown factually wrong by the author of the paper. What was that definition of "denial" again?

 

I apologise for the length of this post but I felt that my reasoning here was important. In our climate debates I and others are asked for refereed papers (and I have no quibble with this) however it is deemed by the opposing side that an unrefereed blog article is sufficient in rebuttal. You will perhaps note that I don't use references to blogs as a tactic, as I think the debate should be about published papers, not what a blogger says about a paper. He may be right or wrong in his opinion, but the correct forum is a refereed journal, not a blog.

 

There is a severe disparity in the standard of evidence required ATM and that thread illustrates it well. To back his claim ttowntom provided a link to a published, peer reviewed paper and the rebuttal was?

The citation of the first paper is just intellectual dishonesty. Another one that RC tore apart not too long ago.

Link? Paper? Proof? Perhaps Chris should have been called on it earlier, however I doubt that even now he could provide a published, peer reviewed paper to refute Douglass 2007.

 

Again, sorry for the long post, but I had to get that off my chest. Thanks for reading.

Link to comment
Share on other sites

To iNow

 

On linear versus non linear. You are correct in suggesting that there is a misunderstanding. The relationship between CO2 and warming is non linear. This means that if CO2 increases in a linear fashion, the warming will slow down. For warming to be linear, as I suggested, it requires CO2 increase to accelerate.

 

However, as I said earlier, please do not take my predictions too seriously. There is an element of irony in the fact that I posted them. They are there more for comparison than anything else. I do not believe any predictions. My own or anyone elses. I suggested that my own simplistic predictions were more likely to be accurate than the current supercomputer based models, and I think that is very likely. However, I could also be totally wrong. The irony lies in the comparison. I am sceptical of the whole bang lot!

 

I know that you have not suggested silly bugger remedial actions, and I am sorry if you think that was a dig at you or anyone else on this forum. I mentioned that to explain why I am opposed to extreme interpretations of global warming. I am fully supportive of carefully researched and properly managed action to combat global warming. The extremists, though, (and I am not accusing you or anyone here of being such an extremist) will push humankind into precipitous action that can only be harmful.

Link to comment
Share on other sites

Swansont. Thanks for seeing that, I was wondering how to rephrase if my point wasn't got across.:) I admit though, that I do take the logic one step further. Even if the Forcings-> Temp change equations are robust, (and they seem to be) since there is a flaw in the GHG-> Forcings relationship, then when taken as a whole, the model can only be described as flawed.

 

inow, I believe I have shown that the model used in Hansen 1988 when taken as a whole is flawed. You might notice that the part of the model concerning the GHG-> Forcing relationship is not mentioned at all in the RC piece. By only talking about the forcings themselves, Gavin strives to create the picture that the complete model is robust. This is simply not true. The politest word I would use here is "spin".

 

I was just reading the paper, trying to wade through it, and I don't think the emissions vs concentrations are necessarily part of the model. They use the term "emission rates" in the main part of the paper, but in Appendix B, where they go into the details, it's all concentrations — I think it's poor use of terminology. And if you look at 1990-2000, it's actually scenario "C" that most closely matches reality (assuming the Mauna Loa data is reality) of a linear 1.5 ppmv increase per year. Scenario "B" assumes a 1% annual increase in concentrations in that time frame, which is too aggressive — it's only after 2000 that scenario "B" is a closer match, because "C" assumes no further increase in CO2.

Link to comment
Share on other sites

I think it's poor use of terminology.

Agreed. In the paragraphs between Fig B1 and B2 (I can't copy the text as my copy is the non OCR scanned version) they speak of reducing the "annual increment" WRT CO2 but in the next sentence refer to the "growth" of CCl3F "emissions" as a %. The terminology appears inconsistent.

 

Looking at Hansen 2006, I would have to agree with you that C is closer to reality (using the Land-Ocean Index) up to 2005, however if you consider only the Land Index, B tracks better I think.

 

I do wonder what the track for B would have been if all the speculative forcings from A were not omitted. While I realise that Hansen was trying to provide an upper limit with A I think he may have artificially increased the spread of results with this methodology. And I still think he created a somewhat "Apples and Oranges" situation.

 

Cheers.

Link to comment
Share on other sites

I suggested that my own simplistic predictions were more likely to be accurate than the current supercomputer based models, and I think that is very likely. However, I could also be totally wrong. The irony lies in the comparison. I am sceptical of the whole bang lot!

 

Well, I predict that the earth will be warm by several thousand degrees. I mean, why listen to people who spent a good portion of their lives studying climate and who have incredible resources, why not believe a number I might or might not have pulled out of my ass?

Link to comment
Share on other sites

To Mr Skeptic

 

That is a frivolous and stupid, and insulting comment.

My predictions, which I admit may well be wrong, were not 'pulled out of my ass'. They were projections based on the past 35 years of climate change.

 

I have followed the teaching of the late, great Dr. Julian Simon. He was an economist, and a believer in progress. He used the tactic of projecting from existing long term trends, and proved himself to be more accurate than those who used models, on several different occasions. He won US$10,000 on a bet with the well known catastrophist Dr. Paul Ehrlich by using long term trends in mineral availability, where Ehrlich allowed himself to be convinced by alarmist rhetoric.

 

While there is absolutely no certainty in predictions, no matter which tactic you use, my approach of projecting long term trends has a good track record.

Link to comment
Share on other sites

That is a frivolous and stupid, and insulting comment.

 

And yet my prediction is based on experts' opinion, and on the equivalent of billions upon billions of years of observation. I didn't put a time frame on my prediction. Within less than 7.5 billion years, the sun will turn red giant and nearly engulf the earth. Which would cause warming by thousands of degrees, as par my prediction. This is predicted by the models, though you would never have been able to predict it from projections from the past.

 

My predictions, which I admit may well be wrong, were not 'pulled out of my ass'. They were projections based on the past 35 years of climate change.

 

I do know that you did some calculations, but for some reason I trust the opinion of experts who spent years studying the question more than yours.

 

I have followed the teaching of the late, great Dr. Julian Simon. He was an economist, and a believer in progress. He used the tactic of projecting from existing long term trends, and proved himself to be more accurate than those who used models, on several different occasions. He won US$10,000 on a bet with the well known catastrophist Dr. Paul Ehrlich by using long term trends in mineral availability, where Ehrlich allowed himself to be convinced by alarmist rhetoric.

 

Yes, the models are really far from perfect. But long term trends are unlikely to be much better, especially when the conditions are changing so rapidly. You don't think that climatologists have ignored the past long term trends when building their models, do you? Remember, models are simply built from past trends.

 

While there is absolutely no certainty in predictions, no matter which tactic you use, my approach of projecting long term trends has a good track record.

 

Only in some circumstances. For example, if you tried to predict the future oil prices based only on past trends while ignoring supply, you'd probably underpredict it. If you'd like, I can do the calculations for a linear increase in oil prices based on the past 35 years :)

Link to comment
Share on other sites

To Mr Skeptic

 

I was not insulted by the red giant prediction, but by the snide 'pull numbers from my ass' comment. And believe it or not, but long term trends do hint at the red giant outcome, since the sun is increasing its thermal output by a miniscule amount each decade, as shown by satellite studies. Of course, the time frame is too long for this to be accurate as a predictor, and astronomers fall back on analogy with other suns.

 

Mr Skeptic said

 

"But long term trends are unlikely to be much better, especially when the conditions are changing so rapidly."

 

If you re-read my post, you will see that I beat you to the punch and already said this. Nor did I suggest that long term trends work every time. However, history shows that they work more often than models.

Link to comment
Share on other sites

Ah yes, I see you are back to your old tricks again SkepticLance. No physical evidence, no data, constant lack of understanding, hand waving, strawmans, et cetera...

 

One would think that after constant criticism by virtually everyone on this site, everyone ranging from admins to physicists to climatologists to college students, and hey, even the general informed layperson, and for over a year, that you would finally learn that you are just plain wrong. But then, you continue to amaze and scare me.

 

Anyways, I don't have the time right now to look over and counter all of your specific claims at this minute, as it is late at night at my part of the world. But I'll get to debunking your B.S. yet again as soon as possible, rest assured.

 

I do know that you did some calculations, but for some reason I trust the opinion of experts who spent years studying the question more than yours.

 

Quoted for emphasis. SkepticLance, I do say that you are very clearly outmatched here.

Link to comment
Share on other sites

Reaper

 

As far as I am concerned, you are not welcome. I enjoy debating with swansont and bascule, who are good with posting scientific data. You have a history of arguing against things I never said, and a habit of covering up your mistakes with ad hom attacks and plain emotional appeals. I do not want to get into a fight based on emotionalism.

Link to comment
Share on other sites

As far as I am concerned, you are not welcome.

 

Gee, a simple hello would have been nice. I should be fortunate that you stand alone in your view :P .

 

 

I enjoy debating with swansont and bascule, who are good with posting scientific data.

 

Of whom you constantly ignore or hand wave away, so what difference does it make?

 

You have a history of arguing against things I never said, and a habit of covering up your mistakes with ad hom attacks and plain emotional appeals. I do not want to get into a fight based on emotionalism.

 

Oh please! I decide to nuke one thread and you get all whiny about it....

 

You could have said something like: "Reaper, you are totally correct, and I, SkepticLance, am wrong. There is no way I could possibly argue or counter against yours and iNow's all powerful arguments because all the evidence is in your favor". Of course, this certainly wouldn't win back any respect anytime soon, given our long debating history, but it would go a long way.

 

Besides which, the reason you are reluctant is because you know you don't stand a chance. Well, whether you like it or not, here I am and it's time to finish what we started.

 

Now then, lets see if you changed your tactics at all or came up with something original....

Link to comment
Share on other sites

Besides which, the reason you are reluctant is because you know you don't stand a chance. Well, whether you like it or not, you are going to have to deal with yet another opponent..

 

SkepticLance has been making intelligent points, backing them up with logic, reason and evidence. You, on the other hand, simply state that he is wrong and that he has been indulging in 'handwaving' 'strawmans' and 'B.S'.

 

If you disagree with his points then say why, otherwise you are the one who is indulging in the 'handwaving'.

Link to comment
Share on other sites

SkepticLance has been making intelligent points, backing them up with logic, reason and evidence. You, on the other hand, simply state that he is wrong and that he has been indulging in 'handwaving' 'strawmans' and 'B.S'.

 

Oh good grief, you haven't even seen what I was going to say yet and already you make rash judgments. First of all, he hasn't been backing them up with anything resembling evidence, logic, or reason. Hell, the figures he posted and "calculated" are made up from thin air, and he doesn't seem like he even knows how interpret data. He has no knowledge of even the fundamental basics of climate science. And he's done this several times before, and has been debunked several times before. He's merely covering old ground again.

 

If you disagree with his points then say why, otherwise you are the one who is indulging in the 'handwaving'.

 

You appear not to be familiar with our history:

 

http://www.scienceforums.net/forum/showthread.php?t=31472

 

http://www.scienceforums.net/forum/showthread.php?t=30362

 

http://www.scienceforums.net/forum/forumdisplay.php?f=99&order=desc&page=3

 

Just to name a few threads. The argument is getting old, and quite frankly this whole issue has been dealt with long ago. All we are doing now is debating over how long it will take for him to either STFU or admit he's wrong, or both.

Link to comment
Share on other sites

Oh good grief, you haven't even seen what I was going to say yet and already you make rash judgments.

 

I make 'rash judgements' on the posts you HAVE made, not posts you plan to make.

 

First of all, he hasn't been backing them up with anything resembling evidence, logic, or reason. Hell, the figures he posted and "calculated" are made up from thin air,

 

He has clearly given his reasons for his opinion that global climate computer models are unreliable. He has demonstrated perfectly reasonably that there are several grounds for holding the opinion that such computer models are still based on a limited understanding of such factors as ocean currents. As for the figures he 'calculated', he quite openly stated that they were a simple extrapolation from the past and that he did not place any faith in them, he was using them as an example of how unreliable such figures can be, a point that seems to have eluded you.

 

 

and he doesn't seem like he even knows how interpret data. He has no knowledge of even the fundamental basics of climate science.

 

He has raised valid points concerning the incomplete level of knowledge underpinning computer models. To try and dismiss that with such a blatant ad hominen does you no credit.

 

And he's done this several times before, and has been debunked several times before. He's merely covering old ground again.

 

 

 

You appear not to be familiar with our history:

 

http://www.scienceforums.net/forum/showthread.php?t=31472

 

http://www.scienceforums.net/forum/showthread.php?t=30362

 

http://www.scienceforums.net/forum/forumdisplay.php?f=99&order=desc&page=3

 

Just to name a few threads. The argument is getting old, and quite frankly this whole issue has been dealt with long ago. All we are doing now is debating over how long it will take for him to either STFU or admit he's wrong, or both.

 

 

I haven't the slightest interest in your 'history'. You may well have a personal grudge against Skepticlance, that doesn't justify attempting to derail a discussion on the accuracy of computer modelling with a series of ad hominen attacks.

Link to comment
Share on other sites

EDIT: Alright, I just read through the old posts. It's the same old stuff. Nothing new. Oh well, I'll just go over the more recent posts:

 

I make 'rash judgements' on the posts you HAVE made, not posts you plan to make.

 

Thanks for confirming that ;). And thank you for confirming that you aren't going to actually adequately counter any future points I may make.

 

 

He has clearly given his reasons for his opinion that global climate computer models are unreliable. He has demonstrated perfectly reasonably that there are several grounds for holding the opinion that such computer models are still based on a limited understanding of such factors as ocean currents. As for the figures he 'calculated', he quite openly stated that they were a simple extrapolation from the past and that he did not place any faith in them, he was using them as an example of how unreliable such figures can be, a point that seems to have eluded you.

 

And we have given a great deal many of rebuttals to his personal opinions. Yet, he still insists that the climate models are still unreliable and pushing that view all over the place. Of course, why take my word for it, this and other debates are all over this site.

 

 

He has raised valid points concerning the incomplete level of knowledge underpinning computer models. To try and dismiss that with such a blatant ad hominen does you no credit.

 

Read the above.

 

 

I haven't the slightest interest in your 'history'....

 

Then stay out of my way. If you aren't actually going to contribute to the discussion, I suggest you keep your big mouth shut and post elsewhere.

 

---------------------------------------------

 

My predictions, which I admit may well be wrong, were not 'pulled out of my ass'. They were projections based on the past 35 years of climate change.

 

And of course they are most likely to be wrong. Do you mind going over the specific details over how you came to your conclusions? You know, show us the math, methodology, etc? This way we can see whether or not they are legitimate.

 

I have followed the teaching of the late, great Dr. Julian Simon. He was an economist, and a believer in progress. He used the tactic of projecting from existing long term trends, and proved himself to be more accurate than those who used models, on several different occasions.

 

Oh my, you quote someone who has no expertise in climate science. And with no way to verify this claim. I wonder why that is..... As I said before, if you want your claims to be taken more seriously, you are going to have to cite data from climate scientists. So far you have failed...

 

He won US$10,000 on a bet with the well known catastrophist Dr. Paul Ehrlich by using long term trends in mineral availability, where Ehrlich allowed himself to be convinced by alarmist rhetoric.

 

Which has absolutely nothing to do with our discussion. I dare say, this is a very desperate appeal, to say the least.

 

While there is absolutely no certainty in predictions, no matter which tactic you use, my approach of projecting long term trends has a good track record.

 

Well, actually, there is reasonable amount of certainty with climate predictions. I could show you the specifics, yet again, but why bother? You certainly don't seem interested in them.

 

 

 

Alright SkepticLance, you've talked the talk, now its time for you to walk the walk. Either debate properly, or give up, or prepare to be torn to shreds. Enough of this; I'm willing to take you seriously, but only if you prove yourself.

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.