ONCE TWO SCIENTISTS--it hardly matters what sort--were walking before dinner beside a pleasant pond with their friend, a reporter for the Dispatch, when they happened to notice a bird standing beside the water.
"I am a skeptic," said the first scientist. "I demand convincing evidence before I make an assertion. But I believe I can identify that bird, beyond all reasonable doubt, as a duck." The journalist nodded silently at this assertion.
"I also am a skeptic," said the second, "but evidently of a more refined sort, for I demand a much higher standard of evidence than you do. I see no irrefutable evidence to back up your assertion that this object before us is even a bird, let alone positively identifying it as a duck." The journalist raised his eyebrow sagely.
I got that chuckle thanks to an interesting post over at InItForTheGold well worth the read for Part 1, all about styles of climate septics.
The third kind is the "throw spaghetti at the wall" type, the one who will wheel out fifteen half-baked arguments for every one you try to refute. This kind seems the most thoroughly trained in political shenanigans. The approach is as common as it is frustrating. They refuse to play by anything resembling the rules of logic, instead resorting to pure polemics. If you score a point of any sort, they will pretend not to notice. Therefore Very Very not the IPCC.
(Bring any local contributors to mind?)
And well worth the read for Part 2:
Anyway, and here is the point, when you have actual scientific knowledge, information from one source or topic can and should influence your thinking on others. Thus a coherent worldview arises. The naysayers on climate change lack a coherent worldview. Their claim is that climate has some magical properties making it unapproachable by science, and that thus very little can be known. But all they know for a fact is that they themselves know very little. Those of us who know enough are uncomfortable with bits of information that don't fit in right. Our experience is that if we look closely enough, there is usually a difference in assumption or nomenclature, not inconsistent evidence. We don't know everything, but what we do know tends to hang together, because we are practicing actual science, not as some philosopher of science would describe it, but as it actually works. Human minds collaborate to produce a robust and coherent view of the world.
Lack of coherence is the hallmark of the run of the mill psuedo skepticism we see so often around here. Anything goes as long as it is Not The IPCC.
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Sorry for the inane comment, but this is magnificent.
Reading the duck story brought back an old story to mind, one that has a related lesson to tell.
There is a storybook for children which I remember from my youth called "Flossie and the Fox." In it, a young girl has to deliver eggs from her family's small Southern farm to an elderly neighbor (in other words, a mile through the woods). Along the way is a fox which would like nothing more than to steal and eat the eggs.
The proud fox appears on cue, and tries to intimidate Flossy into turning over the eggs, but Flossy will not. Her claim is that the fox has not proven itself to be a fox. The fox repeatedly attempts to provide convincing evidence of its fox-hood ("I have sharp claws", "I have a bushy tail", "I have long, luxurious red fur", etc.) but each time Flossy just points to some other animal that has that same characteristic.
At the end, Flossy admits that she knew the fox was one all along, but the game kept it away from the eggs long enough for the elderly neighbor's dogs to come running, forcing the fox to retreat.
The lessons I draw from this, and the duck story, are twofold:
-- First, the convincing argument for duck-ness/fox-ness does not rest in individual characteristics, but in the accumulation of all of them, much as a scientific consensus is drawn from many independent lines of evidence that may not be convincing alone. This means that an effective strategy for something such as Evolution or AGW requires reinforcing the degree to which all the evidence fits into only one reasonable conclusion when taken as a whole.
-- Second, the tactic employed by the pseudo-skeptic and Flossy in the two stories is the same, often referred to in Evolution circles as the "Gish Gallop." The problem is that it is only used in two circumstances; either it is being used to confuse an outsider with semi-plausible sounding BS knowing that they'll lose interest if you respond with long-winded refutations (but the political points are already won and the seed of doubt planted), or it is a set-up to a trap where the topic suddenly shifts to one for which you were not prepared such as questions about morality (in the case of Evolution) or economics and government (in the case of AGW).
Either way, be careful when debating/refuting deniers lest you find yourselves severely in over your head even when you clearly have all the facts - even reality itself - firmly on your side.
You can tell it is not a duck by the blog-nure it left behind.
When AGW alarmists have lost the debate the focus on nonsense like ducks. Very fitting. Why use such childish tactics when the scientific facts would do?
But then when the chairman of the IPCC comes back with statements like:
"They [the skeptics] are the same people who deny the link between smoking and cancer. They are people who say that asbestos is as good as talcum powder â and I hope they put it on their faces every day."
you know they have lost all sense of honesty and truthfulness. I'm now waiting for him to say the skeptics are holocaust deniers (has been said before by others).
http://www.ft.com/cms/s/0/f9f86ef0-10cb-11df-975e-00144feab49a.html?ncl…
Dont let it get to you Pete, i for one am partial to a good joke no matter who it is about. Just read the joke have a laugh and move on.
"They [the skeptics] are the same people who deny the link between smoking and cancer. They are people who say that asbestos is as good as talcum powder â and I hope they put it on their faces every day." - POS
Now THAT is funny!.
Peter,
Talk about missing the point!
Scientific facts have never mattered to those that refuse to see the obvious.
He might have missed the point but her sure embodied it.
Now in Peter's mind AGW believers talk about "nonsense" like "ducks".
Yes? Richard Lindzen is by far the most qualified scientist among the skeptic community.
He denies the science linking smoking and cancer.
'The naysayers on climate change lack a coherent worldview.'
This is a nonsensical statement. The author is trying to make a claim about beliefs rooted in reality, but coherence doesn't necessarily have anything to do with that. A witchdoctor has just as coherent a worldview as a scientist because everything works together. That's coherent.
If we did take the author at his/her intention, however, how does anyone have a coherent view of climate science when very important issues like water vapor transport, the divergence problem and feedbacks are so poorly understood? The latest Science letter concerning water vapor concentrations in the stratosphere and their impact on warming should be a lesson to this author. If scientists are constantly having to change their approach to this problem, how can their worldview, or that of proponents of the worst-case-scenario climate change, be coherent?
It seems that both sides of this debate reach for some level of abstraction to insult their opponents because there is little observational evidence. Sure arguments have been, but few of them provide compelling evidence. So what do you do without observational evidence? You talk about economics and worldviews and investment in abstract ideas like 'the future' or 'nature'. I think that is also a function of the actual science being so far-removed from the reality of the normal blogger's world.
Most importantly, since we, as people, are concerned with how climate will impact society, it's good to have a concrete understanding of the possibilities. Because the range of physical possibilities is still so large, it's basically very hard to make any assertions about having a 'coherent' way of processing all of that information. If there were a way to process that amount of information, gambling wouldn't be as profitable as it is.
dhogaza, don't forget Fred Singer who started SEPP. They had money both from the tobacco industry and the asbestos industry. Initially SEPP focused on asbestos to divert attention away from the tobacco industry.
http://www.sourcewatch.org/index.php?title=SEPP
http://www.sourcewatch.org/index.php?title=International_Center_for_a_S…
As others have pointed out, there really is a strong connection between AGW denial and smoking/asbestos cancer denial. Not necessarily among rank-and-file AGW deniers, but very strong in the industry funded leadership.
Moving on...
Maxwell, it's easy for you to say that a witchdoctor's worldview is coherent, but if you followed one around with a camera for a year you'd find all sorts of glaring inconsistencies in reasoning and "treatment plans".
The point about science is that it continually strives for coherence. New observational data, be it of pulsar timing or stratospheric water vapor results in us deepening our understanding, and refining our models. But the new water vapor data would have to be a 10x bigger effect to really challenge the existing understanding. As it is, it will only be a refinement.
While all you AGW alarmists are "ducking" around, India has threatened to pull out of the IPCC and set up its on climate change body because it cannot rely on the group headed by its own Pachauri. It's no wonder given he has lost all credibility over the recent revelations of falsehoods and allegations of financial irregularities. Now is this a stone I hear dropping in a duck pond, or an asteroid crashing down into the Pacific Ocean?
http://www.telegraph.co.uk/earth/environment/climatechange/7157590/Indi…
What environmental minister Jairam Ramesh *really* said, in your own article:
He acknowledged âgoof upsâ, including the gaffe on Himalayan glacial melt but also said:
"I respect the IPCC but India is a very large country and cannot depend only on [the] IPCC and so we have launched the Indian Network on Comprehensive Climate Change Assessment (INCCA)," he said.
"Through these [additional climate reports] we will demonstrate our commitment to climate science," he said.
Ramesh never questioned the overall veracity of AGW:
"Most glaciers are melting, they are retreating, some glaciers, like the Siachen glacier, are advancing. But overall one can say incontrovertibly that the debris on our glaciers is very high the snow balance is very low. We have to be very cautious because of the water security particularly in north India which depends on the health of the Himalayan glaciers," he added.
There was nothing indicating that they threatened to pull out of the IPCC.
Thanks for the due diligence skip. Now, will Peter acknowledge his error, or is he an unabashed liar?
Maxwell, coherence does not require perfect knowledge only that the knowledge you do have is consistent. Climate denialism is not internally consistent making all kinds of contradictory arguments at once.
Like the "duck skeptic" in the story.
I don't think you lied, Peter. I think you made a mistake of seeing something that was just not there.
In Peter's defense, Coby, a liar has to disbelieve what he's saying. I think Peter believed it. There is shame in lying; no shame in (acknowledged)error .
GFW's comment,
'But the new water vapor data would have to be a 10x bigger effect to really challenge the existing understanding.'
makes me wonder something. What is being equated with 'the existing understanding'? Is it worst-case scenario climate change or is it that CO2 causing warming in the troposphere?
I have a feeling that if the results of that paper didn't affect our understanding of climate, there would have been no need to publish them in the most preeminent journal in the United States.
More to the point, however, I think that the posters here do not have much experience dealing the people who are scientists. They have a great propensity to cite only papers from groups they like or pretend as though papers have not been published that contradict the conclusions of their own papers. It happens in all fields. To most people, it's about getting data to help tell a story. It's not about the inherent goodness or self-consistency of the scientific process, although that helps tell a good story most of the time. It's not a requisite, however, despite what you have heard.
But none of this really has to do with science, as is somewhat expected from this blog. It's just about dressing your opponent in certain garb so that it's easier to dismiss his/her arguments rather than just using observations. Since most of the observational proof of the worst-case scenario climate change doesn't exist at this point, I get it. It just doesn't make you anymore 'right'.
will Peter acknowledge his error, or is he an unabashed liar?
If he acknowledges his error, he is more likely not intentionally spreading false information (aka lying). If he can not admit he was clearly wrong, then the truth does not matter to him and he is very likely to be intentionally spreading false information (aka lying).
To be fair, there are possiblities in between. "The truth proabaly lies somewhere between the two extremes" as our Dispatch reporter in the story would have it!
If I came off as a little grumpy it is probably because I have a bad cold...
[Scientists] have a great propensity to cite only papers from groups they like or pretend as though papers have not been published that contradict the conclusions of their own papers. It happens in all fields.,
Sorry you see it that way, Max.
In my field--and its not rocket science, trust me--if you try that crap the peer reviewers will vivisect you. They will tell you to cite the contrarian view even if they don't agree with it. In my early career I made such mistakes out of simple ignorance and sloth, and it cost me chances to publish in the top journals. In the long run that doesn't fly.
Skip,
I was part of a group that was trying to publish a paper for 2 years that dispelled a theory by a competing group. The PI of that group was the head reviewer everywhere they submitted it. I don't know if he was following them or it was just dumb luck, but it kept the thing held up. The group I work along side now goes to all the same conferences as a competing group who refuses at all costs to cite us even though we cite them as necessary. The project I work on now has several competing theoretical groups who, at times, completely deny the existence of others' papers.
So it's not a matter of seeing things are certain way. That's part of this reality. You have seen a different side of coin in your experience. I didn't deny the existence of that. But it makes me wonder what the norm is. Obviously it's very different if the reviewers or researchers are tenured or not.
On the cutting edge of research it's hard for me to see a coherent picture of what we study because it is very fluid. Things change as fast as week to week when it comes down to the details of all this. I think it comes down to the idea of 'the more I know, the less I understand' which I've heard not a small number of researchers whom I look up to utter to me in confusion. Doesn't sound very coherent to me.
But back to my question. What is 'the existing understanding'? I'm curious to know what the rest of you think.
maxwell
I am really concerned with this statement of yours:
"...But none of this really has to do with science, as is somewhat expected from this blog. It's just about dressing your opponent in certain garb so that it's easier to dismiss his/her arguments rather than just using observations. Since most of the observational proof of the worst-case scenario climate change doesn't exist at this point, I get it. It just doesn't make you anymore 'right'..."
Firstly, the inference regarding attacking a belief system or group of people by pigeon-holing them (or 'dressing them in a certain garb') is - well - insulting. I freely admit (on this subject at least) I will use the term 'denialist' or 'flat-earther', but I do not use that against someone who wants to rationally discuss science . There have been some 'skeptics' who have put forward some good points (tilo is one), and even those from 'my side of the fence' who I have had disagreements with (dhogoza and dendochronology is a case in point) - and that is healthy and good.
But I will use pigeon-holing against someone who shows no interest in science, who just wants to 'baffle with bullshit' using cut-and-paste from other blogs, and who continually refuses to accept incontrovertible evidence just because it disagrees with their world view. And I use it because they have pigeon-holed themselves by adopting an irrational position. You can only try to debate with these people so often before their lack of any reason or willingness to accept the truth becomes overwhelmingly frustrating. Some 'belief systems' deserved to be condemned out of hand. Creationism is one, as are the denialist positions that there is no such thing as climate change or that CO2 is 'plant food', etc.
I am also totally confused by the assertion regarding the observational proof for the worst case scenario. Of course there is no observational proof for the worst case scenario, and I doubt any person here (certainly not coby, skip, dhogoza or myself as regulars) would claim there is. That's the whole point of it being a 'worst case scenario'. There are some things about which we are not 100% sure, so scientists build in bands of error on their calculations, which is why every prediction of future climate change shows different rates of change etc. If the observational proof of the worst case scenario existed, then we would be able to refine our predictions and eliminate the other scenarios.
Having said that, I am going to partially agree with you re the issue of the peer review process sometimes biasing towards like minded individuals and studies - but only partially. It's human nature to do that, and scientists (I am one myself) are human after all.
But skip is also correct. Those sort of actions get caught out eventually. If you fail to consider information which is counter to your hypothesis, or deliberately ommit references to papers with alternate viewpoints, a good review will rightly crucify you. Even if you do get away with it in the short term, in the long run you will get caught, and then your reputation will be severely dented. And that is something that no scientist can afford.
However, it must also be stated that sometimes this claim about corruption in the peer review process or failure to publish dissenting views is completely unjustified, and the reason a paper is refused has more to do with the quality of the paper than anything else. A lot of people just produce crap work - and when the peer review process correctly weeds them out, the authors get their noses out of joint. They should take the criticism and do better work next time.
The IPCC, a major source of global warming advice, is now mired in allegations of bias, exaggeration, censorship, collusion, false claims and conflicts of interest involving its chairman. There's now nothing the IPCC says is correct in the IPCC 2007 report. It stands to reason it's now debunked and should be ignored by all governments and researchers. To think otherwise goes against all common sense let alone the scientific method.
I observe that AGW believers openly deny the existence of evidence against AGW. To me that makes them deniers too. Calling someone a denier is meaningless. Do I have to post a long list of past deniers who were eventually proven right. I'll give just one example: Galileo who denied that the Earth was the center of the Universe. The AGW debate is certainly not over by a long shot. So criticizing someone one one side for denying the other side is right is totally meaningless, childish and extremely arrogant.
"So criticizing someone one one side for denying the other side is right is totally meaningless, childish and extremely arrogant."
Your tone and language just proves that coby is right and you are wrong.
Oh, and "I observe that AGW believers openly deny the existence of evidence against AGW." Citation Needed...
"Do I have to post a long list of past deniers who were eventually proven right." - POS
No, even a short list will suffice, and stick to the topic of climate.
As expected, Peter completely avoided an admission of error in his earlier post. Not sure he even understands why he was wrong.
And please, Pete, spare us the "I'm only a poor, hard-working contrarian, toiling away in obscurity - just like Galileo" bullshit. There's a massive difference and if you knew the slightest thing about how science worked, you'd understand that. Real scientists even have a classification for those that cry "Galileo" and it's not too pretty so I'd concentrate on suppling some evidence for you wildly inaccurate, painfully inarticulate and wilfully ignorant nonsense.
Just a tip. We've seen one or two of 'you' come and go over the years.
Ready to admit your error yet?
Yeah, Matt.
I dunno if we'll get that out of Peter. And it highlights to me the fundamental difference that I see between folk like us and the deniers (at least the ones I see/interact with). They have no compulsion for intellectual honesty. Even Crakar has manned up a couple of times and admitted when he got his facts twisted. And it was either Marco or Mandas that admitted missing an article of interest in our Oregon Petition exchange with Tilo a couple of weeks ago. (I also flubbed an AR1 graph, and let the record show I also publicly acknowledged error.)
But its really, really tough and frustrating when you're debating with people who have no such ethic.
Peter: All you have to do is admit your link did not substantiate your statement and we'll kill the fatted calf for you. Let's keep it honest, mate.
They should take the criticism and do better work next time.--Mandas
Having said that, I am going to partially agree with you re the issue of the peer review process sometimes biasing towards like minded individuals and studies - but only partially.--Mandas
The project I work on now has several competing theoretical groups who, at times, completely deny the existence of others' papers.--Max
Well, then they are being assholes (for now) and I concede that.
But I would add this tidbit: I got rejected by one of our field's top journals a year and a half ago and I was so livid that I for the first (and, I hope, last) time in my career actually wrote a letter to the editor sizzling the reviewers. In it I explained my concern that, since I was offering a whole new view of our field, these grumpy old Limey bastards (it was a UK-based journal and it made me want to grab a Kentucky Long Rifle and snuff some Red Coats) who've been doing and believing the same old shit for 400 years could not stomach it. ("Oh, no no no. I'm afraid not, old chap . . . what would *D'isreali* say . . . Now, back to my tea and Yorkshire pudding . . .)
*But*, the article is coming out in a Canadian journal (not as prestigious, I admit). Why? Because, Max, *I'm right*. The new framework for interpreting phenomena in our field is completely legit and although it won't get the credit it deserves *yet*, eventually the truth filters to the top.
**Because in the long run, peer review WORKS**.
So Max, if I might take the liberty of speaking for Mandas, what he and I are saying is that peer review might not be perfect but its the best thing going. Without the quality control of having your work subjected to the scrutiny of peers--whatever their frailties and biases--then "knowledge" becomes a complete free-for-all, where any fool with a website and an opinion can claim to hold an equal footing in disputes about scientific "truth".
What is 'the existing understanding'? I'm curious to know what the rest of you think. --max
And here is where I go with the overwhelming scientific consensus that (1) CO2 is a GHG and (2) it has been at least a *primary* force in global temperature change for the last several decades.
Why do I accept this? Again,
**Because in the long run, peer review WORKS**.
Skip, I'm happy you feel vindicated with your last comment, but it proves my point rather completely.
Your point that you are correct in the assessment of said rejected paper shows that those who rejected do not have a coherent perspective on the issue at hand. Had it been coherent, they would have repudiated their inconsistencies and accepted the truth that your paper espoused. But they didn't. So how is their worldview 'coherent'? And as you become an older grumpy researcher, less and less likely to accept the new uppity generation's changes to the way you view your field, how is your worldview going to stay 'coherent'?
Science, as an abstraction, may be striving, on longer time scales, for better and better information to informing a community of willing participants. Maybe even some unwilling ones. But the whole point of this posts is to directly assess the worldview of particular individuals who may or may not agree with your opinion. According to your story, as individuals, the worldview of scientists or researchers, is not, by assumption, coherent. I have a scientist on my committee who challenges the notion of a 'photon' despite a scientific consensus of its existence. How is that consistent?
There are always inconsistencies. That is the only point I was making. Research in most fields is so fluid that there can be serious discrepancies between rival theories, even in the same lab, that work to explain a great deal. Those discrepancies can stand for many years unresolved to the unbiased observer, but seemingly in the face of inrefutable evidence to either camp.
I used particular instances of viewing those inconsistencies via the peer-review and publishing experience. I wasn't making an argument against peer-review or saying that it wasn't somehow 'worth it'. But you seemed very ready to make such an argument. I wonder why.
There are always inconsistencies. That is the only point I was making.
Ok but that point by itself is--in my view--a tad less than profound. It seems like the two of us (with perhaps Mandas in my corner) are emphasizing different sides of the same coin. You emphasize its (peer review's) limits; I'm emphasizing that its one of the best defenses we have against epistemological and scientific chaos. Without it, suddenly those who deny evolution or the roundness of the earth are on equal footing with us all.
And I would say you missed the primary lesson of my anecdote, which is that, in the long run, solid arguments will eventually penetrate into the discussion--whatever the human-based limits of peer review.
Skip, I didn't miss the point. I thought we were discussing the merits of making an argument that those who disagree with your opinion on global warming didn't have a coherent worldview. Since you have already pointed out that researchers on the cutting edge of your respective field do not have a coherent picture of the world, as per their rejecting of your paper that espouses a new truth, I think that my point is rather clear. If I thought that what I was doing would be worthless in the future, I wouldn't be wasting my weekends away learning about molecular symmetry.
Since you have already pointed out that researchers on the cutting edge of your respective field do not have a coherent picture of the world,
Actually no. Their view is coherent. Just incomplete. I did not cause a Kuhnian revolution with my paper. (Can I assume people know to what I refer--Kuhn's *The Structure of Scientific Revolutions*?)I just added something useful to the discussion. See the diff?
as per their rejecting of your paper that espouses a new truth,
I think thats a healthier wording--a new truth--not a revolutionary one that upends the whole field.
If I thought that what I was doing would be worthless in the future, I wouldn't be wasting my weekends away learning about molecular symmetry.
Hehe. "Molecular symmetry"?
Are you *trying* to make me feel like I have a small dick or am I just over-reading that last part?
:)
And overall, as for the coherent-worldview concern. Fine, I guess I'm willing to capitulate that maybe some wrong peoples' worldviews are technically "coherent". But then again so was Hitler's . . .or Mao's . . . or Joseph McCarthy's. "Coherence" in the broad sense is an easy standard to meet. "Compelling" is a different matter.
You AGW alarmists make me laugh. I see no error in stating what I said re the Indian article. As usual you twist things around to make your case when the facts are there for all to see. For example, the article stated:
"In India the false claims have heightened tensions between Dr Pachauri and the government, which had earlier questioned his glacial melting claims. In Autumn, its environment minister Mr Jairam Ramesh said while glacial melting in the Himalayas was a real concern, there was evidence that some were actually advancing despite global warming."
To an ordinary person with simple logic the implication here is that the Indian government doesn't trust the IPCC anymore. It doesn't imply they get everything wrong (although many are finding it harder and harder to find anything they have said that's correct). They are simply stating India likes to have a "second opinion" as they don't fully trust the IPCC. If you can read it some other way then I'm sorry I can't help you.
The following quote:
"Dr Pachauri had dismissed challenges like these as based on âvoodoo scienceâ, but last night Mr Ramesh effectively marginalized the IPC chairman even further."
further implies that the IPCC is the one conducting "voodoo science" but I admit that would be stretching it a little, but certainly more accurate than Pachauri's claims of "voodoo science". The Himalayan glaciers "mistake" alone is proof of that.
To an ordinary person with simple logic the implication here is that the Indian government doesn't trust the IPCC anymore.
The simple logic you speak of says that the Indian government thinks that Dr Pachauri has distracted efforts to combat global warming. As you youself quoted, the government admits that the glaciers are melting.
Skip, I try to stay away from references to genitalia, implicitly or explicitly.
I agree that Hitler's worldview was probably coherent, but that's the whole point. The point of the anecdote Coby provides here is meaningless. It's not about saying something substantive about one's scientific argument. It's about insulting one's intellectual opponent on some abstract level that doesn't really deal with current science as much as some ideal that science (as an abstraction) attempts, but sometimes fails, to live up to.
I'm beginning to think that much of this 'debate' (the larger AGW debate) is mostly people that agree on the main points that you see as 'the existing understanding' talking past each other based on some division, mostly political. I'm sure that there are people on both sides of the 'debate' who just don't know what they're talking about nor have any real interest in science, but are rather willing to simply believe and regurgitate what talking heads tell them. That could be the New York Times or Fox News.
Can we agree that there are a large range of possible outcomes in the climate in the near future (next 100 years) and that these different possibilities necessitate vastly different responses from policymakers?
In Peter's defense: It seems this is The Telegraph's screw-up, not Peter's. If WUWT and it's commentators are to be trusted, the Telegraph article did originally included the text:
The article had the title "India to âpull out of IPCCâ". In fact, we can verify this by looking at the URL Peter gave us:
http://www.telegraph.co.uk/earth/environment/climatechange/7157590/Indi…
Which now redirects to the corrected article, "India forms new climate change body". Peter can thus not be blamed of lying (unless he knew it was a mistake), only for trusting bad sources.
Peter can thus not be blamed of lying (unless he knew it was a mistake), only for trusting bad sources.
A failing common to deniers in my experience, but point well taken.
Can we agree that there are a large range of possible outcomes in the climate in the near future (next 100 years) and that these different possibilities necessitate vastly different responses from policymakers?--Max
I think we can, and among that range of possibilities is really, really nasty outcomes. This is where, in my view, the the policy implications are a no-brainer even if the science is not. But we'll save that for another thread. Perhaps "Acting on Climate Change is Suicide".
Not really. The "large range" is highly dependent on responses from policy makers. In the absence of such response, and the absence of unlikely and unpredictable super-disasters (nuclear war, cometary impact, super-volcano, etc.) the range of "business as usual" emissions isn't really that wide, so the uncertainty in outcome is mostly contained in the uncertainty in climate sensitivity - which also isn't as uncertain as deniers claim. 100 years of that will lock us into temperatures that will melt the polar caps (taking at least 500 more years to melt Greenland and thousands to melt Antarctica, but it will be inevitable after 100 years of BAU). Oh right, and the fisheries and coral reefs will be dead.
Yet more ducking and weaving from the IPCC. The article puts it very well: "A LEADING British government scientist has warned the United Nationsâ climate panel to tackle its blunders or lose all credibility."
http://www.timesonline.co.uk/tol/news/environment/article7017907.ece
GFW, what information are you using to determine that fisheries and coral reefs will be dead? I would be interested in reading those articles.
How well do we know climate sensitivity? It seems rather hard to quantify such a parameter when we know little from observations. It's pretty ad hoc at least to me.
The latest IPCC report gave a range of possible temperature change of between 1 and 6 degrees centigrade for the doubling of CO2 in the next 100 years. How is that number dependent on what policymakers do? It is simply taking the hypothesized feedbacks along with direct forcing from CO2 and calculating the change in T. There is also a range of change in sea level between 10 cm and 2 m.
It seems like many of your claims are about very complex systems that depend on climate in an even more complex way. It's not enough to say 'it's get hotter so this and this and this will die'. I'm sure some ecosystems might even benefit from such warming. Is that impossible?
The errors seem likely to bring about change at the IPCC. Field said: âThe IPCC needs to investigate a more sophisticated approach for dealing with emerging errors.â
And if they do, Peter, would you still say there is nothing to worry about regarding AGW?
The ARs are enormous documents and we have seen the fruits of poor quality control.
Nowhere in the article does Field declare the IPCC to actually be wrong in its fundamental assertions regarding climate change and its causes.
The Warren Commission report also contains numerous errors--even regarding the timing of Oswald's bullets. But the fact is Lee Harvey Oswald still acted alone when he assassinated Kennedy.
Your logic amounts to, "The IPCC has made unsubstantiated claims about the following things--Himalayan glaciers, African agriculture, sea level, etc. Therefore climate change is not threatening."
skip, what assessment is your logic that climate change will be threatening (or at least more threatening than the earth already is) based upon? If it is based on the IPCC's using of gray papers as proof, then I would as least say that it's suspect. As I asked GFW, does it seem impossible that some might even benefit from AGW or any other kind of global warming for that matter? If it isn't impossible for such outcomes, the risk-benefit analysis of policy-making becomes much more complicated, doesn't it? Let's say that AGW causing 10 more major hurricanes a century, as proposed in a recent Science letter, but 200 million people have an easier time finding fresh water. What would you do?
@40, Maxwell
So you don't know if climate sensitivity to CO2 can be determined and therefore science can't? Have you actually tried to gather some information before writing this down? Svante Arrhenius computed already in 1896 that CO2 doubling would cause 4-5 degrees warming. Many, many other theoretical, empirical and observational studies have come to similar conclusions.
Take a look at Naomi Oreskes (professor in science history) short presentation on politics and the public understanding of scientific knowledge about global warming: http://video.google.com/videoplay?docid=-7385517651729389593
The fact that the IPCC made a few errors in the sections about the effects does not undermine the understanding of global warming by science in any way. The sceptics can twist and wiggle about much on these imperfections, they'll probably only delay the action that has to be taken now. Which is actually what this wiggling is all about.
Cynicus, if you are determined to misread my comments, there is little I can do to discuss this issue with you.
I do know that the greenhouse effect on earth is not as strong as Arrhenius thought, but have been unable to find a definitive calculation showing what the forcing just from CO2 doubling would be. Have you seen such a calculation?
Since climate does not live in a CO2 vacuum, just because one might possibly calculate such a forcing does not mean that this is the true climate sensitivity. There are feedbacks, both positive and negative, and the argument that climate change is a possible threat to humanity deals specifically with these feedbacks. Since they are hard to observe in satellite data, it's hard to say which hypothesized feedbacks are correct, it's hard to know what climate sensitivity is on earth. I mentioned it seeming ad hoc to me because different sensitivities are plugged into models and backcasted. There is no overarching theory to it. That's the definition of ad hoc.
Maybe you could try to answer the question I posed to GFW. How well do we know climate sensitivity? That is, what are typical values of error on values of climate sensitivity? You might want to check out chapter 9 of the latest IPCC AR4 report.
Maxwell,
Do I really need to do your Google Scholar searches for you?
"Ocean acidification coral reefs"
First hit: http://www.sciencemag.org/cgi/content/abstract/318/5857/1737
"Ocean acidification fisheries"
First hit that isn't about reefs: http://icesjms.oxfordjournals.org/cgi/content/abstract/65/3/414
Don't even bother pointing out that "widespread changes" doesn't necessarily mean they'll be bad changes. Of course they'll mostly be bad changes for organisms evolved for current conditions.
For climate sensitivity, the IPCC is very conservative in giving wide ranges of uncertainty ... but think of it this way: while a sensitivity of 1 would be quite a relief (except for ocean acidification) a sensitivity of 6 would be cause for extreme panic. But a sensitivity of close to 3 is most likely, both for explaining paleo data and emergent from models. Please watch the following video http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml
The IPCC AR4 basically punted on sea level, explicitly leaving out dynamic ice sheet changes. More recent scholarship on that issue suggests 75cm to 195cm by 2100. http://www.environment.arizona.edu/files/env/OverpeckWeissPNAS2009SeaLe… If dynamic ice sheet effects lead to the upper half of that range, then it would only take about five more centuries to melt Greenland.
Note that I am generally referring to BAU (business as usual) emission scenarios. The uncertainty in climate outcome is essentially the uncertainty in emissions (which will be affected by policy makers) combined with the uncertainty in climate sensitivity. I think if you reread my previous post, you'll see that it takes poor reading comprehension to conclude I was saying that policy makers can affect climate sensitivity.
I posted a reply but it has links, so it may take some time to get past moderation.
The one thing I didn't address in that reply was your "what if global warming is good" question. That's why we model. (And if you don't trust the models, the results could also be worse, not better.) Even without modeling, many of the likely effects of completely leaving the climate regime which supported the development of human civilization can be deduced. My answers on ocean acidification should point out that it'll be bad for the ocean systems we know. Eventually new ones may evolve but that's eventually. Your specific example of warming making things better (fresh water, post 42 right now) is pretty funny because it's likely the opposite of what will happen. Glaciers and snow packs serve as water storage, accumulating during winter and doling out in summer. As we warm up, most places will see heavier rain in their wet seasons, but generally the same to less rain in their dry seasons. So the loss of natural storage will be a bad thing. Sea level rise will be a bad thing. The first meter of sea level rise takes out half the agriculture in Bangladesh. You can look and find a few positive impacts, but for the vast majority of humanity, the likely effects of several more decades of business-as-usual emissions are negative.
GFW, I guess I'll have to wait to see your sources.
I agree that there will be change, but I see no reason why everything will have a negative effect on humanity. Surely some will be, but negative change is part of this planet.
As per the example of Bangladesh, any agricultural land lost to sea level rise in that rather small country will be more than made up by vast tracts of land in the northern hemisphere that will be easier to cultivate. As the sea rises there will also be new shallow seas to support disappearing reefs and fish populations. As fresh water is released by land locked glaciers it will also reduce the concentration of dissolved CO2 thus reducing the pH, decreasing ocean acidification. It seems like much of those problems have the possibility of balancing out just from a cursory glance.
You may also be interested in reading the reviewers comments to the section of the IPCC AR4 dealing with climate related disasters or humanitarian needs.
www.ipcc-wg2.gov/AR4/SPM_REVIEWS/SPM_SOD_Experts.pdf
There is an entire literature showing that much of the hub bub over sea level rise, hurricanes, fresh water resources and agriculture is either unfounded or even quite the opposite. This paper,
www.jpands.org/vol4no3/goklany.pdf
also shows that when it at least comes to fresh water, the current models predict that increasing temperatures will make it easier for more people to find more consistent fresh water.
This is about a debate and coming to a solid conclusion. While in the end you may be correct, there is very little evidence at this point to back your position. That does not, however, mean that the opposite is true and I am not making that argument. I am merely pointing out that your argument is not as obvious as you make it out to be.
maxwell said:
Just which part of the northern hemisphere are you referring to? For your information it is not temperature which prohibits growing of agricultural crops as you head north. It is usually soils. If you go north in Canada you hit the Canadian Shield. I doubt very much that a couple of summers of warmer weather will split the bedrock and allow it to be plowed. In other areas such as Alberta, as you head north from the agricultural land you get into muskeg, again completely unsuitable in the short term (100's to 1000's of years) for agricultural use. In fact if you go further north again you do get into agricultural areas because the soil has improved, not because it is warmer e.g Peace River area, Fort Vermilion.
This is a canard put out by the AGW deniers to justify their "do nothing and we will be alright philosophy". It is completely wrong.
maxwell: "I mentioned it seeming ad hoc to me because different sensitivities are plugged into models and backcasted. There is no overarching theory to it. That's the definition of ad hoc."
Sorry, this is completely wrong, at least for any of the models that matter or are cited by the IPCC. Climate sensitivity is an output of models, not an input. That is very basic.
That should fundamentally alter your thinking about the issue.
"Just which part of the northern hemisphere are you referring to? For your information it is not temperature which prohibits growing of agricultural crops as you head north. It is usually soils. . . I doubt very much that a couple of summers of warmer weather will split the bedrock and allow it to be plowed."
And of course, no human innovation will allow sufficient food production in any other way, so I guess we're doomed.
This is a canard put out by the AGW alarmists to justify their "do what I say now and we will be alright philosophy". It is completely wrong.
Coby,
Sorry but i dont understand your last post re sensitivity. I always thought that a model would require you to include all the known forcings as an input which would them determine the resulting output.
For example if we consider all the parameters that effect climate and how they interact with each other and give them a value we will get an output, then if we change an input it will change the output. We can then determine what effect this parameter has on all the other parameters and what effects it will have on future climate.
Now i know this explanation is rather simplistic but i would have thought sensitivity would be something that was considered as an input as it has a direct influence on dictating the output.
I would be interested in hearing how it is an output result rather than a critical input parameter.
Cheers
Crakar
Coby,
I think you need to read the context of the conversation a bit more carefully.
I am not discussing what specific models produce in context of the IPCC. I am saying that calculating climate sensitivity in the absence of CO2 forcing is ad hoc. According to IPCC AR4 report box 10.2,
'Since climate sensitivity of the real
climate system cannot be measured directly,
new methods have been used since the TAR
to establish a relationship between sensitivity
and some observable quantity (either directly
or through a model), and to estimate a range
or probability density function (PDF) of climate
sensitivity consistent with observations.'
According to the Free Online Dictionary ad hoc is an adjective meaning impromptu or improvised. Therefore, such calculations are ad hoc.
If one is interested in knowing how the climate will change with respect to increased GHG emissions from a model, then one must input the climate sensitivity to CO2 into such a model. There doesn't seem to be an overarching theory to how different groups calculate this climate sensitivity, which was my point. So, no, I don't think I need to change the way I need to think about this. Just because researchers have only done so much doesn't mean that's all we can discuss.
Ian,
Paul makes an interesting point. If people can figure out a way to till the land in a place like Phoenix Arizona, I"m sure that there are ways to use land in the great white north.
Since it will take hundreds to thousands of years for the sea level to get to a point where a place like Bangladesh's usable land is under water, we have some time to figure out how to use that land.
Why do you not go and visit these northern areas you talk about? It is obvious that you don't have a clue as to what you are talking about. No new technology will allow you to grow crops on bed rock or in muskeg. Go and read a high school geography book.
Good grief, you deniers are so ignorant of the world around you.
And it won't take thousands of years for the arable land in Bangladesh to be useless, it is happening now with salination from rising sea levels.
This is an interesting topic and i would like to share a story with you.
http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comme…
So even if you could grow crops on bed rock and muskeg (whatever that is) some greenie with a little bit of power would put a stop to it.
Maxwell, my earlier comment popped up at what is now #45. Your non-IPCC link in #47 gives page not found.
Maxwell and Crakar, you've both said (#51 & #52) that you think sensitivity is an input to models. As Coby just told you, you're wrong. This is a massive, fundamental lack of understanding. It's correctable, but you'll have to do some reading. Models take known physical properties of gasses, water, ice, vegetation, the sun, etc., and simulate how the earth system evolves. To greatly simplify, to see what any given model produces as sensitivity, you run it with different levels of CO2 (the amount of CO2 is an input) and see where the temperature winds up. I think I can enter one link without getting stuck in moderation, so read about how GISS-E works here http://www.giss.nasa.gov/tools/modelE/modelE.html This model, like all others, simply (well, not so simply, as you can see) applies physical rules for what happens at each time step. Evaporation rises, rain/snow falls, ice accumulates, ice melts, ocean currents flow, ... and radiative heat transfer takes place in the atmosphere, according to the known IR absorption bands of the constituent gasses. Sensitivity is the result, literally how sensitively the eventual (average temperature) result depends on CO2.
Ian, as the person who brought up Bangladesh, yes, saline infiltration is already a serious problem there - also in the Nile river delta, the Murray river, and some other spots around the world. I use the 1 meter = half the agriculture there gone figure because it should be shocking. We are likely to get 1 meter before 2100, and there are currently >160 million Bangladeshis. (I guess Maxwell figures that in a few decades we can transplant 80 million of them to farm the muskeg in northern Canada.)
"Why do you not go and visit these northern areas you talk about? It is obvious that you don't have a clue as to what you are talking about. No new technology will allow you to grow crops on bed rock or in muskeg. Go and read a high school geography book."
Completely irrelevent, but typical of alarmists. I didn't talk about "northern areas", you did.
I related the creativity of humans on this earth to increase food production as demand dictates, a capitalist solution, also denied by alarmists.
And creativity would allow the food production would probably not be on a rock but, elsewhere. Creativity, also not practiced by alarmists.
And extrapolating from your technology remark, I suppose no new technology will be developed to provide our baseload power demand?
Alarmists are typically trapped into thinking in ways which prevent them from finding solutions, which you have aptly demonstrated.
Thank you, Ian.
@PaulinMI
Allow me to put it into more capitalistic terminology:
Increases in food productivity have often been directly linked to the stability of the country in question. A functional democracy or an enlightened dictatorial regime is generally a requirement, as these are willing to change and often have the technological ability to do so. This is hardly the case for many of the countries that will suffer most from projected climate change, even at the low limit of climate sensitivity (1.5 degrees). The functional democracies and enlightened dictatorships will thus see an influx of climate refugees, essentially destabilising those functional democracies and enlightened dictatorship. This is bad for the free market, as both such regimes will likely attempt to keep those refugees out, which by itself will destabilise the free market.
And yes, this is alarmist writing. Sometimes it needs to be put in extreme terms to get someone to open his eyes to reality.
GFW,
the new link is
www.jpands.org/vol14no3/goklany.pdf
Sorry for the confusion.
I think you need to read my comment a little more thoroughly. The IPCC report clearly states that groups use historical data to help determine the probability that a specific general circulation model for producing a climate sensitivity is likely (box 10.2 of the AR4). That's all I was saying. That's why I didn't say that climate sensitivities are plugged into general circulation models, as Coby is assuming I did. Are you (or Coby) disputing that the determination of probability density functions for climate sensitivity, as per said box, is a model? Since it is, there is nothing fundamentally mistaken about what I said.
Moreover, in chapter 9 of the AR4 report, page 718 to be exact, the authors state,
'Inferences about climate sensitivity from observed climate changes complement approaches in which uncertain parameters in climate models are varied and assessed by evaluating the
resulting skill in reproducing observed mean climate.'
Therefore, there are some models used by the IPCC where the climate sensitivity is an input. Those varied climate model parameters add up to the sensitivity. Historical data is then used to constrain the range the real climate sensitivity may fall within based on that sensitivity's ability to reproduce mean climate.
So you (GFW and Coby) are asserting that I am discussing general circulation models when I am not. Maybe in lieu of accusing me of something because what I have written may not be especially clear, you could ask mo to clarify it for you. That way it doesn't make your contribution to this conversation seem disingenuous.
I also like the caveat that 'widespread changes' must mean what you want it to mean. If the changes were bad, why wouldn't the researchers just write that? I find such projections of your position onto the literature highly problematic.
What is most interesting about this conversation is that there is ample evidence on both to keep a debate going. I don't think that anything will definitively happen. The uncertainty in sensitivity is real and even with the best methods available, there is not really a way to quantify it.
From box 10.2,
'There is no well-established formal way of estimating a single PDF (probability density function) from the individual results, taking account of the different assumptions in each study. Most studies do not account for structural uncertainty, and thus probably tend to underestimate the uncertainty.'
So they ensemble all the different methods for finding climate sensitivity and hope their individuals errors go away. There may be some merit to this approach, but it seems about as ad hoc as an approach can it.
The sensitivity is reasonably between 1.5 and 4.5 degrees centigrade when using historical data, but it's hard to rule out values lower and higher. Doesn't sound too definitive to me. If this is a debate where we are each providing data and arguments based on sources (maybe you could a little harder on this facet however), what's with the disdain?
As for disasters, I find Roger Pielke Jr.'s blog much more instructive than random Google scholar searches.
http://rogerpielkejr.blogspot.com/
"the new link is
www.jpands.org/vol14no3/goklany.pdf
Sorry for the confusion."
Sorry for adding to your confusion, but the JPandS isn't really your most credible journal:
http://en.wikipedia.org/wiki/Association_of_American_Physicians_and_Sur…
@Marco,
Seems we agree, capitalism in a free country is the best solution. Now if we can just get the UN to espouse this . . .
Well, one can hope.
PaulinMI said: "And of course, no human innovation will allow sufficient food production in any other way, so I guess we're doomed."
so there's no need to make contingency plans, for God^W Technology will provide?
i can't say that i share your blind optimism, though i'll admit it's a refreshing change from the usual argument i've seen among deniers: that we cannot possibly move away from fossil fuels without sending ourselves back to the stone-age.
Marco,
every editor has a bias. Find problems with the research and you'll have an easier time catching my attention.
@ligne,
"i can't say that i share your blind optimism"
you lost me on that one
maxwell: there's a huge difference between an editor having a bias, and an editor who is apparently willing to publish any old craziness that happens to support their worldview.
and why on earth should Marco waste his time reading something that's apparently only good enough for a crackpot journal?
PaulinMI: the blind optimism that, at some point before Bad Things start to happen, technology will ride over the horizon like the Cavalry and save the day.
personally, i like to have a bit more of a safety net, especially when the stakes are that high.
@PaulinMI:
Sorry to bust your bubble, but I am actually a realist. The UN can't do something that the majority of its countries either don't support, or have not yet achieved. For example, however much India is a democracy, it simply does not have the tools yet.
@maxwell:
as ligne said. I'm not going to spend time on debunking stuff in a crackpot journal. You'd be wise to try and debunk it yourself, rather than accept it at face value. I prefer to debunk papers in journals which are a) not so bleedingly obviously politically motivated (in fact, preferably not politically motivated at all), and b) actually have a solid impact in the scientific world.
Marco and ligne,
this paper simply looks at the risk to global warming as spelled out by both the World Health Organization and Fast Track Assessments (by authors of relevant IPCC chapters) and analyzes the threat of global warming compared to other health threats as time goes on. All of the data comes from the WHO and FTA's, but has actually been put together in this paper. It simply looks at how global warming changes risks to public health in 4 different scenarios. There is nothing to this paper that screams a bias of any kind. I'm sure that this will not convince you one way or the other, but I thought I would point it out to you both nonetheless.
If only articles from journals you deem worthy of publication are able to be added to this conversation, I would rather pass on continuing it. Thanks anyways though.
@ligne,
"the blind optimism that, at some point before Bad Things start to happen, technology will ride over the horizon like the Cavalry and save the day."
So what are you hoping for to take the place of base load power, if not technology riding over the horizon?
Next I suppose all you AGW alarmists will say that Mann's Hockey stick representation of the trend in global temperatures is correct. You are all alone as in the real world that representation has been debunked many times overs. What's key to it is that the AGW story is primarily based on this. Given that pillar has crumbled, the AGW alarmists have nothing but their egos to hold up their opinions. See for example, http://www.theregister.co.uk/2010/02/08/andrew_montford_interview/
PoS: which hockey stick? MBH98, which had a minor statistical error that changed the result not one iota? or Wahl and Ammann's paper that found the hockey-stick to be robust, when analysed using a variety of statistical techniques? or Mann's 2008 paper that extended it further back, with and without tree-rings, and got a hockey-stick too? i hate to say this, but the hockey-stick is solid, and here to stay.
seriously, if you're going to troll, at least put some effort in. aim high and go for "50 hitlers" or something, rather than just trotting out some tired old rubbish that's been debunked a thousand times.
maxwell, sorry if I have been misreading your comments. I still have not seen anything supporting your statement(s) that climate sensitivity is an input rather than an output of anything referenced by the IPCC.
You wrote:
No, I don't believe so. Your IPCC quote most definately does not support your conclusion.
Sure, the varied parameters, along with the physical priciples and other algorithms that make up the model affect the computed sensitivity. But stretching that to "therefore sensitivity is an input" is semantic gymnastics and certainly an uninteresting place to discuss from.
You have again swapped things around. The sensitivity values produced by model runs using combinations of assumptions of highly uncertain data are constrained by historical observations.
Look, I'm not saying that no one, no where has configured and run climate models where climate sensitivity can be manually adjusted. But in the broad context of climate change discussions that are usual around here, it is simply another contrarian fallacy to claim that high sensitivity to CO2 forcing (or other forcings) are input into the models. Sensitivity is measured from model run outputs.
"@ligne,
"the blind optimism that, at some point before Bad Things start to happen, technology will ride over the horizon like the Cavalry and save the day."
So what are you hoping for to take the place of base load power, if not technology riding over the horizon?"
==================================================
Wow, did I miss it here! I sincerely apologize.
Here we have a half dozen people communicating simultaneously, each half a world a way.
Discussing a science which uses orbiting satellites to measure the earth within a millimeter and have that data readily available, almost in real time. Also measuring temperature to within 0.1? 0.01? by reading a vibrating molecule (at various altitudes?)
Then this same information is fed into computers which can model the climate across the entire globe.
And for historical data we have the ability to date a carbon atom!
And one could go on and on for every field of endeavor!
Well, Hell Yes, technology will save the day! Is there any doubt?
Coby, I think that we are talking past each other. In order to start any climate model, one must 'guess' what the climate sensitivity is. From there, one can vary parameters until there is good agreement between the model and observations and see how the climate sensitivity has changed and possibly even argue that the value found at the end of the model is close to the real climate sensitivity.
Your last comment is rather confusing, especially,
'The sensitivity values produced by model runs using combinations of assumptions of highly uncertain data (that) are constrained by historical observations.'
The AR4 clearly states in box 10.2 that climate sensitivity is not observable. There are no historical observations of climate sensitivity. Therefore a variety of other parameters must be produced by the model to test against historical observations, right?. That is, precipitation or temperature. How does one produce a climate model that has temperature and precipitation changes not based on its sensitivity to those factors to begin with? The physics of what you are proposing do not add up. It's simply an optimization process, but one needs a place to start.
I understand that the climate sensitivity used to get 'off the ground' is not the same as is being discussed as the output. I don't know if you see the difference I am talking about, however.
As far as your last comment is concerned, since I mentioned nothing of sort (high sensitivities being inputted in the models at the get-go) I'm going to assume that you are not talking about me. I would assume, perhaps wrongly, that if one started out the model with an ungodly high sensitivity and tried to optimize your model with historical data, that sensitivity would come down. Maybe now it will be easier to see eye-to-eye.
Hi Peter.
Got a chance to look at your link. (Don't worry Coby and Max I'm still following your discussion about forcing as input versus output.)
So anyway here are my questions, Peter:
(1) Did you read your own link in its entirety?
(2) Do you stand by everything said in it?
(3) Do you still believe the IPCC lacks credibility because of its recent mistakes regarding Himalayan glaciers, etc?
Coby,
Sorry but i still do not follow what you say, of course it should be noted that i would not know a climate model even if it bit me on the arse.
Are you saying that there is no sensitivity factor as an input but after the model is run we can compare the output to the input and work out the sensitivity value is?
The IPCC displayed a graph in one of their reports which predicted the temp in 2100, does this model use a sensitivity value as an input? If not how could they accurately predict the temp by 2100?
Confused
Crakar
maxwell, I think I understand what you are saying, but I think you are wrong. Maybe we have a terminology confusion? The simplest model experiment would be to apply a forcing to the system of x W/m^2 and then observe the change in average surface temperature. You can now say that the climate sensitivity is y oC/W/m^2. Or as is generally measured, you double the CO2 in the model's atmosphere, calculate the radiative forcing that causes using equations that describe energy flow (absorbtion/reemission, convection) - I believe this gets you about 4 Watts/m^2 - apply that forcing to the system and see how much the temperature rises.
By convention, sensitivity to CO2 also includes the "fast" feedbacks of water vapour, sea ice and cloud cover changes. The value that models have been converging on for the past couple of decades is ~3oC / doubling of CO2.
The value is further constrained by historical observations. Sometimes the data is very uncertain so the forcings from various factors are varied until values are found that reproduce the historical temperature record. Are we confusing "forcing" and "sensitivity"?
At no point that I am aware of is a "sensitivity factor" plugged in. I may be wrong but your IPCC quotes do not indicate that I am.
crakar, does that answer you? The IPCC projections are not based on assumed sensitivities, they are based on projected forcing factors (the future trajectory of CO2, volcanic action, soot etc - all unknowable today). Those forcings, or specifically the quantities of insolation or gas concentrations, are run through the models and produce a temperature trajectory (and lots of other amazing stuff, btw).
Yeah i think so Coby, would i be wrong to say that a forcing is a real tangible event that is an input, however the amount of change in temp (output) observed can be seen as the climates sensitivity to the change in a forcing (input).
So we could say that a small increase or decrease in TSI (input forcing) will produce a small change in temp (output) therefore the climate sensitivity to changes in TSI is low. Is that close enough, or is there more to it?
TIA
crakar
The current go-round of AGW has benefited from the propensity of the www. In an article I'm writing, "Ghosts of Greenhouse Past," the history of the idea is shown to go back to post Civil War days where it languished in book selves of dusty Libraries. By the First WW the 'Greenhouse' had been put to laboratory tests and, of course, failed. Many had pointed out the problems Greenhouse had with Thermodynamics and Professor R. W. Wood, in 1909, showed by simple, elegant experiment that there was no Greenhouse Effect as, of course, most of that day knew.
As England was being blown to bits by the Germans in the late nineteen-thirties Guy Callendar was working on a radiation problem at unlit airport runways. Shortly after sunset, a radiation fog would cover and obscure the runways for returning English fighter planes. This fog is condensation developed by the radiation cooling. Smudge pots were used to generate carbon particles on which the fog droplets would condense and fall as rain.
I came across this in Engineering College in the 1950s while researching articles about the Callendar 'Steam Tables,' and finally realized that the WWII Callendar was the Steam Table Callendar's son. Guy's father, Hugh, was a respected Engineer who developed much of Steam Power technology (Thermodynamics) and I suspect that Guy's paper of 1938-39 was published -- after rejection by reviewers -- out of respect for Guy's Father, Hugh.
. . .
Thus, the 'greehouse effect' turned out to be what I call a 'noncept.' It just does not exist and all the foofaraw about it perpetrated over the WWW by the Green Horde will never change that Thermodynamic fact: When a molecule near the planet radiates energy THAT MOLECULE MUST COOL. No other result is tenable. . .
The AGW perps for this go-round have developed a religion, not a science, settled, consensus or otherwise. When you point out the thermodynamic facts of the matter they reply "That's been gone over. . ." or " ..that has been looked at. . ." et c. If it is a religion, the joke's on the perps: For St. Augustine they have a one-eyed itinerant mechanic and for St. Paul, Al Gore.
Thanks and Enjoy the Day,
Robert L Hamilton, Engineer
Sure, but the radiation goes somewhere, and the molecule isn't the only one in the atmosphere, in the case of earth.
I sure hope you're not responsible for any bridges built anywhere in the world (since I travel quite widely).
Oh, and congratulations on figuring out how to write "Hello World" on your web page!
I'm overwhelmed!
And, of course, your history lesson ignores the fact that Tyndall published on the greenhouse effect about a century before your WWII anecdotes begin ...
Sheesh.
a forcing is a real tangible event that is an input, however the amount of change in temp (output) observed can be seen as the climates sensitivity to the change in a forcing (input)
Yes, that is basically it, AFAIUI. I think I have seen them say over at RealClimate that sensitivty is essentially the same per W/m^2 regardless of the underlying cause. So 4W/m^2 of solar output would have the same ultimate effect as doubling CO2
Coby,
I think I see your point. But I still don't see how the model reacts to any forcing if there isn't a climate sensitivity input, even if it is implicit. The physics doesn't seem to add up.
Ok I admit it.
I don't understand the difference between the idea of "forcing" and "sensitivity".
I could probably review the last dozen posts and figure it out but I want to try first for the lazy man's option of having someone explain it in different terms for me.
Skip,
forcing is a measure of how much energy, or potential energy, is added to a system. That is, the sun adds so much energy per unit time per unit area each day. I think the number is around 1000 watts per meter squared.
The sensitivity of the system measures how the system reacts to that added energy. That is, either the system can take that energy and turn it into a change in temperature of one a few different internal systems like the atmosphere or ice sheets, or dissipate it in the form of heat as IR radiation emitted to space. The common units for sensitive are degrees per unit forcing. So the two quantities are related in a hypothetical cause-effect relationship. Forcings cause change in temperature, depending on couplings, via the climate's sensitivity to those forcings.
My point to Coby was, in the context of a climate model, how does one induce a change in the model if the model isn't sensitive to changes in forcings to begin with? It seems that there are some inputs (what Coby calls 'absorption/emission, convection') that determine how energy added in the form of sunlight, molecular vibrations or other forcings moves around in the model. I don't understand how these parameters are different from the sensitivity of the system. I understand that given a set of parameters that control how energy flows through the model it may be hard, or impossible, to directly calculate the sensitivity and that running the model with different forcings produces a value for the sensitivity, but there are no hidden variables in the model.
It's not as though you enter something entirely different from sensitivity, run the model with different forcings, and voila, sensitivity appears. The models have to be self-consistent, meaning that nothing can come out of them that didn't start there.
Note to everyone: I am NOT making an argument that researchers are using improper inputs in ANY way. I am merely pointing out that something seems to be missing, physically, from the explanation that Coby is providing. I'm sure there are good reasons for believing that absorption/emission, convection and other ways that energy moves around in the model the way they do. I'm just having a hard time understanding how starting with those conditions is significantly different from entering an explicit value for the sensitive other than the fact that one cannot directly calculate the sensitivity from those conditions.
of course it should be noted that i would not know a climate model even if it bit me on the arse. --Crakar
Are there circumstances under which you would have to presume it was a sheep dog? (Sorry, mate; sometimes its just too easy.)
forcing is a measure of how much energy, or potential energy, is added to a system . . .
. . .The sensitivity of the system measures how the system reacts to that added energy.--Maxwell
Then, I should note, I have been using the terms interchangeably and incorrectly to mean, "the effect of CO2" on temps.
It's not as though you enter something entirely different from sensitivity, run the model with different forcings, and voila, sensitivity appears. The models have to be self-consistent, meaning that nothing can come out of them that didn't start there.
Ok I think I see yours and Crakar's (there's one for the archives) point.
And I too, as a non-expert, would have just assumed that some presumed sensitivity would have been an input. However,
The AR4 clearly states in box 10.2 that climate sensitivity is not observable. There are no historical observations of climate sensitivity. Therefore a variety of other parameters must be produced by the model to test against historical observations, right? --max from earlier in #73.
If that is correct, then I fully admit that this, as articulated and to the extent I understand it to this point, baffles me.
Skip,
the 'effect of CO2' is two-fold. When a molecule absorbs IR light emitted by the sun or the earth. It wants to get rid of that energy after some internal dissipation. It can do so in two ways. First is just through spontaneous emission. That is, after absorption, there is a finite amount of time that the molecule remains energetically excited. After this time, it will emit the energy in the form of light, IR light to be exact. This IR light is emitted in every direction. So as one moves higher and higher in the atmosphere, this process plays a smaller and smaller role because less of the light is emitted in a direction toward the surface of the earth.
The second way CO2 gets rid of its energy is through inelastic collisions with other molecules and stuff in the atmosphere. It is important because molecular nitrogen and oxygen, which make up the vast majority of molecules in the atmosphere, cannot absorb IR light directly. CO2 then acts like a middleman of sorts absorbing light and transferring it to other molecules so that energy is then trapped in the atmosphere that would have otherwise passed unhindered. This energy can then be used for increasing temperature, depending on the couplings in the rest of the climate system. This is a bit more complicated and has a lower likelihood of happening, but based on the density of molecules in the lower portions of the troposphere, it contributes to the greenhouse effect.
What is noteworthy about these mechanisms is that energy does not start in CO2. Either the IR light is initially emitted by the sun or the earth. That is, when you change the concentration of CO2 in the atmosphere, you are changing both a forcing (because CO2 molecules can transfer energy back into the climate system after absorption) and sensitivity because this forcing of CO2 is directly dependent on the forcings of the sun and emission of gray body radiation by the earth.
Don't worry if all this sounds confusing. I think it makes even less sense to me. Again, sometimes the more you know the less you understand.
Maxwell,
You're asking some good questions there, and I'll try to give as clear an answer as I can. I think Skip will find this of benefit too. Bear in mind I'm not a climate scientist, but I did learn some relevant material in the course of a PhD in physics.
First up, the following diagram is *really* helpful. http://climateknowledge.org/figures/WuGblog_figures/RBRWuG0086_Trenbert…
Note that solar input is expressed in W/m2 over the earth's surface, which is 1/4 what it would be if expressed as W/m2 of a flat cross section facing the sun. This is how all the other numbers are expressed.
Clearly it's an interactive system and the diagram is averaging some things out. For example solar input varies 7% between perihelion and aphelion, but that averages out completely over a year. Solar input varies 0.1% over a solar cycle (which basically averages out over 11 years or so) and the recent solar minimum was 0.005% lower than the last one. Any variation to that input causes immediate proportionate changes to the absorbed and reflected paths on the left, but slower changes on the right as the new equilibrium is found. Similarly, an increase in greenhouse gases will increase the 356 (earth to atmosphere) at the expense of the 40 (atmospheric window) *and* to a lesser extent the 78 direct atmospheric absorption at the expense of the 121+23 ... and then all the numbers out of the atmosphere (169+30 up, 333 back down) would go up.
So, when talking about sensitivity, the steps are:
1) Change something :-)
2) Figure out the consequent instantaneous imbalance in W/m2 at the top of the atmosphere.
3) Figure out the eventual change to surface temperature to eliminate that imbalance (i.e. the new equilibrium).
Now, the details clearly vary, but as long as we're talking about imbalances of less than 1% of solar input, the difference in details are so small that going from step 2 to step 3 is the same, no matter the form of the change in step 1.
Similarly, if you change two things at the same time, but each change has a forcing of less than 1% of solar input, then any interaction between the two things will be on the order of 0.01% ... so you can basically treat the two changes independently. So while it's true that the forcing from a doubling of CO2 would be different on say Mars than it is on Earth, as long as we stick to reasonably sized changes in other parameters, we can consider the forcing from a doubling of CO2 to be a constant W/m2 and therefore a constant degrees C for the temperature range relevant to human habitation of Earth.
I think that diagram does a good job of summarizing the effects you discussed in you second paragraph in #86, Maxwell. There's a relatively unimportant mistake in your first paragraph though. The depth of the atmosphere is quite small compared to the diameter of the Earth. So from the point of view of a molecule in the atmosphere, the Earth always occupies pretty much 50% of the field of view. The effects of greenhouse gasses diminish with altitude simply because the gasses are getting thinner.
GFW, thanks for the pic.
If we're gonna quibble, I'd still say that my elaboration is correct, although maybe not as big a role as the barometric distribution of particles. But it is still correct.
Where does the pick take into account collisions though? I mean, since molecular nitrogen and oxygen can't absorb IR light, they can't emit it. They have to collide with another greenhouse gas molecule like water or methane and transfer the energy back, maybe even lose some energy in the form of frictional heating. It doesn't seem to me that nitrogen or oxygen have a way to internally dissipate energy they get by colliding with a greenhouse gas molecule, but I may be mistaken in that assumption. If they do, doesn't that mean less energy is radiated back to the earth after collisions with homonuclear diatomic molecules?
Have to admit being over my head here.
As a person with an opinion on a serious topic that I cannot completely understand, I fully confess on points like this to making what some critics on this blog have dismissed as "appeals to authority".
The reason I do this repeatedly Maxwell is that, as most laymen go, I have investigated over and over again the contrarian claims that I *can* understand, and find so many of them to be so bloody inane that other potentially more meritorious critiques (as your might well be) get lumped in with these rabble via guilt by association.
Thats not fair and I recognize that. You're a smart, reasonable bloke. But in the end I need a little more than a sound *looking* argument to convince me that the preponderance of climate scientists are wrong because of something that, at first blush, doesn't seem that profound and which I have to assume for the nonce the pros have considered and addressed.
But keep posting. Who knows, maybe you'll upend the whole AGW paradigm and we can all go back to ESPN.
maxwell, regarding transfers via collisions I think this is simply too little to be significant. GHGs are trace gases, all together adding up to less than one percent of the atmosphere. The bulk of energy coming into the atmosphere arrives via conduction from the earth's surface and spreads via convection. One other small quibble is that very little of the sun's energy arrives here in the form of IR, little enough to be ignorable in general.
Back to sensitivity as an input: firstly, I don't think it is correct to call the physical principles encoded in a climate model "parameters". I am taking about equations that take quantities of various things (incoming insolation, concentrations of CO2) and turn them into temperatures and wind speeds, etc)
"It's not as though you enter something entirely different from sensitivity, run the model with different forcings, and voila, sensitivity appears."
Yes, it is. Perhaps it is useful to look at a very simple climate model to illustrate what I mean (and if we all click this link, the good Dr. Grumbine might appear and set us all straight).
http://moregrumbinescience.blogspot.com/2008/09/summary1-of-simplest-cl… summarizes his series of educational posts on simple climate models.
RG has gone through the process of establishing the simplest kind of climate model for determining the earth's surface temperature which is actually one line:
T = (S*(1-a)/r^2/4/s)^(1/4)
So using this to illustrate determining climate sensitivity you can simply plug in the current S of 1367W/m^2, compute T, then plug in 1371W/m^2, compute T and compare them. You have then determined the climate sensitivity to an increase of 4W/m^2. (For the other values please click the link).
Modern GCMs are clearly seveal orders of magnitude more complex, but the principle is the same. Sensitivity is measured.
skip, your understood meaning of "climate sensitivity" is in fact what it is commonly referring to, especially in the climate wars where CO2 is the major issue. Absent any other qualification when you see "climate sensitivity" in our usual context you can take it to mean the expected equilibrium change to the average temperature of the earth's surface that would result from a doubling of CO2 from preindustrial levels taking into account feedbacks from H2O, cloud cover and sea ice albedo.
It is actually just a theoretical number because it ignores slower feedback mechanisms like carbon cycle feedbacks (wht drove the ice ages), changes in ice sheets and biological feedbacks (desertification, other ground cover changes). It is also of questionable utility as CO2 levels are not likely to hold still long enough to come to an equilibrium for quite some time.
Skip, layman's terms:
Forcing = any agent that causes the climate to move from equilibrium, altering the Earth's radiative balance, such as (but not limited to) changes in solar luminosity, orbital or rotational changes of the Earth, volcanism, and in this current case, a vast increase in atmospheric CO2 in a geologically short time frame. These agents/mechanisms "force" the climate to change.
Climate Sensitivity = Typically refers to how much the Earths mean global temperature would change (reaching equilibrium) for a doubling of atmospheric CO2. Much research puts this figure at around 3 degrees C per doubling of CO2.
The GCM's attempt to model the actual physical processes of the Earth's climate system, therefore climate sensitivity cannot be an input as it is an abstract, a quantitative method to estimate the Earth's response to a doubling of CO2.
The problem is of course, that there are gaps in full understanding of the various mechanisms at play in the climate system, carbon & nitrogen cycles for instance are only recently beginning to be incorporated into many of the GCM's. See a recent study here for instance:
http://www.biogeosciences.net/6/2099/2009/bg-6-2099-2009.pdf
Add in the course resolution of the climate models (they lack the fine detail that occurs in the real world) and it's easy to see, that they have some way to go.
An additional confounding factor, in estimating climate sensitivity, is the the climate response to any forcing is dependent in the background state of the climate at the time, and this is where the paleo climate studies strike problems as there is no accurate analogue with today's situation with which to make a direct comparison. They are useful however in constraining the values of climate sensitivity - too small and previous climatic changes cannot be accounted for, too much and one would expect frequent and large swings in global temperatures, something not observed in the Paleo record.
Coby,
I think the problem is that you don't seem to recognize the basic physics that is part of the 'simplest meaningful climate model'.
In order to use a version of the Stefan-Boltzmann law, as is done in this model, one must assume that the system of interest is composed of harmonic oscillators that have particular frequencies at which they vibrate in response to energy, ie a blackbody. That equation didn't just fall out of the air you know. From that point one can calculate partition functions, entropy and, believe it or not, heat capacity, which in the case of this model would be equated with 'sensitivity'. As you add so much energy, the modeled system would change temperature according to that heat capacity. It's a rudimentary 'sensitivity' because there are much fewer degrees of freedom in this model than the real climate, but it's there nonetheless.
So no, the 'simplest meaningful climate model' is not just some equation that a blogger wrote down that produces a temperature out of thin air. It's a set of assumptions about the behavior of a particular system, based on known physics, allowing a researcher to reduce the complexity of the system to the point where calculations are tractable. And guess what, the 'sensitivity' of this modeled system is contained within that equation! You just have to ask 'where did that Stefan-thingy come from?' Since you don't ask any questions like this, it's no wonder so much of this makes sense to you. The rest of us trying to actually understand all of this are left sorting through the details.
Take home point. Models do not exist in a vacuum. They have to be self-consistent. For example, the 'simplest meaningful climate model' cannot produce temperatures that a blackbody would not produce. If forcings changed, then the temperature would have to change according to the heat capacity calculated from the partition function. Since we know this as fact for such a small and simple model, there is no reason to run a simulation. For more complex simulations, however, there has to be some physical assumptions that MUST guide the way the system will respond to changes. The computer sure as hell isn't doing it. Even in a genetic algorithm, we use a couple different ones in the lab from time to time, one has to tell the computer what goal is useful. That goal is informed by the physics of the system, but no new physics is obtained.
I know with more certainty than anything else I have written on this or any other climate related blog that if the models used by climate researchers were prone to 'voila' moments that I described in my earlier comment, the global warming they produced would be the least interesting thing about them.
As for the comment about 'parameters', did I hurt their feelings or something? Give me a break. Equation. Parameters. Who cares as long as you know what I am talking about? You clearly do.
I think it's fair to say that your treatment of arguments that back your position versus the treatment you give to those you disagree with you is a bit inconsistent. Gives a whole new spin on the importance of 'coherence'.
Look maxwell, you are simply defing "input" so broadly that there is no such thing as an output. Yes, a climate model is created by people and there is nothing in there that was not "input" and outputs are 100% dependent on those "inputs" so every output was actually input.
In a very tortured semantics kind of way you are right, but it makes the conversation completely uninteresting. Why don't we remind ourselves where we started in comment #49:
It remains completely wrong.
I should have left it there and spared myself the rather patronizing content of your last remarks...oh well.
Anyone else think it is worth more effort?
Coby,
that has to be about the weakest argument I've seen in some time.
Skip,
my posting on this blog has less to do with 'upending AGW' and more to do with the questions I have about how these things work. I think that I have most likely exhausted the amount of useful information here though. Especially when people are willing to completely ignore the blatant mistakes in their own arguments while maintaining the existence of mistakes in others' arguments. Again, seems like inconsistency gets around fairly well.
If you must know Skip i have been bitten on the arse by a sheep, let me give you a tip the next time you are feeding one of the little bastards and you run out of food back away very, very slowly and NEVER, NEVER turn your back on it.
I have enjoyed reading maxwells and others posts, in fact thats a really good name as it is my middle name. My friends used to call me Max and when they would ring they would say "Hello Max this is the chief" complete with dodgy American accent. It all died a sudden death when they started calling my girlfriend "99". Bloody women spoil everything hey.....but once again i digress.
Although Max put it more eloquently than i, i suspect we are asking the same question. A model can only simulate the climate in the way that we tell it. So if we tell it how to react to a change in one or more forcings (whether -ve or +ve) then it will react in the way it has been instructed.
Therefore the only way a model would know that a doubling of CO2 will produce X temp rise is because it was told before hand, thus would any measure of sensitivity as an output be a product of its input?
If you must know Skip i have been bitten on the arse by a sheep . . .
Would that be a "forcing" or a "sensitivity"?
. . .NEVER turn your back on it.
"Negative feedback"?
Well, let it not be said that I came away from this discussion empty handed.
I'd love to go over this stuff in detail tonight, gents, but I need to write a food review (one of my alternate realities, but don't worry; its nothing you'll read in the New Yorker).
TTFN.
Never ceases to amaze me to think there are people who still think Mann's hockey stick representations are anything but pure fiction.
"Mcintyreâs forensic dissection of the Consensus papers puts cosy scientific peer review to shame. Digging deep into data and computer programs, he has found myriad mistakes in both the statistical technique and the data used to make the famous hockey stick graph, which purported to show that recent temperatures were unprecedented in level and rate of change. But he has also uncovered a mistake in data that conveniently prevented 1934 being warmer than 1998 in America; the splicing together of the records of two Antarctic weather stations as if they were one; the smoothing of sea-level rise in a way that conveniently concealed its recent deceleration; the use of a Swedish lake sediment series upside down so it showed recent warming instead of cooling; and most recently the reliance of an attempt to resuscitate the hockey stick on a ludicrously small sub-sample of just 12 Siberian larch trees. That last one came about when Montford spotted that a scientist who had been refusing McIntyre access to data for ten years had published in a journal with a strict policy of archiving data. Montford tipped off McIntyre, who asked the journal to force the scientist to release the data, which he eventually did." http://www.spectator.co.uk/spectator/thisweek/5749853/part_4/the-global…
There is no Orwellian memory hole big enough to make disappear the historical truth about the Medieval Warm Period and Little Ice Age.
Crakar,
the point that Coby seems to be missing is the difference between a physical model and a computer simulation of that model. It's hardly his fault, however, because the climate literature does a pretty poor job deciphering between the two.
In a physical model, like the equation found in the 'simplest meaningful climate model', all parameters must be there. So the ideas of 'input' and 'output' are really meaningless. The model must contain all the relevant physics one sees as contributing to the system. The picture that GFW provided in #87 gives a visual perspective on a physical model attempting to explaining how the climate works.
One would take that model, which researchers created to fit what they thought the climate did, and simulate outcomes using computer code like that GFW provided in an even earlier comment. This is where 'inputs' and 'outputs' are pertinent. But, as you and I have both pointed out numerous times now, if the simulation cannot find something that isn't in the physical model. The simulation has to be self-consistent.
Now I'll admit, I used sloppy language when I wrote the comment in question, provided by Coby in #94. I think I gave an impression of a situation that doesn't happen and I should have cleared that up earlier. But I'm happy that the conversation went in this direction because it exposed a flaw in Coby's logic about how science works. I find that rather intriguing considering that the original post was lambasting 'deniers' for not have a 'coherent' worldview because they don't use 'science' to guide them. Kind of like the pot calling the kettle black at this point.
Coby,
your last comment, in view of what I have written to Crakar, doesn't make any sense. Since I was talking about physical models and not computer simulations of course everything has to be an 'input'. If someone doesn't put specific physics into the physical model, how is it possible for that physics to show up in a computer simulation? This is the question you have to answer if anyone is going to believe that my perspective is 'completely wrong'.
Because I know you can't, but more likely won't, answer this question, I'll put it to everyone else. It is rather easy, as GFW did, to find the computer simulations that lead to warming. What's the physical model? What are the explicit couplings in it? How do we know that the physical model is appropriate?
Peter:
Would you like me to repeat my questions from earlier?
Coby: :-) Yes, I do check the referrals to see if there are interesting links over to my place. But I don't look at it as much any more, so you're better off (and always welcome) to drop me an email when you've got something interesting going on in the comment section. I read all your posts, but don't look at all the comments.
For the simplest climate model:
Tinkering with the solar constant will give you the right order of change -- if you do it correctly. What you have up there isn't correct, though. The sun's energy hits a disk, area pi*r^2. The surface of the earth, however, has area 4*pi*r^2. 1 W/m^2 in the solar constant is only 1/4th W/m^2 averaged over the surface of the earth. To represent the 4 Watts per meter^2 of a doubled CO2, which is affecting the full surface of the earth, you need to add 16 W/m^2 to the solar constant. (!)
Regarding parameters:
There are several sorts, and it looks like your discussant isn't distinguishing them. One family are fundamental physical constants of the universe -- the Stefan-Boltzmann constant, ideal gas constant, Planck's constant, and so on. A second family are the elementary parameters describing certain important parts of the earth's climate system -- the earth's orbital parameters, the solar constant, the thermodynamics of water, the topography of the continents and bathymetry of the ocean, radiative band locations and intensities for CO2, H2O, etc., and so on. The ideal climate model (and ideal weather prediction model) would only have these two sorts of parameters.
The third family are those generated by the fact that we would need about 10^30 times present most powerful computers in order to run that ideal model. Ideally, in doing dynamics, we would use only molecular viscosity. To do so would require having a global mesh no coarser than 1 mm. That's impossible (by those 30 orders of magnitude), so we have turbulence parameterizations -- something that can be run on a much coarser grid than required for molecular viscosity, but still give pretty good answers for the dynamics. These representations have parameters as well (ideally, very few, and mostly based on the type 1 or type 2 parameters).
We have several different turbulence parameterizations, from exceedingly simple (1 parameter, constant) to quite involved (several parameters, each of which is a function of the atmospheric/oceanic state). The quality of the parameterization is then checked by running the model in conditions where you know the answer and seeing how closely the results match what is observed, mostly in terms of how well it reproduces the turbulence. The 'climate sensitivity' is not one of those observed things, hence in no way can be what is used in selecting parameter values. The parameter values chosen are those that give the best wind speeds, boundary layer thickness, mixing rates, boundary layer wind profile, and so on.
Just to amplify one part of Robert's excellent summary. Amongst the second type of parameter Robert mentioned are the absorption/radiative bands of various gasses. Those are known numbers from laboratory experiment. Those bands have been measured very carefully (strength as a function of wavelength). So one has no choice for those parameters. It is not allowed to "tune" them, because they have known values.
Going to the question of "what is the physical model", that's where you really have to read the original paper introducing a model rather than some later paper showing the latest output. From that GISS documentation page I linked to, it's obvious that GISS E has a rather detailed hydrological model, but you'd have to go back to some early paper to find out exactly how they calibrated any non-obvious parameters in said hydrological model. The calibration there would be analogous to the turbulence model Robert discusses above - that is, it will be calibrated to match relatively short term regional phenomena (annual precipitation patterns and river levels, annual ice melt/regrowth etc.) Long term climate sensitivity is not used to calibrate those parameters.
Only when a model is complete is it compared against reality. See http://tamino.wordpress.com/2010/01/13/models-2/ Tamino finds that 21 of the 23 models in the IPCC AR4 are pretty good at reproducing reality, while two Canadian models aren't so good.
Presumably careful comparison of the differences between the those two physical models and the rest of the batch will illuminate what bit of physics in them is unrealistic. Such a comparison could take a while
Robert,
does the third family of parameters include couplings and feedbacks? For your simplest meaningful climate model, which parameters fall into the third family?
As for the first two families, I thought, perhaps wrongheadedly, that we could assume those parameters were not part of the discussion because, as is pointed out by GFW, one cannot change the vibrational spectrum of water or the speed of light. Maybe we could adjust the distance from the earth to the sun, as per Futurama, but I'm sure that would start another debate altogether.
If the third family of parameters does include ways in which different processes are coupled and the feedbacks associated with those couplings, then that's where all the 'action' is, right? And since one does not have historical observations to check against a set of parameters like feedbacks, the output of your simulation is going to depend heavily on the physical model one concludes feasible to account for what is happening in the real world, right? This seems to be the major point of contention here.
GFW,
'Such a comparison could take a while'
I would assume that this comparison is still in progress since there is disagreement between the major models. I don't think it has much to do with mac vs. pc.
Maxwell:
Glad to see some progress in finding what you mean.
In the simplest model, there are no parameters from the 3rd family. T = f(S, sigma, r, albedo; 4). 4 is a parameter of geometry (follow the link Coby gave to my summary, my summary includes the link to where Atmoz worked out that the correct number is a little larger than 4). Sigma is the stefan-boltzmann constant, safely in class 1. S is the solar constant, r is the earth sun distance, and albedo is ... the albedo. All are in class 2 -- things you observe about the earth to characterize it. In getting to this point, we used two laws you don't have any choice about -- the law of conservation of energy, and the law of Stefan-Boltzmann.
The third family does not include 'couplings' and 'feedbacks' as you seem to be using the term. Feedbacks are conclusions from analyzing the model results, not terms specified beforehand. To illustrate further, I'll stay with turbulence, and take the simplest version of it -- Bulk Aerodynamics. In this, you say that the stress applied by the atmosphere on the surface (which could be the ocean, or land, or grassy field, ...) is proportional to the difference in speed between the air and that other surface. The constant of proportionality is the 'drag coefficient'. (Other terms show up, density of air, for instance, but they're demanded physically and you don't get to choose them.)
Having started with Bulk Aerodynamics as your parameterization, you have only this one number to find. Granted it might be a different number over different surface types, so you'll have to examine that possibility as well. You find your drag coefficient by going out to the field and taking observations of wind speeds with height and seeing what value will give you the best accord with the observations. The number is then nailed down. If you're doing bulk aerodynamics, this is the value you want.
You'll notice there is no 'choosing the feedback' or 'choosing the coupling' present. You don't have that kind of choice available.
When people later talk about a 'feedback' between boundary layer turbulence and, say, surface temperature or boundary layer thickness, it is either an observation or a paired model run. The observation would be to observe boundary layer turbulence, observe temperature, and start disentangling the causes/effects/and feedbacks. Or to do likewise in a model where you, for instance, nudge the drag coefficient around inside the range that your observations permit. Either way, the feedback or coupling strength you arrive at is a conclusion -- not something you specified.
Emphasize that -- you did not, and in fact could not specify a strength for those feedbacks or couplings beforehand. If you could, we would have much better weather prediction models than we do -- we know quite well things like the daily range of temperatures, but can't turn any particular knob to control that. The knobs we can turn are things like drag coefficients, and nobody can say beforehand whether one value that's permitted by observation will give a better result for diurnal temperature range than some other value also permitted by observation. You can then run further experiments with the drag coefficient to get the best representation of the diurnal cycle, while staying inside the range allowed by your original profile studies. But after this you have exceedingly little freedom to adjust it to give a best fit to the boundary layer thickness, or the other several dozen things people are interested in. The result being, there's actually very little tuning of parameters for purposes other than their most fundamental use.
'Either way, the feedback or coupling strength you arrive at is a conclusion -- not something you specified.'
But in the physical model for the system, the equations of motion if you will, the information about those feedbacks must exist, right? The simulation is not going to produce a feedback after parallel runs or fudging parameters in the way you mention if the information necessary for that feedback wasn't present in the physical model. It's just hard to see it, thus the necessity for the simulation.
Thanks for the posts Robert, i said earlier i would not know a climate model if it bit me on the arse (as opposed to a sheep) and that statement still stands. However your posts have given me a more greater understanding of the complexities involved so i thank you for that.
From what you have said is it wrong of me to say that the models are only limited by processing power? Or do you think our knowledge at this stage is also a limiting factor?
Once again thanks for your contribution.
Maxwell:
There's no 'fudging'. You look for a simpler way of representing the real processes realistically. It generally does exist. How well you can represent the full reality with a simpler model is a question you do more research on. If you're interested in this, there is an enormous literature that you can examine.
The feedbacks are what we (people examining model results, or observations of nature) use to describe nature. Nature doesn't care about how we choose to describe it, a philosophical point that's perhaps not well-suited to blog comments. Still, that's the case. The parameters we're setting, choosing, or tuning, however, are not and cannot be the feedback magnitudes. I'm not sure why you're locked on to that concept. I realize that in particle physics, say, the coupling constant for the fundamental forces, or at least for the electromagnetic and weak forces, where a unified theory has been well-tested and demonstrated, is a vital point. But an awful lot of physics is not like elementary particle physics, and climate is one of those many areas.
crakar:
Not sure I understand you. There are two things involved. On one hand, I have no doubt that if we had computers that were 10^30 times more powerful than the current ones are, we'd have better climate models. Computational resources are definitely a limit to our ability to model climate. Our knowledge of the fundamental physics greatly outstrips our ability to run the programs.
On the other hand, I also believe that we don't need those computers to obtain meaningful results today (or, for that matter, 100 years ago). Much of climate is really rather simple computationally. The simplest climate model, that I wrote up and Coby linked to, is something you can do by hand. (Literally, ignore the calculator or slide rule and you could still do it by hand. Or at least I could. I have my grandfather's log tables.) Arrhenius arrived at a perfectly good description working by hand in 1896 -- including a reasonable sensitivity to CO2 doubling (4 C) and the fact that the pole would show more warming than the equator (already observed).
So, on one hand, yes -- if you gave me a computer 10^30 times more powerful than any that now exist, I could very rapidly get better and more detailed answers to whatever questions we have about climate. Much of our efforts today is devoted to the business I mentioned before -- of how to get good answers without having computers powerful enough to let us simply toss in the fundamentals we're all sure of and let them run.
On the other hand, I also don't think we need such computers to get usable answers today (or 20 years ago, or 100 years ago). Our simpler representations, the parameterizations, are generally pretty good, even if we know they are missing some of the details.
By your answer it would appear that you have understood me Robert, better computer = a better model which = a more accurate result and whilst we do not have a full understanding of climate we know enough to produce an accurate enough result. So a better computer would but merely fine tune the result shall we say.
In case anyone cares (not that I assume anyone does), I am in fact parceling through this discussion and waiting for a chance to chime in something . . . Ok, "profound" might be a strong term . . . but maybe potentially meaningful--although I advise that no one hold their breath.
Thanks Rob for your contribution. Thanks Max for your persistence. Thanks Coby, again, for the milieu.
Robert,
I think I have a better understanding of what you're saying. But I think I am not doing a good job of explaining the point I am making in distinguishing between a physical model and the simulation of said model. I'll think about it a bit more and maybe hit you up on your blog about it.
I was harping on the point, however, because Coby was trying to convince me that computer simulations can 'create' new information about a physical model that wasn't contained in the model already, implicitly or explicitly. I see there is a subtle distinction between 'interpretation' and 'information', however. So that the 'information' in a climate simulation starts with the physical model, but running a simulation allows one to 'interpret' how the parameters interact in a way that simply staring at the equations that make up the physical model would not. Is that more correct?
I don't think I quite understand your point concerning Nature not caring which way we describe it. Is that in reference to my language of couplings and feedbacks? Or is it some kind of underlying point you just wanted to make in that context? It was a bit confusing to me and I don't understand how it is supposed to better inform me in this conversation. It is obviously true and I understand what it means in the context of my own work, but I don't see the connection here.
Do you have any good references for how the physical models that climate simulations use are formulated or tested? Thanks for your patience.
Maxwell,
That's a pretty good way of saying it. Let me give you an example from engineering simulation that will show how you can get a result from basic physics input that is completely unanticipated. We understand very well how things like steel cables and concrete react to forces on them. We can then build a model of a bridge and predict very well how much it will flex under a certain weight of traffic. We also understand fluid motion pretty well including the turbulence Robert's been talking about. With a bridge, we can simulate wind and the resultant turbulence in much more detail than we can with the entire planet. With sufficient detail, we learn that the turbulence behind the bridge structures can do something really nifty. When the turbulence is behind a structure with two sides, it can perform "alternating vortex shedding". And it turns out that each time a vortex is shed, it effectively gives a little nudge of force against the structure. Like I said above, we have a great understanding of how steel and concrete will react to those nudges, and ordinarily they'd be trivially small. But there's this thing called harmonic motion. It's what a plucked guitar string (or piano wire, or whathaveyou) does. We can easily predict the harmonic frequencies of a single cable, but it's harder to predict the harmonics of a complex structure. A simulation will reveal them however. The final point to all the above is that bridge builders are careful to try to minimize vortex shedding, and in particular make sure that the harmonic frequencies of bridges are far from the likely frequency of vortex shedding in any reasonable wind scenario. That the above is not obvious just by looking at the equations for fluid motion and building material elasticity, is demonstrated by this video from before the age of computer simulation. http://www.youtube.com/watch?v=j-zczJXSxnw
Aside: Some of the comments attached to that youtube show the same "amateur arrogance" (commenter naflodii) or "raving conspiracy lunacy" (commenter JoEiScOoL24) that has been directed at climate science recently.
Actually, commenter naflodii on that youtube is only partly wrong - aeroelastic flutter is more complex than just vortex shedding, although vortex shedding can definitely be part of aeroelastic flutter. The trick is that aeroelastic flutter brings the forcing into tune with the resonant frequencies of the structure. Resonance is still important, but it's not a coincidence of external forcing having the same frequency. So my undertanding was incomplete as well. Nonetheless the comment is still arrogant because I'm sure the relevant professors he called "silly" know the above better than he does. Finally, the overall example is still a good one regarding unexpected phenomena emerging from simulation (or from reality, if there wasn't a good simulation done).
Maxwell:
I'm afraid I still don't see the distinction you're trying to draw.
The one I was referring to is one that I've borrowed from a philosopher of science friend. You and I talk about feedbacks and couplings. With a bit more work we'll be talking about the same things, or at least be more aware of what the other means. But nature, reality, doesn't care about such things at all. You and I, for our convenience in understanding reality, could talk about the ice-albedo feedback, or the roughness-boundary layer thickness feedback, or any of a number of feedbacks that climate modelers refer to. But, push come to shove, reality doesn't care about this. Reality is just CO2 molecules absorbing and emitting radiation according to quantum mechanics, or passing the energy on by collision with N2 and O2 molecules (again quantum). But the feedbacks that you and I might build in talking about CO2 play no role in what the CO2 molecule does or 'thinks'. Not a big point in its own right except that it seems to me you have a philosophical distinction you're trying to draw, and I'm not sure you're being careful of the difference between how you and I choose to look at things, and how things really behave. Since I'm not sure I know what you mean, though, this isn't one to worry about.
For climate modeling, one good text is Introduction to Three Dimensional Climate Modeling, by Parkinson and Washington. There are two reasons I recommend it. First, and most important, I've read it and think it's a good book. Second, I know both authors (so you're warned of my bias).
It might be a good idea to buy or borrow a copy of this and take a look. I have a fairly strong feeling that right now you and I are having a language issue. After you read this, you should have a much better idea of how climate modelers speak. You may wind up being more concerned about how we do the work than you are now. If so, fine. Bring up a question or comment in whatever is my most recent 'question place' post and I'll try to respond. I put those up about once a month. (They're always open.)
GFW,
In regards to aeronautical flutter it works the same way, the wings begin to oscillate at their resonate frquency which then feeds back in and makes things worse. This can happen very very quickly. A plane can have its wings flapping like a bird depending on what is bolted on to them and the planes attitude (speed, angle of attack and g forces etc) moments before they break off of course.
To test this a model just dont cut it, too many variables to be able to simulate the real world. You can get a plane to flutter two ways. First, push it to the limits and hope like hell you survive or two, initiate a flutter when flying straight and level in a safe manner.
Max are you thinking "if you cant explain it you cant model it" this is one area that troubles me with models.
This impossibility explains the appearance of papers with titles like "Nonlinear mathematical modeling of aircraft wing flutter in transonic range", of course.
Thanks Dhog.
That is of course, what I was trying to get at with my analogy (and as our host has just reminded us, analogies are like models).
What I was trying to explain is that climate sensitivity, like "amount of flutter a particular structure will experience" is not easily deduced from the plain underlying physics, nor is it an input into a model, but a model running the plain underlying physics will produce it (and yes, there are is active development of models of both).
Ok two dogs how many test programs for aircraft flutter have you been involved in? None? thought so. So beyond the title i would say that everything about your link is above your comprehension.
But maybe i am selling you short, just wait a second while i go and ask the scientists that conduct these trials i speak of.................................................................................................................................still there? Good i told him that "i had a friend who claims we can use models to do our testing instead of spending hundreds of thousands of dollars a year"
His response "What f*^$@&g model" he then went on to say that models have a use but unfortunately they are limited by the virtual bubble world they live in. They are detached and isolated from the real world. A real world where empirical data is king and not some guess work.
So there you have it two dogs, i will be keeping a closer eye on your turds of disinformation from now on.
crakar, was this fictional scientist friend of yours related, by any chance, to the fictional mathematician that agreed with Monckton's fictional calculation of climate sensitivity?
Sounds like they should know each other, maybe they even appeared in a fictional novel about climate change written by Crichton and accepted as fact by all AGW deniers.
Well at least you did not call me rotting pond scum, you do however accuse a person of being a fictional character of mine.
I could give you examples of flutter and of how your beloved models are inaccurate but i feel i would be simply wasting my time as you would deny everything i say. There is some irony in that statement inst there Ian.
Have no enough cash to buy a building? Worry no more, because this is possible to get the loan to solve such problems. So take a commercial loan to buy all you need.
[spam neutered but left in so Chris does not appear schizophrenic...at least on this thread! ;-)]
From the OP "They refuse to play by anything resembling the rules of logic, instead resorting to pure polemics. If you score a point of any sort, they will pretend not to notice."
Man, these spambots have such a sense of timing.