The following comment appeared on this post:
I don’t see why if this is the theory we shouldn’t see some evidence of uniformity in temp increases.
This is exactly what I’m looking for. It’s an interesting question, and if the reader really wants to know, and hasn’t already made up her mind, then she has come to the right place.
But the same reader later posts this:
… please, no hodge-podge, magic-wand “aerosol” explanations…
This is not the comment of the curious, or even of a skeptic. It’s the statement of a denialist.
I made the mistake of being goaded into debate on this very blog. It became increasingly clear that the adversary was not a skeptic but a denialist. No amount of reason or facts will change his mind. But I owe him a debt of gratitude, for making me realize what I don’t want my blog to become.
I’ll repeat myself. As I commented on this post, this is not a forum for denialists. This is not an arena for debate. This led to the question,
Is it a forum for credulists only?
Call global-warming advocates whatever you want. Do it somewhere else.
Denialists get way too much “air time” already. They pollute blogs with garbage. They make statements with no basis in fact, and when their errors are pointed out, they remain obstinate in denial, and simply find another ridiculous denialist argument to pollute the bandwidth. This was well described in a comment from this post:
And you will not persuade them otherwise. I have found that no combination of scientific evidence or rational argument will change the mind of an AGW skeptic as there is a counter, however wrong or misleading, for every argument…
My only disagreement is the terminology. These people I call denialists. True skeptics are better described by this comment:
With all due respect, Ender, I have to disagree with the idea that one can never change a skeptic’s mind. Skeptical, after all, doesn’t mean you absolutely don’t believe something is true and will not listen to evidence; if one is skeptical, one is not sure whether or not to believe something until presented with further evidence.
Well said.
If I were to host a blog about evolution, I would not give any airtime to creationists. I’d give them all the attention they deserve: zero.
The situation with global warming is exactly the same. So I’m no longer giving any airtime to denialists. This is not a forum for denialists to spread more compost, and is not an arena for debating the closed-minded. If that’s what you want, you have an abundance of sites to choose from. But in my opinion, creating yet another debate site is about as useful as inviting an “opposing viewpoint” every time the news runs a story on global warming.
The truly skeptical, the curious, and the confused, need a place to give and receive information, and to ask questions, which is not plagued by denialist crap. If this is what you’re looking for, welcome. If you have a question you’re afraid to ask at other sites, this is a safe place to do it. If you want to get, or to give, solid scientific information, you’re more than welcome.
Denialists are the “creationists” of global warming. They are not welcome. Take it somewhere else; you’re done hijacking my blog. You think that’s one-sided? You bet it is. The side is called “truth.” I’m sure you find it inconvenient.
I’m confident this policy will reduce the popularity of my blog. People (on both sides) love to argue. People love flame-wars. There’ll be none of that here. If that means reduced readership, I can live with that. But from now on, denialists get all the attention they deserve: zero.
33 responses so far ↓
Glen Raphael // January 17, 2007 at 6:55 am |
Of course this is your blog and you are free to do what you like with it. But that said, I disagree that what you briefly seemed to be offering was redundant with what is available elsewhere. (Though if it was, I’d appreciate a pointer!)
What “your side” of this debate desperately needs is an equivalent of Milton Friedman or Richard Dawkins – someone with technical depth who isn’t afraid to directly engage the arguments of “the other side” and make a strong case for the truth as they see it.
RealClimate has technical depth, but refuses to allow dissenting views to be discussed. Coby is willing to engage, but doesn’t have the necessary background and research outlook to investigate and debunk /specific/ opposing claims. (A few of his postings amount to throwing up the hands and saying “this is all too complicated to work out, but the people on my side say X.”)
If your side is right and you want to get the word out, the world needs somebody as smart and well-informed as you to make the case and support it in the face of dissenting views.
The answer to bad speech is more speech. The answer to bad arguments is good arguments. When one side in a debate puts hands over ears and shouts “la la la I’m not LISTENING!” while the other side responds, the audience is inclined to sympathize with the other side.
Sure, there are rabid partisans on both sides who hold forth and belittle and censor those on the other side. But where can one find /honest/ discussion between thick-skinned adversaries who respect the possibility of honest disagreement? Your blog’s name and initial contents suggested a possibility of finding that here. Close off the debate and you might as well change the name of the blog.
Then again, I used to enjoy arguing with creationists (and learned a lot from seeing others do the same!), so what do I know? :-)
[Response: I actually do understand, and appreciate, your viewpoint.
RealClimate actually does allow opposing viewpoints. Nir Shaviv showed up not too long ago to argue his "galactic cosmic rays" ideas; Niccola Scafetta likewise made many posts about his (in my opinion ridiculous) methodology for measuring sensitivity to solar variations. But RealClimate has a team of climate scientists as moderators, and dozens, perhaps hundreds of regulars who love to argue against idiocy and are ready to pounce at a moments notice -- so denialists who show up generally end up embarrassed so quickly that they lose their taste for the place. You could try climateaudit; some of the denialists who wanted to hijack my house are regulars there.
When I talk to people (actual vocal communication, face to face) I often recommend RealClimate, and I suggest they look for other blogs as well. Some of them have already been to RC, but complain that it's rather intimidating, they're not confident enough to post a question. Some of those who have checked out other blogs complain that there's so much heated argument, they're afraid to ask a question for fear of being attacked and/or ridiculed. There should be a safe place to ask, give, and receive, without being perpetually pestered by idiots. This is it.
When someone says that the total downwelling greenhouse radiation is 325 W/m^2 and the sensitivity to climate forcing is 0.1 deg.C per W/m^2, THEY have their hands over their ears going "la-la-la-solar-la-la-galactic-cosmic-rays-la-la-medieval-warm-period..." When someone says, "please, no hodge-podge, magic-wand "aerosol" explanations," that person has a closed mind. This is not just due to naivete or skepticism; it's hard work to be that wrong. And I don't think it's very productive, actually, to repeatedly answer moronic arguments from denialists -- any more than it's productive to argue with creationists (if you find it entertaining, more power to ya). The title of this blog, is also an entrance requirement.
I hope you find what you're looking for.]
Andrew Dodds // January 17, 2007 at 9:57 am |
Don’t blame you, to be honest..
I’ve recently been (re)reading 1984, and there is an interesting comparison between the way in which a Party member is expected to think in the novel and the way in which Denialists/Creationists/whatevers seem to think.
http://en.wikipedia.org/wiki/Blackwhite
I particularly like the word ‘CrimeStop’, which refers to the habit of always stopping short of any idea that may be dangerous; so a denialist will always stop themselves short of understanding an argument which refutes their position, and simply lose interest and/or change the subject.
Of course, the person doing this appears to think (or cannot think otherwise) that the scientist that they are arguing with is doing exactly the same thing – the style of argumentation is very post-modern in this regard – as in ‘Your worldview is that of a global warming proponent, my worldview is that of a global warming denier and all worldviews are equal’. This is enhanced by the attempt at equivilent presentation – the denialist always seeks to appear as the reasonable and informed scientist even whilst presenting the most insane logic.
Of course, anyone trying to stop this will quickly be accused of doing exactly what the denialist wants to do – shutting down debate and censoring opinions..
inel // January 17, 2007 at 10:45 am |
Dear tamino,
Good for you! I am a member of the public interested in understanding and learning more about the climate challenge. Curious and confused I may be, but thanks to you, I have learned much from your posts, and those of other sensible contributors here.
Now, thanks to your stance, I shall not have to wade through all the web-clogging, time-wasting, space-cluttering arguments that are thrown up by people who do not want to learn or understand (and may even be paid to keep others in a state of blissful ignorance).
As far as the bogus argument for balanced reporting/air-time/blog-footprint is concerned, I agree completely that there are some issues that are true and for which there is no need to manufacture another side. It’s just another example of non-scientific (e.g. business and political journalism?) expectations being applied to science, i.e. outside their proper place.
Petro // January 17, 2007 at 11:00 am |
Anyone who has ever debated with a creationist knows how frustrating it is when the other side a) don’t know basic fact, b) don’t want to read the articles where those basic facts are represented, c) don’t comprehend the basic facts they read and d) comprehend the basic facts, but still continue to claim the opposite.
Similarly debate with true denialist is both futile and frustrating. I applaud your approach to cut the crap in this site!
nanny_govt_sucks // January 17, 2007 at 4:12 pm |
RealClimate is infamous for its censorship of opposing viewpoints. Back when I could get a post through it was maybe 2 out of 3 that would make it. Now I’ve been completely shut out of the debate there.
Fergus Brown // January 17, 2007 at 4:28 pm |
On the subject of blogs which both contain sound science and encourage debate, there are several which stand out: Andrew Dessler, on Gristmill, William Connolley on Stoat, Roger Pielke Sr., and Jr., on Climate science and Prometheus respectively, Eli Rabett on Rabett Run and, of course, RC. Whislt Steve McIntyre himself is a decent enough bloke, the posters on Climate Audit are often hostile and irrational.
I’d recommend any of the above for regular discussion and updates on what’s going on, as well as the CRU’s weekly newswatch portal. Even the innocent should not be discouraged from posting legitimate questions on the ‘high-end’ sites like RC, though; when I email them, I often get replies from Gavin in person. When I post, I often get responses.
In addition to recommending the sites, I would also recommend that people actually post themselves; this way, you’ll find out fairly quickly what you do and don’t ‘know’, and, more importantly, what you think you know that ain’t so.
PS. Open Mind has now joined the list of the above & has already been recommended to others.
Regards,
Writer’s Blog » Blog Archive » A Conflict of Viewpoints // January 17, 2007 at 4:47 pm |
[...] I really hate falling under a label that seems to generate so much animosity and antagonism from folks in the scientific community – [...]
Petro // January 17, 2007 at 5:17 pm |
Typically, the Commentator get oneself banned from scientifically oriented blog this way:
Following statements are scientifically true:
1) C02 absorbs heat i.e. long-wave infared radiance.
2) Ability to absorb heat by CO2 happens logaritmically. Doubling the amount of CO2 does not mean that it absorbs double amount of heat.
3) CO2 in the atmosphere absorbs heat radiating from the Earth. This increase the temperature of the hear radiating object, the Earth.
4) Amount of CO2 in the lower part of atmosphere – troposphere – has increased from 280ppm 150 years ago to the current level 380ppm.
5) CO2 levels in the troposphere has raised exceptionally rapidly during last 150 years.
6) CO2 stays in atmosphere around 100 years.
7) The increase in the atmospheric CO2 leves are caused by the burning of fossil fuels (oil, gas, coal).
8) Burning of fossil fuels is done by human beings.
9) The temperature of the Earth has increased 1K during last 100 hundred year. During last 30 years the increase has been 0,6K.
10) Other factors affect to temperature of atmosphere as well.
11) None of the other factors can explain the observed rise the global mean temperature of the Earth during last 30 years.
As a conclusion, increase in atmospheric CO2-levels causes the increase in the temperature of the Earth.
Each of the statements is supported by hundreds of scientific articles. The conclusion is supported by tens of thousands scientific articles.
The Commentator challenges one or several of the statements without giving any reference. When explained why scientists have reached to such a statement, the Commentator ignore the explanations and continue repeating that his point of is still correct and the one or some statements are false, thus the conclusion is false too. After couple rounds of heated discussion, language of the Commentator starts to be abusive. Then ban happen.
For those of us who want to follow scientific discourse, baseless challenges to these statements or any other scientific statement are annoying noise, which has been encountered few dozen times earlier. To get rid of that crap is a service to a reader, not a form of censorship.
djangone // January 17, 2007 at 8:51 pm |
There’s a difference between ‘tolerance’ and ’suffering fools.’
But maybe you’ve already said it best: ‘it’s hard work to be that wrong.’ Exactly. It takes effort–the most masturbatory of efforts–to assert that 2+2=3,359, and what’s more to crow about it in public. Repeatedly. Loudly. Despite being corrected.
My favorite old Mandarin saying: ‘Dragons in shallow waters are the sport of prawns.’ Keep to the deep.
nanny_govt_sucks // January 17, 2007 at 9:29 pm |
CO2 affects climate directly and indirectly in many different ways. Certainly the open minded approach is to consider all effects, instead of focusing on just one. Once each is examined and quantified, then we can begin to asses the full effect of increased CO2 on global climate.
How would anyone know this? There have been tremendous volcanic events in our planet’s past that surely dwarf today’s CO2 increase. Do you have a reference for your claim?
I’ve heard otherwise. Do you have a reference for this claim?
There are other sources of CO2 as well.
Are you basing this on CRU data that has never been audited? Many questions about the veracity of this warming claim remain.
This sounds like a repetition of the IPCC TAR verbiage. The IPCC only considered volcanic and solar as other possible factors. Hardly thourough. I believe only solar TSI was considered, and of course there are many other solar factors including CME’s, solar wind, Cosmic Rays, etc..
I welcome open minded consideration of these issues.
[Response: It's a fine line between skeptical and obstinate. But for now, I'm going with the "benefit of the doubt."
Let's start with this one:
Since 1958, atmospheric CO2 concentration has been measured at a number of locations, the best-known being the Mauna Loa atmospheric observatory in Hawaii. These show two primary changes: 1. a consistent rise since observations began; 2. an annual cycle due to the respiration of land plants.
The volcanic events that have happened during this time have had no visible impact on CO2 concentration, which is no surprise since the CO2 output from a large volcanic eruption is measured in megatons, the emissions from the U.S. alone in one year are measured in gigatons (1 giga = 1000 mega). There's no sign of impact from Mt. St. Helens, or from Mt. Pinatubo (which was 10 times larger than Mt. St. Helens).
Prior to 1958, CO2 estimates come from air bubbles trapped in ice cores. The standard source for CO2 estimates for the last thousand years is the Law Dome ice core. It shows that CO2 concentration was remarkably stable during that time period, fluctuating between 275 and 285 ppmv (parts per million by volume), until the start of the industrial revolution. The volcanic eruptions that happened during this period have had no visible impact on the CO2 concentration.
Other ice cores give us information going much further back. The Vostok ice core goes back about 420,000 years, and shows that CO2 concentration experienced large fluctuations, between about 180 ppmv and 280 ppmv (never exceeding 299 ppmv). However, these large swings generally take at least 5,000 years. By modern standards, that's achingly slow.
The modern level is about 382 ppmv. The rise from pre-industrial (about 280) to modern has taken less than 200 years. I'd say that "raised exceptionally rapidly during last 150 years" is a pretty good description. You can find graphs of all these records on this post.
Do you agree?]
Hank Roberts // January 18, 2007 at 2:42 am |
It’s often useful to try a poster’s user name in quotes in a search with Google, perhaps +climate, or + any easily recognized word strings in quotes. Much is repeated.
[Response: Since I am now excluding argumentative denialists, I hope there's never any motivation to do so. Even with motivation, I advise against it. If you have to "hunt someone down" on the internet ... you're taking things too seriously. This is just a blog.]
timethief // January 18, 2007 at 3:18 am |
YAY! I’ve had it to the eyeballs with the denialists. Thanks for giving them the boot. You did the right thing.
Petro // January 18, 2007 at 6:01 am |
Nanny wrote:
“CO2 affects climate directly and indirectly in many different ways. Certainly the open minded approach is to consider all effects, instead of focusing on just one. Once each is examined and quantified, then we can begin to asses the full effect of increased CO2 on global climate.”
Please tell how these other ways of CO2 effect in the climate renders the original statement questionable.
Nanny wrote:
“6) CO2 stays in atmosphere around 100 years.
I’ve heard otherwise. Do you have a reference for this claim?”
I have the foggest idea what kind of voices you have heard. Could you please elaborate, give an example and reference.
Nanny wrote:
” 7) The increase in the atmospheric CO2 leves are caused by the burning of fossil fuels (oil, gas, coal).
There are other sources of CO2 as well.”
Indeed. Please show data or at least a reasonable theory of the other sources atmospheric CO2 during recent hundred year.
Nanny wrote:
“9) The temperature of the Earth has increased 1K during last 100 hundred year. During last 30 years the increase has been 0,6K.
Are you basing this on CRU data that has never been audited? Many questions about the veracity of this warming claim remain.”
Please show a graph or table which show that there is no increase in the global temperature during recent century.
Nanny wrote:
“This sounds like a repetition of the IPCC TAR verbiage. The IPCC only considered volcanic and solar as other possible factors. Hardly thourough. I believe only solar TSI was considered, and of course there are many other solar factors including CME’s, solar wind, Cosmic Rays, etc..”
Once again, show the references, where it is shown that the current warming is mainly caused by solar radiance.
Tamino covered number 5).
I have an impression that during recent couple of years Nanny has been answered to his dubio several hundred times in different forums. Please tell us is there any single answer you have found acceptable enough to alter your preformed opinion about antropogenic climate warming toward the scientific consensus?
[Response: You were so right about how people get banned.
But I'm still not banning nanny_govt_sucks. I am, however, blocking endless repetition of already-covered issues. Those who wish to do so, can take it somewhere else. If someone posts something astoundingly wrong, it'll probably get through -- the first time. If they are shown the error of their ways but still won't listen to reason, the dispute will simply not appear.
I suspect that denialists in general will get bored with this site. Their posts will not appear, and there'll be no arguing over established fact.]
nanny_govt_sucks // January 18, 2007 at 7:10 am |
Recent eruptiosn were not tremendous events as volcanos go. A megavolcano supererutpion (I didn’t make these terms up) is on the order of thousands of times greater than a pinatubo. Mor info: http://www.pbs.org/wgbh/nova/megavolcano/bigone.html
I doubt that 1000 years is a long enough period of time to really understand what is or isn’t normal about Earth’s atmospheric CO2 concentrations.
Also contained in the Vostok cores record are huge gaps of 500 to 700 years between datapoints. Plenty of space for uncertainty.
I don’t think we know enough about the history of Earth’s CO2 concentrations to be saying that the recent rise is exceptionally rapid. The data points are sparse, the capacity of the Earth to burp out or bake out large amounts of CO2 in one way or another is well known. I’d like to see a clearer picture of CO2 concentration history in more detail and from independent proxies. I don’t think we have that right now.
[Response I let this comment through to make a point.
Petro was right about how people's comments get removed. He made a completely correct statement about CO2 rise. You asked for sources. I gave 'em to you -- in spades. I even referred you to a previous post with nice graphs. And if you were passionate about the issue AND open-minded, you'd do some online research yourself and discover that Law Dome and Vostok are not the only ice cores, that ice cores are not the only estimates of pre-industrial CO2, and that all those mega-eruptions were a long long long time ago, absolutely not relevant to the point. But you won't accept that. You won't even say, "OK, so CO2 rose dramatically, but what about my other points?" Instead you argue about something that is not a matter of dispute, it's an established fact.
You are entitled to your own opinion. But I suggest you should start your own blog; I intend to spare my readers this kind of dispute. You can comment here all you want. Stay reasonable, your comments will get through. But expect that comments like the one above, will not appear. In my opinion, you simply won't listen to reason.
And on that topic, it's my opinion that counts. This is my house.]
Andrew Dodds // January 18, 2007 at 2:11 pm |
Nanny -
It is estimated that a Yellowstone Super-Eruption of around 1000 km3 would represent around 40 times usual average volcanic activity for the world for a year. So the CO2 emissions would equal around 6 months of human emissions. And of course the side effects would make AGW look like a walk in the park.
Indeed, there is essentially no way of raising natural emissions of CO2 to Anthropogenic levels without invoking planetery scale disasters. This is not a good line of argument to try if you are in the ‘everything will be fine’ camp.
Doug Watts // January 18, 2007 at 3:04 pm |
re: skeptics or denialists.
The rule I apply is that a “skeptic” of a particular theoretical regime is obligated to present their own alternative regime that explains the data set as well or better; and be willing to defend their own alternative regime when given sincere, probative questions.
In the climate arena, I see very little difference between ’skeptics’ and ‘deniers.’ For a ’skeptic’ the first question to ask is what precisely are you skeptical of: the overall theory, specific predictions of theory or specific data points? An honest ’skeptic’ should be able to clearly answer that question.
Petro // January 18, 2007 at 3:10 pm |
Nanny,
You have been asking these same questions and raising same doubts in different climate blogs for two years or so. In that time you should have grasped the basic facts correctly. That you still ask these questions, begs for an explanation on your motives. Would you mind tell what motives you for this effort against climate warming by CO2.
Do you have novel scientific theory that contradicts with current theory? Please present your theory then. “I don’t believe X is true” is hardly a theory.
Or maybe you have some financial interests, you belong to an oil company or something?
To me your rethoric resembles that one of the creationists. Are you religiously motivated?
Do you have political reason to hate scientists? Do you think all scientists are leftists, that’s why everything coming from their mouth is false?
Or is climate warming somehow morally wrong to you? Something so severe it can’t be true?
So, if you have a scientific theory, great, show it! If you are motivated by something else, you have hard time to get your point through in scientific forums. Scientific argumentation follows certain rules, which should be abided to take part in that debate.
[Response: OK, point made. But I don't want to beat up on denialists, any more than I want to dispute established fact. And "maybe you have some financial interests, you belong to an oil company or something" is just speculation, and not relevant to the science. It's time to let it go.]
Yelling in the fog // January 18, 2007 at 4:00 pm |
After some reflection I have to agree with the course of action you have taken regarding the removal of comments that go beyond skeptcism into denial. I have argued on and off with Nanny over the last 3 or 4 years on the Yahoo message boards and in all that time I can never recall him actually admiting that something he said was wrong. His usual tactic is to change the topic.
However on to more productive issues. If you were looking for interesting topics that might be a little more technical, I would appreciate a good discussion on the physics of the greenhouse effect. I understand the basics, but there are details where I tend to get lost. For example, I was reading through this paper the other day:
http://www-ramanathan.ucsd.edu/RamAmbio.pdf
If you look at page 190, in the second column there is a paragraph titled “Importance of Backradiation at the Surface”.
In it they say that the increased radiation at the surface is 1.2 W/m2 and 4.3 at the tropopause. However when they calculate the increase temperature at the surface (top of the next page) they use deltaT = 4.2/3.3 to get 1.3K change. There are a number of things I am not clear on here (due to my lack of background probably) but to start, why did they use the tropopause forcing to calculate surface temperature?
Or, have I got everything totally wrong? ;-}
Best,
Y.
[Response: Thanks for the link to an outstanding paper. It especially drives home the fact that CO2 is not the only greenhouse gas! There's methane, oxides of nitrogen, CFCs, ...
I think the answer to your question is best summed up earlier in the paper (pg. 187, right-hand column) that,
In other words, the surface and the troposphere are so strongly coupled, they act almost as a "single element" -- the surface/troposphere -- in the analysis. So, the relevant forcing is determined by what goes into this single element, and "in" is defined by the top of that element, the tropopause.
The comment about back-radiation at the surface on pg. 190 is, I believe, simply meant to illustrate that just because CO2 is causing a change of 4.3 W/m^2 in the tropopause energy flux, we shouldn't expect to see that much back-radiation at the surface. This is because of the absorbtion of that radiation by H2O, which prevents it from getting all the way to the surface. But it is still trapped in the surface/troposphere system -- being absorbed in the troposphere by H2O -- so all 4.3 W/m^2 is leading to warming of the surface/troposphere system. And whatever energy we trap in the surface/troposphere system, will get distributed by convective heat and moisture transport, hence will end up heating the system. So, we'll see the warming effect of 4.3 W/m^2, but we'll only see direct CO2 back-radiation of 1.2 W/m^2.]
nanny_govt_sucks // January 19, 2007 at 1:40 am |
Petro, the burden of proof (or compelling evidence) rests with the proponents of the hypothesis.
My “alternative hypothesis” if you want to call it that is that we simply don’t know enough about the climate to be saying anything definitive about the role of CO2 in any recent warming.
nanny_govt_sucks // January 19, 2007 at 1:51 am |
Tamino, there is another proxy for pre-industrial CO2 – stomatal frequency – that tells a different story than the ice cores, and in much more detail. Much higher CO2 levels have been proxy-measured compared to the cores and century-scale fluxuations that somewhat rival today’s have also been documented – many in just the last 1000 years. Surely these must be considered in an open minded discussion.
Chris O'Neill // January 19, 2007 at 6:56 am |
“Also contained in the Vostok cores record are huge gaps of 500 to 700 years between datapoints.”
The Vostok icecore record has no gap of 700 years. The longest gap, which was between 392,972 and 393,636 years ago, was 664 years. (It’s actually an average rather than a gap.) Back until 326,952 years ago, the longest gap is 313 years. Back until 243,714 years ago, all gaps were less than 200 years. And back until 136,103 years ago, no gap is more than 101 years long.
Plainly wrong and misleading strawman statements such as the above made by n_g_s are characteristic of denialists.
Petro // January 19, 2007 at 7:03 am |
Nanny wrote:
“Petro, the burden of proof (or compelling evidence) rests with the proponents of the hypothesis.”
In the scientific forums, the one who challenges the facts should show evidence.
[... edit ...]
Petro // January 19, 2007 at 10:12 am |
The reason I keep insisting the basis for Nanny’s motivation is that the questions he poses are not scientific, but philosophical. By ignoring all the answers received by the scientific methods, his basic question is: Is it possible to get knowledge by scientific methods?
This question has no answer within the domain of science. For scientifically educated the answer is a definite yes. To the one coming from religious background, the answer is not such obvious. In that sense the debate with Nanny is as fruitful as debating about the existence of god. We in the science have adopted scientific method and the results received by them as a part for our conviction, and we found it extremely hard to believe that there are people, who doubt its explanatory power. Those who believe to the alternative ways of getting knowledge are not so convinced that the results of the science are accurate.
[Response: And that's one of the reasons contentious posts won't make it through.
But the latest post from nanny_govt_sucks, whether right or wrong, raises a scientific issue (the conflict between ice-core estimates of past CO2 and stomatal-index estimates) which has not previously been dealt with here. If you want to comment on that scientific issue, great! In the absence of reader responses, I'll probably do a post on that topic myself (as soon as time permits)]
Andrew Dodds // January 19, 2007 at 1:53 pm |
NGS -
Do you have any references for what you are saying? From what I can find online, the flucuation range from anassumed pre-industrial is around -25 to +40 ppm (no error bars given). Within the last century the range is more like -5..+5. Obviously, I could be looking at the wrong pages, which is why I’m asking for more info.
The current change is +100ppm and rising, which looks to be at least 20 times anything that has hapopened in the last 1000 years.
Yelling in the fog // January 19, 2007 at 2:22 pm |
Nanny, of course they should be considered in an open minded discussion and of course they are.
You state that Much higher CO2 levels have been proxy-measured compared to the cores and century-scale fluxuations that somewhat rival today’s have also been documented – many in just the last 1000 years.
The answer to this has two parts. The first part is based on one of the most influential papers in this idea of a link between CO2 and stomatal frequency (also called stomatal density). Royer looked at this issue in 2001 in this paper. However he notes that SD is not a good measurement for short timescales and in this context, many in just the last 100o years would certainly qualify as short timescales.
The second point deals with the more recent literature where there have been a number of longer term studies that look at SD in more controlled environments. For example this paper and this paper and this one do not support a change in SD in response to elevated CO2.
My own guess is that the longterm response is tied up to transpiration rates. In addition, I think all the papers point to SD being a genotype response, not a phenotype response – thus it is not good for short time scale detection (and we are talking evolutionary time scales here).
Dano // January 19, 2007 at 2:26 pm |
Stomatal frequency is a thin reed indeed. If that’s all one has to grasp, it’s a good sign: not only is the dataset weaker than, oh, tree-rings, the data have not been audited nor is the spatial continuity as good.
Best,
D
nanny_govt_sucks // January 19, 2007 at 10:59 pm |
Yelling in the fog, I had a look at the papers you linked, but did not see that the Birch species was tested. For more, see Wagner et al “Century-Scale Shifts in Early Holocene Atmospheric CO2 Concentration”. Does the stomatal frequency as a detailed short-term proxy depend on species? I don’t know.
But even if stomatal proxies are completely unreliable, that doesn’t make the ice cores record any more accurate.
Is it too much to ask for a second opinion? An independent method estimating historical CO2 concentrations that near-duplicates the ice cores record while providing greater detail will provide very compelling evidence that the modern CO2 rise is “exceptionally rapid”. If we don’t have that independent method yet, then I’ll be happy to wait until we do.
Petro, you didn’t present any “facts” that I’m aware of. This from wikipedia (http://en.wikipedia.org/wiki/Science): “Scientists never claim absolute knowledge of nature or the behavior of the subject of the field of study. Certain scientific “facts” are linguistic (such as the fact that humans are mammals), but these are true only by definition, and they reflect only truths relative to agreed convention.”
Chris, I amend my statement to “Also contained in the Vostok cores record are huge gaps of up to 664 years between datapoints.”
[Response: My compliments. I don't happen to agree with your position, and I'll be doing a post on stomatal-frequency CO2 estimates pretty soon. But your argument is cogent, polite, doesn't re-hash what's been beaten to death already, and even has a reference to the scientific literature (Wagner et al. 1999, Science, vol. 284, pg. 1971) to support your position.
Now that's the kind of discussion I'm looking for.]
Dano // January 20, 2007 at 12:02 am |
Does the stomatal frequency as a detailed short-term proxy depend on species? I don’t know.
It does. And more.
It depends upon both genotypic and phenotypic response, making stomatal density problematic. In addition, leaf response may also depend upon hydrostatic pressure so individual leaf selection may be important as well.
Meaning you have to have a large sample size and apply statistics to it, and have lots of papers to find a consensus of opinion (none of this cr*p talking point garbage about ‘concencus science’ that people who aren’t scientists yap on about).
There is neither a large sample size with sufficient areal coverage nor a large literature to make touts about, nor to have an alternative theory about.
Best,
D
Peaseblossom // January 20, 2007 at 1:24 am |
Allow me to add my voice to those in support of your “taking out the trash”. I think it’s very important for people to be able to question and be skeptical and not take what they’re told at face-value; but there’s a difference between not knowing and not wanting to know.
Steve Bloom // January 20, 2007 at 3:26 am |
I spent more time on GS than I had planned, and to all appearances the first paper Yelling cited seems to have been the death knell for the hypothesis of stomata as a proxy for subtle early Holocene CO2 variations. See also some of the papers that cite it in turn. Stomata do seem to still be thought useful for other paleo uses, though.
I’ve noticed that sometimes it’s a little difficult with such things to spot exactly where the shiv went in. There are other indications, but the main one is that the competing authors (the main one of whom seems to have been a recent PhD, another hint) didn’t respond.
Steve Bloom // January 20, 2007 at 3:45 am |
Upon re-reading Nanny’s most recent comment I see that he was more or less in the process of abandoning the stomata argument anyway. As for another good test for the ice cores, there is indeed one — sediments, mainly oceanic and mainly involving foraminifers as the proxy. This is a good place to start. Of course the forams confirm the ice core CO2 record rather than duplicate it, but that will have to do.
nanny_govt_sucks // January 21, 2007 at 8:38 am |
Steve, the foraminifers are used as a proxy for SST, not CO2 as far as I understand.
JohnFrangerson // February 1, 2007 at 6:11 pm |
Nice Post.
That was well said. Always appreciate your indepth views. Keep up the great work!
John