There’s no longer any serious debate among climate scientists about either the reality of global warming or about the fact that its substantially caused by human activity, but, as 500+ comments on my previous post on this topic show, neither the judgement of the overwhelming majority of climate scientists, nor the evidence that led them to that judgement, has had much effect on the denialists[1].
And the Australian media are doing a terrible job in covering the issue. I’ve seen at least half a dozen pieces this year claiming that the whole issue is a fraud cooked up by left-wing greenies, and January isn’t over yet.
The latest is from Peter Walsh in the Oz. Walsh is still banging on about the satellite data, and the Medieval Warm Period, suggesting that his reading, if any, in the last few years has been confined to publications emanating from the right-wing parallel universe. But that hasn’t stopped the Australian from running him, and a string of others.
If an issue like genetically modified food, or the dangers of mobile phones was treated in this way, with alarmist cranks being given hectares of column space, most of those who sympathise with Walsh would be outraged and rightly so.
Walsh does make one valid point however, saying. “If your case is immaculate, why feed lies into it?” To which, I can only respond, “If the cap fits …”
fn1. At this point, the term “sceptic” is no longer remotely applicable. Only dogmatic commitment to a long-held position (or an ideological or financial motive for distorting the evidence) can explain continued rejection of the evidence.
John Quiggin 
JQ
Well done! as ever a single folly is enough to condemn Newton or the likes of Karlen; having worked in Scandinavia I know their devotion to tobaco and as a libertarian I would not condemn anybody’s work because of it or addictions to say cocaine for that matter. Karlen is actually a professional in the field, I believe some of his work has been cited by Osborn and co, does that condemn all their work? If so, hooray! By the way how do you calibrate the tree rings with the instrumental arctic record, given lack of trees in the arctic at any time, and does that explain the apparent exclusion of some of the instrumental record? How convenient. Instead of attacking Karlen’s associations, you should have contested his temperature data. But if guilt by asociation is what matters then you must be a Luddite like your co-author and publisher, Clive Hamilton, who constantly attacks what he calls consumerism, hence my offer of some pedal power.
Tim
Simonjm,
Fair enough, but I don’t care to be called a “biased recalcitrant�. I have no vested interest in this, and I call the science as I see it.
The rest of your post is basically an appeal to authority, which is a well known logical fallacy.
Finally, I posted this on realclimate at 6.04pm 13 Feb (Sydney time):
“Mike, on the subject of robustness, do you believe that the MBH98 reconstruction is robust to the presence/absence of the North American bristlecone pine series?�
Let’s see what happens.
“The rest of your post is basically an appeal to authority, which is a well known logical fallacy.”
It’s a fallacy in syllogistic logic but not in inference from evidence which is what we are doing here. We all rely on appeals to authority constantly, since none of us can possibly be experts in everything.
JQ, he’s not drawing inference from evidence, he’s saying these organisations can draw on the expertise of statisticians. It’s an appeal to authority.
If he wants to cite the mooted statisticians, that’s fine.
Ken,
I have a reply to your post, but JQ’s blog won’t let me post it. I have been able to send other posts, so I’m not suggesting censorship, it may be that something is flagging his spam trap.
However, it is frustrating not to be able to respond to your patronising reply, so I’ll try to send it broken into a couple of posts.
***
Let’s start with C02. This is what I wrote:
“A final point, commenters should realise that CO2 is a minor greenhouse gas. It’s not “basic physics�. AGW model predictions rely on massive positive feedback effects relating to water vapour (by far the most important greenhouse gas).�
This statement is correct. The atmospheric concentration of C02 is 0.036%. It might be the “second most important greenhouse gas� but it is completely dwarfed by water vapour.
Ken (continued):
This seems to be the paragaph that upsets JQ’s spam filter – I have idea why.
For the feedback effects to require C02 to significantly increase warming, see the IPCC TAR 7.2.1.1
Should be: “I have no idea why”
The quote I wanted was the first paragraph of that TAR section.
Ken (continued):
And while we’re on models, it is also true, as I stated, that the attribution studies are dependent on climate models. Could you explain how you separate the anthropogenic contribution to warming from natural warming without having a climate model and running it with and without anthropogenic increases in C02?
Your court
(I apologise to everone for this crude posting, somethig in the IPCC quote seems to be upsetting the spam filter. It seems to me that it is Ken that doesn’t understand the science.)
This statement is correct. The atmospheric concentration of C02 is 0.036%. It might be the “second most important greenhouse gas� but it is completely dwarfed by water vapour.
The concentration of CO2 is only of peripheral importance to its importance as a greenhouse gas. For example diatomic gases, while dwarfing water vapour totally, are transparent at the relevant wavelengths, so aren’t particularly important. What is far more important is the frequencies at which a gas absorbs radiation.
CO2 is minor greenhouse gas in the same sense that Australia’s second biggest industry is a minor contributor to the Australian economy.
Could you explain how you separate the anthropogenic contribution to warming from natural warming without having a climate model and running it with and without anthropogenic increases in C02?
A good starting point would be to compare changes in the temperture record with changes in forcings.
Ken,
Nobody is talking about the diatomic gases. What would be relevant would be a comparison of C02 and water vapour in terms of their greenhouse contribution. Do you not agree that water vapour dwarfs C02 as a greenhouse gas? Yes or no will do.
I’ll trust you’ll get back to us on the water vapour feedback issue, and the relevance of climate models to attribution, the other areas in which I demonstrated my lack of understding of climate science?
“Mike (Mann), on the subject of robustness, do you believe that the MBH98 reconstruction is robust to the presence/absence of the North American bristlecone pine series?� aks James Lane.
I dare say Mike Mann has been asked this same type of question hundreds of times before, including famously by a US Congressman. Have you tried Googling “bristlecone pine” site:realclimate.org? I get 15 hits which should keep you busy for quite a while. If I was Mike Mann and was asked a question I knew I had answered in an easily available document and was asked these questions over and over again, I would think the logical response is to ignore it. Such questions show that the questioner is very lazy and answering them is just a waste of time when they could easily get it for themselves.
James,
I thought that the relevance of diatomic gases would be obvious, given that you’re happy to cite the concentration of CO2 as evidence for it being a minor GHG.
Both yes and no are stupid answers to your question – so I won’t give either. “Dwarfs” is a bad term. It’s the sort of term that somebody who was more interested in scoring cheap points rather than making a relevant point would use. The contribution of CO2 is less than water vapour – how much so is hard to quantify due to the overlap of spectral bands. But CO2 is an extremely important greenhouse gas.
I’ll trust you’ll get back to us on the water vapour feedback issue,
I’m drafting a comment on it.
and the relevance of climate models to attribution, the other areas in which I demonstrated my lack of understding of climate science?
See my above post.
Chris, the point is that the MBH98 reconstruction is demonstrably not robust to the presence/absence of the bristlecones, although Mann has claimed that it is. That’s why I asked that question in response to Simonsj challenge.
In any case, I’ve posted it, let’s see if it appears and what the response is.
Ken,
It’s really hard to debate with you. I say:
“Could you explain how you separate the anthropogenic contribution to warming from natural warming without having a climate model and running it with and without anthropogenic increases in C02?”
You say:
“A good starting point would be to compare changes in the temperture record with changes in forcings.”
Well, derr. So we rely on the models. Ken, I’m getting the impression that you don’t know anything about anything? You accuse me of knowing nothing about science!!!!
James,
I’m not sure what your point is with regards to water vapour feedbacks. I agree the IPCC report on them. But this doesn’t change my point about it being basic physics in the first place.
However, this does not change my initial point (made way back up this thread in response to Willis’ silly demand for evidence of AGW).
That carbon dioxide warms the troposphere is basic physics. One can argue over how much it does, but (unless your going seriously off the wall, eg. Tim Curtin) not that it doesn’t warm the troposphere.
Now, that this heating then causes more heating, doesn’t change the fact that it is basic physics that causes the initial heating in the first place.
Well, derr. So we rely on the models. Ken, I’m getting the impression that you don’t know anything about anything? You accuse me of knowing nothing about science!!!!
No no no. Once again you’ve completely misunderstood.
Temps you get from thermometers.
Forcings you get from satellites, sunspot records, greenhouse detectors, isotope data etc.
No climate models here.
James I don’t have to, the implications of why is apparent if we extrapolate your reasoning.
(1st fallacies in isolation lose their teeth, the fallacy from authority is fine when relying on individual cases but almost impossible against a mainstream scientific ‘working’ consensus or do statisticians know enough about everything to confidentially question experts in any field?)
Let’s instead tease out the sort of world you think you are living in.
Not only do we have fields of science where the scientists aren’t schooled enough to understand the mathematics required to do-how did they get their degrees out of corn flake packets- their work but that the peer review process in prestigious journals is also totally worthless and no scientists only statisticians are qualified to understand the maths.
We have the mystery of why, even with the glaring errors in the paleoclimatic work that hoards of statisticians aren’t clamoring to write papers that could make a name for themselves and debunk a whole discipline.
“In 2005 the national science academies of the G8 nations (including the US’ National Academy of Sciences) – and Brazil, China and India, three of the largest emitters of greenhouse gases in the developing world, signed a statement on the global response to climate change. The statement stresses that the scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action, and explicitly endorsed the IPCC consensusâ€?.
That the worlds leading scientific academies , the ones that give advice to the G8 nations on important government policy, made up of the worlds leading scientists-Nobel laureates, national science medals etc- again don’t either have the qualifications to understand the mathematics or the resources or sense to call up assistance from different experts in fields when investigating matters of not only national but global importance.
Or do they exclude mathematicians 😉
What a really sad state of affairs global science is in with mainstream science deluded that they know their maths and that the advice from the best and most resourced scientific intuitions -to the worlds economic powerhouses- is so flawed that fringe academics and industry lobbyists from outside the fields in question can so easily prove them wrong.
Opps James there went the baby!!
How is any science been achieved at all under these circumstances?
I think we can safely state James you are indeed in the Willis class of AGW recalcitrant, just keep going to the Astroturf sites it will soothe your confirmation bias. No wonder they don’t reply to your posts at realclimate.
opps confidently 😮
BTW anyone catch the climate mafia on 4corners who said we cannot muzzle like the big boys in the US.
“Chris, the point is that the MBH98 reconstruction is demonstrably not robust to the presence/absence of the bristlecones,”
If you say so James.
I caught parts of the 4Corners piece. The story implied that there was a consipiracy in Canberra. It did’nt seem to be a very strong case. The fellow who said that industry representatives actually wrote cabinet papers seemed sincere enough, however without corroborating evidence one is inclined to think he was duped by somebody that was just keen to brag and exagerate. It is not as if the interview with either industry represenatives or the environment minister produced any embarrasing revelations.
The CSIRO seems to have a management structure that wants to avoid advocating government policy. This is a reasonable position although it seems that they may be over zealous in policing the distinction between advocacy and analysis.
Terje says: “The CSIRO seems to have a management structure that wants to avoid advocating government policy.”
No Terje, you have it back to front. CSIRO managers and even the Prime Minister’s department apparently censor CSIRO scientists when they stray into the discussion of “policy”. The definition of policy also seemed rather broad and murky.
The censorship issue is troubling. Whether the scientists who were interviewed were correct in their fears that they might lose their jobs/funding is in many respects beside the point. If they believe it, and self censor accordingly, then we have a problem.
Government scientists should be free to speak on both the science and the policy issues. The public’s right to know is far more important than the Government’s desire not to be embarrassed.
Terje says:
I don’t think the discussion will make 600 this time round.
Actually, it might. Are there some “sceptics” willing to step upto the plate?
I started out as a sceptic but over time I have become a cynic.
I am bored with dealing with AGW sceptics. Going 20 rounds with Willis was enough.
My advice to Ken and Simonjm is to ignore James Lane and eventually he might go away.
I’ll revisit the AGW issue if, and only if, we have a long term cooling trend (5 years plus) that AGW proponents can’t explain.
I think PrQ should kill this thread off as it only acts as a magnet for sceptics who are full of themselves. Let them go argue their cases at the numerous websites that are specific to the AGW debate.
Yeh, just let democracy sort it out.
I thought the main 4corners ‘smoking gun’ was the new climate change expert chappie at the CSIRO, who point blank refused to discuss the issue of whether climate change would lead to south pacific nations having to be evacuated. This is clearly an issue implicit in the science – the policy issue would be how to respond to the predicted event – accept the refugees or abandon them. The Howard regime is clearly out to stitch up the lips of the scientists where their findings conflict with the warm and comfortable scenario so appealing to the electorate. We certainly don’t want the electors imagining that their government has been irresponsible in rejecting all action to mitigate greenhouse gas emissions.
Steve Munn I’d like to move onto the solutions policy, costings and technology.
If something from mainstream sources pops up by all means reopen the debate.
What a laugh listening to the environment minister on 4C spin that we are doing a lot on cutting emissions and are well thought of in the world on this topic.
Just have a search for what other countries are doing in renewables and energy efficiency to see how much the energy lobby has hobbled the gov.
Ken, are you serious?
Instrumental temperature is the dependant variable.
The various forcings (solar, GHGs (e.g. C02, methane, water vapour), albedo, aerosols, cloud cover etc.) are the “independent� variables. ( I use the quotation marks, because they are not independent, but subject to profound interactions.
The only way to relate these variables is to use models so complex they are run on super-computers. Or are you asking us to belive that it’s as simple as:
Forcing (A) + Forcing (B) – Forcing (C)…. = global temperature.
For someone who accused me of knowing little about the science, you seem to be completely clueless.
Steve Munn,
Actually, I’m impressed with the futility of arguing with people like Ken Miles, and I will go away.
However, I’ll hang around long enough to hear the outcome of Simonjm’s enquiry to realclimate re not posting my question to Mike Mann about the robustness of MBH98 to the presence/absence of bristlecone pines.
Chris O’Neill.
I did google “bristlecone” on the realclimate site, and none of the hits address the question of whether MBH98 is robust to the presence/absence of the bristlecone series. That is precisely the reason I framed the question in response to Simonjm’s challenge.
Here you can see the MBH98 reconstruction sans bristlecones:
http://www.climateaudit.org/?p=21
These graphs are plotted from Mann’s own data, which establish that he did, in fact, examine the sensitivity of the PCs to the presence/absence of the bristlecones. Nevertheless, he claimed that his reconstruction was robust to the presence/absence of individual proxies.
You also seem to think it would be tedious for Mann to respond to my question. Actually, he only needs to answer “yes” or “no”.
“Chris, the point is that the MBH98 reconstruction is demonstrably not robust to the presence/absence of the bristlecones, although Mann has claimed that it is”
I should have also mentioned that if James is not going to be straight when he asks a question of Mann, as he shows with the above statement, then it’s not really surprising that his question is ignored. James, try to be straight when asking a question and you’ll be much more likely to get an answer.
“I did google “bristleconeâ€? on the realclimate site, and none of the hits address the question of whether MBH98 is robust to the presence/absence of the bristlecone series.”
In http://www.realclimate.org/index.php?p=128 it says
“In other words, using correct PC methodology, how much does the large-scale hockey-stick shape change if the bristlecone pine data are excluded?”
To which Mike Mann gave his answer. This looks like the same issue that James is asking about to me. So the point stands. Mann has been asked this issue before so it’s plainly a waste of his time to answer again for the sake of someone who’s very lazy. If you didn’t like his answer in http://www.realclimate.org/index.php?p=128 then at least have the courtesy to ask him about his answer and not waste his time asking him to repeat something he’s already done.
“You also seem to think it would be tedious for Mann to respond to my question. Actually, he only needs to answer “yesâ€? or “noâ€?.”
Yeah right, why not just ask him if he thinks he’s incompetent. That only takes a yes or no answer too.
Chris,
That quote doesn’t appear in the link you provided.
It does appear here though:
http://www.climateaudit.org/?p=148
As McIntyre notes, a simple yes or no would be nice.
In any case, I posted the question in response to a challenge by Simonjm, who thinks realclimate’s posting policy is tickity-boo.
How are your enquiries going, Simon?
After 532 comments, I think we’ve amply demonstrated the validity of the final sentence of the post. Only dogmatic commitment to a long-held position (or an ideological or financial motive for distorting the evidence) can explain continued rejection of the evidence of Stephen McIntyre.
Ken, you say:
Ken, I asked for “evidence of AGW”. You didn’t like that framing? So sue me … but it was crystal clear what I was asking for.
As you recall, I was waiting for the other pieces of evidence that you said you had. You have never provided this evidence, despite saying that it existed, so I have to assume that you were making it up. So we are left with one, poor, forlorn piece of evidence: the fact that CO2 is a greenhouse gas.
Was I “stalling”, as you claim? No way. You had said there was lots of evidence, and you were providing one example. I asked for the other examples … and oh, surprise, you don’t have them, the dog ate your homework.
JQ, on the other hand, said the evidence is in the IPCC report, and if I don’t find it there, look in the 1,000 papers reviewed by Oreskes … which of course means he doesn’t have the evidence either. If he knew where it was, he would say so. He’s making it up as well, lots of handwaving, no evidence.
So, to the serious discussion of the one piece of evidence. You say that the fact that CO2 absorbs longwave radiation is evidence that humans are warming the world. You are right that CO2 absorbs longwave radiation. However, there are a number of missing steps in your argument between “absorption” and “human caused warming”, and you certainly have not connected the dots.
The problem is this: we don’t know why the climate is stable. We know that it is stable, but we don’t know why. This is shown by the fact that, despite the sun’s heating up by about 30% in the last couple of billion years, the temperature of the earth has not gone up by 30%. Why not? Clearly, there is a limiting mechanism of some kind that has kept the earth’s temperature from rising.
We do not know what the internal limiting mechanism is that has kept the earth’s temperature within a fairly narrow range for millions and millions of years. However, it obviously exists, and is strong enough to counteract a change in solar forcing of ~70 watts/m2. Compared to that, CO2 doubling is a very minor forcing.
My own feeling is that the limit on the earth’s temperature exists because of the following physical mechanism:
More forcing –> more evaporation –> more clouds –> less sun –> less forcing.
My theory on this may be totally incorrect … but something has kept the earth’s temperature from responding to a massive 30% increase, a 70 w/m2 change in forcing.
Now you come along to say that a change in forcing of a couple of watts/m2 is going to raise the temperature of the earth, and you may be correct, it might do that. You may be surprised to know that I myself think, on the balance of probability, that it likely will raise the temperature … but that only gets us past the boring questions, and brings us to the interesting question …
How much will it raise the temperature?
That’s the missing link. That’s why I wanted to point out to you that the IR absorption evidence stands alone, and it is not enough on its own to tell us what we want to know.
Will doubling CO2 increase the temperature by 1°, or by 10°? Computer models give both answers, which of course only shows once again why models do not provide evidence.
We can, however, put an upper limit on the maximum possible effect. We know that the earth has warmed by about 0.6° over the last century. We know that the CO2 concentration went from about 295 ppm to 370 ppm over the century. Assuming the forcing numbers for CO2 of 3.7 w/m2 for a doubling are correct, we also know that this represents an additional forcing of about 1.2 watts/m2.
Finally, we know that the sun’s total irradiation has increased by about the same amount over the century, about 1.4 w/m2. Assuming once again that these are the main variables (which we don’t know, but we can assume for the moment), this gives a net temperature change of 0.6° C for a forcing change of 2.6 watts/m2.
This, of course, means that the climate sensitivity to a forcing change is less than a quarter of a degree per watt/m2 … and that a doubling of the CO2 might result in a temperature change of around 0.85° or so. (I say “might result” because as I have said many times, we have a very poor understanding of climate.) However, this estimate is likely to be in the ballpark, as it is based, not on computer models, but on historical evidence.
This historical evidence is also supported, as I showed long ago on this thread, by direct thermodynamic calculations. These show that at the earth’s surface temperature, a forcing change of 3.7 w/m2 gives a difference in temperature of ~0.7 degrees.
So. There’s your serious discussion about your one, lone, solitary piece of evidence. You and JQ are welcome to let us know if you ever happen to stumble across some more evidence. I will be more than happy to seriously discuss it.
In the meantime, our (poor) evidence and our (poor) understanding of the climate indicates that a doubling of CO2 is unlikely to cause even one degree of temperature increase … be still, my beating heart …
w.
James sorry been busy, can you give me what thread you posted on, the exact topics and when they were made?
The thread was “New take on an old millenium”
The post was at 6.04pm 13 Feb (Sydney time):
“Mike, on the subject of robustness, do you believe that the MBH98 reconstruction is robust to the presence/absence of the North American bristlecone pine series?�
I’ll note in advance that that Mann’s response in the “Dummies Guide” (7) does not answer the question. A simple “yes” or “no” would be sufiicient.
Thanks for answering the question Willis. The suspense was killing me.
I take it that we are all supposed to jump ship again and join up with JQs third thread on this topic where he might once again make bold and important statements.
https://johnquiggin.com/index.php/archives/2006/02/14/global-warming-and-careerism/#comments
Willis says: “I say ‘might result’ because as I have said many times, we have a very poor understanding of climate.”
I assume Willis is using the royal “we”. For once I think Willis is correct. Willis’s poor understanding of climate issues has been revealed numerous times during this discussion.
I suggest he gets back to us after your frog and magnetic field papers are published in reputable journals. Then his ramblings may be taken a little more seriously.
James believes “That quote doesn’t appear in the link you provided.”
It does James. Try it again. http://www.realclimate.org/index.php?p=128 Try using your browser’s search function to look on that page for “In other words” or some small part of the quote.
According to James “As McIntyre notes, a simple yes or no would be nice.”
As I’ve previously advised James “Yeah right, why not just ask him if he thinks he’s incompetent. That only takes a yes or no answer too.”
James just doesn’t get it.
Sorry for the delay, Terje, I had been away writing, and waited to see if any other evidence turned up. Onwards to the new blog, thanks for the link.
Steve, any honest climatologist will tell you that our understanding of the climate is poor. In the last year we have discovered two large climate forcings (plankton controlling clouds, and trees emitting methane) which were completely unknown to science. In addition, we’ve seen the first definitive paper conclusively showing a long term relationship between cosmic rays and clouds. This is not a sign of a mature science, bro’, when new stuff like this is published every month. It is a sign of a science which is in turmoil, a science which is poorly understood. Do you think these are the last major discoveries to be made in the field?
I also notice that, as usual, you are attacking me, rather than responding to a single one of the various points that I have made.
While you might be deluded enough to think that attacking me constitutes a valid discussion of the issues, I rather doubt that. Which leave me to conclude that you are just pulling your …
…
You know, on second thought, never mind, Steve. Do your thing. Snap and growl and tug at my pants leg, I give up. I’m not going to change you, so all that’s left is to laugh at your foolishness, let you bite at my shoelaces, and keep going. I can’t stop your nasty personal attacks, I won’t try.
Moving on, … thanks to everyone else, at least, catch you on the next blog.
w.
Real climate has an interesting introductory piece on whether water vapour is a feedback or a forcing :http://www.realclimate.org/index.php?p=142
James he didn’t post my question probably thought I was you and now I may be banned. Oh well I tried and doesn’t prove anything either way.
Simonjm,
Well thanks for trying, but it’s not correct that it doesn’t prove anything either way. In fact, it explicitly confirms my point.
You asked why I didn’t send my arguments on realclimate. I replied “because they wouldn’t post them, why would I bother”. You challenged me to send a comment, and if not posted, to ask why.
We agreed on a question (polite, on topic). I sent it, it wasn’t posted, you asked, and you weren’t posted either.
That proves my point. Realclimate doesn’t allow awkward posts, which is one of the reasons that it is such a dull blog.
As I say, thanks for trying. Actually, I’m going to retire from the “climate wars” as a participant, except for one final post that sums up my impressions of the debate, most likely on this thread in a couple of days.
Oh, also, I never claimed I was “banned” at realclimate, and in fact doubt that I am. I’ve never tried to post anything abusive or inappropriate at that site.
The point I was making is that they won’t allow “inconvenient” posts.
Actually James there are characters like nanny_govt_sucks who have posted literally dozens of post to RealClimate that dispute the AGW theory.
The folks at RealClimate are likely to delete posts that are not on topic, constitute a personal attack or ask a question that has been answered many times before.
I can’t fault such a policy.
Sure Steve, realclimate is a paradise of light and reason.
“Realclimate doesn’t allow awkward posts, which is one of the reasons that it is such a dull blog.”
Realclimate is such a dull blog because scientific detail is hard work (for most people anyway).
Willis Eschenbach wrote:
“…we know that the sun’s total irradiation has increased by about the same amount over the century, about 1.4 w/m2”.
Really? How do we know this? Direct measurements by satellite of solar irradiance have only been made since late 1978, and have shown a change of only about 0.3 W/m^2, with a quite large error bar. Willis, are we not dealing with rather indirect methods of inferring changes in solar irradiance prior to 1979?
I think you are attaching too much importance to small changes in solar forcing. At the start of this discussion, Prof Q. pointed out, correctly in my view, that earlier “sceptics” of the theory of CFC-based ozone depletion also claimed that the cause of ozone deplation was “natural” and linked to solar cycles. This was perhaps a plausible view to hold, until the cycle swung around and the ozone kept going down. I suspect much the same thing will happen with AGW: the CO2 will keep going up, the warming will continue, and “natural” causes, such as solar variability, will become less and less plausible.
I find some of your other figures open to question, and can’t suppress a feeling of disappointment that noone has picked you up on them, but this is all for the moment.
AGW: The Role of Models
This is a reply to Willis Eshcenbach and all the other posters here who have pooh-poohed the role of models in predicting climate change. I suggest they get over to their closest library and pull down ‘Contemporary Physics’ for 1995. An article by Sir John Mason of Imperial College in issue 3 is a review of the science of “climate change caused by man-made emissions of greenhouse gases”. On page 303, Mason has this to say about modelling: “Changes in global and regional climates due to greenhouse gases will be small, slow and difficult to detect above natural fluctuations during the next 10-20 years. It will therefore be necessary to rely heavily on model predictions of changes in temperature, rainfall, soil moisture, ice cover, sea level, etc. Indeed, in the absence of any convincing direct evidence, concern over an enhanced greenhouse effect is based almost entirely on model predictions, the credibility of which must be largely judged on the ability of the models to simulate the present observed climate and its variability on seasonal, decadal and longer time scales.”
Instead of knocking the models and the modellers, Willis & co. should be supporting efforts to improve the models.
psdoidge says the following in relation to Willis:
“I find some of your other figures open to question, and can’t suppress a feeling of disappointment that noone has picked you up on them, but this is all for the moment.”
I think most of us have grown tired of pointing out Willis’s wobbly facts and figures.